leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
6ada4e2826
linux/arch/powerpc/mm/hash64_64k.c

334 lines
9.0 KiB
C
Raw Normal View History

powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
/*
* Copyright IBM Corporation, 2015
* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*/
#include <linux/mm.h>
#include <asm/machdep.h>
#include <asm/mmu.h>
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
powerpc/mm: Don't track subpage valid bit in pte_t This free up 11 bits in pte_t. In the later patch we also change the pte_t format so that we can start supporting migration pte at pmd level. We now track 4k subpage valid bit as below If we have _PAGE_COMBO set, we override the _PAGE_F_GIX_SHIFT and _PAGE_F_SECOND. Together we have 4 bits, each of them used to indicate whether any of the 4 4k subpage in that group is valid. ie, [ group 1 bit ] [ group 2 bit ] ..... [ group 4 ] [ subpage 1 - 4] [ subpage 5- 8] ..... [ subpage 13 - 16] We still track each 4k subpage slot number and secondary hash information in the second half of pgtable_t. Removing the subpage tracking have some significant overhead on aim9 and ebizzy benchmark and to support THP with 4K subpage, we do need a pgtable_t of 4096 bytes. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:45 +00:00
/*
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
* Return true, if the entry has a slot value which
* the software considers as invalid.
powerpc/mm: Don't track subpage valid bit in pte_t This free up 11 bits in pte_t. In the later patch we also change the pte_t format so that we can start supporting migration pte at pmd level. We now track 4k subpage valid bit as below If we have _PAGE_COMBO set, we override the _PAGE_F_GIX_SHIFT and _PAGE_F_SECOND. Together we have 4 bits, each of them used to indicate whether any of the 4 4k subpage in that group is valid. ie, [ group 1 bit ] [ group 2 bit ] ..... [ group 4 ] [ subpage 1 - 4] [ subpage 5- 8] ..... [ subpage 13 - 16] We still track each 4k subpage slot number and secondary hash information in the second half of pgtable_t. Removing the subpage tracking have some significant overhead on aim9 and ebizzy benchmark and to support THP with 4K subpage, we do need a pgtable_t of 4096 bytes. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:45 +00:00
*/
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
static inline bool hpte_soft_invalid(unsigned long hidx)
powerpc/mm: Don't track subpage valid bit in pte_t This free up 11 bits in pte_t. In the later patch we also change the pte_t format so that we can start supporting migration pte at pmd level. We now track 4k subpage valid bit as below If we have _PAGE_COMBO set, we override the _PAGE_F_GIX_SHIFT and _PAGE_F_SECOND. Together we have 4 bits, each of them used to indicate whether any of the 4 4k subpage in that group is valid. ie, [ group 1 bit ] [ group 2 bit ] ..... [ group 4 ] [ subpage 1 - 4] [ subpage 5- 8] ..... [ subpage 13 - 16] We still track each 4k subpage slot number and secondary hash information in the second half of pgtable_t. Removing the subpage tracking have some significant overhead on aim9 and ebizzy benchmark and to support THP with 4K subpage, we do need a pgtable_t of 4096 bytes. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:45 +00:00
{
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
return ((hidx & 0xfUL) == 0xfUL);
powerpc/mm: Don't track subpage valid bit in pte_t This free up 11 bits in pte_t. In the later patch we also change the pte_t format so that we can start supporting migration pte at pmd level. We now track 4k subpage valid bit as below If we have _PAGE_COMBO set, we override the _PAGE_F_GIX_SHIFT and _PAGE_F_SECOND. Together we have 4 bits, each of them used to indicate whether any of the 4 4k subpage in that group is valid. ie, [ group 1 bit ] [ group 2 bit ] ..... [ group 4 ] [ subpage 1 - 4] [ subpage 5- 8] ..... [ subpage 13 - 16] We still track each 4k subpage slot number and secondary hash information in the second half of pgtable_t. Removing the subpage tracking have some significant overhead on aim9 and ebizzy benchmark and to support THP with 4K subpage, we do need a pgtable_t of 4096 bytes. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:45 +00:00
}
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
powerpc/mm: Don't track subpage valid bit in pte_t This free up 11 bits in pte_t. In the later patch we also change the pte_t format so that we can start supporting migration pte at pmd level. We now track 4k subpage valid bit as below If we have _PAGE_COMBO set, we override the _PAGE_F_GIX_SHIFT and _PAGE_F_SECOND. Together we have 4 bits, each of them used to indicate whether any of the 4 4k subpage in that group is valid. ie, [ group 1 bit ] [ group 2 bit ] ..... [ group 4 ] [ subpage 1 - 4] [ subpage 5- 8] ..... [ subpage 13 - 16] We still track each 4k subpage slot number and secondary hash information in the second half of pgtable_t. Removing the subpage tracking have some significant overhead on aim9 and ebizzy benchmark and to support THP with 4K subpage, we do need a pgtable_t of 4096 bytes. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:45 +00:00
/*
* index from 0 - 15
*/
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
bool __rpte_sub_valid(real_pte_t rpte, unsigned long index)
powerpc/mm: Don't track subpage valid bit in pte_t This free up 11 bits in pte_t. In the later patch we also change the pte_t format so that we can start supporting migration pte at pmd level. We now track 4k subpage valid bit as below If we have _PAGE_COMBO set, we override the _PAGE_F_GIX_SHIFT and _PAGE_F_SECOND. Together we have 4 bits, each of them used to indicate whether any of the 4 4k subpage in that group is valid. ie, [ group 1 bit ] [ group 2 bit ] ..... [ group 4 ] [ subpage 1 - 4] [ subpage 5- 8] ..... [ subpage 13 - 16] We still track each 4k subpage slot number and secondary hash information in the second half of pgtable_t. Removing the subpage tracking have some significant overhead on aim9 and ebizzy benchmark and to support THP with 4K subpage, we do need a pgtable_t of 4096 bytes. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:45 +00:00
{
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
return !(hpte_soft_invalid(__rpte_to_hidx(rpte, index)));
powerpc/mm: Don't track subpage valid bit in pte_t This free up 11 bits in pte_t. In the later patch we also change the pte_t format so that we can start supporting migration pte at pmd level. We now track 4k subpage valid bit as below If we have _PAGE_COMBO set, we override the _PAGE_F_GIX_SHIFT and _PAGE_F_SECOND. Together we have 4 bits, each of them used to indicate whether any of the 4 4k subpage in that group is valid. ie, [ group 1 bit ] [ group 2 bit ] ..... [ group 4 ] [ subpage 1 - 4] [ subpage 5- 8] ..... [ subpage 13 - 16] We still track each 4k subpage slot number and secondary hash information in the second half of pgtable_t. Removing the subpage tracking have some significant overhead on aim9 and ebizzy benchmark and to support THP with 4K subpage, we do need a pgtable_t of 4096 bytes. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:45 +00:00
}
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
pte_t *ptep, unsigned long trap, unsigned long flags,
int ssize, int subpg_prot)
{
real_pte_t rpte;
unsigned long hpte_group;
unsigned int subpg_index;
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
unsigned long rflags, pa;
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
unsigned long old_pte, new_pte, subpg_pte;
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
unsigned long vpn, hash, slot, gslot;
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
unsigned long shift = mmu_psize_defs[MMU_PAGE_4K].shift;
/*
* atomically mark the linux large page PTE busy and dirty
*/
do {
pte_t pte = READ_ONCE(*ptep);
old_pte = pte_val(pte);
/* If PTE busy, retry the access */
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
if (unlikely(old_pte & H_PAGE_BUSY))
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
return 0;
/* If PTE permissions don't match, take page fault */
powerpc/mm: Replace _PAGE_USER with _PAGE_PRIVILEGED _PAGE_PRIVILEGED means the page can be accessed only by the kernel. This is done to keep pte bits similar to PowerISA 3.0 Radix PTE format. User pages are now marked by clearing _PAGE_PRIVILEGED bit. Previously we allowed the kernel to have a privileged page in the lower address range (USER_REGION). With this patch such access is denied. We also prevent a kernel access to a non-privileged page in higher address range (ie, REGION_ID != 0). Both the above access scenarios should never happen. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:34 +00:00
if (unlikely(!check_pte_access(access, old_pte)))
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
return 1;
/*
* Try to lock the PTE, add ACCESSED and DIRTY if it was
* a write access. Since this is 4K insert of 64K page size
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
* also add H_PAGE_COMBO
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
*/
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
new_pte = old_pte | H_PAGE_BUSY | _PAGE_ACCESSED | H_PAGE_COMBO;
powerpc/mm: Use _PAGE_READ to indicate Read access This splits the _PAGE_RW bit into _PAGE_READ and _PAGE_WRITE. It also removes the dependency on _PAGE_USER for implying read only. Few things to note here is that, we have read implied with write and execute permission. Hence we should always find _PAGE_READ set on hash pte fault. We still can't switch PROT_NONE to !(_PAGE_RWX). Auto numa depends on marking a prot none pte _PAGE_WRITE. (For more details look at b191f9b106ea "mm: numa: preserve PTE write permissions across a NUMA hinting fault") Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:30 +00:00
if (access & _PAGE_WRITE)
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
new_pte |= _PAGE_DIRTY;
powerpc/mm: Add pte_xchg() helper We have five locations in 64-bit hash MMU code that do a cmpxchg() of a PTE. Currently doing it inline OK, but in a future patch we will be converting the PTEs to __be64 in some configs. In that case we will need casts at every cmpxchg() site in order to keep sparse happy. So move the logic into a helper, this is a reasonably nice cleanup on its own. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:27 +00:00
} while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
/*
* Handle the subpage protection bits
*/
subpg_pte = new_pte & ~subpg_prot;
powerpc/mm: Add helper for converting pte bit to hpte bits Instead of open coding it in multiple code paths, export the helper and add more documentation. Also make sure we don't make assumption regarding pte bit position Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:50 +00:00
rflags = htab_convert_pte_flags(subpg_pte);
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
powerpc/mm: Fix lazy icache flush on pre-POWER5 On 64-bit CPUs with no-execute support and non-snooping icache, such as 970 or POWER4, we have a software mechanism to ensure coherency of the cache (using exec faults when needed). This was broken due to a logic error when the code was rewritten from assembly to C, previously the assembly code did: BEGIN_FTR_SECTION mr r4,r30 mr r5,r7 bl hash_page_do_lazy_icache END_FTR_SECTION(CPU_FTR_NOEXECUTE|CPU_FTR_COHERENT_ICACHE, CPU_FTR_NOEXECUTE) Which tests that: (cpu_features & (NOEXECUTE | COHERENT_ICACHE)) == NOEXECUTE Which says that the current cpu does have NOEXECUTE, but does not have COHERENT_ICACHE. Fixes: 91f1da99792a ("powerpc/mm: Convert 4k hash insert to C") Fixes: 89ff725051d1 ("powerpc/mm: Convert __hash_page_64K to C") Fixes: a43c0eb8364c ("powerpc/mm: Convert 4k insert from asm to C") Cc: stable@vger.kernel.org # v4.5+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Change log verbosification] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-29 02:13:46 +00:00
if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
!cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
/*
* No CPU has hugepages but lacks no execute, so we
* don't need to worry about that case
*/
rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
}
subpg_index = (ea & (PAGE_SIZE - 1)) >> shift;
vpn = hpt_vpn(ea, vsid, ssize);
powerpc/mm/hash64: Store the slot information at the right offset for hugetlb The hugetlb pte entries are at the PMD and PUD level, so we can't use PTRS_PER_PTE to find the second half of the page table. Use the right offset for PUD/PMD to get to the second half of the table. Fixes: bf9a95f9a648 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-11 15:00:08 +00:00
rpte = __real_pte(__pte(old_pte), ptep, PTRS_PER_PTE);
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
/*
*None of the sub 4k page is hashed
*/
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
if (!(old_pte & H_PAGE_HASHPTE))
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
goto htab_insert_hpte;
/*
* Check if the pte was already inserted into the hash table
* as a 64k HW page, and invalidate the 64k HPTE if so.
*/
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
if (!(old_pte & H_PAGE_COMBO)) {
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
flush_hash_page(vpn, rpte, MMU_PAGE_64K, ssize, flags);
powerpc/mm/hash: Clear the invalid slot information correctly We can get a hash pte fault with 4k base page size and find the pte already inserted with 64K base page size. In that case we need to clear the existing slot information from the old pte. Fix this correctly With THP, we also clear the slot information with respect to all the 64K hash pte mapping that 16MB page. They are all invalid now. This make sure we don't find the slot valid when we fault with 4k base page size. Finding the slot valid should not result in any wrong behavior because we do check again in hash page table for the validity. But we can avoid that check completely. Fixes: a43c0eb8364c022 ("powerpc/mm: Convert 4k hash insert to C") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-20 15:11:54 +00:00
/*
* clear the old slot details from the old and new pte.
* On hash insert failure we use old pte value and we don't
* want slot information there if we have a insert failure.
*/
powerpc: Free up four 64K PTE bits in 64K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6 in the 64K backed HPTE pages. This along with the earlier patch will entirely free up the four bits from 64K PTE. The bit numbers are big-endian as defined in the ISA3.0 This patch does the following change to 64K PTE backed by 64K HPTE. H_PAGE_F_SECOND (S) which occupied bit 4 moves to the second part of the pte to bit 60. H_PAGE_F_GIX (G,I,X) which occupied bit 5, 6 and 7 also moves to the second part of the pte to bit 61, 62, 63, 64 respectively since bit 7 is now freed up, we move H_PAGE_BUSY (B) from bit 9 to bit 7. The second part of the PTE will hold (H_PAGE_F_SECOND|H_PAGE_F_GIX) at bit 60,61,62,63. NOTE: None of the bits in the secondary PTE were not used by 64k-HPTE backed PTE. Before the patch, the 64K HPTE backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| |S |G |I |X |x|B| |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' | | | | | | | | | | | | |..................| | | | | <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 64k HPTE backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | |B |x| | |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' | | | | | | | | | | | | |..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' The above PTE changes is applicable to hugetlbpages aswell. The patch does the following code changes: a) moves the H_PAGE_F_SECOND and H_PAGE_F_GIX to 4k PTE header since it is no more needed b the 64k PTEs. b) abstracts out __real_pte() and __rpte_to_hidx() so the caller need not know the bit location of the slot. c) moves the slot bits to the secondary pte. Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:48 +00:00
old_pte &= ~H_PAGE_HASHPTE;
new_pte &= ~H_PAGE_HASHPTE;
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
goto htab_insert_hpte;
}
/*
* Check for sub page valid and update
*/
if (__rpte_sub_valid(rpte, subpg_index)) {
int ret;
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
gslot = pte_get_hash_gslot(vpn, shift, ssize, rpte,
subpg_index);
ret = mmu_hash_ops.hpte_updatepp(gslot, rflags, vpn,
powerpc/mm: Move hash table ops to a separate structure Moving probe_machine() to after mmu init will cause the ppc_md fields relative to the hash table management to be overwritten. Since we have essentially disconnected the machine type from the hash backend ops, finish the job by moving them to a different structure. The only callback that didn't quite fix is update_partition_table since this is not specific to hash, so I moved it to a standalone variable for now. We can revisit later if needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Fix ppc64e build failure in kexec] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 05:03:58 +00:00
MMU_PAGE_4K, MMU_PAGE_4K,
ssize, flags);
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
/*
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
* If we failed because typically the HPTE wasn't really here
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
* we try an insertion.
*/
if (ret == -1)
goto htab_insert_hpte;
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
*ptep = __pte(new_pte & ~H_PAGE_BUSY);
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
return 0;
}
htab_insert_hpte:
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
/*
* Initialize all hidx entries to invalid value, the first time
* the PTE is about to allocate a 4K HPTE.
*/
if (!(old_pte & H_PAGE_COMBO))
rpte.hidx = INVALID_RPTE_HIDX;
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
/*
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
* handle H_PAGE_4K_PFN case
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
*/
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
if (old_pte & H_PAGE_4K_PFN) {
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
/*
* All the sub 4k page have the same
* physical address.
*/
pa = pte_pfn(__pte(old_pte)) << HW_PAGE_SHIFT;
} else {
pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
pa += (subpg_index << shift);
}
hash = hpt_hash(vpn, shift, ssize);
repeat:
powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group When computing the starting slot number for a hash page table group we used to do this hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; Multiplying with 8 (HPTES_PER_GROUP) imply the last three bits are 0. Hence we really don't need to clear then separately. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-29 08:36:29 +00:00
hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
/* Insert into the hash table, primary slot */
powerpc/mm: Move hash table ops to a separate structure Moving probe_machine() to after mmu init will cause the ppc_md fields relative to the hash table management to be overwritten. Since we have essentially disconnected the machine type from the hash backend ops, finish the job by moving them to a different structure. The only callback that didn't quite fix is update_partition_table since this is not specific to hash, so I moved it to a standalone variable for now. We can revisit later if needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Fix ppc64e build failure in kexec] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 05:03:58 +00:00
slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, 0,
MMU_PAGE_4K, MMU_PAGE_4K, ssize);
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
/*
* Primary is full, try the secondary
*/
if (unlikely(slot == -1)) {
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
bool soft_invalid;
powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group When computing the starting slot number for a hash page table group we used to do this hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; Multiplying with 8 (HPTES_PER_GROUP) imply the last three bits are 0. Hence we really don't need to clear then separately. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-29 08:36:29 +00:00
hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
powerpc/mm: Move hash table ops to a separate structure Moving probe_machine() to after mmu init will cause the ppc_md fields relative to the hash table management to be overwritten. Since we have essentially disconnected the machine type from the hash backend ops, finish the job by moving them to a different structure. The only callback that didn't quite fix is update_partition_table since this is not specific to hash, so I moved it to a standalone variable for now. We can revisit later if needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Fix ppc64e build failure in kexec] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 05:03:58 +00:00
slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa,
rflags, HPTE_V_SECONDARY,
MMU_PAGE_4K, MMU_PAGE_4K,
ssize);
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
soft_invalid = hpte_soft_invalid(slot);
if (unlikely(soft_invalid)) {
/*
* We got a valid slot from a hardware point of view.
* but we cannot use it, because we use this special
* value; as defined by hpte_soft_invalid(), to track
* invalid slots. We cannot use it. So invalidate it.
*/
gslot = slot & _PTEIDX_GROUP_IX;
mmu_hash_ops.hpte_invalidate(hpte_group + gslot, vpn,
MMU_PAGE_4K, MMU_PAGE_4K,
ssize, 0);
}
if (unlikely(slot == -1 || soft_invalid)) {
/*
* For soft invalid slot, let's ensure that we release a
* slot from the primary, with the hope that we will
* acquire that slot next time we try. This will ensure
* that we do not get the same soft-invalid slot.
*/
if (soft_invalid || (mftb() & 0x1))
powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group When computing the starting slot number for a hash page table group we used to do this hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; Multiplying with 8 (HPTES_PER_GROUP) imply the last three bits are 0. Hence we really don't need to clear then separately. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-29 08:36:29 +00:00
hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
powerpc/mm: Move hash table ops to a separate structure Moving probe_machine() to after mmu init will cause the ppc_md fields relative to the hash table management to be overwritten. Since we have essentially disconnected the machine type from the hash backend ops, finish the job by moving them to a different structure. The only callback that didn't quite fix is update_partition_table since this is not specific to hash, so I moved it to a standalone variable for now. We can revisit later if needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Fix ppc64e build failure in kexec] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 05:03:58 +00:00
mmu_hash_ops.hpte_remove(hpte_group);
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
/*
* FIXME!! Should be try the group from which we removed ?
*/
goto repeat;
}
}
/*
powerp/mm: Update code comments We are updating pte in those functions. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-01 07:29:17 +00:00
* Hypervisor failure. Restore old pte and return -1
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
* similar to __hash_page_*
*/
if (unlikely(slot == -2)) {
*ptep = __pte(old_pte);
hash_failure_debug(ea, access, vsid, trap, ssize,
MMU_PAGE_4K, MMU_PAGE_4K, old_pte);
return -1;
}
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
powerpc/mm/hash64: Store the slot information at the right offset for hugetlb The hugetlb pte entries are at the PMD and PUD level, so we can't use PTRS_PER_PTE to find the second half of the page table. Use the right offset for PUD/PMD to get to the second half of the table. Fixes: bf9a95f9a648 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-11 15:00:08 +00:00
new_pte |= pte_set_hidx(ptep, rpte, subpg_index, slot, PTRS_PER_PTE);
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6, in the 4K backed HPTE pages.These bits continue to be used for 64K backed HPTE pages in this patch, but will be freed up in the next patch. The bit numbers are big-endian as defined in the ISA3.0 The patch does the following change to the 4k HTPE backed 64K PTE's format. H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure below) V0 which occupied bit 4 is not used anymore. V1 which occupied bit 5 is not used anymore. V2 which occupied bit 6 is not used anymore. V3 which occupied bit 7 is not used anymore. Before the patch, the 4k backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 4k backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | | |x|B| |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' the four bits S,G,I,X (one quadruplet per 4k HPTE) that cache the hash-bucket slot value, is initialized to 1,1,1,1 indicating -- an invalid slot. If a HPTE gets cached in a 1111 slot(i.e 7th slot of secondary hash bucket), it is released immediately. In other words, even though 1111 is a valid slot value in the hash bucket, we consider it invalid and release the slot and the HPTE. This gives us the opportunity to determine the validity of S,G,I,X bits based on its contents and not on any of the bits V0,V1,V2 or V3 in the primary PTE When we release a HPTE cached in the 1111 slot we also release a legitimate slot in the primary hash bucket and unmap its corresponding HPTE. This is to ensure that we do get a HPTE cached in a slot of the primary hash bucket, the next time we retry. Though treating 1111 slot as invalid, reduces the number of available slots in the hash bucket and may have an effect on the performance, the probabilty of hitting a 1111 slot is extermely low. Compared to the current scheme, the above scheme reduces the number of false hash table updates significantly and has the added advantage of releasing four valuable PTE bits for other purpose. NOTE:even though bits 3, 4, 5, 6, 7 are not used when the 64K PTE is backed by 4k HPTE, they continue to be used if the PTE gets backed by 64k HPTE. The next patch will decouple that aswell, and truely release the bits. This idea was jointly developed by Paul Mackerras, Aneesh, Michael Ellermen and myself. 4K PTE format remains unchanged currently. The patch does the following code changes a) PTE flags are split between 64k and 4k header files. b) __hash_page_4K() is reimplemented to reflect the above logic. Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:47 +00:00
new_pte |= H_PAGE_HASHPTE;
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
*ptep = __pte(new_pte & ~H_PAGE_BUSY);
powerpc/mm: Convert 4k hash insert to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:43 +00:00
return 0;
}
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
int __hash_page_64K(unsigned long ea, unsigned long access,
unsigned long vsid, pte_t *ptep, unsigned long trap,
unsigned long flags, int ssize)
{
powerpc: Free up four 64K PTE bits in 64K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6 in the 64K backed HPTE pages. This along with the earlier patch will entirely free up the four bits from 64K PTE. The bit numbers are big-endian as defined in the ISA3.0 This patch does the following change to 64K PTE backed by 64K HPTE. H_PAGE_F_SECOND (S) which occupied bit 4 moves to the second part of the pte to bit 60. H_PAGE_F_GIX (G,I,X) which occupied bit 5, 6 and 7 also moves to the second part of the pte to bit 61, 62, 63, 64 respectively since bit 7 is now freed up, we move H_PAGE_BUSY (B) from bit 9 to bit 7. The second part of the PTE will hold (H_PAGE_F_SECOND|H_PAGE_F_GIX) at bit 60,61,62,63. NOTE: None of the bits in the secondary PTE were not used by 64k-HPTE backed PTE. Before the patch, the 64K HPTE backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| |S |G |I |X |x|B| |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' | | | | | | | | | | | | |..................| | | | | <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 64k HPTE backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | |B |x| | |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' | | | | | | | | | | | | |..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' The above PTE changes is applicable to hugetlbpages aswell. The patch does the following code changes: a) moves the H_PAGE_F_SECOND and H_PAGE_F_GIX to 4k PTE header since it is no more needed b the 64k PTEs. b) abstracts out __real_pte() and __rpte_to_hidx() so the caller need not know the bit location of the slot. c) moves the slot bits to the secondary pte. Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:48 +00:00
real_pte_t rpte;
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
unsigned long hpte_group;
unsigned long rflags, pa;
unsigned long old_pte, new_pte;
unsigned long vpn, hash, slot;
unsigned long shift = mmu_psize_defs[MMU_PAGE_64K].shift;
/*
* atomically mark the linux large page PTE busy and dirty
*/
do {
pte_t pte = READ_ONCE(*ptep);
old_pte = pte_val(pte);
/* If PTE busy, retry the access */
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
if (unlikely(old_pte & H_PAGE_BUSY))
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
return 0;
/* If PTE permissions don't match, take page fault */
powerpc/mm: Replace _PAGE_USER with _PAGE_PRIVILEGED _PAGE_PRIVILEGED means the page can be accessed only by the kernel. This is done to keep pte bits similar to PowerISA 3.0 Radix PTE format. User pages are now marked by clearing _PAGE_PRIVILEGED bit. Previously we allowed the kernel to have a privileged page in the lower address range (USER_REGION). With this patch such access is denied. We also prevent a kernel access to a non-privileged page in higher address range (ie, REGION_ID != 0). Both the above access scenarios should never happen. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:34 +00:00
if (unlikely(!check_pte_access(access, old_pte)))
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
return 1;
/*
* Check if PTE has the cache-inhibit bit set
* If so, bail out and refault as a 4k page
*/
if (!mmu_has_feature(MMU_FTR_CI_LARGE_PAGE) &&
powerpc/mm: Drop WIMG in favour of new constants PowerISA 3.0 introduces two pte bits with the below meaning for radix: 00 -> Normal Memory 01 -> Strong Access Order (SAO) 10 -> Non idempotent I/O (Cache inhibited and guarded) 11 -> Tolerant I/O (Cache inhibited) We drop the existing WIMG bits in the Linux page table in favour of the above constants. We loose _PAGE_WRITETHRU with this conversion. We only use writethru via pgprot_cached_wthru() which is used by fbdev/controlfb.c which is Apple control display and also PPC32. With respect to _PAGE_COHERENCE, we have been marking hpte always coherent for some time now. htab_convert_pte_flags() always added HPTE_R_M. NOTE: KVM changes need closer review. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:38 +00:00
unlikely(pte_ci(pte)))
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
return 0;
/*
* Try to lock the PTE, add ACCESSED and DIRTY if it was
powerpc/mm/book3s-64: Clean up some obsolete or misleading comments No code changes. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-22 02:41:12 +00:00
* a write access.
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
*/
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
new_pte = old_pte | H_PAGE_BUSY | _PAGE_ACCESSED;
powerpc/mm: Use _PAGE_READ to indicate Read access This splits the _PAGE_RW bit into _PAGE_READ and _PAGE_WRITE. It also removes the dependency on _PAGE_USER for implying read only. Few things to note here is that, we have read implied with write and execute permission. Hence we should always find _PAGE_READ set on hash pte fault. We still can't switch PROT_NONE to !(_PAGE_RWX). Auto numa depends on marking a prot none pte _PAGE_WRITE. (For more details look at b191f9b106ea "mm: numa: preserve PTE write permissions across a NUMA hinting fault") Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:30 +00:00
if (access & _PAGE_WRITE)
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
new_pte |= _PAGE_DIRTY;
powerpc/mm: Add pte_xchg() helper We have five locations in 64-bit hash MMU code that do a cmpxchg() of a PTE. Currently doing it inline OK, but in a future patch we will be converting the PTEs to __be64 in some configs. In that case we will need casts at every cmpxchg() site in order to keep sparse happy. So move the logic into a helper, this is a reasonably nice cleanup on its own. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:27 +00:00
} while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));
powerpc/mm: Add helper for converting pte bit to hpte bits Instead of open coding it in multiple code paths, export the helper and add more documentation. Also make sure we don't make assumption regarding pte bit position Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:50 +00:00
rflags = htab_convert_pte_flags(new_pte);
powerpc/mm/hash64: Store the slot information at the right offset for hugetlb The hugetlb pte entries are at the PMD and PUD level, so we can't use PTRS_PER_PTE to find the second half of the page table. Use the right offset for PUD/PMD to get to the second half of the table. Fixes: bf9a95f9a648 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-11 15:00:08 +00:00
rpte = __real_pte(__pte(old_pte), ptep, PTRS_PER_PTE);
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
powerpc/mm: Fix lazy icache flush on pre-POWER5 On 64-bit CPUs with no-execute support and non-snooping icache, such as 970 or POWER4, we have a software mechanism to ensure coherency of the cache (using exec faults when needed). This was broken due to a logic error when the code was rewritten from assembly to C, previously the assembly code did: BEGIN_FTR_SECTION mr r4,r30 mr r5,r7 bl hash_page_do_lazy_icache END_FTR_SECTION(CPU_FTR_NOEXECUTE|CPU_FTR_COHERENT_ICACHE, CPU_FTR_NOEXECUTE) Which tests that: (cpu_features & (NOEXECUTE | COHERENT_ICACHE)) == NOEXECUTE Which says that the current cpu does have NOEXECUTE, but does not have COHERENT_ICACHE. Fixes: 91f1da99792a ("powerpc/mm: Convert 4k hash insert to C") Fixes: 89ff725051d1 ("powerpc/mm: Convert __hash_page_64K to C") Fixes: a43c0eb8364c ("powerpc/mm: Convert 4k insert from asm to C") Cc: stable@vger.kernel.org # v4.5+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Change log verbosification] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-29 02:13:46 +00:00
if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
vpn = hpt_vpn(ea, vsid, ssize);
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
if (unlikely(old_pte & H_PAGE_HASHPTE)) {
powerpc: Free up four 64K PTE bits in 64K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6 in the 64K backed HPTE pages. This along with the earlier patch will entirely free up the four bits from 64K PTE. The bit numbers are big-endian as defined in the ISA3.0 This patch does the following change to 64K PTE backed by 64K HPTE. H_PAGE_F_SECOND (S) which occupied bit 4 moves to the second part of the pte to bit 60. H_PAGE_F_GIX (G,I,X) which occupied bit 5, 6 and 7 also moves to the second part of the pte to bit 61, 62, 63, 64 respectively since bit 7 is now freed up, we move H_PAGE_BUSY (B) from bit 9 to bit 7. The second part of the PTE will hold (H_PAGE_F_SECOND|H_PAGE_F_GIX) at bit 60,61,62,63. NOTE: None of the bits in the secondary PTE were not used by 64k-HPTE backed PTE. Before the patch, the 64K HPTE backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| |S |G |I |X |x|B| |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' | | | | | | | | | | | | |..................| | | | | <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 64k HPTE backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | |B |x| | |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' | | | | | | | | | | | | |..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' The above PTE changes is applicable to hugetlbpages aswell. The patch does the following code changes: a) moves the H_PAGE_F_SECOND and H_PAGE_F_GIX to 4k PTE header since it is no more needed b the 64k PTEs. b) abstracts out __real_pte() and __rpte_to_hidx() so the caller need not know the bit location of the slot. c) moves the slot bits to the secondary pte. Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:48 +00:00
unsigned long gslot;
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
/*
* There MIGHT be an HPTE for this pte
*/
powerpc: Free up four 64K PTE bits in 64K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6 in the 64K backed HPTE pages. This along with the earlier patch will entirely free up the four bits from 64K PTE. The bit numbers are big-endian as defined in the ISA3.0 This patch does the following change to 64K PTE backed by 64K HPTE. H_PAGE_F_SECOND (S) which occupied bit 4 moves to the second part of the pte to bit 60. H_PAGE_F_GIX (G,I,X) which occupied bit 5, 6 and 7 also moves to the second part of the pte to bit 61, 62, 63, 64 respectively since bit 7 is now freed up, we move H_PAGE_BUSY (B) from bit 9 to bit 7. The second part of the PTE will hold (H_PAGE_F_SECOND|H_PAGE_F_GIX) at bit 60,61,62,63. NOTE: None of the bits in the secondary PTE were not used by 64k-HPTE backed PTE. Before the patch, the 64K HPTE backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| |S |G |I |X |x|B| |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' | | | | | | | | | | | | |..................| | | | | <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 64k HPTE backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | |B |x| | |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' | | | | | | | | | | | | |..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' The above PTE changes is applicable to hugetlbpages aswell. The patch does the following code changes: a) moves the H_PAGE_F_SECOND and H_PAGE_F_GIX to 4k PTE header since it is no more needed b the 64k PTEs. b) abstracts out __real_pte() and __rpte_to_hidx() so the caller need not know the bit location of the slot. c) moves the slot bits to the secondary pte. Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:48 +00:00
gslot = pte_get_hash_gslot(vpn, shift, ssize, rpte, 0);
if (mmu_hash_ops.hpte_updatepp(gslot, rflags, vpn, MMU_PAGE_64K,
powerpc/mm: Move hash table ops to a separate structure Moving probe_machine() to after mmu init will cause the ppc_md fields relative to the hash table management to be overwritten. Since we have essentially disconnected the machine type from the hash backend ops, finish the job by moving them to a different structure. The only callback that didn't quite fix is update_partition_table since this is not specific to hash, so I moved it to a standalone variable for now. We can revisit later if needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Fix ppc64e build failure in kexec] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 05:03:58 +00:00
MMU_PAGE_64K, ssize,
flags) == -1)
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
old_pte &= ~_PAGE_HPTEFLAGS;
}
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
if (likely(!(old_pte & H_PAGE_HASHPTE))) {
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
hash = hpt_hash(vpn, shift, ssize);
repeat:
powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group When computing the starting slot number for a hash page table group we used to do this hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; Multiplying with 8 (HPTES_PER_GROUP) imply the last three bits are 0. Hence we really don't need to clear then separately. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-29 08:36:29 +00:00
hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
/* Insert into the hash table, primary slot */
powerpc/mm: Move hash table ops to a separate structure Moving probe_machine() to after mmu init will cause the ppc_md fields relative to the hash table management to be overwritten. Since we have essentially disconnected the machine type from the hash backend ops, finish the job by moving them to a different structure. The only callback that didn't quite fix is update_partition_table since this is not specific to hash, so I moved it to a standalone variable for now. We can revisit later if needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Fix ppc64e build failure in kexec] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 05:03:58 +00:00
slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, 0,
MMU_PAGE_64K, MMU_PAGE_64K,
ssize);
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
/*
* Primary is full, try the secondary
*/
if (unlikely(slot == -1)) {
powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group When computing the starting slot number for a hash page table group we used to do this hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; Multiplying with 8 (HPTES_PER_GROUP) imply the last three bits are 0. Hence we really don't need to clear then separately. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-29 08:36:29 +00:00
hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
powerpc/mm: Move hash table ops to a separate structure Moving probe_machine() to after mmu init will cause the ppc_md fields relative to the hash table management to be overwritten. Since we have essentially disconnected the machine type from the hash backend ops, finish the job by moving them to a different structure. The only callback that didn't quite fix is update_partition_table since this is not specific to hash, so I moved it to a standalone variable for now. We can revisit later if needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Fix ppc64e build failure in kexec] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 05:03:58 +00:00
slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa,
rflags,
HPTE_V_SECONDARY,
MMU_PAGE_64K,
MMU_PAGE_64K, ssize);
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
if (slot == -1) {
if (mftb() & 0x1)
powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group When computing the starting slot number for a hash page table group we used to do this hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; Multiplying with 8 (HPTES_PER_GROUP) imply the last three bits are 0. Hence we really don't need to clear then separately. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-29 08:36:29 +00:00
hpte_group = (hash & htab_hash_mask) *
HPTES_PER_GROUP;
powerpc/mm: Move hash table ops to a separate structure Moving probe_machine() to after mmu init will cause the ppc_md fields relative to the hash table management to be overwritten. Since we have essentially disconnected the machine type from the hash backend ops, finish the job by moving them to a different structure. The only callback that didn't quite fix is update_partition_table since this is not specific to hash, so I moved it to a standalone variable for now. We can revisit later if needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Fix ppc64e build failure in kexec] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 05:03:58 +00:00
mmu_hash_ops.hpte_remove(hpte_group);
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
/*
* FIXME!! Should be try the group from which we removed ?
*/
goto repeat;
}
}
/*
powerp/mm: Update code comments We are updating pte in those functions. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-01 07:29:17 +00:00
* Hypervisor failure. Restore old pte and return -1
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
* similar to __hash_page_*
*/
if (unlikely(slot == -2)) {
*ptep = __pte(old_pte);
hash_failure_debug(ea, access, vsid, trap, ssize,
MMU_PAGE_64K, MMU_PAGE_64K, old_pte);
return -1;
}
powerpc: Free up four 64K PTE bits in 64K backed HPTE pages Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6 in the 64K backed HPTE pages. This along with the earlier patch will entirely free up the four bits from 64K PTE. The bit numbers are big-endian as defined in the ISA3.0 This patch does the following change to 64K PTE backed by 64K HPTE. H_PAGE_F_SECOND (S) which occupied bit 4 moves to the second part of the pte to bit 60. H_PAGE_F_GIX (G,I,X) which occupied bit 5, 6 and 7 also moves to the second part of the pte to bit 61, 62, 63, 64 respectively since bit 7 is now freed up, we move H_PAGE_BUSY (B) from bit 9 to bit 7. The second part of the PTE will hold (H_PAGE_F_SECOND|H_PAGE_F_GIX) at bit 60,61,62,63. NOTE: None of the bits in the secondary PTE were not used by 64k-HPTE backed PTE. Before the patch, the 64K HPTE backed 64k PTE format was as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| |S |G |I |X |x|B| |x|x|................|x|x|x|x| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' | | | | | | | | | | | | |..................| | | | | <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' After the patch, the 64k HPTE backed 64k PTE format is as follows 0 1 2 3 4 5 6 7 8 9 10...........................63 : : : : : : : : : : : : v v v v v v v v v v v v ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-, |x|x|x| | | | |B |x| | |x|x|................|.|.|.|.| <- primary pte '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_' | | | | | | | | | | | | |..................|S|G|I|X| <- secondary pte '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_' The above PTE changes is applicable to hugetlbpages aswell. The patch does the following code changes: a) moves the H_PAGE_F_SECOND and H_PAGE_F_GIX to 4k PTE header since it is no more needed b the 64k PTEs. b) abstracts out __real_pte() and __rpte_to_hidx() so the caller need not know the bit location of the slot. c) moves the slot bits to the secondary pte. Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06 08:50:48 +00:00
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | H_PAGE_HASHPTE;
powerpc/mm/hash64: Store the slot information at the right offset for hugetlb The hugetlb pte entries are at the PMD and PUD level, so we can't use PTRS_PER_PTE to find the second half of the page table. Use the right offset for PUD/PMD to get to the second half of the table. Fixes: bf9a95f9a648 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-11 15:00:08 +00:00
new_pte |= pte_set_hidx(ptep, rpte, 0, slot, PTRS_PER_PTE);
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
}
powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefix This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 13:25:45 +00:00
*ptep = __pte(new_pte & ~H_PAGE_BUSY);
powerpc/mm: Convert __hash_page_64K to C Convert from asm to C Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 03:36:48 +00:00
return 0;
}
Reference in New Issue Copy Permalink