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powerpc/book3s64/hash/4k: Support large linear mapping range with 4K

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With commit: 0034d395f8 ("powerpc/mm/hash64: Map all the kernel
regions in the same 0xc range"), we now split the 64TB address range
into 4 contexts each of 16TB. That implies we can do only 16TB linear
mapping.

On some systems, eg. Power9, memory attached to nodes > 0 will appear
above 16TB in the linear mapping. This resulted in kernel crash when
we boot such systems in hash translation mode with 4K PAGE_SIZE.

This patch updates the kernel mapping such that we now start supporting upto
61TB of memory with 4K. The kernel mapping now looks like below 4K PAGE_SIZE
and hash translation.

    vmalloc start     = 0xc0003d0000000000
    IO start          = 0xc0003e0000000000
    vmemmap start     = 0xc0003f0000000000

Our MAX_PHYSMEM_BITS for 4K is still 64TB even though we can only map 61TB.
We prevent bolt mapping anything outside 61TB range by checking against
H_VMALLOC_START.

Fixes: 0034d395f8 ("powerpc/mm/hash64: Map all the kernel regions in the same 0xc range")
Reported-by: Cameron Berkenpas <cam@neo-zeon.de>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200608070904.387440-3-aneesh.kumar@linux.ibm.com
This commit is contained in:
Aneesh Kumar K.V 2020-06-08 12:39:03 +05:30 committed by Michael Ellerman
parent eb553f1697
commit 7746406baa
1 changed files with 6 additions and 7 deletions
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13
arch/powerpc/include/asm/book3s/64/hash-4k.h
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@ -13,20 +13,19 @@
*/
#define MAX_EA_BITS_PER_CONTEXT 46
#define REGION_SHIFT (MAX_EA_BITS_PER_CONTEXT - 2)
/*
* Our page table limit us to 64TB. Hence for the kernel mapping,
* each MAP area is limited to 16 TB.
* The four map areas are: linear mapping, vmap, IO and vmemmap
* Our page table limit us to 64TB. For 64TB physical memory, we only need 64GB
* of vmemmap space. To better support sparse memory layout, we use 61TB
* linear map range, 1TB of vmalloc, 1TB of I/O and 1TB of vmememmap.
*/
#define REGION_SHIFT (40)
#define H_KERN_MAP_SIZE (ASM_CONST(1) << REGION_SHIFT)
/*
* Define the address range of the kernel non-linear virtual area
* 16TB
* Define the address range of the kernel non-linear virtual area (61TB)
*/
#define H_KERN_VIRT_START ASM_CONST(0xc000100000000000)
#define H_KERN_VIRT_START ASM_CONST(0xc0003d0000000000)
#ifndef __ASSEMBLY__
#define H_PTE_TABLE_SIZE (sizeof(pte_t) << H_PTE_INDEX_SIZE)