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linux/arch/powerpc/kernel/misc_32.S
David Gibson aa1cf632bd [POWERPC] Fix small race in 44x tlbie function 
The 440 family of processors don't have a tlbie instruction.  So, we
implement TLB invalidates by explicitly searching the TLB with tlbsx.,
then clobbering the relevant entry, if any.  Unfortunately the PID for
the search needs to be stored in the MMUCR register, which is also
used by the TLB miss handler.  Interrupts were enabled in _tlbie(), so
an interrupt between loading the MMUCR and the tlbsx could cause
incorrect search results, and thus a failure to invalide TLB entries
which needed to be invalidated.

This fixes the problem in both arch/ppc and arch/powerpc by inhibiting
interrupts (even critical and debug interrupts) across the relevant
instructions.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-08-15 15:12:50 +10:00

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/*
* This file contains miscellaneous low-level functions.
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
* and Paul Mackerras.
*
* kexec bits:
* Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com>
* GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/sys.h>
#include <asm/unistd.h>
#include <asm/errno.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/cache.h>
#include <asm/cputable.h>
#include <asm/mmu.h>
#include <asm/ppc_asm.h>
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#include <asm/processor.h>
#include <asm/kexec.h>
.text
/*
* This returns the high 64 bits of the product of two 64-bit numbers.
*/
_GLOBAL(mulhdu)
cmpwi r6,0
cmpwi cr1,r3,0
mr r10,r4
mulhwu r4,r4,r5
beq 1f
mulhwu r0,r10,r6
mullw r7,r10,r5
addc r7,r0,r7
addze r4,r4
1: beqlr cr1 /* all done if high part of A is 0 */
mr r10,r3
mullw r9,r3,r5
mulhwu r3,r3,r5
beq 2f
mullw r0,r10,r6
mulhwu r8,r10,r6
addc r7,r0,r7
adde r4,r4,r8
addze r3,r3
2: addc r4,r4,r9
addze r3,r3
blr
/*
* sub_reloc_offset(x) returns x - reloc_offset().
*/
_GLOBAL(sub_reloc_offset)
mflr r0
bl 1f
1: mflr r5
lis r4,1b@ha
addi r4,r4,1b@l
subf r5,r4,r5
subf r3,r5,r3
mtlr r0
blr
/*
* reloc_got2 runs through the .got2 section adding an offset
* to each entry.
*/
_GLOBAL(reloc_got2)
mflr r11
lis r7,__got2_start@ha
addi r7,r7,__got2_start@l
lis r8,__got2_end@ha
addi r8,r8,__got2_end@l
subf r8,r7,r8
srwi. r8,r8,2
beqlr
mtctr r8
bl 1f
1: mflr r0
lis r4,1b@ha
addi r4,r4,1b@l
subf r0,r4,r0
add r7,r0,r7
2: lwz r0,0(r7)
add r0,r0,r3
stw r0,0(r7)
addi r7,r7,4
bdnz 2b
mtlr r11
blr
/*
* call_setup_cpu - call the setup_cpu function for this cpu
* r3 = data offset, r24 = cpu number
*
* Setup function is called with:
* r3 = data offset
* r4 = ptr to CPU spec (relocated)
*/
_GLOBAL(call_setup_cpu)
addis r4,r3,cur_cpu_spec@ha
addi r4,r4,cur_cpu_spec@l
lwz r4,0(r4)
add r4,r4,r3
lwz r5,CPU_SPEC_SETUP(r4)
cmpwi 0,r5,0
add r5,r5,r3
beqlr
mtctr r5
bctr
#if defined(CONFIG_CPU_FREQ_PMAC) && defined(CONFIG_6xx)
/* This gets called by via-pmu.c to switch the PLL selection
* on 750fx CPU. This function should really be moved to some
* other place (as most of the cpufreq code in via-pmu
*/
_GLOBAL(low_choose_750fx_pll)
/* Clear MSR:EE */
mfmsr r7
rlwinm r0,r7,0,17,15
mtmsr r0
/* If switching to PLL1, disable HID0:BTIC */
cmplwi cr0,r3,0
beq 1f
mfspr r5,SPRN_HID0
rlwinm r5,r5,0,27,25
sync
mtspr SPRN_HID0,r5
isync
sync
1:
/* Calc new HID1 value */
mfspr r4,SPRN_HID1 /* Build a HID1:PS bit from parameter */
rlwinm r5,r3,16,15,15 /* Clear out HID1:PS from value read */
rlwinm r4,r4,0,16,14 /* Could have I used rlwimi here ? */
or r4,r4,r5
mtspr SPRN_HID1,r4
/* Store new HID1 image */
rlwinm r6,r1,0,0,18
lwz r6,TI_CPU(r6)
slwi r6,r6,2
addis r6,r6,nap_save_hid1@ha
stw r4,nap_save_hid1@l(r6)
/* If switching to PLL0, enable HID0:BTIC */
cmplwi cr0,r3,0
bne 1f
mfspr r5,SPRN_HID0
ori r5,r5,HID0_BTIC
sync
mtspr SPRN_HID0,r5
isync
sync
1:
/* Return */
mtmsr r7
blr
_GLOBAL(low_choose_7447a_dfs)
/* Clear MSR:EE */
mfmsr r7
rlwinm r0,r7,0,17,15
mtmsr r0
/* Calc new HID1 value */
mfspr r4,SPRN_HID1
insrwi r4,r3,1,9 /* insert parameter into bit 9 */
sync
mtspr SPRN_HID1,r4
sync
isync
/* Return */
mtmsr r7
blr
#endif /* CONFIG_CPU_FREQ_PMAC && CONFIG_6xx */
/*
* complement mask on the msr then "or" some values on.
* _nmask_and_or_msr(nmask, value_to_or)
*/
_GLOBAL(_nmask_and_or_msr)
mfmsr r0 /* Get current msr */
andc r0,r0,r3 /* And off the bits set in r3 (first parm) */
or r0,r0,r4 /* Or on the bits in r4 (second parm) */
SYNC /* Some chip revs have problems here... */
mtmsr r0 /* Update machine state */
isync
blr /* Done */
/*
* Flush MMU TLB
*/
_GLOBAL(_tlbia)
#if defined(CONFIG_40x)
sync /* Flush to memory before changing mapping */
tlbia
isync /* Flush shadow TLB */
#elif defined(CONFIG_44x)
li r3,0
sync
/* Load high watermark */
lis r4,tlb_44x_hwater@ha
lwz r5,tlb_44x_hwater@l(r4)
1: tlbwe r3,r3,PPC44x_TLB_PAGEID
addi r3,r3,1
cmpw 0,r3,r5
ble 1b
isync
#elif defined(CONFIG_FSL_BOOKE)
/* Invalidate all entries in TLB0 */
li r3, 0x04
tlbivax 0,3
/* Invalidate all entries in TLB1 */
li r3, 0x0c
tlbivax 0,3
/* Invalidate all entries in TLB2 */
li r3, 0x14
tlbivax 0,3
/* Invalidate all entries in TLB3 */
li r3, 0x1c
tlbivax 0,3
msync
#ifdef CONFIG_SMP
tlbsync
#endif /* CONFIG_SMP */
#else /* !(CONFIG_40x || CONFIG_44x || CONFIG_FSL_BOOKE) */
#if defined(CONFIG_SMP)
rlwinm r8,r1,0,0,18
lwz r8,TI_CPU(r8)
oris r8,r8,10
mfmsr r10
SYNC
rlwinm r0,r10,0,17,15 /* clear bit 16 (MSR_EE) */
rlwinm r0,r0,0,28,26 /* clear DR */
mtmsr r0
SYNC_601
isync
lis r9,mmu_hash_lock@h
ori r9,r9,mmu_hash_lock@l
tophys(r9,r9)
10: lwarx r7,0,r9
cmpwi 0,r7,0
bne- 10b
stwcx. r8,0,r9
bne- 10b
sync
tlbia
sync
TLBSYNC
li r0,0
stw r0,0(r9) /* clear mmu_hash_lock */
mtmsr r10
SYNC_601
isync
#else /* CONFIG_SMP */
sync
tlbia
sync
#endif /* CONFIG_SMP */
#endif /* ! defined(CONFIG_40x) */
blr
/*
* Flush MMU TLB for a particular address
*/
_GLOBAL(_tlbie)
#if defined(CONFIG_40x)
tlbsx. r3, 0, r3
bne 10f
sync
/* There are only 64 TLB entries, so r3 < 64, which means bit 25 is clear.
* Since 25 is the V bit in the TLB_TAG, loading this value will invalidate
* the TLB entry. */
tlbwe r3, r3, TLB_TAG
isync
10:
#elif defined(CONFIG_44x)
mfspr r4,SPRN_MMUCR
mfspr r5,SPRN_PID /* Get PID */
rlwimi r4,r5,0,24,31 /* Set TID */
/* We have to run the search with interrupts disabled, even critical
* and debug interrupts (in fact the only critical exceptions we have
* are debug and machine check). Otherwise an interrupt which causes
* a TLB miss can clobber the MMUCR between the mtspr and the tlbsx. */
mfmsr r5
lis r6,(MSR_EE|MSR_CE|MSR_ME|MSR_DE)@ha
addi r6,r6,(MSR_EE|MSR_CE|MSR_ME|MSR_DE)@l
andc r6,r5,r6
mtmsr r6
mtspr SPRN_MMUCR,r4
tlbsx. r3, 0, r3
mtmsr r5
bne 10f
sync
/* There are only 64 TLB entries, so r3 < 64,
* which means bit 22, is clear. Since 22 is
* the V bit in the TLB_PAGEID, loading this
* value will invalidate the TLB entry.
*/
tlbwe r3, r3, PPC44x_TLB_PAGEID
isync
10:
#elif defined(CONFIG_FSL_BOOKE)
rlwinm r4, r3, 0, 0, 19
ori r5, r4, 0x08 /* TLBSEL = 1 */
ori r6, r4, 0x10 /* TLBSEL = 2 */
ori r7, r4, 0x18 /* TLBSEL = 3 */
tlbivax 0, r4
tlbivax 0, r5
tlbivax 0, r6
tlbivax 0, r7
msync
#if defined(CONFIG_SMP)
tlbsync
#endif /* CONFIG_SMP */
#else /* !(CONFIG_40x || CONFIG_44x || CONFIG_FSL_BOOKE) */
#if defined(CONFIG_SMP)
rlwinm r8,r1,0,0,18
lwz r8,TI_CPU(r8)
oris r8,r8,11
mfmsr r10
SYNC
rlwinm r0,r10,0,17,15 /* clear bit 16 (MSR_EE) */
rlwinm r0,r0,0,28,26 /* clear DR */
mtmsr r0
SYNC_601
isync
lis r9,mmu_hash_lock@h
ori r9,r9,mmu_hash_lock@l
tophys(r9,r9)
10: lwarx r7,0,r9
cmpwi 0,r7,0
bne- 10b
stwcx. r8,0,r9
bne- 10b
eieio
tlbie r3
sync
TLBSYNC
li r0,0
stw r0,0(r9) /* clear mmu_hash_lock */
mtmsr r10
SYNC_601
isync
#else /* CONFIG_SMP */
tlbie r3
sync
#endif /* CONFIG_SMP */
#endif /* ! CONFIG_40x */
blr
/*
* Flush instruction cache.
* This is a no-op on the 601.
*/
_GLOBAL(flush_instruction_cache)
#if defined(CONFIG_8xx)
isync
lis r5, IDC_INVALL@h
mtspr SPRN_IC_CST, r5
#elif defined(CONFIG_4xx)
#ifdef CONFIG_403GCX
li r3, 512
mtctr r3
lis r4, KERNELBASE@h
1: iccci 0, r4
addi r4, r4, 16
bdnz 1b
#else
lis r3, KERNELBASE@h
iccci 0,r3
#endif
#elif CONFIG_FSL_BOOKE
BEGIN_FTR_SECTION
mfspr r3,SPRN_L1CSR0
ori r3,r3,L1CSR0_CFI|L1CSR0_CLFC
/* msync; isync recommended here */
mtspr SPRN_L1CSR0,r3
isync
blr
END_FTR_SECTION_IFSET(CPU_FTR_UNIFIED_ID_CACHE)
mfspr r3,SPRN_L1CSR1
ori r3,r3,L1CSR1_ICFI|L1CSR1_ICLFR
mtspr SPRN_L1CSR1,r3
#else
mfspr r3,SPRN_PVR
rlwinm r3,r3,16,16,31
cmpwi 0,r3,1
beqlr /* for 601, do nothing */
/* 603/604 processor - use invalidate-all bit in HID0 */
mfspr r3,SPRN_HID0
ori r3,r3,HID0_ICFI
mtspr SPRN_HID0,r3
#endif /* CONFIG_8xx/4xx */
isync
blr
/*
* Write any modified data cache blocks out to memory
* and invalidate the corresponding instruction cache blocks.
* This is a no-op on the 601.
*
* flush_icache_range(unsigned long start, unsigned long stop)
*/
_GLOBAL(__flush_icache_range)
BEGIN_FTR_SECTION
blr /* for 601, do nothing */
END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
li r5,L1_CACHE_BYTES-1
andc r3,r3,r5
subf r4,r3,r4
add r4,r4,r5
srwi. r4,r4,L1_CACHE_SHIFT
beqlr
mtctr r4
mr r6,r3
1: dcbst 0,r3
addi r3,r3,L1_CACHE_BYTES
bdnz 1b
sync /* wait for dcbst's to get to ram */
mtctr r4
2: icbi 0,r6
addi r6,r6,L1_CACHE_BYTES
bdnz 2b
sync /* additional sync needed on g4 */
isync
blr
/*
* Write any modified data cache blocks out to memory.
* Does not invalidate the corresponding cache lines (especially for
* any corresponding instruction cache).
*
* clean_dcache_range(unsigned long start, unsigned long stop)
*/
_GLOBAL(clean_dcache_range)
li r5,L1_CACHE_BYTES-1
andc r3,r3,r5
subf r4,r3,r4
add r4,r4,r5
srwi. r4,r4,L1_CACHE_SHIFT
beqlr
mtctr r4
1: dcbst 0,r3
addi r3,r3,L1_CACHE_BYTES
bdnz 1b
sync /* wait for dcbst's to get to ram */
blr
/*
* Write any modified data cache blocks out to memory and invalidate them.
* Does not invalidate the corresponding instruction cache blocks.
*
* flush_dcache_range(unsigned long start, unsigned long stop)
*/
_GLOBAL(flush_dcache_range)
li r5,L1_CACHE_BYTES-1
andc r3,r3,r5
subf r4,r3,r4
add r4,r4,r5
srwi. r4,r4,L1_CACHE_SHIFT
beqlr
mtctr r4
1: dcbf 0,r3
addi r3,r3,L1_CACHE_BYTES
bdnz 1b
sync /* wait for dcbst's to get to ram */
blr
/*
* Like above, but invalidate the D-cache. This is used by the 8xx
* to invalidate the cache so the PPC core doesn't get stale data
* from the CPM (no cache snooping here :-).
*
* invalidate_dcache_range(unsigned long start, unsigned long stop)
*/
_GLOBAL(invalidate_dcache_range)
li r5,L1_CACHE_BYTES-1
andc r3,r3,r5
subf r4,r3,r4
add r4,r4,r5
srwi. r4,r4,L1_CACHE_SHIFT
beqlr
mtctr r4
1: dcbi 0,r3
addi r3,r3,L1_CACHE_BYTES
bdnz 1b
sync /* wait for dcbi's to get to ram */
blr
/*
* Flush a particular page from the data cache to RAM.
* Note: this is necessary because the instruction cache does *not*
* snoop from the data cache.
* This is a no-op on the 601 which has a unified cache.
*
* void __flush_dcache_icache(void *page)
*/
_GLOBAL(__flush_dcache_icache)
BEGIN_FTR_SECTION
blr
END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
rlwinm r3,r3,0,0,19 /* Get page base address */
li r4,4096/L1_CACHE_BYTES /* Number of lines in a page */
mtctr r4
mr r6,r3
0: dcbst 0,r3 /* Write line to ram */
addi r3,r3,L1_CACHE_BYTES
bdnz 0b
sync
mtctr r4
1: icbi 0,r6
addi r6,r6,L1_CACHE_BYTES
bdnz 1b
sync
isync
blr
/*
* Flush a particular page from the data cache to RAM, identified
* by its physical address. We turn off the MMU so we can just use
* the physical address (this may be a highmem page without a kernel
* mapping).
*
* void __flush_dcache_icache_phys(unsigned long physaddr)
*/
_GLOBAL(__flush_dcache_icache_phys)
BEGIN_FTR_SECTION
blr /* for 601, do nothing */
END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
mfmsr r10
rlwinm r0,r10,0,28,26 /* clear DR */
mtmsr r0
isync
rlwinm r3,r3,0,0,19 /* Get page base address */
li r4,4096/L1_CACHE_BYTES /* Number of lines in a page */
mtctr r4
mr r6,r3
0: dcbst 0,r3 /* Write line to ram */
addi r3,r3,L1_CACHE_BYTES
bdnz 0b
sync
mtctr r4
1: icbi 0,r6
addi r6,r6,L1_CACHE_BYTES
bdnz 1b
sync
mtmsr r10 /* restore DR */
isync
blr
/*
* Clear pages using the dcbz instruction, which doesn't cause any
* memory traffic (except to write out any cache lines which get
* displaced). This only works on cacheable memory.
*
* void clear_pages(void *page, int order) ;
*/
_GLOBAL(clear_pages)
li r0,4096/L1_CACHE_BYTES
slw r0,r0,r4
mtctr r0
#ifdef CONFIG_8xx
li r4, 0
1: stw r4, 0(r3)
stw r4, 4(r3)
stw r4, 8(r3)
stw r4, 12(r3)
#else
1: dcbz 0,r3
#endif
addi r3,r3,L1_CACHE_BYTES
bdnz 1b
blr
/*
* Copy a whole page. We use the dcbz instruction on the destination
* to reduce memory traffic (it eliminates the unnecessary reads of
* the destination into cache). This requires that the destination
* is cacheable.
*/
#define COPY_16_BYTES \
lwz r6,4(r4); \
lwz r7,8(r4); \
lwz r8,12(r4); \
lwzu r9,16(r4); \
stw r6,4(r3); \
stw r7,8(r3); \
stw r8,12(r3); \
stwu r9,16(r3)
_GLOBAL(copy_page)
addi r3,r3,-4
addi r4,r4,-4
#ifdef CONFIG_8xx
/* don't use prefetch on 8xx */
li r0,4096/L1_CACHE_BYTES
mtctr r0
1: COPY_16_BYTES
bdnz 1b
blr
#else /* not 8xx, we can prefetch */
li r5,4
#if MAX_COPY_PREFETCH > 1
li r0,MAX_COPY_PREFETCH
li r11,4
mtctr r0
11: dcbt r11,r4
addi r11,r11,L1_CACHE_BYTES
bdnz 11b
#else /* MAX_COPY_PREFETCH == 1 */
dcbt r5,r4
li r11,L1_CACHE_BYTES+4
#endif /* MAX_COPY_PREFETCH */
li r0,4096/L1_CACHE_BYTES - MAX_COPY_PREFETCH
crclr 4*cr0+eq
2:
mtctr r0
1:
dcbt r11,r4
dcbz r5,r3
COPY_16_BYTES
#if L1_CACHE_BYTES >= 32
COPY_16_BYTES
#if L1_CACHE_BYTES >= 64
COPY_16_BYTES
COPY_16_BYTES
#if L1_CACHE_BYTES >= 128
COPY_16_BYTES
COPY_16_BYTES
COPY_16_BYTES
COPY_16_BYTES
#endif
#endif
#endif
bdnz 1b
beqlr
crnot 4*cr0+eq,4*cr0+eq
li r0,MAX_COPY_PREFETCH
li r11,4
b 2b
#endif /* CONFIG_8xx */
/*
* void atomic_clear_mask(atomic_t mask, atomic_t *addr)
* void atomic_set_mask(atomic_t mask, atomic_t *addr);
*/
_GLOBAL(atomic_clear_mask)
10: lwarx r5,0,r4
andc r5,r5,r3
PPC405_ERR77(0,r4)
stwcx. r5,0,r4
bne- 10b
blr
_GLOBAL(atomic_set_mask)
10: lwarx r5,0,r4
or r5,r5,r3
PPC405_ERR77(0,r4)
stwcx. r5,0,r4
bne- 10b
blr
/*
* Extended precision shifts.
*
* Updated to be valid for shift counts from 0 to 63 inclusive.
* -- Gabriel
*
* R3/R4 has 64 bit value
* R5 has shift count
* result in R3/R4
*
* ashrdi3: arithmetic right shift (sign propagation)
* lshrdi3: logical right shift
* ashldi3: left shift
*/
_GLOBAL(__ashrdi3)
subfic r6,r5,32
srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count
addi r7,r5,32 # could be xori, or addi with -32
slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count)
rlwinm r8,r7,0,32 # t3 = (count < 32) ? 32 : 0
sraw r7,r3,r7 # t2 = MSW >> (count-32)
or r4,r4,r6 # LSW |= t1
slw r7,r7,r8 # t2 = (count < 32) ? 0 : t2
sraw r3,r3,r5 # MSW = MSW >> count
or r4,r4,r7 # LSW |= t2
blr
_GLOBAL(__ashldi3)
subfic r6,r5,32
slw r3,r3,r5 # MSW = count > 31 ? 0 : MSW << count
addi r7,r5,32 # could be xori, or addi with -32
srw r6,r4,r6 # t1 = count > 31 ? 0 : LSW >> (32-count)
slw r7,r4,r7 # t2 = count < 32 ? 0 : LSW << (count-32)
or r3,r3,r6 # MSW |= t1
slw r4,r4,r5 # LSW = LSW << count
or r3,r3,r7 # MSW |= t2
blr
_GLOBAL(__lshrdi3)
subfic r6,r5,32
srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count
addi r7,r5,32 # could be xori, or addi with -32
slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count)
srw r7,r3,r7 # t2 = count < 32 ? 0 : MSW >> (count-32)
or r4,r4,r6 # LSW |= t1
srw r3,r3,r5 # MSW = MSW >> count
or r4,r4,r7 # LSW |= t2
blr
_GLOBAL(abs)
srawi r4,r3,31
xor r3,r3,r4
sub r3,r3,r4
blr
/*
* Create a kernel thread
* kernel_thread(fn, arg, flags)
*/
_GLOBAL(kernel_thread)
stwu r1,-16(r1)
stw r30,8(r1)
stw r31,12(r1)
mr r30,r3 /* function */
mr r31,r4 /* argument */
ori r3,r5,CLONE_VM /* flags */
oris r3,r3,CLONE_UNTRACED>>16
li r4,0 /* new sp (unused) */
li r0,__NR_clone
sc
cmpwi 0,r3,0 /* parent or child? */
bne 1f /* return if parent */
li r0,0 /* make top-level stack frame */
stwu r0,-16(r1)
mtlr r30 /* fn addr in lr */
mr r3,r31 /* load arg and call fn */
PPC440EP_ERR42
blrl
li r0,__NR_exit /* exit if function returns */
li r3,0
sc
1: lwz r30,8(r1)
lwz r31,12(r1)
addi r1,r1,16
blr
_GLOBAL(kernel_execve)
li r0,__NR_execve
sc
bnslr
neg r3,r3
blr
/*
* This routine is just here to keep GCC happy - sigh...
*/
_GLOBAL(__main)
blr
#ifdef CONFIG_KEXEC
/*
* Must be relocatable PIC code callable as a C function.
*/
.globl relocate_new_kernel
relocate_new_kernel:
/* r3 = page_list */
/* r4 = reboot_code_buffer */
/* r5 = start_address */
li r0, 0
/*
* Set Machine Status Register to a known status,
* switch the MMU off and jump to 1: in a single step.
*/
mr r8, r0
ori r8, r8, MSR_RI|MSR_ME
mtspr SPRN_SRR1, r8
addi r8, r4, 1f - relocate_new_kernel
mtspr SPRN_SRR0, r8
sync
rfi
1:
/* from this point address translation is turned off */
/* and interrupts are disabled */
/* set a new stack at the bottom of our page... */
/* (not really needed now) */
addi r1, r4, KEXEC_CONTROL_CODE_SIZE - 8 /* for LR Save+Back Chain */
stw r0, 0(r1)
/* Do the copies */
li r6, 0 /* checksum */
mr r0, r3
b 1f
0: /* top, read another word for the indirection page */
lwzu r0, 4(r3)
1:
/* is it a destination page? (r8) */
rlwinm. r7, r0, 0, 31, 31 /* IND_DESTINATION (1<<0) */
beq 2f
rlwinm r8, r0, 0, 0, 19 /* clear kexec flags, page align */
b 0b
2: /* is it an indirection page? (r3) */
rlwinm. r7, r0, 0, 30, 30 /* IND_INDIRECTION (1<<1) */
beq 2f
rlwinm r3, r0, 0, 0, 19 /* clear kexec flags, page align */
subi r3, r3, 4
b 0b
2: /* are we done? */
rlwinm. r7, r0, 0, 29, 29 /* IND_DONE (1<<2) */
beq 2f
b 3f
2: /* is it a source page? (r9) */
rlwinm. r7, r0, 0, 28, 28 /* IND_SOURCE (1<<3) */
beq 0b
rlwinm r9, r0, 0, 0, 19 /* clear kexec flags, page align */
li r7, PAGE_SIZE / 4
mtctr r7
subi r9, r9, 4
subi r8, r8, 4
9:
lwzu r0, 4(r9) /* do the copy */
xor r6, r6, r0
stwu r0, 4(r8)
dcbst 0, r8
sync
icbi 0, r8
bdnz 9b
addi r9, r9, 4
addi r8, r8, 4
b 0b
3:
/* To be certain of avoiding problems with self-modifying code
* execute a serializing instruction here.
*/
isync
sync
/* jump to the entry point, usually the setup routine */
mtlr r5
blrl
1: b 1b
relocate_new_kernel_end:
.globl relocate_new_kernel_size
relocate_new_kernel_size:
.long relocate_new_kernel_end - relocate_new_kernel
#endif
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