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powerpc/e500: free r10 for FIND_PTE

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Move r13 load after the call to FIND_PTE, and use r13 instead of r10 for
storing fault address.  This will allow using r10 freely in FIND_PTE in
following patch to handle hugepage size.

Link: https://lkml.kernel.org/r/a3ee563ad5b13c891a15d3aae6c136c44ce8aa63.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Christophe Leroy 2024-07-02 15:51:31 +02:00 committed by Andrew Morton
parent 276d5affbb
commit dc0aa538a9
1 changed files with 16 additions and 14 deletions
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30
arch/powerpc/kernel/head_85xx.S
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@ -294,9 +294,10 @@ set_ivor:
/* Macros to hide the PTE size differences
*
* FIND_PTE -- walks the page tables given EA & pgdir pointer
* r10 -- EA of fault
* r10 -- free
* r11 -- PGDIR pointer
* r12 -- free
* r13 -- EA of fault
* label 2: is the bailout case
*
* if we find the pte (fall through):
@ -307,7 +308,7 @@ set_ivor:
#ifdef CONFIG_PTE_64BIT
#ifdef CONFIG_HUGETLB_PAGE
#define FIND_PTE \
rlwinm r12, r10, 14, 18, 28; /* Compute pgdir/pmd offset */ \
rlwinm r12, r13, 14, 18, 28; /* Compute pgdir/pmd offset */ \
add r12, r11, r12; \
lwz r11, 4(r12); /* Get pgd/pmd entry */ \
rlwinm. r12, r11, 0, 0, 20; /* Extract pt base address */ \
@ -317,26 +318,26 @@ set_ivor:
andi. r10, r11, HUGEPD_SHIFT_MASK@l; /* extract size field */ \
xor r12, r10, r11; /* drop size bits from pointer */ \
b 1001f; \
1000: rlwimi r12, r10, 23, 20, 28; /* Compute pte address */ \
1000: rlwimi r12, r13, 23, 20, 28; /* Compute pte address */ \
li r10, 0; /* clear r10 */ \
1001: lwz r11, 4(r12); /* Get pte entry */
#else
#define FIND_PTE \
rlwinm r12, r10, 14, 18, 28; /* Compute pgdir/pmd offset */ \
rlwinm r12, r13, 14, 18, 28; /* Compute pgdir/pmd offset */ \
add r12, r11, r12; \
lwz r11, 4(r12); /* Get pgd/pmd entry */ \
rlwinm. r12, r11, 0, 0, 20; /* Extract pt base address */ \
beq 2f; /* Bail if no table */ \
rlwimi r12, r10, 23, 20, 28; /* Compute pte address */ \
rlwimi r12, r13, 23, 20, 28; /* Compute pte address */ \
lwz r11, 4(r12); /* Get pte entry */
#endif /* HUGEPAGE */
#else /* !PTE_64BIT */
#define FIND_PTE \
rlwimi r11, r10, 12, 20, 29; /* Create L1 (pgdir/pmd) address */ \
rlwimi r11, r13, 12, 20, 29; /* Create L1 (pgdir/pmd) address */ \
lwz r11, 0(r11); /* Get L1 entry */ \
rlwinm. r12, r11, 0, 0, 19; /* Extract L2 (pte) base address */ \
beq 2f; /* Bail if no table */ \
rlwimi r12, r10, 22, 20, 29; /* Compute PTE address */ \
rlwimi r12, r13, 22, 20, 29; /* Compute PTE address */ \
lwz r11, 0(r12); /* Get Linux PTE */
#endif
@ -443,13 +444,13 @@ START_BTB_FLUSH_SECTION
BTB_FLUSH(r10)
1:
END_BTB_FLUSH_SECTION
mfspr r10, SPRN_DEAR /* Get faulting address */
mfspr r13, SPRN_DEAR /* Get faulting address */
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
lis r11, PAGE_OFFSET@h
cmplw 5, r10, r11
cmplw 5, r13, r11
blt 5, 3f
lis r11, swapper_pg_dir@h
ori r11, r11, swapper_pg_dir@l
@ -472,14 +473,14 @@ END_BTB_FLUSH_SECTION
#endif
4:
FIND_PTE
#ifdef CONFIG_PTE_64BIT
li r13,_PAGE_PRESENT|_PAGE_BAP_SR
oris r13,r13,_PAGE_ACCESSED@h
#else
li r13,_PAGE_PRESENT|_PAGE_READ|_PAGE_ACCESSED
#endif
FIND_PTE
andc. r13,r13,r11 /* Check permission */
#ifdef CONFIG_PTE_64BIT
@ -536,13 +537,13 @@ START_BTB_FLUSH_SECTION
1:
END_BTB_FLUSH_SECTION
mfspr r10, SPRN_SRR0 /* Get faulting address */
mfspr r13, SPRN_SRR0 /* Get faulting address */
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
lis r11, PAGE_OFFSET@h
cmplw 5, r10, r11
cmplw 5, r13, r11
blt 5, 3f
lis r11, swapper_pg_dir@h
ori r11, r11, swapper_pg_dir@l
@ -551,6 +552,7 @@ END_BTB_FLUSH_SECTION
rlwinm r12,r12,0,16,1
mtspr SPRN_MAS1,r12
FIND_PTE
/* Make up the required permissions for kernel code */
#ifdef CONFIG_PTE_64BIT
li r13,_PAGE_PRESENT | _PAGE_BAP_SX
@ -571,6 +573,7 @@ END_BTB_FLUSH_SECTION
beq 2f /* KUAP fault */
#endif
FIND_PTE
/* Make up the required permissions for user code */
#ifdef CONFIG_PTE_64BIT
li r13,_PAGE_PRESENT | _PAGE_BAP_UX
@ -580,7 +583,6 @@ END_BTB_FLUSH_SECTION
#endif
4:
FIND_PTE
andc. r13,r13,r11 /* Check permission */
#ifdef CONFIG_PTE_64BIT