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authorNicholas Piggin <npiggin@gmail.com>2021-02-08 09:34:06 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2021-02-11 15:35:05 +0300
commitac7c5e9b08acdb54ef3525abcad24bdb3ed05551 (patch)
treee6424ec04c8c9aea8883ab44d1dc7665ac43c7ab /arch/powerpc
parent14ad0e7d04f46865775fb010ccd96fb1cc83433a (diff)
downloadlinux-ac7c5e9b08acdb54ef3525abcad24bdb3ed05551.tar.xz
powerpc/64s: Remove EXSLB interrupt save area
SLB faults should not be taken while the PACA save areas are live, all memory accesses should be fetches from the kernel text, and access to PACA and the current stack, before C code is called or any other accesses are made. All of these have pinned SLBs so will not take a SLB fault. Therefore EXSLB is not be required. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210208063406.331655-1-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/include/asm/paca.h3
-rw-r--r--arch/powerpc/kernel/asm-offsets.c1
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S5
3 files changed, 1 insertions, 8 deletions
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 169e687fd479..ec18ac818e3a 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -109,8 +109,7 @@ struct paca_struct {
*/
/* used for most interrupts/exceptions */
u64 exgen[EX_SIZE] __attribute__((aligned(0x80)));
- u64 exslb[EX_SIZE]; /* used for SLB/segment table misses
- * on the linear mapping */
+
/* SLB related definitions */
u16 vmalloc_sllp;
u8 slb_cache_ptr;
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index b12d7c049bfe..31edd9bbce75 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -255,7 +255,6 @@ int main(void)
#endif /* CONFIG_PPC_MM_SLICES */
OFFSET(PACA_EXGEN, paca_struct, exgen);
OFFSET(PACA_EXMC, paca_struct, exmc);
- OFFSET(PACA_EXSLB, paca_struct, exslb);
OFFSET(PACA_EXNMI, paca_struct, exnmi);
#ifdef CONFIG_PPC_PSERIES
OFFSET(PACALPPACAPTR, paca_struct, lppaca_ptr);
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index de3e335bd931..a4bd3c114a0a 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1412,13 +1412,9 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
* on user-handler data structures.
*
* KVM: Same as 0x300, DSLB must test for KVM guest.
- *
- * A dedicated save area EXSLB is used (XXX: but it actually need not be
- * these days, we could use EXGEN).
*/
INT_DEFINE_BEGIN(data_access_slb)
IVEC=0x380
- IAREA=PACA_EXSLB
IDAR=1
IKVM_SKIP=1
IKVM_REAL=1
@@ -1501,7 +1497,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
*/
INT_DEFINE_BEGIN(instruction_access_slb)
IVEC=0x480
- IAREA=PACA_EXSLB
IISIDE=1
IDAR=1
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE