diff options
| author | Mihai Caraman <mihai.caraman@freescale.com> | 2012-08-06 03:27:07 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-09-05 15:35:52 +1000 |
| commit | 8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad (patch) | |
| tree | 9d0bfd7ecd07c02fef68e7b198a0560340bf0846 /arch/powerpc/kernel/exceptions-64e.S | |
| parent | 79b5c8dbaa4528a6fd03a4d9d8a6d56a46293a3a (diff) | |
powerpc/booke64: Use SPRG0/3 scratch for bolted TLB miss & crit int
Embedded.Hypervisor category defines GSPRG0..3 physical registers for guests.
Avoid SPRG4-7 usage as scratch in host exception handlers, otherwise guest
SPRG4-7 registers will be clobbered.
For bolted TLB miss exception handlers, which is the version currently
supported by KVM, use SPRN_SPRG_GEN_SCRATCH aka SPRG0 instead of
SPRN_SPRG_TLB_SCRATCH aka SPRG6. Keep using TLB PACA slots to fit in one
64-byte cache line.
For critical exception handlers use SPRG3 instead of SPRG7. Provide a routine
to store and restore user-visible SPRGs. This will be subsequently used
to restore VDSO information in SPRG3. Add EX_R13 to paca slots to free up
SPRG3 and change the critical exception epilog to use it.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64e.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64e.S | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 83c20e84a4f..7476b0ae09f 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -42,6 +42,7 @@ mfspr r13,SPRN_SPRG_PACA; /* get PACA */ \ std r10,PACA_EX##type+EX_R10(r13); \ std r11,PACA_EX##type+EX_R11(r13); \ + PROLOG_STORE_RESTORE_SCRATCH_##type; \ mfcr r10; /* save CR */ \ mfspr r11,SPRN_##type##_SRR1;/* what are we coming from */ \ DO_KVM intnum,SPRN_##type##_SRR1; /* KVM hook */ \ @@ -99,6 +100,18 @@ #define GDBELL_EXCEPTION_PROLOG(n, intnum, addition) \ EXCEPTION_PROLOG(n, intnum, GDBELL, addition##_GDBELL(n)) +/* + * Store user-visible scratch in PACA exception slots and restore proper value + */ +#define PROLOG_STORE_RESTORE_SCRATCH_GEN +#define PROLOG_STORE_RESTORE_SCRATCH_GDBELL +#define PROLOG_STORE_RESTORE_SCRATCH_DBG +#define PROLOG_STORE_RESTORE_SCRATCH_MC + +#define PROLOG_STORE_RESTORE_SCRATCH_CRIT \ + mfspr r10,SPRN_SPRG_CRIT_SCRATCH; /* get r13 */ \ + std r10,PACA_EXCRIT+EX_R13(r13) + /* Variants of the "addition" argument for the prolog */ #define PROLOG_ADDITION_NONE_GEN(n) @@ -454,7 +467,7 @@ interrupt_end_book3e: mtcr r10 ld r10,PACA_EXCRIT+EX_R10(r13) /* restore registers */ ld r11,PACA_EXCRIT+EX_R11(r13) - mfspr r13,SPRN_SPRG_CRIT_SCRATCH + ld r13,PACA_EXCRIT+EX_R13(r13) rfci /* Normal debug exception */ @@ -467,7 +480,7 @@ interrupt_end_book3e: /* Now we mash up things to make it look like we are coming on a * normal exception */ - mfspr r15,SPRN_SPRG_CRIT_SCRATCH + ld r15,PACA_EXCRIT+EX_R13(r13) mtspr SPRN_SPRG_GEN_SCRATCH,r15 mfspr r14,SPRN_DBSR EXCEPTION_COMMON(0xd00, PACA_EXCRIT, INTS_DISABLE) |