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| 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/include/asm/reg.h | |
| parent | 79b5c8dbaa4528a6fd03a4d9d8a6d56a46293a3a (diff) | |
| download | linux-8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad.tar.bz2 | |
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/include/asm/reg.h')
| -rw-r--r-- | arch/powerpc/include/asm/reg.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index c195bf0e6241..a391244c18e1 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -761,7 +761,8 @@ * 64-bit embedded * - SPRG0 generic exception scratch * - SPRG2 TLB exception stack - * - SPRG3 CPU and NUMA node for VDSO getcpu (user visible) + * - SPRG3 critical exception scratch and + * CPU and NUMA node for VDSO getcpu (user visible) * - SPRG4 unused (user visible) * - SPRG6 TLB miss scratch (user visible, sorry !) * - SPRG7 critical exception scratch @@ -858,7 +859,7 @@ #ifdef CONFIG_PPC_BOOK3E_64 #define SPRN_SPRG_MC_SCRATCH SPRN_SPRG8 -#define SPRN_SPRG_CRIT_SCRATCH SPRN_SPRG7 +#define SPRN_SPRG_CRIT_SCRATCH SPRN_SPRG3 #define SPRN_SPRG_DBG_SCRATCH SPRN_SPRG9 #define SPRN_SPRG_TLB_EXFRAME SPRN_SPRG2 #define SPRN_SPRG_TLB_SCRATCH SPRN_SPRG6 |