diff options
| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-07-16 19:36:57 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-08-20 10:12:28 +1000 |
| commit | c5a8c0c99f67ae8a784faafbaaea1529825796e2 (patch) | |
| tree | 731b07d0ac0414dbeac5ce940fe59a04a8d63c3f /arch/powerpc/include/asm | |
| parent | ee43eb788b3a06425fffb912677e2e1c8b00dd3b (diff) | |
powerpc: Remove use of a second scratch SPRG in STAB code
The STAB code used on Power3 and RS/64 uses a second scratch SPRG to
save a GPR in order to decide whether to go to do_stab_bolted_* or
to handle a normal data access exception.
This prevents our scheme of freeing SPRG3 which is user visible for
user uses since we cannot use SPRG0 which, on RS/64, seems to be
read-only for supervisor mode (like POWER4).
This reworks the STAB exception entry to use the PACA as temporary
storage instead.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include/asm')
| -rw-r--r-- | arch/powerpc/include/asm/exception-64s.h | 7 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/reg.h | 3 |
2 files changed, 6 insertions, 4 deletions
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index 773e380b5fe..a98653b2623 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -66,8 +66,7 @@ std r9,area+EX_R13(r13); \ mfcr r9 -#define EXCEPTION_PROLOG_PSERIES(area, label) \ - EXCEPTION_PROLOG_1(area); \ +#define EXCEPTION_PROLOG_PSERIES_1(label) \ ld r12,PACAKBASE(r13); /* get high part of &label */ \ ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \ mfspr r11,SPRN_SRR0; /* save SRR0 */ \ @@ -78,6 +77,10 @@ rfid; \ b . /* prevent speculative execution */ +#define EXCEPTION_PROLOG_PSERIES(area, label) \ + EXCEPTION_PROLOG_1(area); \ + EXCEPTION_PROLOG_PSERIES_1(label); + /* * The common exception prolog is used for all except a few exceptions * such as a segment miss on a kernel address. We have to be prepared diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index a8179cc99ac..d17af2b3d4c 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -654,7 +654,7 @@ * 64-bit server: * - SPRG0 unused (reserved for HV on Power4) * - SPRG1 scratch for exception vectors - * - SPRG2 scratch for exception vectors + * - SPRG2 unused * * All 32-bit: * - SPRG3 current thread_info pointer @@ -707,7 +707,6 @@ #ifdef CONFIG_PPC_BOOK3S_64 #define SPRN_SPRG_SCRATCH0 SPRN_SPRG1 -#define SPRN_SPRG_SCRATCH1 SPRN_SPRG2 #endif #ifdef CONFIG_PPC_BOOK3S_32 |