diff options
author | Scott Wood <scottwood@freescale.com> | 2014-03-10 22:29:38 (GMT) |
---|---|---|
committer | Jose Rivera <German.Rivera@freescale.com> | 2014-03-28 13:57:22 (GMT) |
commit | 6ed7acddc9c54ab170e077c868fd72f89c72d018 (patch) | |
tree | bfbf3fa4619a825550c4761d755c940605dcca17 /arch | |
parent | e2929e1e0ab910995090ce0714beab75618db694 (diff) | |
download | linux-fsl-qoriq-6ed7acddc9c54ab170e077c868fd72f89c72d018.tar.xz |
powerpc/booke64: Use SPRG7 for VDSO
Previously SPRG3 was marked for use by both VDSO and critical
interrupts (though critical interrupts were not fully implemented).
In commit 8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad ("powerpc/booke64:
Use SPRG0/3 scratch for bolted TLB miss & crit int"), Mihai Caraman
made an attempt to resolve this conflict by restoring the VDSO value
early in the critical interrupt, but this has some issues:
- It's incompatible with EXCEPTION_COMMON which restores r13 from the
by-then-overwritten scratch (this cost me some debugging time).
- It forces critical exceptions to be a special case handled
differently from even machine check and debug level exceptions.
- It didn't occur to me that it was possible to make this work at all
(by doing a final "ld r13, PACA_EXCRIT+EX_R13(r13)") until after
I made (most of) this patch. :-)
It might be worth investigating using a load rather than SPRG on return
from all exceptions (except TLB misses where the scratch never leaves
the SPRG) -- it could save a few cycles. Until then, let's stick with
SPRG for all exceptions.
Since we cannot use SPRG4-7 for scratch without corrupting the state of
a KVM guest, move VDSO to SPRG7 on book3e. Since neither SPRG4-7 nor
critical interrupts exist on book3s, SPRG3 is still used for VDSO
there.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: kvm-ppc@vger.kernel.org
Change-Id: Ibc9f776435583a75c04e7662d5a863cae3b2ab6b
Reviewed-on: http://git.am.freescale.net:8181/10265
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Reviewed-by: Jose Rivera <German.Rivera@freescale.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/powerpc/include/asm/exception-64e.h | 5 | ||||
-rw-r--r-- | arch/powerpc/include/asm/kvm_booke_hv_asm.h | 9 | ||||
-rw-r--r-- | arch/powerpc/include/asm/paca.h | 2 | ||||
-rw-r--r-- | arch/powerpc/include/asm/reg.h | 13 | ||||
-rw-r--r-- | arch/powerpc/kernel/asm-offsets.c | 2 | ||||
-rw-r--r-- | arch/powerpc/kernel/exceptions-64e.S | 19 | ||||
-rw-r--r-- | arch/powerpc/kernel/vdso.c | 8 | ||||
-rw-r--r-- | arch/powerpc/kernel/vdso32/getcpu.S | 2 | ||||
-rw-r--r-- | arch/powerpc/kernel/vdso64/getcpu.S | 2 | ||||
-rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 4 | ||||
-rw-r--r-- | arch/powerpc/kvm/book3s_interrupts.S | 4 | ||||
-rw-r--r-- | arch/powerpc/kvm/bookehv_interrupts.S | 10 |
12 files changed, 33 insertions, 47 deletions
diff --git a/arch/powerpc/include/asm/exception-64e.h b/arch/powerpc/include/asm/exception-64e.h index 51fa43e..e73452f 100644 --- a/arch/powerpc/include/asm/exception-64e.h +++ b/arch/powerpc/include/asm/exception-64e.h @@ -46,9 +46,8 @@ #define EX_CR (1 * 8) #define EX_R10 (2 * 8) #define EX_R11 (3 * 8) -#define EX_R13 (4 * 8) -#define EX_R14 (5 * 8) -#define EX_R15 (6 * 8) +#define EX_R14 (4 * 8) +#define EX_R15 (5 * 8) /* * The TLB miss exception uses different slots. diff --git a/arch/powerpc/include/asm/kvm_booke_hv_asm.h b/arch/powerpc/include/asm/kvm_booke_hv_asm.h index 3a79f53..c3e3fd5 100644 --- a/arch/powerpc/include/asm/kvm_booke_hv_asm.h +++ b/arch/powerpc/include/asm/kvm_booke_hv_asm.h @@ -36,20 +36,13 @@ * *(r8 + GPR11) = saved r11 * * 64-bit host - * Expected inputs (GEN/GDBELL/DBG/MC exception types): + * Expected inputs (GEN/GDBELL/DBG/CRIT/MC exception types): * r10 = saved CR * r13 = PACA_POINTER * *(r13 + PACA_EX##type + EX_R10) = saved r10 * *(r13 + PACA_EX##type + EX_R11) = saved r11 * SPRN_SPRG_##type##_SCRATCH = saved r13 * - * Expected inputs (CRIT exception type): - * r10 = saved CR - * r13 = PACA_POINTER - * *(r13 + PACA_EX##type + EX_R10) = saved r10 - * *(r13 + PACA_EX##type + EX_R11) = saved r11 - * *(r13 + PACA_EX##type + EX_R13) = saved r13 - * * Expected inputs (TLB exception type): * r10 = saved CR * r13 = PACA_POINTER diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index 7c70312..ead2d39 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -160,7 +160,7 @@ struct paca_struct { u8 io_sync; /* writel() needs spin_unlock sync */ u8 irq_work_pending; /* IRQ_WORK interrupt while soft-disable */ u8 nap_state_lost; /* NV GPR values lost in power7_idle */ - u64 sprg3; /* Saved user-visible sprg */ + u64 sprg_vdso; /* Saved user-visible sprg */ #ifdef CONFIG_PPC_TRANSACTIONAL_MEM u64 tm_scratch; /* TM scratch area for reclaim */ #endif diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 62b114e..24eda19 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -556,9 +556,13 @@ #define SPRN_SPRG3 0x113 /* Special Purpose Register General 3 */ #define SPRN_USPRG3 0x103 /* SPRG3 userspace read */ #define SPRN_SPRG4 0x114 /* Special Purpose Register General 4 */ +#define SPRN_USPRG4 0x104 /* SPRG4 userspace read */ #define SPRN_SPRG5 0x115 /* Special Purpose Register General 5 */ +#define SPRN_USPRG5 0x105 /* SPRG5 userspace read */ #define SPRN_SPRG6 0x116 /* Special Purpose Register General 6 */ +#define SPRN_USPRG6 0x106 /* SPRG6 userspace read */ #define SPRN_SPRG7 0x117 /* Special Purpose Register General 7 */ +#define SPRN_USPRG7 0x107 /* SPRG7 userspace read */ #define SPRN_SRR0 0x01A /* Save/Restore Register 0 */ #define SPRN_SRR1 0x01B /* Save/Restore Register 1 */ #define SRR1_ISI_NOPT 0x40000000 /* ISI: Not found in hash */ @@ -852,11 +856,10 @@ * 64-bit embedded * - SPRG0 generic exception scratch * - SPRG2 TLB exception stack - * - SPRG3 critical exception scratch and - * CPU and NUMA node for VDSO getcpu (user visible) + * - SPRG3 critical exception scratch (user visible, sorry!) * - SPRG4 unused (user visible) * - SPRG6 TLB miss scratch (user visible, sorry !) - * - SPRG7 critical exception scratch + * - SPRG7 CPU and NUMA node for VDSO getcpu (user visible) * - SPRG8 machine check exception scratch * - SPRG9 debug exception scratch * @@ -913,6 +916,8 @@ #define SPRN_SPRG_SCRATCH0 SPRN_SPRG2 #define SPRN_SPRG_HPACA SPRN_HSPRG0 #define SPRN_SPRG_HSCRATCH0 SPRN_HSPRG1 +#define SPRN_SPRG_VDSO_READ SPRN_USPRG3 +#define SPRN_SPRG_VDSO_WRITE SPRN_SPRG3 #define GET_PACA(rX) \ BEGIN_FTR_SECTION_NESTED(66); \ @@ -956,6 +961,8 @@ #define SPRN_SPRG_TLB_SCRATCH SPRN_SPRG6 #define SPRN_SPRG_GEN_SCRATCH SPRN_SPRG0 #define SPRN_SPRG_GDBELL_SCRATCH SPRN_SPRG_GEN_SCRATCH +#define SPRN_SPRG_VDSO_READ SPRN_USPRG7 +#define SPRN_SPRG_VDSO_WRITE SPRN_SPRG7 #define SET_PACA(rX) mtspr SPRN_SPRG_PACA,rX #define GET_PACA(rX) mfspr rX,SPRN_SPRG_PACA diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 1d08f49..d2950df 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -245,7 +245,7 @@ int main(void) DEFINE(PACA_SYSTEM_TIME, offsetof(struct paca_struct, system_time)); DEFINE(PACA_TRAP_SAVE, offsetof(struct paca_struct, trap_save)); DEFINE(PACA_NAPSTATELOST, offsetof(struct paca_struct, nap_state_lost)); - DEFINE(PACA_SPRG3, offsetof(struct paca_struct, sprg3)); + DEFINE(PACA_SPRG_VDSO, offsetof(struct paca_struct, sprg_vdso)); #endif /* CONFIG_PPC64 */ /* RTAS */ diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 45f77aa..fbdd088 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -55,7 +55,6 @@ 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 */ \ @@ -116,20 +115,6 @@ #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); \ - ld r11,PACA_SPRG3(r13); \ - mtspr SPRN_SPRG_CRIT_SCRATCH,r11; - /* Variants of the "addition" argument for the prolog */ #define PROLOG_ADDITION_NONE_GEN(n) @@ -537,7 +522,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) mtcr r10 ld r10,PACA_EXCRIT+EX_R10(r13) /* restore registers */ ld r11,PACA_EXCRIT+EX_R11(r13) - ld r13,PACA_EXCRIT+EX_R13(r13) + mfspr r13,SPRN_SPRG_CRIT_SCRATCH rfci /* Normal debug exception */ @@ -550,7 +535,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) /* Now we mash up things to make it look like we are coming on a * normal exception */ - ld r15,PACA_EXCRIT+EX_R13(r13) + mfspr r15,SPRN_SPRG_CRIT_SCRATCH mtspr SPRN_SPRG_GEN_SCRATCH,r15 mfspr r14,SPRN_DBSR EXCEPTION_COMMON(0xd00, PACA_EXCRIT, INTS_DISABLE) diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index 094e45c..ce74c33 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -715,8 +715,8 @@ int vdso_getcpu_init(void) unsigned long cpu, node, val; /* - * SPRG3 contains the CPU in the bottom 16 bits and the NUMA node in - * the next 16 bits. The VDSO uses this to implement getcpu(). + * SPRG_VDSO contains the CPU in the bottom 16 bits and the NUMA node + * in the next 16 bits. The VDSO uses this to implement getcpu(). */ cpu = get_cpu(); WARN_ON_ONCE(cpu > 0xffff); @@ -725,8 +725,8 @@ int vdso_getcpu_init(void) WARN_ON_ONCE(node > 0xffff); val = (cpu & 0xfff) | ((node & 0xffff) << 16); - mtspr(SPRN_SPRG3, val); - get_paca()->sprg3 = val; + mtspr(SPRN_SPRG_VDSO_WRITE, val); + get_paca()->sprg_vdso = val; put_cpu(); diff --git a/arch/powerpc/kernel/vdso32/getcpu.S b/arch/powerpc/kernel/vdso32/getcpu.S index 47afd08..23eb9a9 100644 --- a/arch/powerpc/kernel/vdso32/getcpu.S +++ b/arch/powerpc/kernel/vdso32/getcpu.S @@ -29,7 +29,7 @@ */ V_FUNCTION_BEGIN(__kernel_getcpu) .cfi_startproc - mfspr r5,SPRN_USPRG3 + mfspr r5,SPRN_SPRG_VDSO_READ cmpdi cr0,r3,0 cmpdi cr1,r4,0 clrlwi r6,r5,16 diff --git a/arch/powerpc/kernel/vdso64/getcpu.S b/arch/powerpc/kernel/vdso64/getcpu.S index 47afd08..23eb9a9 100644 --- a/arch/powerpc/kernel/vdso64/getcpu.S +++ b/arch/powerpc/kernel/vdso64/getcpu.S @@ -29,7 +29,7 @@ */ V_FUNCTION_BEGIN(__kernel_getcpu) .cfi_startproc - mfspr r5,SPRN_USPRG3 + mfspr r5,SPRN_SPRG_VDSO_READ cmpdi cr0,r3,0 cmpdi cr1,r4,0 clrlwi r6,r5,16 diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index bc8de75..a03d8f9 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -68,8 +68,8 @@ kvmppc_call_hv_entry: mtspr SPRN_DABRX,r6 /* Restore SPRG3 */ - ld r3,PACA_SPRG3(r13) - mtspr SPRN_SPRG3,r3 + ld r3,PACA_SPRG_VDSO(r13) + mtspr SPRN_SPRG_VDSO_WRITE,r3 /* * Reload DEC. HDEC interrupts were disabled when diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S index f4dd041..2d88672 100644 --- a/arch/powerpc/kvm/book3s_interrupts.S +++ b/arch/powerpc/kvm/book3s_interrupts.S @@ -149,8 +149,8 @@ kvm_start_lightweight: * Reload kernel SPRG3 value. * No need to save guest value as usermode can't modify SPRG3. */ - ld r3, PACA_SPRG3(r13) - mtspr SPRN_SPRG3, r3 + ld r3, PACA_SPRG_VDSO(r13) + mtspr SPRN_SPRG_VDSO_WRITE, r3 #endif /* CONFIG_PPC_BOOK3S_64 */ diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S index 63ce811..e8db127 100644 --- a/arch/powerpc/kvm/bookehv_interrupts.S +++ b/arch/powerpc/kvm/bookehv_interrupts.S @@ -185,11 +185,7 @@ stw r10, VCPU_CR(r4) PPC_STL r11, VCPU_GPR(R4)(r4) PPC_STL r5, VCPU_GPR(R5)(r4) - .if \type == EX_CRIT - PPC_LL r5, (\paca_ex + EX_R13)(r13) - .else mfspr r5, \scratch - .endif PPC_STL r6, VCPU_GPR(R6)(r4) PPC_STL r8, VCPU_GPR(R8)(r4) PPC_STL r9, VCPU_GPR(R9)(r4) @@ -389,10 +385,16 @@ _GLOBAL(kvmppc_resume_host) PPC_STL r5, VCPU_LR(r4) mfspr r7, SPRN_SPRG5 stw r3, VCPU_VRSAVE(r4) +#ifdef CONFIG_64BIT + PPC_LL r3, PACA_SPRG_VDSO(r13) +#endif PPC_STD(r6, VCPU_SHARED_SPRG4, r11) mfspr r8, SPRN_SPRG6 PPC_STD(r7, VCPU_SHARED_SPRG5, r11) mfspr r9, SPRN_SPRG7 +#ifdef CONFIG_64BIT + mtspr SPRN_SPRG_VDSO_WRITE, r3 +#endif PPC_STD(r8, VCPU_SHARED_SPRG6, r11) mfxer r3 PPC_STD(r9, VCPU_SHARED_SPRG7, r11) |