[PATCH 05/15] powerpc: In HV mode, use HSPRG0 for PACA
Benjamin Herrenschmidt
benh at kernel.crashing.org
Tue Apr 5 16:14:01 EST 2011
When running in Hypervisor mode (arch 2.06 or later), we store the PACA
in HSPRG0 instead of SPRG1. The architecture specifies that SPRGs may be
lost during a "nap" power management operation (though they aren't
currently on POWER7) and this enables use of SPRG1 by KVM guests.
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
arch/powerpc/include/asm/exception-64s.h | 6 +++---
arch/powerpc/include/asm/reg.h | 27 ++++++++++++++++++++++++++-
arch/powerpc/kernel/entry_64.S | 4 ++--
arch/powerpc/kernel/exceptions-64s.S | 8 ++++----
arch/powerpc/kernel/head_64.S | 4 ++--
arch/powerpc/kernel/paca.c | 13 ++++++++++++-
arch/powerpc/kvm/book3s_rmhandlers.S | 4 +---
7 files changed, 50 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 7778d6f..337b6fa 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -56,8 +56,8 @@
#define LOAD_HANDLER(reg, label) \
addi reg,reg,(label)-_stext; /* virt addr of handler ... */
-#define EXCEPTION_PROLOG_1(area) \
- mfspr r13,SPRN_SPRG_PACA; /* get paca address into r13 */ \
+#define EXCEPTION_PROLOG_1(area) \
+ GET_PACA(r13); \
std r9,area+EX_R9(r13); /* save r9 - r12 */ \
std r10,area+EX_R10(r13); \
std r11,area+EX_R11(r13); \
@@ -174,7 +174,7 @@ label##_pSeries: \
HMT_MEDIUM; \
DO_KVM n; \
mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
- mfspr r13,SPRN_SPRG_PACA; /* get paca address into r13 */ \
+ GET_PACA(r13); \
std r9,PACA_EXGEN+EX_R9(r13); /* save r9, r10 */ \
std r10,PACA_EXGEN+EX_R10(r13); \
lbz r10,PACASOFTIRQEN(r13); \
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 6eb1d77..13429a0 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -715,12 +715,15 @@
* SPRG usage:
*
* All 64-bit:
- * - SPRG1 stores PACA pointer
+ * - SPRG1 stores PACA pointer except 64-bit server in
+ * HV mode in which case it is HSPRG0
*
* 64-bit server:
* - SPRG0 unused (reserved for HV on Power4)
* - SPRG2 scratch for exception vectors
* - SPRG3 unused (user visible)
+ * - HSPRG0 stores PACA in HV mode
+ * - HSPRG1 scratch for "HV" exceptions
*
* 64-bit embedded
* - SPRG0 generic exception scratch
@@ -783,6 +786,22 @@
#ifdef CONFIG_PPC_BOOK3S_64
#define SPRN_SPRG_SCRATCH0 SPRN_SPRG2
+#define SPRN_SPRG_HPACA SPRN_HSPRG0
+#define SPRN_SPRG_HSCRATCH0 SPRN_HSPRG1
+
+#define GET_PACA(rX) \
+ BEGIN_FTR_SECTION_NESTED(66); \
+ mfspr rX,SPRN_SPRG_PACA; \
+ FTR_SECTION_ELSE_NESTED(66); \
+ mfspr rX,SPRN_SPRG_HPACA; \
+ ALT_FTR_SECTION_END_NESTED_IFCLR(CPU_FTR_HVMODE_206, 66)
+
+#define SET_PACA(rX) \
+ BEGIN_FTR_SECTION_NESTED(66); \
+ mtspr SPRN_SPRG_PACA,rX; \
+ FTR_SECTION_ELSE_NESTED(66); \
+ mtspr SPRN_SPRG_HPACA,rX; \
+ ALT_FTR_SECTION_END_NESTED_IFCLR(CPU_FTR_HVMODE_206, 66)
#endif
#ifdef CONFIG_PPC_BOOK3E_64
@@ -792,6 +811,10 @@
#define SPRN_SPRG_TLB_EXFRAME SPRN_SPRG2
#define SPRN_SPRG_TLB_SCRATCH SPRN_SPRG6
#define SPRN_SPRG_GEN_SCRATCH SPRN_SPRG0
+
+#define SET_PACA(rX) mtspr SPRN_SPRG_PACA,rX
+#define GET_PACA(rX) mfspr rX,SPRN_SPRG_PACA
+
#endif
#ifdef CONFIG_PPC_BOOK3S_32
@@ -842,6 +865,8 @@
#define SPRN_SPRG_SCRATCH1 SPRN_SPRG1
#endif
+
+
/*
* An mtfsf instruction with the L bit set. On CPUs that support this a
* full 64bits of FPSCR is restored and on other CPUs the L bit is ignored.
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index d82878c..dbf5bfa 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -838,7 +838,7 @@ _GLOBAL(enter_rtas)
_STATIC(rtas_return_loc)
/* relocation is off at this point */
- mfspr r4,SPRN_SPRG_PACA /* Get PACA */
+ GET_PACA(r4)
clrldi r4,r4,2 /* convert to realmode address */
bcl 20,31,$+4
@@ -869,7 +869,7 @@ _STATIC(rtas_restore_regs)
REST_8GPRS(14, r1) /* Restore the non-volatiles */
REST_10GPRS(22, r1) /* ditto */
- mfspr r13,SPRN_SPRG_PACA
+ GET_PACA(r13)
ld r4,_CCR(r1)
mtcr r4
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index c532cb2..4ea3cc6 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -53,7 +53,7 @@ data_access_pSeries:
DO_KVM 0x300
mtspr SPRN_SPRG_SCRATCH0,r13
BEGIN_FTR_SECTION
- mfspr r13,SPRN_SPRG_PACA
+ GET_PACA(r13)
std r9,PACA_EXSLB+EX_R9(r13)
std r10,PACA_EXSLB+EX_R10(r13)
mfspr r10,SPRN_DAR
@@ -82,7 +82,7 @@ data_access_slb_pSeries:
HMT_MEDIUM
DO_KVM 0x380
mtspr SPRN_SPRG_SCRATCH0,r13
- mfspr r13,SPRN_SPRG_PACA /* get paca address into r13 */
+ GET_PACA(r13)
std r3,PACA_EXSLB+EX_R3(r13)
mfspr r3,SPRN_DAR
std r9,PACA_EXSLB+EX_R9(r13) /* save r9 - r12 */
@@ -121,7 +121,7 @@ instruction_access_slb_pSeries:
HMT_MEDIUM
DO_KVM 0x480
mtspr SPRN_SPRG_SCRATCH0,r13
- mfspr r13,SPRN_SPRG_PACA /* get paca address into r13 */
+ GET_PACA(r13)
std r3,PACA_EXSLB+EX_R3(r13)
mfspr r3,SPRN_SRR0 /* SRR0 is faulting address */
std r9,PACA_EXSLB+EX_R9(r13) /* save r9 - r12 */
@@ -165,7 +165,7 @@ BEGIN_FTR_SECTION
beq- 1f
END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
mr r9,r13
- mfspr r13,SPRN_SPRG_PACA
+ GET_PACA(r13)
mfspr r11,SPRN_SRR0
ld r12,PACAKBASE(r13)
ld r10,PACAKMSR(r13)
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 271140b..53d3bfd 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -228,7 +228,7 @@ generic_secondary_common_init:
mr r3,r24 /* not found, copy phys to r3 */
b .kexec_wait /* next kernel might do better */
-2: mtspr SPRN_SPRG_PACA,r13 /* Save vaddr of paca in an SPRG */
+2: SET_PACA(r13)
#ifdef CONFIG_PPC_BOOK3E
addi r12,r13,PACA_EXTLB /* and TLB exc frame in another */
mtspr SPRN_SPRG_TLB_EXFRAME,r12
@@ -534,7 +534,7 @@ _GLOBAL(pmac_secondary_start)
ld r4,0(r4) /* Get base vaddr of paca array */
mulli r13,r24,PACA_SIZE /* Calculate vaddr of right paca */
add r13,r13,r4 /* for this processor. */
- mtspr SPRN_SPRG_PACA,r13 /* Save vaddr of paca in an SPRG*/
+ SET_PACA(r13) /* Save vaddr of paca in an SPRG*/
/* Mark interrupts soft and hard disabled (they might be enabled
* in the PACA when doing hotplug)
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 10f0aad..102244e 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -156,11 +156,22 @@ void __init initialise_paca(struct paca_struct *new_paca, int cpu)
/* Put the paca pointer into r13 and SPRG_PACA */
void setup_paca(struct paca_struct *new_paca)
{
+ /* Setup r13 */
local_paca = new_paca;
- mtspr(SPRN_SPRG_PACA, local_paca);
+
#ifdef CONFIG_PPC_BOOK3E
+ /* On Book3E, initialize the TLB miss exception frames */
mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
+#else
+ /* In HV mode, we setup both HPACA and PACA to avoid problems
+ * if we do a GET_PACA() before the feature fixups have been
+ * applied
+ */
+ if (cpu_has_feature(CPU_FTR_HVMODE_206))
+ mtspr(SPRN_SPRG_HPACA, local_paca);
#endif
+ mtspr(SPRN_SPRG_PACA, local_paca);
+
}
static int __initdata paca_size;
diff --git a/arch/powerpc/kvm/book3s_rmhandlers.S b/arch/powerpc/kvm/book3s_rmhandlers.S
index 2b9c908..b0ff5ff 100644
--- a/arch/powerpc/kvm/book3s_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_rmhandlers.S
@@ -35,9 +35,7 @@
#if defined(CONFIG_PPC_BOOK3S_64)
-#define LOAD_SHADOW_VCPU(reg) \
- mfspr reg, SPRN_SPRG_PACA
-
+#define LOAD_SHADOW_VCPU(reg) GET_PACA(reg)
#define SHADOW_VCPU_OFF PACA_KVM_SVCPU
#define MSR_NOIRQ MSR_KERNEL & ~(MSR_IR | MSR_DR)
#define FUNC(name) GLUE(.,name)
--
1.7.1
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