[PATCH 5/5] powerpc/powernv: POWER9 support for msgsnd/doorbell IPI
Nicholas Piggin
npiggin at gmail.com
Fri Apr 7 22:56:02 AEST 2017
POWER9 requires msgsync for receiver-side synchronization,
and a DD1 workaround that uses the darn instruction.
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
arch/powerpc/include/asm/dbell.h | 8 ++++++++
arch/powerpc/include/asm/feature-fixups.h | 20 ++++++++++++++++++++
arch/powerpc/include/asm/ppc-opcode.h | 6 ++++++
arch/powerpc/include/asm/ppc_asm.h | 15 +++++++++++++++
arch/powerpc/platforms/powernv/smp.c | 8 ++++++--
5 files changed, 55 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/dbell.h b/arch/powerpc/include/asm/dbell.h
index 8ad66ccb7180..2cdad4381045 100644
--- a/arch/powerpc/include/asm/dbell.h
+++ b/arch/powerpc/include/asm/dbell.h
@@ -51,6 +51,14 @@ static inline void ppc_msgsnd_sync(void)
/* sync after taking message interrupt */
static inline void ppc_msgsync(void)
{
+ /* sync is not required when taking messages from the same core */
+ if (cpu_has_feature(CPU_FTR_ARCH_300) && cpu_has_feature(CPU_FTR_HVMODE)) {
+ unsigned long reg;
+ __asm__ __volatile__ (ASM_FTR_IFCLR(
+ PPC_MSGSYNC " ; lwsync",
+ PPC_DARN(%0, 2) " ; lwsync",
+ %1) : "=r" (reg) : "i" (CPU_FTR_POWER9_DD1) : "memory");
+ }
}
#else /* CONFIG_PPC_BOOK3S */
diff --git a/arch/powerpc/include/asm/feature-fixups.h b/arch/powerpc/include/asm/feature-fixups.h
index ddf54f5bbdd1..d6b8c9a20496 100644
--- a/arch/powerpc/include/asm/feature-fixups.h
+++ b/arch/powerpc/include/asm/feature-fixups.h
@@ -66,7 +66,14 @@ label##5: \
#define END_FTR_SECTION(msk, val) \
END_FTR_SECTION_NESTED(msk, val, 97)
+#define END_FTR_SECTION_NESTED_IFSET(msk, label) \
+ END_FTR_SECTION_NESTED((msk), (msk), label)
+
#define END_FTR_SECTION_IFSET(msk) END_FTR_SECTION((msk), (msk))
+
+#define END_FTR_SECTION_NESTED_IFCLR(msk, label) \
+ END_FTR_SECTION_NESTED((msk), 0, label)
+
#define END_FTR_SECTION_IFCLR(msk) END_FTR_SECTION((msk), 0)
/* CPU feature sections with alternatives, use BEGIN_FTR_SECTION to start */
@@ -153,12 +160,25 @@ label##5: \
section_else "; " \
stringify_in_c(ALT_FTR_SECTION_END((msk), (val)))
+#define ASM_FTR_IF_NESTED(section_if, section_else, msk, val, label) \
+ stringify_in_c(BEGIN_FTR_SECTION_NESTED(label)) \
+ section_if "; " \
+ stringify_in_c(FTR_SECTION_ELSE_NESTED(label)) \
+ section_else "; " \
+ stringify_in_c(ALT_FTR_SECTION_END_NESTED((msk), (val), label))
+
#define ASM_FTR_IFSET(section_if, section_else, msk) \
ASM_FTR_IF(section_if, section_else, (msk), (msk))
+#define ASM_FTR_IFSET_NESTED(section_if, section_else, msk, label) \
+ ASM_FTR_IF(section_if, section_else, (msk), (msk), label)
+
#define ASM_FTR_IFCLR(section_if, section_else, msk) \
ASM_FTR_IF(section_if, section_else, (msk), 0)
+#define ASM_FTR_IFCLR_NESTED(section_if, section_else, msk, label) \
+ ASM_FTR_IF(section_if, section_else, (msk), 0, label)
+
#define ASM_MMU_FTR_IF(section_if, section_else, msk, val) \
stringify_in_c(BEGIN_MMU_FTR_SECTION) \
section_if "; " \
diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index e7d6d86563ee..44009dfeab69 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -134,6 +134,7 @@
#define PPC_INST_COPY 0x7c00060c
#define PPC_INST_COPY_FIRST 0x7c20060c
#define PPC_INST_CP_ABORT 0x7c00068c
+#define PPC_INST_DARN 0x7c0005e6
#define PPC_INST_DCBA 0x7c0005ec
#define PPC_INST_DCBA_MASK 0xfc0007fe
#define PPC_INST_DCBAL 0x7c2005ec
@@ -161,6 +162,7 @@
#define PPC_INST_MFTMR 0x7c0002dc
#define PPC_INST_MSGSND 0x7c00019c
#define PPC_INST_MSGCLR 0x7c0001dc
+#define PPC_INST_MSGSYNC 0x7c0006ec
#define PPC_INST_MSGSNDP 0x7c00011c
#define PPC_INST_MTTMR 0x7c0003dc
#define PPC_INST_NOP 0x60000000
@@ -310,6 +312,7 @@
#define __PPC_XS(s) ((((s) & 0x1f) << 21) | (((s) & 0x20) >> 5))
#define __PPC_XT(s) __PPC_XS(s)
#define __PPC_T_TLB(t) (((t) & 0x3) << 21)
+#define __PPC_L_DARN(l) (((l) & 0x3) << 16)
#define __PPC_WC(w) (((w) & 0x3) << 21)
#define __PPC_WS(w) (((w) & 0x1f) << 11)
#define __PPC_SH(s) __PPC_WS(s)
@@ -333,6 +336,8 @@
/* Deal with instructions that older assemblers aren't aware of */
#define PPC_CP_ABORT stringify_in_c(.long PPC_INST_CP_ABORT)
+#define PPC_DARN(t, l) stringify_in_c(.long PPC_INST_DARN | \
+ ___PPC_RT(t) | __PPC_L_DARN(l))
#define PPC_DCBAL(a, b) stringify_in_c(.long PPC_INST_DCBAL | \
__PPC_RA(a) | __PPC_RB(b))
#define PPC_DCBZL(a, b) stringify_in_c(.long PPC_INST_DCBZL | \
@@ -345,6 +350,7 @@
___PPC_RB(b) | __PPC_EH(eh))
#define PPC_MSGSND(b) stringify_in_c(.long PPC_INST_MSGSND | \
___PPC_RB(b))
+#define PPC_MSGSYNC stringify_in_c(.long PPC_INST_MSGSYNC)
#define PPC_MSGCLR(b) stringify_in_c(.long PPC_INST_MSGCLR | \
___PPC_RB(b))
#define PPC_MSGSNDP(b) stringify_in_c(.long PPC_INST_MSGSNDP | \
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 359c44341761..8ab5dc554ca5 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -402,6 +402,21 @@ END_FTR_SECTION_IFCLR(CPU_FTR_601)
FTR_SECTION_ELSE_NESTED(848); \
mtocrf (FXM), RS; \
ALT_FTR_SECTION_END_NESTED_IFCLR(CPU_FTR_NOEXECUTE, 848)
+
+#if defined(CONFIG_BOOKS)
+#define MSGSYNC(reg) \
+ BEGIN_FTR_SECTION_NESTED(849); \
+ \
+ BEGIN_FTR_SECTION_NESTED(850); \
+ PPC_MSGSYNC; \
+ lwsync; \
+ FTR_SECTION_ELSE_NESTED(850); \
+ PPC_DARN(reg, 2); \
+ lwsync; \
+ ALT_FTR_SECTION_END_NESTED_IFCLR(CPU_FTR_POWER9_DD1, 850); \
+ \
+ END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE|CPU_FTR_ARCH_300, 849)
+#endif
#endif
/*
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c
index c86b3693bcae..45a7efa3f03c 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -249,6 +249,7 @@ static int pnv_cpu_bootable(unsigned int nr)
static void pnv_cause_ipi(int cpu)
{
+ /* Pre-POWER9 has only core-local dbell IPIs. Must fall back to IC. */
if (try_core_doorbell_cause_ipi(cpu))
return;
icp_ops->cause_ipi(cpu);
@@ -258,8 +259,11 @@ static __init void pnv_smp_probe(void)
{
xics_smp_probe();
- if (cpu_has_feature(CPU_FTR_DBELL) && !cpu_has_feature(CPU_FTR_ARCH_300)) {
- smp_ops->cause_ipi = pnv_cause_ipi;
+ if (cpu_has_feature(CPU_FTR_DBELL)) {
+ if (cpu_has_feature(CPU_FTR_ARCH_300))
+ smp_ops->cause_ipi = global_doorbell_cause_ipi;
+ else
+ smp_ops->cause_ipi = pnv_cause_ipi;
} else {
smp_ops->cause_ipi = icp_ops->cause_ipi;
}
--
2.11.0
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