[PATCH] powerpc/powernv: fix POWER9 msgsnd addressing

[Nicholas Piggin]

ISAv3 changes the addressing mode of msgsnd from TIR to PIR. Without
this change, all doorbell IPIs on bare metal go to core 0 threads.

Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
 arch/powerpc/include/asm/dbell.h |  4 ----
 arch/powerpc/kernel/dbell.c      | 12 +++++++++++-
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/dbell.h b/arch/powerpc/include/asm/dbell.h
index 378167377065..b9d3b52e2a2c 100644
--- a/arch/powerpc/include/asm/dbell.h
+++ b/arch/powerpc/include/asm/dbell.h
@@ -35,8 +35,6 @@ enum ppc_dbell {
 #ifdef CONFIG_PPC_BOOK3S
 
 #define PPC_DBELL_MSGTYPE		PPC_DBELL_SERVER
-#define SPRN_DOORBELL_CPUTAG		SPRN_TIR
-#define PPC_DBELL_TAG_MASK		0x7f
 
 static inline void _ppc_msgsnd(u32 msg)
 {
@@ -49,8 +47,6 @@ static inline void _ppc_msgsnd(u32 msg)
 #else /* CONFIG_PPC_BOOK3S */
 
 #define PPC_DBELL_MSGTYPE		PPC_DBELL
-#define SPRN_DOORBELL_CPUTAG		SPRN_PIR
-#define PPC_DBELL_TAG_MASK		0x3fff
 
 static inline void _ppc_msgsnd(u32 msg)
 {
diff --git a/arch/powerpc/kernel/dbell.c b/arch/powerpc/kernel/dbell.c
index 2128f3a96c32..b2011a261045 100644
--- a/arch/powerpc/kernel/dbell.c
+++ b/arch/powerpc/kernel/dbell.c
@@ -22,7 +22,17 @@
 #ifdef CONFIG_SMP
 void doorbell_setup_this_cpu(void)
 {
-	unsigned long tag = mfspr(SPRN_DOORBELL_CPUTAG) & PPC_DBELL_TAG_MASK;
+	unsigned long tag;
+
+#ifdef CONFIG_PPC_BOOK3S
+	if (cpu_has_feature(CPU_FTR_HVMODE) && cpu_has_feature(CPU_FTR_ARCH_300))
+		tag = mfspr(SPRN_PIR) & 0xfffff;
+	else
+		tag = mfspr(SPRN_TIR) & 0x7f;
+
+#else
+	tag = mfspr(SPRN_PIR) & 0x3fff;
+#endif
 
 	smp_muxed_ipi_set_data(smp_processor_id(), tag);
 }
-- 
2.11.0