From: Ian Munsie <imun...@au1.ibm.com>
There are a few key differences between doorbells on server compared
with embedded that we care about on Linux, namely:
- We have a new msgsndp instruction for directed privileged doorbells.
msgsnd is used for directed hypervisor doorbells.
- The tag we use in the instruction is the Thread Identification
Register of the recipient thread (since server doorbells can only
occur between threads within a single core), and is only 7 bits wide.
- A new message type is introduced for server doorbells (none of the
existing book3e message types are currently supported on book3s).
Signed-off-by: Ian Munsie <imun...@au1.ibm.com>
Tested-by: Michael Neuling <mi...@neuling.org>
---
arch/powerpc/include/asm/dbell.h | 15 +++++++++++++++
arch/powerpc/include/asm/ppc-opcode.h | 3 +++
arch/powerpc/include/asm/reg.h | 1 +
arch/powerpc/kernel/dbell.c | 4 ++--
4 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/dbell.h b/arch/powerpc/include/asm/dbell.h
index 607e4ee..3b33856 100644
--- a/arch/powerpc/include/asm/dbell.h
+++ b/arch/powerpc/include/asm/dbell.h
@@ -28,8 +28,23 @@ enum ppc_dbell {
PPC_G_DBELL = 2, /* guest doorbell */
PPC_G_DBELL_CRIT = 3, /* guest critical doorbell */
PPC_G_DBELL_MC = 4, /* guest mcheck doorbell */
+ PPC_DBELL_SERVER = 5, /* doorbell on server */
};
+#ifdef CONFIG_PPC_BOOK3S
+
+#define PPC_DBELL_MSGTYPE PPC_DBELL_SERVER
+#define SPRN_DOORBELL_CPUTAG SPRN_TIR
+#define PPC_DBELL_TAG_MASK 0x7f
+
+#else /* CONFIG_PPC_BOOK3S */
+
+#define PPC_DBELL_MSGTYPE PPC_DBELL
+#define SPRN_DOORBELL_CPUTAG SPRN_PIR
+#define PPC_DBELL_TAG_MASK 0x3fff
+
+#endif /* CONFIG_PPC_BOOK3S */
+
extern void doorbell_cause_ipi(int cpu, unsigned long data);
extern void doorbell_exception(struct pt_regs *regs);
extern void doorbell_setup_this_cpu(void);
diff --git a/arch/powerpc/include/asm/ppc-opcode.h
b/arch/powerpc/include/asm/ppc-opcode.h
index e434d8b..45fd394 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -100,6 +100,7 @@
#define PPC_INST_MFSPR_PVR 0x7c1f42a6
#define PPC_INST_MFSPR_PVR_MASK 0xfc1fffff
#define PPC_INST_MSGSND 0x7c00019c
+#define PPC_INST_MSGSNDP 0x7c00011c
#define PPC_INST_NOP 0x60000000
#define PPC_INST_POPCNTB 0x7c0000f4
#define PPC_INST_POPCNTB_MASK 0xfc0007fe
@@ -224,6 +225,8 @@
___PPC_RB(b) | __PPC_EH(eh))
#define PPC_MSGSND(b) stringify_in_c(.long PPC_INST_MSGSND | \
___PPC_RB(b))
+#define PPC_MSGSNDP(b) stringify_in_c(.long PPC_INST_MSGSNDP | \
+ ___PPC_RB(b))
#define PPC_POPCNTB(a, s) stringify_in_c(.long PPC_INST_POPCNTB | \
__PPC_RA(a) | __PPC_RS(s))
#define PPC_POPCNTD(a, s) stringify_in_c(.long PPC_INST_POPCNTD | \
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 1b853f7..736c6af 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -483,6 +483,7 @@
#ifndef SPRN_PIR
#define SPRN_PIR 0x3FF /* Processor Identification Register */
#endif
+#define SPRN_TIR 0x1BE /* Thread Identification Register */
#define SPRN_PTEHI 0x3D5 /* 981 7450 PTE HI word (S/W TLB load) */
#define SPRN_PTELO 0x3D6 /* 982 7450 PTE LO word (S/W TLB load) */
#define SPRN_PURR 0x135 /* Processor Utilization of Resources Reg */
diff --git a/arch/powerpc/kernel/dbell.c b/arch/powerpc/kernel/dbell.c
index a892680..9ebbc24 100644
--- a/arch/powerpc/kernel/dbell.c
+++ b/arch/powerpc/kernel/dbell.c
@@ -21,7 +21,7 @@
#ifdef CONFIG_SMP
void doorbell_setup_this_cpu(void)
{
- unsigned long tag = mfspr(SPRN_PIR) & 0x3fff;
+ unsigned long tag = mfspr(SPRN_DOORBELL_CPUTAG) & PPC_DBELL_TAG_MASK;
smp_muxed_ipi_set_data(smp_processor_id(), tag);
}
@@ -30,7 +30,7 @@ void doorbell_cause_ipi(int cpu, unsigned long data)
{
/* Order previous accesses vs. msgsnd, which is treated as a store */
mb();
- ppc_msgsnd(PPC_DBELL, 0, data);
+ ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, data);
}
void doorbell_exception(struct pt_regs *regs)
--
1.7.10.4
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