powerpc: Define differences between doorbells on book3e and book3s

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 <imunsie@au1.ibm.com>
Tested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/dbell.h b/arch/powerpc/include/asm/dbell.h
index 607e4eeeb694..3b338565f992 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);