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>
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 3d5c9dc..af88486 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 */