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/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 @@
{
/* 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)