tree 057869a84883845ac91f536a683a0b9e9829e45c
parent 41c7b401b9c131a53823673a788d73e340ce4d2a
author Ian Munsie <imunsie@au1.ibm.com> 1352918984 +0000
committer Benjamin Herrenschmidt <benh@kernel.crashing.org> 1357790945 +1100

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>