diff options
| author | Tseng-Hui (Frank) Lin <thlin@linux.vnet.ibm.com> | 2011-05-02 20:43:04 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-05-04 15:19:26 +1000 |
| commit | 851d2e2fe8dbcbe3afcad6fc4569c881d8ad4ce9 (patch) | |
| tree | 94082e7751a66236febed1cf18a1f01a02084ae9 /arch/powerpc/platforms | |
| parent | a32e252f7cdfb3675a4e50215cfac356ed8952c4 (diff) | |
powerpc: Add Initiate Coprocessor Store Word (icswx) support
Icswx is a PowerPC instruction to send data to a co-processor. On Book-S
processors the LPAR_ID and process ID (PID) of the owning process are
registered in the window context of the co-processor at initialization
time. When the icswx instruction is executed the L2 generates a cop-reg
transaction on PowerBus. The transaction has no address and the
processor does not perform an MMU access to authenticate the transaction.
The co-processor compares the LPAR_ID and the PID included in the
transaction and the LPAR_ID and PID held in the window context to
determine if the process is authorized to generate the transaction.
The OS needs to assign a 16-bit PID for the process. This cop-PID needs
to be updated during context switch. The cop-PID needs to be destroyed
when the context is destroyed.
Signed-off-by: Sonny Rao <sonnyrao@linux.vnet.ibm.com>
Signed-off-by: Tseng-Hui (Frank) Lin <thlin@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms')
| -rw-r--r-- | arch/powerpc/platforms/Kconfig.cputype | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 7c1e1c64437..a1e623822a3 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -230,6 +230,24 @@ config VSX If in doubt, say Y here. +config PPC_ICSWX + bool "Support for PowerPC icswx coprocessor instruction" + depends on POWER4 + default n + ---help--- + + This option enables kernel support for the PowerPC Initiate + Coprocessor Store Word (icswx) coprocessor instruction on POWER7 + or newer processors. + + This option is only useful if you have a processor that supports + the icswx coprocessor instruction. It does not have any effect + on processors without the icswx coprocessor instruction. + + This option slightly increases kernel memory usage. + + If in doubt, say N here. + config SPE bool "SPE Support" depends on E200 || (E500 && !PPC_E500MC) |