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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-07-14 20:52:54 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-08-20 10:12:27 +1000
commitee43eb788b3a06425fffb912677e2e1c8b00dd3b (patch)
tree7233cb47647837ab00af81270b3a16555d88a1f1 /arch/powerpc/kernel/entry_64.S
parent8aa34ab8b2dc96ca6c4feecfb87ed13f0d40ef98 (diff)
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powerpc: Use names rather than numbers for SPRGs (v2)
The kernel uses SPRG registers for various purposes, typically in low level assembly code as scratch registers or to hold per-cpu global infos such as the PACA or the current thread_info pointer. We want to be able to easily shuffle the usage of those registers as some implementations have specific constraints realted to some of them, for example, some have userspace readable aliases, etc.. and the current choice isn't always the best. This patch should not change any code generation, and replaces the usage of SPRN_SPRGn everywhere in the kernel with a named replacement and adds documentation next to the definition of the names as to what those are used for on each processor family. The only parts that still use the original numbers are bits of KVM or suspend/resume code that just blindly needs to save/restore all the SPRGs. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
-rw-r--r--arch/powerpc/kernel/entry_64.S4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 43e073477c34..dbf0e3115611 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -762,7 +762,7 @@ _GLOBAL(enter_rtas)
_STATIC(rtas_return_loc)
/* relocation is off at this point */
- mfspr r4,SPRN_SPRG3 /* Get PACA */
+ mfspr r4,SPRN_SPRG_PACA /* Get PACA */
clrldi r4,r4,2 /* convert to realmode address */
bcl 20,31,$+4
@@ -793,7 +793,7 @@ _STATIC(rtas_restore_regs)
REST_8GPRS(14, r1) /* Restore the non-volatiles */
REST_10GPRS(22, r1) /* ditto */
- mfspr r13,SPRN_SPRG3
+ mfspr r13,SPRN_SPRG_PACA
ld r4,_CCR(r1)
mtcr r4