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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-07-15 00:52:54 +0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-08-20 04:12:27 +0400
commitee43eb788b3a06425fffb912677e2e1c8b00dd3b (patch)
tree7233cb47647837ab00af81270b3a16555d88a1f1 /arch/powerpc/kernel/fpu.S
parent8aa34ab8b2dc96ca6c4feecfb87ed13f0d40ef98 (diff)
downloadlinux-ee43eb788b3a06425fffb912677e2e1c8b00dd3b.tar.xz
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/fpu.S')
-rw-r--r--arch/powerpc/kernel/fpu.S2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index 2436df33c6f4..fc8f5b14019c 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -91,7 +91,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif /* CONFIG_SMP */
/* enable use of FP after return */
#ifdef CONFIG_PPC32
- mfspr r5,SPRN_SPRG3 /* current task's THREAD (phys) */
+ mfspr r5,SPRN_SPRG_THREAD /* current task's THREAD (phys) */
lwz r4,THREAD_FPEXC_MODE(r5)
ori r9,r9,MSR_FP /* enable FP for current */
or r9,r9,r4