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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_32.S
parent8aa34ab8b2dc96ca6c4feecfb87ed13f0d40ef98 (diff)
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_32.S')
-rw-r--r--arch/powerpc/kernel/entry_32.S20
1 files changed, 10 insertions, 10 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 3cadba60a4b6..1175a8539e6c 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -88,7 +88,7 @@ crit_transfer_to_handler:
mfspr r0,SPRN_SRR1
stw r0,_SRR1(r11)
- mfspr r8,SPRN_SPRG3
+ mfspr r8,SPRN_SPRG_THREAD
lwz r0,KSP_LIMIT(r8)
stw r0,SAVED_KSP_LIMIT(r11)
rlwimi r0,r1,0,0,(31-THREAD_SHIFT)
@@ -108,7 +108,7 @@ crit_transfer_to_handler:
mfspr r0,SPRN_SRR1
stw r0,crit_srr1@l(0)
- mfspr r8,SPRN_SPRG3
+ mfspr r8,SPRN_SPRG_THREAD
lwz r0,KSP_LIMIT(r8)
stw r0,saved_ksp_limit@l(0)
rlwimi r0,r1,0,0,(31-THREAD_SHIFT)
@@ -138,7 +138,7 @@ transfer_to_handler:
mfspr r2,SPRN_XER
stw r12,_CTR(r11)
stw r2,_XER(r11)
- mfspr r12,SPRN_SPRG3
+ mfspr r12,SPRN_SPRG_THREAD
addi r2,r12,-THREAD
tovirt(r2,r2) /* set r2 to current */
beq 2f /* if from user, fix up THREAD.regs */
@@ -680,7 +680,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_SPE)
tophys(r0,r4)
CLR_TOP32(r0)
- mtspr SPRN_SPRG3,r0 /* Update current THREAD phys addr */
+ mtspr SPRN_SPRG_THREAD,r0 /* Update current THREAD phys addr */
lwz r1,KSP(r4) /* Load new stack pointer */
/* save the old current 'last' for return value */
@@ -1057,7 +1057,7 @@ exc_exit_restart_end:
#ifdef CONFIG_40x
.globl ret_from_crit_exc
ret_from_crit_exc:
- mfspr r9,SPRN_SPRG3
+ mfspr r9,SPRN_SPRG_THREAD
lis r10,saved_ksp_limit@ha;
lwz r10,saved_ksp_limit@l(r10);
tovirt(r9,r9);
@@ -1074,7 +1074,7 @@ ret_from_crit_exc:
#ifdef CONFIG_BOOKE
.globl ret_from_crit_exc
ret_from_crit_exc:
- mfspr r9,SPRN_SPRG3
+ mfspr r9,SPRN_SPRG_THREAD
lwz r10,SAVED_KSP_LIMIT(r1)
stw r10,KSP_LIMIT(r9)
RESTORE_xSRR(SRR0,SRR1);
@@ -1083,7 +1083,7 @@ ret_from_crit_exc:
.globl ret_from_debug_exc
ret_from_debug_exc:
- mfspr r9,SPRN_SPRG3
+ mfspr r9,SPRN_SPRG_THREAD
lwz r10,SAVED_KSP_LIMIT(r1)
stw r10,KSP_LIMIT(r9)
lwz r9,THREAD_INFO-THREAD(r9)
@@ -1097,7 +1097,7 @@ ret_from_debug_exc:
.globl ret_from_mcheck_exc
ret_from_mcheck_exc:
- mfspr r9,SPRN_SPRG3
+ mfspr r9,SPRN_SPRG_THREAD
lwz r10,SAVED_KSP_LIMIT(r1)
stw r10,KSP_LIMIT(r9)
RESTORE_xSRR(SRR0,SRR1);
@@ -1255,7 +1255,7 @@ _GLOBAL(enter_rtas)
MTMSRD(r0) /* don't get trashed */
li r9,MSR_KERNEL & ~(MSR_IR|MSR_DR)
mtlr r6
- mtspr SPRN_SPRG2,r7
+ mtspr SPRN_SPRG_RTAS,r7
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
RFI
@@ -1265,7 +1265,7 @@ _GLOBAL(enter_rtas)
FIX_SRR1(r9,r0)
addi r1,r1,INT_FRAME_SIZE
li r0,0
- mtspr SPRN_SPRG2,r0
+ mtspr SPRN_SPRG_RTAS,r0
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
RFI /* return to caller */