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authorKumar Gala <galak@kernel.crashing.org>2009-03-19 03:55:41 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-03-24 13:47:32 +1100
commit2319f1239592d0de80414ad2338c2bd7384a2a41 (patch)
tree805de041dfc84ae9ca767c9767d833977654dbe0 /arch/powerpc/kernel/head_32.S
parenteb3436a0139a651a39dbb37a75b10a2cccd00ad5 (diff)
powerpc/mm: e300c2/c3/c4 TLB errata workaround
Complete workaround for DTLB errata in e300c2/c3/c4 processors. Due to the bug, the hardware-implemented LRU algorythm always goes to way 1 of the TLB. This fix implements the proposed software workaround in form of a LRW table for chosing the TLB-way. Based on patch from David Jander <david@protonic.nl> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/head_32.S')
-rw-r--r--arch/powerpc/kernel/head_32.S32
1 files changed, 28 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 58dcc7c03109..54e68c11ae15 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -593,9 +593,21 @@ BEGIN_FTR_SECTION
rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
mtspr SPRN_RPA,r1
+ mfspr r2,SPRN_SRR1 /* Need to restore CR0 */
+ mtcrf 0x80,r2
+BEGIN_MMU_FTR_SECTION
+ li r0,1
+ mfspr r1,SPRN_SPRG4
+ rlwinm r2,r3,20,27,31 /* Get Address bits 15:19 */
+ slw r0,r0,r2
+ xor r1,r0,r1
+ srw r0,r1,r2
+ mtspr SPRN_SPRG4,r1
+ mfspr r2,SPRN_SRR1
+ rlwimi r2,r0,31-14,14,14
+ mtspr SPRN_SRR1,r2
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
tlbld r3
- mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
- mtcrf 0x80,r3
rfi
DataAddressInvalid:
mfspr r3,SPRN_SRR1
@@ -661,9 +673,21 @@ BEGIN_FTR_SECTION
rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
mtspr SPRN_RPA,r1
+ mfspr r2,SPRN_SRR1 /* Need to restore CR0 */
+ mtcrf 0x80,r2
+BEGIN_MMU_FTR_SECTION
+ li r0,1
+ mfspr r1,SPRN_SPRG4
+ rlwinm r2,r3,20,27,31 /* Get Address bits 15:19 */
+ slw r0,r0,r2
+ xor r1,r0,r1
+ srw r0,r1,r2
+ mtspr SPRN_SPRG4,r1
+ mfspr r2,SPRN_SRR1
+ rlwimi r2,r0,31-14,14,14
+ mtspr SPRN_SRR1,r2
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
tlbld r3
- mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
- mtcrf 0x80,r3
rfi
#ifndef CONFIG_ALTIVEC