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Diffstat (limited to 'arch/powerpc/kernel/head_8xx.S')
-rw-r--r--arch/powerpc/kernel/head_8xx.S150
1 files changed, 56 insertions, 94 deletions
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 7ee876d2adb5..fafff8dbd5d9 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -104,12 +104,15 @@ turn_on_mmu:
* task's thread_struct.
*/
#define EXCEPTION_PROLOG \
- mtspr SPRN_SPRG_SCRATCH0,r10; \
- mtspr SPRN_SPRG_SCRATCH1,r11; \
- mfcr r10; \
+ EXCEPTION_PROLOG_0; \
EXCEPTION_PROLOG_1; \
EXCEPTION_PROLOG_2
+#define EXCEPTION_PROLOG_0 \
+ mtspr SPRN_SPRG_SCRATCH0,r10; \
+ mtspr SPRN_SPRG_SCRATCH1,r11; \
+ mfcr r10
+
#define EXCEPTION_PROLOG_1 \
mfspr r11,SPRN_SRR1; /* check whether user or kernel */ \
andi. r11,r11,MSR_PR; \
@@ -145,6 +148,14 @@ turn_on_mmu:
SAVE_2GPRS(7, r11)
/*
+ * Exception exit code.
+ */
+#define EXCEPTION_EPILOG_0 \
+ mtcr r10; \
+ mfspr r10,SPRN_SPRG_SCRATCH0; \
+ mfspr r11,SPRN_SPRG_SCRATCH1
+
+/*
* Note: code which follows this uses cr0.eq (set if from kernel),
* r11, r12 (SRR0), and r9 (SRR1).
*
@@ -293,16 +304,8 @@ InstructionTLBMiss:
#ifdef CONFIG_8xx_CPU6
stw r3, 8(r0)
#endif
- DO_8xx_CPU6(0x3f80, r3)
- mtspr SPRN_M_TW, r10 /* Save a couple of working registers */
- mfcr r10
-#ifdef CONFIG_8xx_CPU6
- stw r10, 0(r0)
- stw r11, 4(r0)
-#else
- mtspr SPRN_DAR, r10
- mtspr SPRN_SPRG2, r11
-#endif
+ EXCEPTION_PROLOG_0
+ mtspr SPRN_SPRG_SCRATCH2, r10
mfspr r10, SPRN_SRR0 /* Get effective address of fault */
#ifdef CONFIG_8xx_CPU15
addi r11, r10, 0x1000
@@ -359,18 +362,11 @@ InstructionTLBMiss:
mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
/* Restore registers */
-#ifndef CONFIG_8xx_CPU6
- mfspr r10, SPRN_DAR
- mtcr r10
- mtspr SPRN_DAR, r11 /* Tag DAR */
- mfspr r11, SPRN_SPRG2
-#else
- lwz r11, 0(r0)
- mtcr r11
- lwz r11, 4(r0)
+#ifdef CONFIG_8xx_CPU6
lwz r3, 8(r0)
#endif
- mfspr r10, SPRN_M_TW
+ mfspr r10, SPRN_SPRG_SCRATCH2
+ EXCEPTION_EPILOG_0
rfi
2:
mfspr r11, SPRN_SRR1
@@ -381,19 +377,11 @@ InstructionTLBMiss:
mtspr SPRN_SRR1, r11
/* Restore registers */
-#ifndef CONFIG_8xx_CPU6
- mfspr r10, SPRN_DAR
- mtcr r10
- li r11, 0x00f0
- mtspr SPRN_DAR, r11 /* Tag DAR */
- mfspr r11, SPRN_SPRG2
-#else
- lwz r11, 0(r0)
- mtcr r11
- lwz r11, 4(r0)
+#ifdef CONFIG_8xx_CPU6
lwz r3, 8(r0)
#endif
- mfspr r10, SPRN_M_TW
+ mfspr r10, SPRN_SPRG_SCRATCH2
+ EXCEPTION_EPILOG_0
b InstructionAccess
. = 0x1200
@@ -401,16 +389,8 @@ DataStoreTLBMiss:
#ifdef CONFIG_8xx_CPU6
stw r3, 8(r0)
#endif
- DO_8xx_CPU6(0x3f80, r3)
- mtspr SPRN_M_TW, r10 /* Save a couple of working registers */
- mfcr r10
-#ifdef CONFIG_8xx_CPU6
- stw r10, 0(r0)
- stw r11, 4(r0)
-#else
- mtspr SPRN_DAR, r10
- mtspr SPRN_SPRG2, r11
-#endif
+ EXCEPTION_PROLOG_0
+ mtspr SPRN_SPRG_SCRATCH2, r10
mfspr r10, SPRN_M_TWB /* Get level 1 table entry address */
/* If we are faulting a kernel address, we have to use the
@@ -483,19 +463,12 @@ DataStoreTLBMiss:
mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
/* Restore registers */
-#ifndef CONFIG_8xx_CPU6
- mfspr r10, SPRN_DAR
- mtcr r10
- mtspr SPRN_DAR, r11 /* Tag DAR */
- mfspr r11, SPRN_SPRG2
-#else
- mtspr SPRN_DAR, r11 /* Tag DAR */
- lwz r11, 0(r0)
- mtcr r11
- lwz r11, 4(r0)
+#ifdef CONFIG_8xx_CPU6
lwz r3, 8(r0)
#endif
- mfspr r10, SPRN_M_TW
+ mtspr SPRN_DAR, r11 /* Tag DAR */
+ mfspr r10, SPRN_SPRG_SCRATCH2
+ EXCEPTION_EPILOG_0
rfi
/* This is an instruction TLB error on the MPC8xx. This could be due
@@ -507,35 +480,18 @@ InstructionTLBError:
b InstructionAccess
/* This is the data TLB error on the MPC8xx. This could be due to
- * many reasons, including a dirty update to a pte. We can catch that
- * one here, but anything else is an error. First, we track down the
- * Linux pte. If it is valid, write access is allowed, but the
- * page dirty bit is not set, we will set it and reload the TLB. For
- * any other case, we bail out to a higher level function that can
- * handle it.
+ * many reasons, including a dirty update to a pte. We bail out to
+ * a higher level function that can handle it.
*/
. = 0x1400
DataTLBError:
-#ifdef CONFIG_8xx_CPU6
- stw r3, 8(r0)
-#endif
- DO_8xx_CPU6(0x3f80, r3)
- mtspr SPRN_M_TW, r10 /* Save a couple of working registers */
- mfcr r10
- stw r10, 0(r0)
- stw r11, 4(r0)
+ EXCEPTION_PROLOG_0
- mfspr r10, SPRN_DAR
- cmpwi cr0, r10, 0x00f0
+ mfspr r11, SPRN_DAR
+ cmpwi cr0, r11, 0x00f0
beq- FixupDAR /* must be a buggy dcbX, icbi insn. */
-DARFixed:/* Return from dcbx instruction bug workaround, r10 holds value of DAR */
- mfspr r10, SPRN_M_TW /* Restore registers */
- lwz r11, 0(r0)
- mtcr r11
- lwz r11, 4(r0)
-#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0)
-#endif
+DARFixed:/* Return from dcbx instruction bug workaround */
+ EXCEPTION_EPILOG_0
b DataAccess
EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
@@ -559,11 +515,15 @@ DARFixed:/* Return from dcbx instruction bug workaround, r10 holds value of DAR
/* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions
* by decoding the registers used by the dcbx instruction and adding them.
- * DAR is set to the calculated address and r10 also holds the EA on exit.
+ * DAR is set to the calculated address.
*/
/* define if you don't want to use self modifying code */
#define NO_SELF_MODIFYING_CODE
FixupDAR:/* Entry point for dcbx workaround. */
+#ifdef CONFIG_8xx_CPU6
+ stw r3, 8(r0)
+#endif
+ mtspr SPRN_SPRG_SCRATCH2, r10
/* fetch instruction from memory. */
mfspr r10, SPRN_SRR0
andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
@@ -579,16 +539,17 @@ FixupDAR:/* Entry point for dcbx workaround. */
mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
mfspr r11, SPRN_MD_TWC /* ....and get the pte address */
lwz r11, 0(r11) /* Get the pte */
+#ifdef CONFIG_8xx_CPU6
+ lwz r3, 8(r0) /* restore r3 from memory */
+#endif
/* concat physical page address(r11) and page offset(r10) */
rlwimi r11, r10, 0, 20, 31
lwz r11,0(r11)
/* Check if it really is a dcbx instruction. */
/* dcbt and dcbtst does not generate DTLB Misses/Errors,
* no need to include them here */
- srwi r10, r11, 26 /* check if major OP code is 31 */
- cmpwi cr0, r10, 31
- bne- 141f
- rlwinm r10, r11, 0, 21, 30
+ xoris r10, r11, 0x7c00 /* check if major OP code is 31 */
+ rlwinm r10, r10, 0, 21, 5
cmpwi cr0, r10, 2028 /* Is dcbz? */
beq+ 142f
cmpwi cr0, r10, 940 /* Is dcbi? */
@@ -599,16 +560,13 @@ FixupDAR:/* Entry point for dcbx workaround. */
beq+ 142f
cmpwi cr0, r10, 1964 /* Is icbi? */
beq+ 142f
-141: mfspr r10, SPRN_DAR /* r10 must hold DAR at exit */
+141: mfspr r10,SPRN_SPRG_SCRATCH2
b DARFixed /* Nope, go back to normal TLB processing */
144: mfspr r10, SPRN_DSISR
rlwinm r10, r10,0,7,5 /* Clear store bit for buggy dcbst insn */
mtspr SPRN_DSISR, r10
142: /* continue, it was a dcbx, dcbi instruction. */
-#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0) /* restore r3 from memory */
-#endif
#ifndef NO_SELF_MODIFYING_CODE
andis. r10,r11,0x1f /* test if reg RA is r0 */
li r10,modified_instr@l
@@ -619,14 +577,15 @@ FixupDAR:/* Entry point for dcbx workaround. */
stw r11,0(r10) /* store add/and instruction */
dcbf 0,r10 /* flush new instr. to memory. */
icbi 0,r10 /* invalidate instr. cache line */
- lwz r11, 4(r0) /* restore r11 from memory */
- mfspr r10, SPRN_M_TW /* restore r10 from M_TW */
+ mfspr r11, SPRN_SPRG_SCRATCH1 /* restore r11 */
+ mfspr r10, SPRN_SPRG_SCRATCH0 /* restore r10 */
isync /* Wait until new instr is loaded from memory */
modified_instr:
.space 4 /* this is where the add instr. is stored */
bne+ 143f
subf r10,r0,r10 /* r10=r10-r0, only if reg RA is r0 */
143: mtdar r10 /* store faulting EA in DAR */
+ mfspr r10,SPRN_SPRG_SCRATCH2
b DARFixed /* Go back to normal TLB handling */
#else
mfctr r10
@@ -680,13 +639,16 @@ modified_instr:
mfdar r11
mtctr r11 /* restore ctr reg from DAR */
mtdar r10 /* save fault EA to DAR */
+ mfspr r10,SPRN_SPRG_SCRATCH2
b DARFixed /* Go back to normal TLB handling */
/* special handling for r10,r11 since these are modified already */
-153: lwz r11, 4(r0) /* load r11 from memory */
- b 155f
-154: mfspr r11, SPRN_M_TW /* load r10 from M_TW */
-155: add r10, r10, r11 /* add it */
+153: mfspr r11, SPRN_SPRG_SCRATCH1 /* load r11 from SPRN_SPRG_SCRATCH1 */
+ add r10, r10, r11 /* add it */
+ mfctr r11 /* restore r11 */
+ b 151b
+154: mfspr r11, SPRN_SPRG_SCRATCH0 /* load r10 from SPRN_SPRG_SCRATCH0 */
+ add r10, r10, r11 /* add it */
mfctr r11 /* restore r11 */
b 151b
#endif