diff options
| author | LEROY Christophe <christophe.leroy@c-s.fr> | 2014-09-19 10:36:10 +0200 |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2014-11-08 01:10:45 +0100 |
| commit | 83c17ba35e0306e671b5c9ab622535f23a9a3e78 (patch) | |
| tree | 4405a996b06488e310470cf917a2202056e4e3c1 /arch/powerpc/kernel | |
| parent | powerpc/8xx: Don't restore regs to save them again. (diff) | |
| download | linux-83c17ba35e0306e671b5c9ab622535f23a9a3e78.tar.xz linux-83c17ba35e0306e671b5c9ab622535f23a9a3e78.zip | |
powerpc/8xx: Use DAR to save r3 for CPU6 ERRATA
As we are not using anymore DAR to save registers, it is now available for
saving the r3 register used for CPU6 ERRATA handling. Therefore we can
remove the major hack which was to use memory location 0 to save r3.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/head_8xx.S | 33 |
1 files changed, 15 insertions, 18 deletions
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 330d54418494..acf6d7eab6d5 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -83,13 +83,6 @@ _ENTRY(_start); * 8M 1:1. I also mapped an additional I/O space 1:1 so we can get to * the "internal" processor registers before MMU_init is called. * - * The TLB code currently contains a major hack. Since I use the condition - * code register, I have to save and restore it. I am out of registers, so - * I just store it in memory location 0 (the TLB handlers are not reentrant). - * To avoid making any decisions, I need to use the "segment" valid bit - * in the first level table, but that would require many changes to the - * Linux page directory/table functions that I don't want to do right now. - * * -- Dan */ .globl __start @@ -306,7 +299,7 @@ SystemCall: */ InstructionTLBMiss: #ifdef CONFIG_8xx_CPU6 - stw r3, 8(r0) + mtspr SPRN_DAR, r3 #endif EXCEPTION_PROLOG_0 mtspr SPRN_SPRG_SCRATCH2, r10 @@ -351,7 +344,10 @@ InstructionTLBMiss: #ifdef CONFIG_SWAP andi. r11, r10, _PAGE_ACCESSED | _PAGE_PRESENT cmpwi cr0, r11, _PAGE_ACCESSED | _PAGE_PRESENT + li r11, RPN_PATTERN bne- cr0, 2f +#else + li r11, RPN_PATTERN #endif /* The Linux PTE won't go exactly into the MMU TLB. * Software indicator bits 21 and 28 must be clear. @@ -359,28 +355,29 @@ InstructionTLBMiss: * set. All other Linux PTE bits control the behavior * of the MMU. */ - li r11, RPN_PATTERN rlwimi r10, r11, 0, 0x07f8 /* Set 24-27, clear 21-23,28 */ MTSPR_CPU6(SPRN_MI_RPN, r10, r3) /* Update TLB entry */ /* Restore registers */ #ifdef CONFIG_8xx_CPU6 - lwz r3, 8(r0) + mfspr r3, SPRN_DAR + mtspr SPRN_DAR, r11 /* Tag DAR */ #endif mfspr r10, SPRN_SPRG_SCRATCH2 EXCEPTION_EPILOG_0 rfi 2: - mfspr r11, SPRN_SRR1 + mfspr r10, SPRN_SRR1 /* clear all error bits as TLB Miss * sets a few unconditionally */ - rlwinm r11, r11, 0, 0xffff - mtspr SPRN_SRR1, r11 + rlwinm r10, r10, 0, 0xffff + mtspr SPRN_SRR1, r10 /* Restore registers */ #ifdef CONFIG_8xx_CPU6 - lwz r3, 8(r0) + mfspr r3, SPRN_DAR + mtspr SPRN_DAR, r11 /* Tag DAR */ #endif mfspr r10, SPRN_SPRG_SCRATCH2 b InstructionTLBError1 @@ -388,7 +385,7 @@ InstructionTLBMiss: . = 0x1200 DataStoreTLBMiss: #ifdef CONFIG_8xx_CPU6 - stw r3, 8(r0) + mtspr SPRN_DAR, r3 #endif EXCEPTION_PROLOG_0 mtspr SPRN_SPRG_SCRATCH2, r10 @@ -459,7 +456,7 @@ DataStoreTLBMiss: /* Restore registers */ #ifdef CONFIG_8xx_CPU6 - lwz r3, 8(r0) + mfspr r3, SPRN_DAR #endif mtspr SPRN_DAR, r11 /* Tag DAR */ mfspr r10, SPRN_SPRG_SCRATCH2 @@ -531,7 +528,7 @@ DARFixed:/* Return from dcbx instruction bug workaround */ #define NO_SELF_MODIFYING_CODE FixupDAR:/* Entry point for dcbx workaround. */ #ifdef CONFIG_8xx_CPU6 - stw r3, 8(r0) + mtspr SPRN_DAR, r3 #endif mtspr SPRN_SPRG_SCRATCH2, r10 /* fetch instruction from memory. */ @@ -550,7 +547,7 @@ FixupDAR:/* Entry point for dcbx workaround. */ rlwinm r11, r11, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29 lwzx r11, r10, r11 /* Get the pte */ #ifdef CONFIG_8xx_CPU6 - lwz r3, 8(r0) /* restore r3 from memory */ + mfspr r3, SPRN_DAR #endif /* concat physical page address(r11) and page offset(r10) */ mfspr r10, SPRN_SRR0 |