[PATCH v2 17/19] powerpc/8xx: set PTE bit 22 off TLBmiss
From: Christophe Leroy <hidden>
Date: 2014-08-29 09:32:14
No need to re-set this bit at each TLB miss. Let's set it in the PTE. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/include/asm/pgtable-ppc32.h | 21 +++++++++++++++++++++ arch/powerpc/include/asm/pte-8xx.h | 7 +++++-- arch/powerpc/kernel/head_8xx.S | 10 ++-------- 3 files changed, 28 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index 47edde8..c261792 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h@@ -172,6 +172,26 @@ static inline unsigned long pte_update(pte_t *p, #ifdef PTE_ATOMIC_UPDATES unsigned long old, tmp; +#ifdef CONFIG_PPC_8xx + unsigned long tmp2; + + __asm__ __volatile__("\ +1: lwarx %0,0,%4\n\ + andc %1,%0,%5\n\ + or %1,%1,%6\n\ + /* 0x200 == Extended encoding, bit 22 */ \ + /* Bit 22 has to be 1 if neither _PAGE_USER nor _PAGE_RW are set */ \ + rlwimi %1,%1,32-2,0x200\n /* get _PAGE_USER */ \ + rlwinm %3,%1,32-1,0x200\n /* get _PAGE_RW */ \ + or %1,%3,%1\n\ + xori %1,%1,0x200\n" + PPC405_ERR77(0,%4) +" stwcx. %1,0,%4\n\ + bne- 1b" + : "=&r" (old), "=&r" (tmp), "=m" (*p), "=&r" (tmp2) + : "r" (p), "r" (clr), "r" (set), "m" (*p) + : "cc" ); +#else /* CONFIG_PPC_8xx */ __asm__ __volatile__("\ 1: lwarx %0,0,%3\n\ andc %1,%0,%4\n\
@@ -182,6 +202,7 @@ static inline unsigned long pte_update(pte_t *p, : "=&r" (old), "=&r" (tmp), "=m" (*p) : "r" (p), "r" (clr), "r" (set), "m" (*p) : "cc" ); +#endif /* CONFIG_PPC_8xx */ #else /* PTE_ATOMIC_UPDATES */ unsigned long old = pte_val(*p); *p = __pte((old & ~clr) | set);
diff --git a/arch/powerpc/include/asm/pte-8xx.h b/arch/powerpc/include/asm/pte-8xx.h
index d44826e..dede1e7 100644
--- a/arch/powerpc/include/asm/pte-8xx.h
+++ b/arch/powerpc/include/asm/pte-8xx.h@@ -48,19 +48,22 @@ */ #define _PAGE_RW 0x0400 /* lsb PP bits, inverted in HW */ #define _PAGE_USER 0x0800 /* msb PP bits */ +/* set when neither _PAGE_USER nor _PAGE_RW are set */ +#define _PAGE_KNLRO 0x0200 #define _PMD_PRESENT 0x0001 #define _PMD_BAD 0x0ff0 #define _PMD_PAGE_MASK 0x000c #define _PMD_PAGE_8M 0x000c -#define _PTE_NONE_MASK _PAGE_ACCESSED +#define _PTE_NONE_MASK (_PAGE_ACCESSED | _PAGE_KNLRO) /* Until my rework is finished, 8xx still needs atomic PTE updates */ #define PTE_ATOMIC_UPDATES 1 /* We need to add _PAGE_SHARED to kernel pages */ -#define _PAGE_KERNEL_RO (_PAGE_SHARED) +#define _PAGE_KERNEL_RO (_PAGE_SHARED | _PAGE_KNLRO) +#define _PAGE_KERNEL_ROX (_PAGE_EXEC | _PAGE_KNLRO) #define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE) #endif /* __KERNEL__ */
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index a7af26e..48d3de8 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S@@ -445,14 +445,8 @@ DataStoreTLBMiss: and r11, r11, r10 rlwimi r10, r11, 0, _PAGE_PRESENT #endif - /* Honour kernel RO, User NA */ - /* 0x200 == Extended encoding, bit 22 */ - rlwimi r10, r10, 32-2, 0x200 /* Copy USER to bit 22, 0x200 */ - /* r11 = (r10 & _PAGE_RW) >> 1 */ - rlwinm r11, r10, 32-1, 0x200 - or r10, r11, r10 - /* invert RW and 0x200 bits */ - xori r10, r10, _PAGE_RW | 0x200 + /* invert RW */ + xori r10, r10, _PAGE_RW /* The Linux PTE won't go exactly into the MMU TLB. * Software indicator bits 22 and 28 must be clear.
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1.7.1