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powerpc/8xx: set PTE bit 22 off TLBmiss

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No need to re-set this bit at each TLB miss. Let's set it in the PTE.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
This commit is contained in:
LEROY Christophe 2014-09-19 10:36:09 +02:00 committed by Scott Wood
parent d3e40262e7
commit 4094f28f90
3 changed files with 27 additions and 10 deletions
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20
arch/powerpc/include/asm/pgtable-ppc32.h
View File

@ -170,6 +170,25 @@ 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"
" 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\
@ -180,6 +199,7 @@ 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);

7
arch/powerpc/include/asm/pte-8xx.h
View File

@ -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_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__ */

10
arch/powerpc/kernel/head_8xx.S
View File

@ -447,14 +447,8 @@ 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.