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[PATCH] FRV: Use the correct preemption primitives in kmap_atomic() and co

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Use inc/dec_preempt_count() rather than preempt_enable/disable() and manually
add in the compiler barriers that were provided by the latter.  This makes FRV
consistent with other archs.

Furthermore, the compiler barrier effects are now there unconditionally - at
least as far as preemption is concerned - because we don't want the compiler
moving memory accesses out of the section of code in which the mapping is in
force - in effect the kmap_atomic() must imply a LOCK-class barrier and the
kunmap_atomic() must imply an UNLOCK-class barrier to the compiler.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
David Howells 2006-10-16 14:10:49 +01:00 committed by Linus Torvalds
parent 8741ca71a3
commit 29da7eb0ec
1 changed files with 14 additions and 13 deletions
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27
include/asm-frv/highmem.h
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@ -82,11 +82,11 @@ extern struct page *kmap_atomic_to_page(void *ptr);
dampr = paddr | xAMPRx_L | xAMPRx_M | xAMPRx_S | xAMPRx_SS_16Kb | xAMPRx_V; \
\
if (type != __KM_CACHE) \
asm volatile("movgs %0,dampr"#ampr :: "r"(dampr)); \
asm volatile("movgs %0,dampr"#ampr :: "r"(dampr) : "memory"); \
else \
asm volatile("movgs %0,iampr"#ampr"\n" \
"movgs %0,dampr"#ampr"\n" \
:: "r"(dampr) \
:: "r"(dampr) : "memory" \
); \
\
asm("movsg damlr"#ampr",%0" : "=r"(damlr)); \
@ -104,7 +104,7 @@ extern struct page *kmap_atomic_to_page(void *ptr);
asm volatile("movgs %0,tplr \n" \
"movgs %1,tppr \n" \
"tlbpr %0,gr0,#2,#1" \
: : "r"(damlr), "r"(dampr)); \
: : "r"(damlr), "r"(dampr) : "memory"); \
\
/*printk("TLB: SECN sl=%d L=%08lx P=%08lx\n", slot, damlr, dampr);*/ \
\
@ -115,7 +115,7 @@ static inline void *kmap_atomic(struct page *page, enum km_type type)
{
unsigned long paddr;
preempt_disable();
inc_preempt_count();
paddr = page_to_phys(page);
switch (type) {
@ -138,16 +138,16 @@ static inline void *kmap_atomic(struct page *page, enum km_type type)
}
}
#define __kunmap_atomic_primary(type, ampr) \
do { \
asm volatile("movgs gr0,dampr"#ampr"\n"); \
if (type == __KM_CACHE) \
asm volatile("movgs gr0,iampr"#ampr"\n"); \
#define __kunmap_atomic_primary(type, ampr) \
do { \
asm volatile("movgs gr0,dampr"#ampr"\n" ::: "memory"); \
if (type == __KM_CACHE) \
asm volatile("movgs gr0,iampr"#ampr"\n" ::: "memory"); \
} while(0)
#define __kunmap_atomic_secondary(slot, vaddr) \
do { \
asm volatile("tlbpr %0,gr0,#4,#1" : : "r"(vaddr)); \
#define __kunmap_atomic_secondary(slot, vaddr) \
do { \
asm volatile("tlbpr %0,gr0,#4,#1" : : "r"(vaddr) : "memory"); \
} while(0)
static inline void kunmap_atomic(void *kvaddr, enum km_type type)
@ -170,7 +170,8 @@ static inline void kunmap_atomic(void *kvaddr, enum km_type type)
default:
BUG();
}
preempt_enable();
dec_preempt_count();
preempt_check_resched();
}
#endif /* !__ASSEMBLY__ */