Messages in this thread Patch in this message | | | From | David Howells <> | Subject | [PATCH] FRV: Use the correct preemption primitives in kmap_atomic() and co [try #2] | Date | Mon, 16 Oct 2006 14:10:49 +0100 |
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From: David Howells <dhowells@redhat.com>
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> ---
include/asm-frv/highmem.h | 27 ++++++++++++++------------- 1 files changed, 14 insertions(+), 13 deletions(-)
diff --git a/include/asm-frv/highmem.h b/include/asm-frv/highmem.h index e2247c2..0f390f4 100644 --- a/include/asm-frv/highmem.h +++ b/include/asm-frv/highmem.h @@ -82,11 +82,11 @@ ({ \ 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 @@ ({ \ 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 p { 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 p } } -#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 *k default: BUG(); } - preempt_enable(); + dec_preempt_count(); + preempt_check_resched(); } #endif /* !__ASSEMBLY__ */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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