On Mon, 2006-10-16 at 14:10 +0100, David Howells wrote:
> From: David Howells <[email protected]>
>
> 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 <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
> ---
>
> 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__ */
-
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