[PATCH] FRV: Use the correct preemption primitives in kmap_atomic() and co
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>
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 @@
{
unsigned long paddr;
- preempt_disable();
+ inc_preempt_count();
paddr = page_to_phys(page);
switch (type) {
@@ -138,16 +138,16 @@
}
}
-#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 @@
default:
BUG();
}
- preempt_enable();
+ dec_preempt_count();
+ preempt_check_resched();
}
#endif /* !__ASSEMBLY__ */