diff options
author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-10-26 21:21:51 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-26 23:52:08 (GMT) |
commit | 3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73 (patch) | |
tree | 2ce507f7ec7275563653e52f18606aba4f99b7f1 /arch/mn10300 | |
parent | 61ecdb801ef2cd28e32442383106d7837d76deac (diff) | |
download | linux-fsl-qoriq-3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73.tar.xz |
mm: stack based kmap_atomic()
Keep the current interface but ignore the KM_type and use a stack based
approach.
The advantage is that we get rid of crappy code like:
#define __KM_PTE \
(in_nmi() ? KM_NMI_PTE : \
in_irq() ? KM_IRQ_PTE : \
KM_PTE0)
and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.
The downside is that FRV kmap_atomic() gets more expensive.
For now we use a CPP trick suggested by Andrew:
#define kmap_atomic(page, args...) __kmap_atomic(page)
to avoid having to touch all kmap_atomic() users in a single patch.
[ not compiled on:
- mn10300: the arch doesn't actually build with highmem to begin with ]
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/mn10300')
-rw-r--r-- | arch/mn10300/include/asm/highmem.h | 42 |
1 files changed, 26 insertions, 16 deletions
diff --git a/arch/mn10300/include/asm/highmem.h b/arch/mn10300/include/asm/highmem.h index b0b187a..f577ba2 100644 --- a/arch/mn10300/include/asm/highmem.h +++ b/arch/mn10300/include/asm/highmem.h @@ -70,15 +70,16 @@ static inline void kunmap(struct page *page) * be used in IRQ contexts, so in some (very limited) cases we need * it. */ -static inline unsigned long kmap_atomic(struct page *page, enum km_type type) +static inline unsigned long __kmap_atomic(struct page *page) { - enum fixed_addresses idx; unsigned long vaddr; + int idx, type; + pagefault_disable(); if (page < highmem_start_page) return page_address(page); - debug_kmap_atomic(type); + type = kmap_atomic_idx_push(); idx = type + KM_TYPE_NR * smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); #if HIGHMEM_DEBUG @@ -91,26 +92,35 @@ static inline unsigned long kmap_atomic(struct page *page, enum km_type type) return vaddr; } -static inline void kunmap_atomic_notypecheck(unsigned long vaddr, enum km_type type) +static inline void __kunmap_atomic(unsigned long vaddr) { -#if HIGHMEM_DEBUG - enum fixed_addresses idx = type + KM_TYPE_NR * smp_processor_id(); + int type; - if (vaddr < FIXADDR_START) /* FIXME */ + if (vaddr < FIXADDR_START) { /* FIXME */ + pagefault_enable(); return; + } - if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)) - BUG(); + type = kmap_atomic_idx_pop(); - /* - * force other mappings to Oops if they'll try to access - * this pte without first remap it - */ - pte_clear(kmap_pte - idx); - __flush_tlb_one(vaddr); +#if HIGHMEM_DEBUG + { + unsigned int idx; + idx = type + KM_TYPE_NR * smp_processor_id(); + + if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)) + BUG(); + + /* + * force other mappings to Oops if they'll try to access + * this pte without first remap it + */ + pte_clear(kmap_pte - idx); + __flush_tlb_one(vaddr); + } #endif + pagefault_enable(); } - #endif /* __KERNEL__ */ #endif /* _ASM_HIGHMEM_H */ |