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author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-10-26 14:21:51 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-26 16:52:08 -0700 |
commit | 3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73 (patch) | |
tree | 2ce507f7ec7275563653e52f18606aba4f99b7f1 /arch/mips | |
parent | 61ecdb801ef2cd28e32442383106d7837d76deac (diff) | |
download | kernel_samsung_smdk4412-3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73.zip kernel_samsung_smdk4412-3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73.tar.gz kernel_samsung_smdk4412-3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73.tar.bz2 |
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/mips')
-rw-r--r-- | arch/mips/include/asm/highmem.h | 18 | ||||
-rw-r--r-- | arch/mips/mm/highmem.c | 50 |
2 files changed, 33 insertions, 35 deletions
diff --git a/arch/mips/include/asm/highmem.h b/arch/mips/include/asm/highmem.h index 75753ca..77e6440 100644 --- a/arch/mips/include/asm/highmem.h +++ b/arch/mips/include/asm/highmem.h @@ -45,18 +45,12 @@ extern pte_t *pkmap_page_table; extern void * kmap_high(struct page *page); extern void kunmap_high(struct page *page); -extern void *__kmap(struct page *page); -extern void __kunmap(struct page *page); -extern void *__kmap_atomic(struct page *page, enum km_type type); -extern void __kunmap_atomic_notypecheck(void *kvaddr, enum km_type type); -extern void *kmap_atomic_pfn(unsigned long pfn, enum km_type type); -extern struct page *__kmap_atomic_to_page(void *ptr); - -#define kmap __kmap -#define kunmap __kunmap -#define kmap_atomic __kmap_atomic -#define kunmap_atomic_notypecheck __kunmap_atomic_notypecheck -#define kmap_atomic_to_page __kmap_atomic_to_page +extern void *kmap(struct page *page); +extern void kunmap(struct page *page); +extern void *__kmap_atomic(struct page *page); +extern void __kunmap_atomic(void *kvaddr); +extern void *kmap_atomic_pfn(unsigned long pfn); +extern struct page *kmap_atomic_to_page(void *ptr); #define flush_cache_kmaps() flush_cache_all() diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c index 6a2b1bf..1e69b1f 100644 --- a/arch/mips/mm/highmem.c +++ b/arch/mips/mm/highmem.c @@ -9,7 +9,7 @@ static pte_t *kmap_pte; unsigned long highstart_pfn, highend_pfn; -void *__kmap(struct page *page) +void *kmap(struct page *page) { void *addr; @@ -21,16 +21,16 @@ void *__kmap(struct page *page) return addr; } -EXPORT_SYMBOL(__kmap); +EXPORT_SYMBOL(kmap); -void __kunmap(struct page *page) +void kunmap(struct page *page) { BUG_ON(in_interrupt()); if (!PageHighMem(page)) return; kunmap_high(page); } -EXPORT_SYMBOL(__kunmap); +EXPORT_SYMBOL(kunmap); /* * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because @@ -41,17 +41,17 @@ EXPORT_SYMBOL(__kunmap); * kmaps are appropriate for short, tight code paths only. */ -void *__kmap_atomic(struct page *page, enum km_type type) +void *__kmap_atomic(struct page *page) { - enum fixed_addresses idx; unsigned long vaddr; + int idx, type; /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ pagefault_disable(); if (!PageHighMem(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); #ifdef CONFIG_DEBUG_HIGHMEM @@ -64,43 +64,47 @@ void *__kmap_atomic(struct page *page, enum km_type type) } EXPORT_SYMBOL(__kmap_atomic); -void __kunmap_atomic_notypecheck(void *kvaddr, enum km_type type) +void __kunmap_atomic(void *kvaddr) { -#ifdef CONFIG_DEBUG_HIGHMEM unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; - enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); + int type; if (vaddr < FIXADDR_START) { // FIXME pagefault_enable(); return; } - BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); + type = kmap_atomic_idx_pop(); +#ifdef CONFIG_DEBUG_HIGHMEM + { + int idx = type + KM_TYPE_NR * smp_processor_id(); - /* - * force other mappings to Oops if they'll try to access - * this pte without first remap it - */ - pte_clear(&init_mm, vaddr, kmap_pte-idx); - local_flush_tlb_one(vaddr); -#endif + BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); + /* + * force other mappings to Oops if they'll try to access + * this pte without first remap it + */ + pte_clear(&init_mm, vaddr, kmap_pte-idx); + local_flush_tlb_one(vaddr); + } +#endif pagefault_enable(); } -EXPORT_SYMBOL(__kunmap_atomic_notypecheck); +EXPORT_SYMBOL(__kunmap_atomic); /* * This is the same as kmap_atomic() but can map memory that doesn't * have a struct page associated with it. */ -void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) +void *kmap_atomic_pfn(unsigned long pfn) { - enum fixed_addresses idx; unsigned long vaddr; + int idx, type; pagefault_disable(); - 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); set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL)); @@ -109,7 +113,7 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) return (void*) vaddr; } -struct page *__kmap_atomic_to_page(void *ptr) +struct page *kmap_atomic_to_page(void *ptr) { unsigned long idx, vaddr = (unsigned long)ptr; pte_t *pte; |