From 3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 26 Oct 2010 14:21:51 -0700 Subject: 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 Signed-off-by: Peter Zijlstra Acked-by: Chris Metcalf Cc: David Howells Cc: Hugh Dickins Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: Steven Rostedt Cc: Russell King Cc: Ralf Baechle Cc: David Miller Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Dave Airlie Cc: Li Zefan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/mn10300/include/asm/highmem.h | 42 +++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 16 deletions(-) (limited to 'arch/mn10300/include') 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 */ -- cgit v1.1