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/powerpc/include/asm/highmem.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'arch/powerpc/include') diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h index d10d64a4be3..dbc264010d0 100644 --- a/arch/powerpc/include/asm/highmem.h +++ b/arch/powerpc/include/asm/highmem.h @@ -60,9 +60,8 @@ extern pte_t *pkmap_page_table; extern void *kmap_high(struct page *page); extern void kunmap_high(struct page *page); -extern void *kmap_atomic_prot(struct page *page, enum km_type type, - pgprot_t prot); -extern void kunmap_atomic_notypecheck(void *kvaddr, enum km_type type); +extern void *kmap_atomic_prot(struct page *page, pgprot_t prot); +extern void __kunmap_atomic(void *kvaddr); static inline void *kmap(struct page *page) { @@ -80,9 +79,9 @@ static inline void kunmap(struct page *page) kunmap_high(page); } -static inline void *kmap_atomic(struct page *page, enum km_type type) +static inline void *__kmap_atomic(struct page *page) { - return kmap_atomic_prot(page, type, kmap_prot); + return kmap_atomic_prot(page, kmap_prot); } static inline struct page *kmap_atomic_to_page(void *ptr) -- cgit v1.2.3-70-g09d2