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/frv/mm/cache-page.c | 8 ++++---- arch/frv/mm/highmem.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+), 4 deletions(-) (limited to 'arch/frv/mm') diff --git a/arch/frv/mm/cache-page.c b/arch/frv/mm/cache-page.c index 0261cbe153b..b24ade27a0f 100644 --- a/arch/frv/mm/cache-page.c +++ b/arch/frv/mm/cache-page.c @@ -26,11 +26,11 @@ void flush_dcache_page(struct page *page) dampr2 = __get_DAMPR(2); - vaddr = kmap_atomic(page, __KM_CACHE); + vaddr = kmap_atomic_primary(page, __KM_CACHE); frv_dcache_writeback((unsigned long) vaddr, (unsigned long) vaddr + PAGE_SIZE); - kunmap_atomic(vaddr, __KM_CACHE); + kunmap_atomic_primary(vaddr, __KM_CACHE); if (dampr2) { __set_DAMPR(2, dampr2); @@ -54,12 +54,12 @@ void flush_icache_user_range(struct vm_area_struct *vma, struct page *page, dampr2 = __get_DAMPR(2); - vaddr = kmap_atomic(page, __KM_CACHE); + vaddr = kmap_atomic_primary(page, __KM_CACHE); start = (start & ~PAGE_MASK) | (unsigned long) vaddr; frv_cache_wback_inv(start, start + len); - kunmap_atomic(vaddr, __KM_CACHE); + kunmap_atomic_primary(vaddr, __KM_CACHE); if (dampr2) { __set_DAMPR(2, dampr2); diff --git a/arch/frv/mm/highmem.c b/arch/frv/mm/highmem.c index eadd0765807..61088dcc159 100644 --- a/arch/frv/mm/highmem.c +++ b/arch/frv/mm/highmem.c @@ -36,3 +36,53 @@ struct page *kmap_atomic_to_page(void *ptr) { return virt_to_page(ptr); } + +void *__kmap_atomic(struct page *page) +{ + unsigned long paddr; + int type; + + pagefault_disable(); + type = kmap_atomic_idx_push(); + paddr = page_to_phys(page); + + switch (type) { + /* + * The first 4 primary maps are reserved for architecture code + */ + case 0: return __kmap_atomic_primary(4, paddr, 6); + case 1: return __kmap_atomic_primary(5, paddr, 7); + case 2: return __kmap_atomic_primary(6, paddr, 8); + case 3: return __kmap_atomic_primary(7, paddr, 9); + case 4: return __kmap_atomic_primary(8, paddr, 10); + + case 5 ... 5 + NR_TLB_LINES - 1: + return __kmap_atomic_secondary(type - 5, paddr); + + default: + BUG(); + return NULL; + } +} +EXPORT_SYMBOL(__kmap_atomic); + +void __kunmap_atomic(void *kvaddr) +{ + int type = kmap_atomic_idx_pop(); + switch (type) { + case 0: __kunmap_atomic_primary(4, 6); break; + case 1: __kunmap_atomic_primary(5, 7); break; + case 2: __kunmap_atomic_primary(6, 8); break; + case 3: __kunmap_atomic_primary(7, 9); break; + case 4: __kunmap_atomic_primary(8, 10); break; + + case 5 ... 5 + NR_TLB_LINES - 1: + __kunmap_atomic_secondary(type - 5, kvaddr); + break; + + default: + BUG(); + } + pagefault_enable(); +} +EXPORT_SYMBOL(__kunmap_atomic); -- cgit v1.2.3