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highmem: Provide generic variant of kmap_atomic*
The kmap_atomic* interfaces in all architectures are pretty much the same except for post map operations (flush) and pre- and post unmap operations. Provide a generic variant for that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/r/20201103095857.175939340@linutronix.de
This commit is contained in:
Thomas Gleixner
parent
4f8b96cd47
commit
298fa1ad55
@ -31,9 +31,16 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
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#include <asm/kmap_types.h>
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/*
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* Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
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*/
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#ifdef CONFIG_KMAP_LOCAL
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void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
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void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
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void kunmap_local_indexed(void *vaddr);
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#endif
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#ifdef CONFIG_HIGHMEM
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extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
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extern void kunmap_atomic_high(void *kvaddr);
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#include <asm/highmem.h>
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#ifndef ARCH_HAS_KMAP_FLUSH_TLB
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@ -81,6 +88,11 @@ static inline void kunmap(struct page *page)
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* be used in IRQ contexts, so in some (very limited) cases we need
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* it.
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*/
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#ifndef CONFIG_KMAP_LOCAL
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void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
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void kunmap_atomic_high(void *kvaddr);
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static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
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{
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preempt_disable();
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@ -89,7 +101,38 @@ static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
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return page_address(page);
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return kmap_atomic_high_prot(page, prot);
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}
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#define kmap_atomic(page) kmap_atomic_prot(page, kmap_prot)
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static inline void __kunmap_atomic(void *vaddr)
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{
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kunmap_atomic_high(vaddr);
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}
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#else /* !CONFIG_KMAP_LOCAL */
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static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
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{
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preempt_disable();
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pagefault_disable();
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return __kmap_local_page_prot(page, prot);
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}
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static inline void *kmap_atomic_pfn(unsigned long pfn)
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{
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preempt_disable();
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pagefault_disable();
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return __kmap_local_pfn_prot(pfn, kmap_prot);
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}
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static inline void __kunmap_atomic(void *addr)
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{
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kunmap_local_indexed(addr);
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}
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#endif /* CONFIG_KMAP_LOCAL */
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static inline void *kmap_atomic(struct page *page)
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{
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return kmap_atomic_prot(page, kmap_prot);
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}
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/* declarations for linux/mm/highmem.c */
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unsigned int nr_free_highpages(void);
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@ -147,25 +190,33 @@ static inline void *kmap_atomic(struct page *page)
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pagefault_disable();
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return page_address(page);
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}
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#define kmap_atomic_prot(page, prot) kmap_atomic(page)
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static inline void kunmap_atomic_high(void *addr)
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static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
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{
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return kmap_atomic(page);
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}
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static inline void *kmap_atomic_pfn(unsigned long pfn)
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{
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return kmap_atomic(pfn_to_page(pfn));
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}
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static inline void __kunmap_atomic(void *addr)
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{
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/*
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* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
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* handles re-enabling faults + preemption
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* handles re-enabling faults and preemption
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*/
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#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
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kunmap_flush_on_unmap(addr);
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#endif
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}
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#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
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#define kmap_flush_unused() do {} while(0)
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#endif /* CONFIG_HIGHMEM */
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#if !defined(CONFIG_KMAP_LOCAL)
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#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
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DECLARE_PER_CPU(int, __kmap_atomic_idx);
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@ -196,22 +247,21 @@ static inline void kmap_atomic_idx_pop(void)
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__this_cpu_dec(__kmap_atomic_idx);
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#endif
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}
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#endif
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#endif
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/*
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* Prevent people trying to call kunmap_atomic() as if it were kunmap()
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* kunmap_atomic() should get the return value of kmap_atomic, not the page.
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*/
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#define kunmap_atomic(addr) \
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do { \
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BUILD_BUG_ON(__same_type((addr), struct page *)); \
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kunmap_atomic_high(addr); \
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pagefault_enable(); \
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preempt_enable(); \
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#define kunmap_atomic(__addr) \
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do { \
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BUILD_BUG_ON(__same_type((__addr), struct page *)); \
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__kunmap_atomic(__addr); \
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pagefault_enable(); \
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preempt_enable(); \
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} while (0)
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/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
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#ifndef clear_user_highpage
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static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
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@ -872,4 +872,7 @@ config ARCH_HAS_HUGEPD
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config MAPPING_DIRTY_HELPERS
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bool
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config KMAP_LOCAL
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bool
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endmenu
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144
mm/highmem.c
144
mm/highmem.c
@ -31,9 +31,11 @@
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#include <asm/tlbflush.h>
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#include <linux/vmalloc.h>
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#ifndef CONFIG_KMAP_LOCAL
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#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
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DEFINE_PER_CPU(int, __kmap_atomic_idx);
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#endif
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#endif
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/*
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* Virtual_count is not a pure "count".
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@ -365,9 +367,147 @@ void kunmap_high(struct page *page)
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if (need_wakeup)
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wake_up(pkmap_map_wait);
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}
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EXPORT_SYMBOL(kunmap_high);
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#endif /* CONFIG_HIGHMEM */
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#endif /* CONFIG_HIGHMEM */
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#ifdef CONFIG_KMAP_LOCAL
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#include <asm/kmap_size.h>
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static DEFINE_PER_CPU(int, __kmap_local_idx);
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static inline int kmap_local_idx_push(void)
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{
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int idx = __this_cpu_inc_return(__kmap_local_idx) - 1;
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WARN_ON_ONCE(in_irq() && !irqs_disabled());
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BUG_ON(idx >= KM_MAX_IDX);
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return idx;
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}
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static inline int kmap_local_idx(void)
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{
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return __this_cpu_read(__kmap_local_idx) - 1;
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}
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static inline void kmap_local_idx_pop(void)
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{
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int idx = __this_cpu_dec_return(__kmap_local_idx);
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BUG_ON(idx < 0);
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}
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#ifndef arch_kmap_local_post_map
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# define arch_kmap_local_post_map(vaddr, pteval) do { } while (0)
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#endif
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#ifndef arch_kmap_local_pre_unmap
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# define arch_kmap_local_pre_unmap(vaddr) do { } while (0)
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#endif
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#ifndef arch_kmap_local_post_unmap
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# define arch_kmap_local_post_unmap(vaddr) do { } while (0)
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#endif
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#ifndef arch_kmap_local_map_idx
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#define arch_kmap_local_map_idx(idx, pfn) kmap_local_calc_idx(idx)
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#endif
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#ifndef arch_kmap_local_unmap_idx
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#define arch_kmap_local_unmap_idx(idx, vaddr) kmap_local_calc_idx(idx)
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#endif
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#ifndef arch_kmap_local_high_get
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static inline void *arch_kmap_local_high_get(struct page *page)
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{
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return NULL;
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}
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#endif
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/* Unmap a local mapping which was obtained by kmap_high_get() */
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static inline void kmap_high_unmap_local(unsigned long vaddr)
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{
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#ifdef ARCH_NEEDS_KMAP_HIGH_GET
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if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP))
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kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
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#endif
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}
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static inline int kmap_local_calc_idx(int idx)
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{
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return idx + KM_MAX_IDX * smp_processor_id();
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}
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static pte_t *__kmap_pte;
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static pte_t *kmap_get_pte(void)
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{
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if (!__kmap_pte)
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__kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
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return __kmap_pte;
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}
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void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
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{
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pte_t pteval, *kmap_pte = kmap_get_pte();
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unsigned long vaddr;
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int idx;
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preempt_disable();
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idx = arch_kmap_local_map_idx(kmap_local_idx_push(), pfn);
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
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BUG_ON(!pte_none(*(kmap_pte - idx)));
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pteval = pfn_pte(pfn, prot);
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set_pte_at(&init_mm, vaddr, kmap_pte - idx, pteval);
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arch_kmap_local_post_map(vaddr, pteval);
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preempt_enable();
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return (void *)vaddr;
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}
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EXPORT_SYMBOL_GPL(__kmap_local_pfn_prot);
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void *__kmap_local_page_prot(struct page *page, pgprot_t prot)
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{
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void *kmap;
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if (!PageHighMem(page))
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return page_address(page);
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/* Try kmap_high_get() if architecture has it enabled */
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kmap = arch_kmap_local_high_get(page);
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if (kmap)
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return kmap;
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return __kmap_local_pfn_prot(page_to_pfn(page), prot);
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}
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EXPORT_SYMBOL(__kmap_local_page_prot);
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void kunmap_local_indexed(void *vaddr)
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{
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unsigned long addr = (unsigned long) vaddr & PAGE_MASK;
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pte_t *kmap_pte = kmap_get_pte();
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int idx;
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if (addr < __fix_to_virt(FIX_KMAP_END) ||
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addr > __fix_to_virt(FIX_KMAP_BEGIN)) {
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WARN_ON_ONCE(addr < PAGE_OFFSET);
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/* Handle mappings which were obtained by kmap_high_get() */
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kmap_high_unmap_local(addr);
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return;
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}
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preempt_disable();
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idx = arch_kmap_local_unmap_idx(kmap_local_idx(), addr);
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WARN_ON_ONCE(addr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
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arch_kmap_local_pre_unmap(addr);
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pte_clear(&init_mm, addr, kmap_pte - idx);
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arch_kmap_local_post_unmap(addr);
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kmap_local_idx_pop();
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preempt_enable();
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}
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EXPORT_SYMBOL(kunmap_local_indexed);
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#endif
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#if defined(HASHED_PAGE_VIRTUAL)
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