60e64d46a5
This patch provides the interfaces necessary to read the dump contents, treating it as a high memory device. Signed off by Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
105 lines
2.5 KiB
C
105 lines
2.5 KiB
C
#ifndef _LINUX_HIGHMEM_H
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#define _LINUX_HIGHMEM_H
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#include <linux/config.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <asm/cacheflush.h>
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#ifdef CONFIG_HIGHMEM
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#include <asm/highmem.h>
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/* declarations for linux/mm/highmem.c */
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unsigned int nr_free_highpages(void);
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#else /* CONFIG_HIGHMEM */
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static inline unsigned int nr_free_highpages(void) { return 0; }
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static inline void *kmap(struct page *page)
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{
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might_sleep();
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return page_address(page);
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}
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#define kunmap(page) do { (void) (page); } while (0)
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#define kmap_atomic(page, idx) page_address(page)
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#define kunmap_atomic(addr, idx) do { } while (0)
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#define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn))
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#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
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#endif /* CONFIG_HIGHMEM */
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/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
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static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
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{
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void *addr = kmap_atomic(page, KM_USER0);
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clear_user_page(addr, vaddr, page);
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kunmap_atomic(addr, KM_USER0);
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/* Make sure this page is cleared on other CPU's too before using it */
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smp_wmb();
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}
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#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
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static inline struct page *
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alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
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{
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struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr);
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if (page)
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clear_user_highpage(page, vaddr);
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return page;
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}
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#endif
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static inline void clear_highpage(struct page *page)
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{
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void *kaddr = kmap_atomic(page, KM_USER0);
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clear_page(kaddr);
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kunmap_atomic(kaddr, KM_USER0);
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}
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/*
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* Same but also flushes aliased cache contents to RAM.
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*/
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static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size)
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{
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void *kaddr;
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BUG_ON(offset + size > PAGE_SIZE);
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kaddr = kmap_atomic(page, KM_USER0);
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memset((char *)kaddr + offset, 0, size);
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flush_dcache_page(page);
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kunmap_atomic(kaddr, KM_USER0);
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}
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static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr)
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{
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char *vfrom, *vto;
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vfrom = kmap_atomic(from, KM_USER0);
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vto = kmap_atomic(to, KM_USER1);
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copy_user_page(vto, vfrom, vaddr, to);
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kunmap_atomic(vfrom, KM_USER0);
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kunmap_atomic(vto, KM_USER1);
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/* Make sure this page is cleared on other CPU's too before using it */
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smp_wmb();
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}
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static inline void copy_highpage(struct page *to, struct page *from)
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{
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char *vfrom, *vto;
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vfrom = kmap_atomic(from, KM_USER0);
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vto = kmap_atomic(to, KM_USER1);
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copy_page(vto, vfrom);
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kunmap_atomic(vfrom, KM_USER0);
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kunmap_atomic(vto, KM_USER1);
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}
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#endif /* _LINUX_HIGHMEM_H */
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