Messages in this thread Patch in this message | | | Date | Wed, 15 Sep 2004 18:24:22 +0530 | From | Hariprasad Nellitheertha <> | Subject | Re: [PATCH][3/6]Routines for copying the dump pages |
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Regards, Hari -- Hariprasad Nellitheertha Linux Technology Center India Software Labs IBM India, Bangalore
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>
---
linux-2.6.9-rc1-hari/arch/i386/mm/highmem.c | 18 +++++++++++++ linux-2.6.9-rc1-hari/include/asm-i386/highmem.h | 1 linux-2.6.9-rc1-hari/include/linux/highmem.h | 31 ++++++++++++++++++++++++ 3 files changed, 50 insertions(+)
diff -puN arch/i386/mm/highmem.c~kd-copy-269rc1-mm5 arch/i386/mm/highmem.c --- linux-2.6.9-rc1/arch/i386/mm/highmem.c~kd-copy-269rc1-mm5 2004-09-15 17:36:33.000000000 +0530 +++ linux-2.6.9-rc1-hari/arch/i386/mm/highmem.c 2004-09-15 17:36:33.000000000 +0530 @@ -74,6 +74,24 @@ void kunmap_atomic(void *kvaddr, enum km preempt_check_resched(); } +/* This is the same as kmap_atomic() but can map memory that doesn't + * have a struct page associated with it. + */ +void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) +{ + enum fixed_addresses idx; + unsigned long vaddr; + + inc_preempt_count(); + + idx = type + KM_TYPE_NR*smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot)); + __flush_tlb_one(vaddr); + + return (void*) vaddr; +} + struct page *kmap_atomic_to_page(void *ptr) { unsigned long idx, vaddr = (unsigned long)ptr; diff -puN include/asm-i386/highmem.h~kd-copy-269rc1-mm5 include/asm-i386/highmem.h --- linux-2.6.9-rc1/include/asm-i386/highmem.h~kd-copy-269rc1-mm5 2004-09-15 17:36:33.000000000 +0530 +++ linux-2.6.9-rc1-hari/include/asm-i386/highmem.h 2004-09-15 17:36:33.000000000 +0530 @@ -61,6 +61,7 @@ void *kmap(struct page *page); void kunmap(struct page *page); void *kmap_atomic(struct page *page, enum km_type type); void kunmap_atomic(void *kvaddr, enum km_type type); +void *kmap_atomic_pfn(unsigned long pfn, enum km_type type); struct page *kmap_atomic_to_page(void *ptr); #define flush_cache_kmaps() do { } while (0) diff -puN include/linux/highmem.h~kd-copy-269rc1-mm5 include/linux/highmem.h --- linux-2.6.9-rc1/include/linux/highmem.h~kd-copy-269rc1-mm5 2004-09-15 17:36:33.000000000 +0530 +++ linux-2.6.9-rc1-hari/include/linux/highmem.h 2004-09-15 17:36:33.000000000 +0530 @@ -6,6 +6,7 @@ #include <linux/mm.h> #include <asm/cacheflush.h> +#include <asm/uaccess.h> #ifdef CONFIG_HIGHMEM @@ -30,6 +31,7 @@ static inline void *kmap(struct page *pa #define kmap_atomic(page, idx) page_address(page) #define kunmap_atomic(addr, idx) do { } while (0) +#define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn)) #define kmap_atomic_to_page(ptr) virt_to_page(ptr) #endif /* CONFIG_HIGHMEM */ @@ -86,4 +88,33 @@ static inline void copy_highpage(struct kunmap_atomic(vto, KM_USER1); } +/* + * Copy a page from "oldmem". For this page, there is no pte mapped + * in the current kernel. We stitch up a pte, similar to kmap_atomic. + */ +static inline ssize_t copy_oldmem_page(unsigned long pfn, + char *buf, size_t csize, int userbuf) +{ + void *page, *vaddr; + + if (!csize) + return 0; + + page = kmalloc(PAGE_SIZE, GFP_KERNEL); + + vaddr = kmap_atomic_pfn(pfn, KM_PTE0); + copy_page(page, vaddr); + kunmap_atomic(vaddr, KM_PTE0); + + if (userbuf) { + if (copy_to_user(buf, page, csize)) { + kfree(page); + return -EFAULT; + } + } else + memcpy(buf, page, csize); + kfree(page); + + return 0; +} #endif /* _LINUX_HIGHMEM_H */ _
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