Messages in this thread Patch in this message | | | Date | Fri, 24 Sep 2004 23:58:16 -0700 | From | William Lee Irwin III <> | Subject | [vm 1/76] introduce remap_pfn_range() |
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This patch introduces remap_pfn_range(), destined to replace remap_page_range(). In the sequel, the callers of remap_page_range() will be converted one at a time.
By using a pfn to specify its physical address argument, remap_pfn_range() resolves a longstanding physical address overflow issue.
Index: mm3-2.6.9-rc2/include/linux/mm.h =================================================================== --- mm3-2.6.9-rc2.orig/include/linux/mm.h 2004-09-24 19:17:00.863688360 -0700 +++ mm3-2.6.9-rc2/include/linux/mm.h 2004-09-24 22:01:48.366559448 -0700 @@ -856,8 +856,15 @@ extern struct page * vmalloc_to_page(void *addr); extern struct page * follow_page(struct mm_struct *mm, unsigned long address, int write); -extern int remap_page_range(struct vm_area_struct *vma, unsigned long from, - unsigned long to, unsigned long size, pgprot_t prot); +int remap_pfn_range(struct vm_area_struct *, unsigned long, + unsigned long, unsigned long, pgprot_t); + +static inline +int remap_page_range(struct vm_area_struct *vma, unsigned long uvaddr, + unsigned long paddr, unsigned long size, pgprot_t prot) +{ + return remap_pfn_range(vma, uvaddr, paddr >> PAGE_SHIFT, size, prot); +} #ifdef CONFIG_PROC_FS void __vm_stat_account(struct mm_struct *, unsigned long, struct file *, long); Index: mm3-2.6.9-rc2/mm/memory.c =================================================================== --- mm3-2.6.9-rc2.orig/mm/memory.c 2004-09-24 17:37:15.000000000 -0700 +++ mm3-2.6.9-rc2/mm/memory.c 2004-09-24 21:58:50.300629584 -0700 @@ -945,16 +945,14 @@ * in null mappings (currently treated as "copy-on-access") */ static inline void remap_pte_range(pte_t * pte, unsigned long address, unsigned long size, - unsigned long phys_addr, pgprot_t prot) + unsigned long pfn, pgprot_t prot) { unsigned long end; - unsigned long pfn; address &= ~PMD_MASK; end = address + size; if (end > PMD_SIZE) end = PMD_SIZE; - pfn = phys_addr >> PAGE_SHIFT; do { BUG_ON(!pte_none(*pte)); if (!pfn_valid(pfn) || PageReserved(pfn_to_page(pfn))) @@ -966,7 +964,7 @@ } static inline int remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size, - unsigned long phys_addr, pgprot_t prot) + unsigned long pfn, pgprot_t prot) { unsigned long base, end; @@ -975,12 +973,12 @@ end = address + size; if (end > PGDIR_SIZE) end = PGDIR_SIZE; - phys_addr -= address; + pfn -= address >> PAGE_SHIFT; do { pte_t * pte = pte_alloc_map(mm, pmd, base + address); if (!pte) return -ENOMEM; - remap_pte_range(pte, base + address, end - address, address + phys_addr, prot); + remap_pte_range(pte, base + address, end - address, pfn + (address >> PAGE_SHIFT), prot); pte_unmap(pte); address = (address + PMD_SIZE) & PMD_MASK; pmd++; @@ -989,7 +987,7 @@ } /* Note: this is only safe if the mm semaphore is held when called. */ -int remap_page_range(struct vm_area_struct *vma, unsigned long from, unsigned long phys_addr, unsigned long size, pgprot_t prot) +int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot) { int error = 0; pgd_t * dir; @@ -997,7 +995,7 @@ unsigned long end = from + size; struct mm_struct *mm = vma->vm_mm; - phys_addr -= from; + pfn -= from >> PAGE_SHIFT; dir = pgd_offset(mm, from); flush_cache_range(vma, beg, end); if (from >= end) @@ -1009,7 +1007,7 @@ error = -ENOMEM; if (!pmd) break; - error = remap_pmd_range(mm, pmd, from, end - from, phys_addr + from, prot); + error = remap_pmd_range(mm, pmd, from, end - from, pfn + (from >> PAGE_SHIFT), prot); if (error) break; from = (from + PGDIR_SIZE) & PGDIR_MASK; @@ -1022,8 +1020,7 @@ spin_unlock(&mm->page_table_lock); return error; } - -EXPORT_SYMBOL(remap_page_range); +EXPORT_SYMBOL(remap_pfn_range); /* * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when Index: mm3-2.6.9-rc2/mm/nommu.c =================================================================== --- mm3-2.6.9-rc2.orig/mm/nommu.c 2004-09-24 02:10:30.000000000 -0700 +++ mm3-2.6.9-rc2/mm/nommu.c 2004-09-24 22:06:16.400812048 -0700 @@ -560,7 +560,7 @@ return NULL; } -int remap_page_range(struct vm_area_struct *vma, unsigned long from, +int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long to, unsigned long size, pgprot_t prot) { return -EPERM; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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