From 24e6c6996fb6e0e716c1dda1def1bb023a0fe43b Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 21 Apr 2007 10:21:28 +0100 Subject: [PATCH] [ARM] mm 4: make create_mapping() more conventional Rather than our three separate loops to setup mappings (by page mappings up to a section boundary, then section mappings, and the remainder by page mappings) convert this to a more conventional Linux style of a loop over each page table level. Signed-off-by: Russell King --- arch/arm/mm/mmu.c | 114 ++++++++++++++++++++++------------------------ 1 file changed, 55 insertions(+), 59 deletions(-) diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 32139800d939..5821e67cf8c2 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -380,45 +380,55 @@ static void __init build_mem_type_table(void) #define vectors_base() (vectors_high() ? 0xffff0000 : 0) -/* - * Create a SECTION PGD between VIRT and PHYS in domain - * DOMAIN with protection PROT. This operates on half- - * pgdir entry increments. - */ -static inline void -alloc_init_section(unsigned long virt, unsigned long phys, int prot) +static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, + unsigned long end, unsigned long pfn, + const struct mem_type *type) { - pmd_t *pmdp = pmd_off_k(virt); + pte_t *pte; - if (virt & (1 << 20)) - pmdp++; + if (pmd_none(*pmd)) { + pte = alloc_bootmem_low_pages(2 * PTRS_PER_PTE * sizeof(pte_t)); + __pmd_populate(pmd, __pa(pte) | type->prot_l1); + } - *pmdp = __pmd(phys | prot); - flush_pmd_entry(pmdp); + pte = pte_offset_kernel(pmd, addr); + do { + set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 0); + pfn++; + } while (pte++, addr += PAGE_SIZE, addr != end); } -/* - * Add a PAGE mapping between VIRT and PHYS in domain - * DOMAIN with protection PROT. Note that due to the - * way we map the PTEs, we must allocate two PTE_SIZE'd - * blocks - one for the Linux pte table, and one for - * the hardware pte table. - */ -static inline void -alloc_init_page(unsigned long virt, unsigned long phys, const struct mem_type *type) +static void __init alloc_init_section(pgd_t *pgd, unsigned long addr, + unsigned long end, unsigned long phys, + const struct mem_type *type) { - pmd_t *pmdp = pmd_off_k(virt); - pte_t *ptep; + pmd_t *pmd = pmd_offset(pgd, addr); - if (pmd_none(*pmdp)) { - ptep = alloc_bootmem_low_pages(2 * PTRS_PER_PTE * - sizeof(pte_t)); + /* + * Try a section mapping - end, addr and phys must all be aligned + * to a section boundary. Note that PMDs refer to the individual + * L1 entries, whereas PGDs refer to a group of L1 entries making + * up one logical pointer to an L2 table. + */ + if (((addr | end | phys) & ~SECTION_MASK) == 0) { + pmd_t *p = pmd; - __pmd_populate(pmdp, __pa(ptep) | type->prot_l1); - } - ptep = pte_offset_kernel(pmdp, virt); + if (addr & SECTION_SIZE) + pmd++; + + do { + *pmd = __pmd(phys | type->prot_sect); + phys += SECTION_SIZE; + } while (pmd++, addr += SECTION_SIZE, addr != end); - set_pte_ext(ptep, pfn_pte(phys >> PAGE_SHIFT, __pgprot(type->prot_pte)), 0); + flush_pmd_entry(p); + } else { + /* + * No need to loop; pte's aren't interested in the + * individual L1 entries. + */ + alloc_init_pte(pmd, addr, end, __phys_to_pfn(phys), type); + } } static void __init create_36bit_mapping(struct map_desc *md, @@ -488,9 +498,9 @@ static void __init create_36bit_mapping(struct map_desc *md, */ void __init create_mapping(struct map_desc *md) { - unsigned long virt, length; - unsigned long off = (u32)__pfn_to_phys(md->pfn); + unsigned long phys, addr, length, end; const struct mem_type *type; + pgd_t *pgd; if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) { printk(KERN_WARNING "BUG: not creating mapping for " @@ -516,41 +526,27 @@ void __init create_mapping(struct map_desc *md) return; } - virt = md->virtual; - off -= virt; - length = md->length; + addr = md->virtual; + phys = (unsigned long)__pfn_to_phys(md->pfn); + length = PAGE_ALIGN(md->length); - if (type->prot_l1 == 0 && - (virt & 0xfffff || (virt + off) & 0xfffff || (virt + length) & 0xfffff)) { + if (type->prot_l1 == 0 && ((addr | phys | length) & ~SECTION_MASK)) { printk(KERN_WARNING "BUG: map for 0x%08lx at 0x%08lx can not " "be mapped using pages, ignoring.\n", - __pfn_to_phys(md->pfn), md->virtual); + __pfn_to_phys(md->pfn), addr); return; } - while ((virt & 0xfffff || (virt + off) & 0xfffff) && length >= PAGE_SIZE) { - alloc_init_page(virt, virt + off, type); - - virt += PAGE_SIZE; - length -= PAGE_SIZE; - } - - /* - * A section mapping covers half a "pgdir" entry. - */ - while (length >= (PGDIR_SIZE / 2)) { - alloc_init_section(virt, virt + off, type->prot_sect); - - virt += (PGDIR_SIZE / 2); - length -= (PGDIR_SIZE / 2); - } + pgd = pgd_offset_k(addr); + end = addr + length; + do { + unsigned long next = pgd_addr_end(addr, end); - while (length >= PAGE_SIZE) { - alloc_init_page(virt, virt + off, type); + alloc_init_section(pgd, addr, next, phys, type); - virt += PAGE_SIZE; - length -= PAGE_SIZE; - } + phys += next - addr; + addr = next; + } while (pgd++, addr != end); } /* -- 2.30.2