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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2007-04-21 10:21:28 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2007-04-21 20:35:55 +0100
commit24e6c6996fb6e0e716c1dda1def1bb023a0fe43b (patch)
tree91e507dd9a071d7e6d68bd06120f6538c92b1cec /arch
parent4a56c1e41f19393577bdd5c774c289c199b7269d (diff)
downloadlinux-24e6c6996fb6e0e716c1dda1def1bb023a0fe43b.tar.gz
[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 <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mm/mmu.c114
1 files changed, 55 insertions, 59 deletions
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 32139800d93..5821e67cf8c 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);
}
/*