powerpc/mm: add radix__remove_section_mapping()

[linux-2.6-block.git] / arch / powerpc / mm / pgtable-radix.c

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 7829e09ab4ddf5bc27ef30c8aad890b0c5f21791..aef9d49f70ce627d41e91fcf99acbdf6020ef84d 100644 (file)
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -482,10 +482,143 @@ void radix__setup_initial_memory_limit(phys_addr_t first_memblock_base,
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
+static void free_pte_table(pte_t *pte_start, pmd_t *pmd)
+{
+       pte_t *pte;
+       int i;
+
+       for (i = 0; i < PTRS_PER_PTE; i++) {
+               pte = pte_start + i;
+               if (!pte_none(*pte))
+                       return;
+       }
+
+       pte_free_kernel(&init_mm, pte_start);
+       pmd_clear(pmd);
+}
+
+static void free_pmd_table(pmd_t *pmd_start, pud_t *pud)
+{
+       pmd_t *pmd;
+       int i;
+
+       for (i = 0; i < PTRS_PER_PMD; i++) {
+               pmd = pmd_start + i;
+               if (!pmd_none(*pmd))
+                       return;
+       }
+
+       pmd_free(&init_mm, pmd_start);
+       pud_clear(pud);
+}
+
+static void remove_pte_table(pte_t *pte_start, unsigned long addr,
+                            unsigned long end)
+{
+       unsigned long next;
+       pte_t *pte;
+
+       pte = pte_start + pte_index(addr);
+       for (; addr < end; addr = next, pte++) {
+               next = (addr + PAGE_SIZE) & PAGE_MASK;
+               if (next > end)
+                       next = end;
+
+               if (!pte_present(*pte))
+                       continue;
+
+               pte_clear(&init_mm, addr, pte);
+       }
+}
+
+static void remove_pmd_table(pmd_t *pmd_start, unsigned long addr,
+                            unsigned long end)
+{
+       unsigned long next;
+       pte_t *pte_base;
+       pmd_t *pmd;
+
+       pmd = pmd_start + pmd_index(addr);
+       for (; addr < end; addr = next, pmd++) {
+               next = pmd_addr_end(addr, end);
+
+               if (!pmd_present(*pmd))
+                       continue;
+
+               if (pmd_huge(*pmd)) {
+                       pte_clear(&init_mm, addr, (pte_t *)pmd);
+                       continue;
+               }
+
+               pte_base = (pte_t *)pmd_page_vaddr(*pmd);
+               remove_pte_table(pte_base, addr, next);
+               free_pte_table(pte_base, pmd);
+       }
+}
+
+static void remove_pud_table(pud_t *pud_start, unsigned long addr,
+                            unsigned long end)
+{
+       unsigned long next;
+       pmd_t *pmd_base;
+       pud_t *pud;
+
+       pud = pud_start + pud_index(addr);
+       for (; addr < end; addr = next, pud++) {
+               next = pud_addr_end(addr, end);
+
+               if (!pud_present(*pud))
+                       continue;
+
+               if (pud_huge(*pud)) {
+                       pte_clear(&init_mm, addr, (pte_t *)pud);
+                       continue;
+               }
+
+               pmd_base = (pmd_t *)pud_page_vaddr(*pud);
+               remove_pmd_table(pmd_base, addr, next);
+               free_pmd_table(pmd_base, pud);
+       }
+}
+
+static void remove_pagetable(unsigned long start, unsigned long end)
+{
+       unsigned long addr, next;
+       pud_t *pud_base;
+       pgd_t *pgd;
+
+       spin_lock(&init_mm.page_table_lock);
+
+       for (addr = start; addr < end; addr = next) {
+               next = pgd_addr_end(addr, end);
+
+               pgd = pgd_offset_k(addr);
+               if (!pgd_present(*pgd))
+                       continue;
+
+               if (pgd_huge(*pgd)) {
+                       pte_clear(&init_mm, addr, (pte_t *)pgd);
+                       continue;
+               }
+
+               pud_base = (pud_t *)pgd_page_vaddr(*pgd);
+               remove_pud_table(pud_base, addr, next);
+       }
+
+       spin_unlock(&init_mm.page_table_lock);
+       radix__flush_tlb_kernel_range(start, end);
+}
+
 int __ref radix__create_section_mapping(unsigned long start, unsigned long end)
 {
        return create_physical_mapping(start, end);
 }
+
+int radix__remove_section_mapping(unsigned long start, unsigned long end)
+{
+       remove_pagetable(start, end);
+       return 0;
+}
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
 #ifdef CONFIG_SPARSEMEM_VMEMMAP