Tear down and free the four-level page tables of the linear mapping
during memory hotremove.
We borrow the basic structure of remove_pagetable() and friends from the
identically-named x86 functions.
Signed-off-by: Reza Arbab <ar...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/book3s/64/radix.h | 1 +
arch/powerpc/mm/pgtable-book3s64.c | 2 +-
arch/powerpc/mm/pgtable-radix.c | 163 +++++++++++++++++++++++++++++
3 files changed, 165 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/book3s/64/radix.h
b/arch/powerpc/include/asm/book3s/64/radix.h
index 43c2571..0032b66 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -294,6 +294,7 @@ static inline unsigned long radix__get_tree_size(void)
#ifdef CONFIG_MEMORY_HOTPLUG
int radix__create_section_mapping(unsigned long start, unsigned long end);
+int radix__remove_section_mapping(unsigned long start, unsigned long end);
#endif /* CONFIG_MEMORY_HOTPLUG */
#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/powerpc/mm/pgtable-book3s64.c
b/arch/powerpc/mm/pgtable-book3s64.c
index 2b13f6b..b798ff6 100644
--- a/arch/powerpc/mm/pgtable-book3s64.c
+++ b/arch/powerpc/mm/pgtable-book3s64.c
@@ -139,7 +139,7 @@ int create_section_mapping(unsigned long start, unsigned
long end)
int remove_section_mapping(unsigned long start, unsigned long end)
{
if (radix_enabled())
- return -ENODEV;
+ return radix__remove_section_mapping(start, end);
return hash__remove_section_mapping(start, end);
}
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 8201d1f..315237c 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -466,6 +466,159 @@ 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);
+ spin_lock(&init_mm.page_table_lock);
+ pmd_clear(pmd);
+ spin_unlock(&init_mm.page_table_lock);
+}
+
+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);
+ spin_lock(&init_mm.page_table_lock);
+ pud_clear(pud);
+ spin_unlock(&init_mm.page_table_lock);
+}
+
+static void free_pud_table(pud_t *pud_start, pgd_t *pgd)
+{
+ pud_t *pud;
+ int i;
+
+ for (i = 0; i < PTRS_PER_PUD; i++) {
+ pud = pud_start + i;
+ if (!pud_none(*pud))
+ return;
+ }
+
+ pud_free(&init_mm, pud_start);
+ spin_lock(&init_mm.page_table_lock);
+ pgd_clear(pgd);
+ spin_unlock(&init_mm.page_table_lock);
+}
+
+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;
+
+ spin_lock(&init_mm.page_table_lock);
+ pte_clear(&init_mm, addr, pte);
+ spin_unlock(&init_mm.page_table_lock);
+ }
+
+ flush_tlb_mm(&init_mm);
+}
+
+static void remove_pmd_table(pmd_t *pmd_start, unsigned long addr,
+ unsigned long end, unsigned long map_page_size)
+{
+ 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 (map_page_size == PMD_SIZE) {
+ spin_lock(&init_mm.page_table_lock);
+ pte_clear(&init_mm, addr, (pte_t *)pmd);
+ spin_unlock(&init_mm.page_table_lock);
+
+ 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 map_page_size)
+{
+ 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 (map_page_size == PUD_SIZE) {
+ spin_lock(&init_mm.page_table_lock);
+ pte_clear(&init_mm, addr, (pte_t *)pud);
+ spin_unlock(&init_mm.page_table_lock);
+
+ continue;
+ }
+
+ pmd_base = (pmd_t *)pud_page_vaddr(*pud);
+ remove_pmd_table(pmd_base, addr, next, map_page_size);
+ free_pmd_table(pmd_base, pud);
+ }
+}
+
+static void remove_pagetable(unsigned long start, unsigned long end,
+ unsigned long map_page_size)
+{
+ unsigned long next;
+ unsigned long addr;
+ pgd_t *pgd;
+ pud_t *pud;
+
+ for (addr = start; addr < end; addr = next) {
+ next = pgd_addr_end(addr, end);
+
+ pgd = pgd_offset_k(addr);
+ if (!pgd_present(*pgd))
+ continue;
+
+ pud = (pud_t *)pgd_page_vaddr(*pgd);
+ remove_pud_table(pud, addr, next, map_page_size);
+ free_pud_table(pud, pgd);
+ }
+
+ flush_tlb_mm(&init_mm);
+}
+
int radix__create_section_mapping(unsigned long start, unsigned long end)
{
unsigned long page_size = 1 << mmu_psize_defs[mmu_linear_psize].shift;
@@ -482,6 +635,16 @@ int radix__create_section_mapping(unsigned long start,
unsigned long end)
return 0;
}
+
+int radix__remove_section_mapping(unsigned long start, unsigned long end)
+{
+ unsigned long page_size = 1 << mmu_psize_defs[mmu_linear_psize].shift;
+
+ start = _ALIGN_DOWN(start, page_size);
+ remove_pagetable(start, end, page_size);
+
+ return 0;
+}
#endif /* CONFIG_MEMORY_HOTPLUG */
#ifdef CONFIG_SPARSEMEM_VMEMMAP
--
1.8.3.1
