summaryrefslogtreecommitdiffstats
path: root/arch/x86
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/pgtable_types.h1
-rw-r--r--arch/x86/mm/init_64.c304
-rw-r--r--arch/x86/mm/pageattr.c47
3 files changed, 330 insertions, 22 deletions
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index e6423002c10..567b5d0632b 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -351,6 +351,7 @@ static inline void update_page_count(int level, unsigned long pages) { }
* as a pte too.
*/
extern pte_t *lookup_address(unsigned long address, unsigned int *level);
+extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase);
extern phys_addr_t slow_virt_to_phys(void *__address);
#endif /* !__ASSEMBLY__ */
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index f17aa76dc1a..ca6cd403a27 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -707,6 +707,310 @@ int arch_add_memory(int nid, u64 start, u64 size)
}
EXPORT_SYMBOL_GPL(arch_add_memory);
+#define PAGE_INUSE 0xFD
+
+static void __meminit free_pagetable(struct page *page, int order)
+{
+ struct zone *zone;
+ bool bootmem = false;
+ unsigned long magic;
+ unsigned int nr_pages = 1 << order;
+
+ /* bootmem page has reserved flag */
+ if (PageReserved(page)) {
+ __ClearPageReserved(page);
+ bootmem = true;
+
+ magic = (unsigned long)page->lru.next;
+ if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
+ while (nr_pages--)
+ put_page_bootmem(page++);
+ } else
+ __free_pages_bootmem(page, order);
+ } else
+ free_pages((unsigned long)page_address(page), order);
+
+ /*
+ * SECTION_INFO pages and MIX_SECTION_INFO pages
+ * are all allocated by bootmem.
+ */
+ if (bootmem) {
+ zone = page_zone(page);
+ zone_span_writelock(zone);
+ zone->present_pages += nr_pages;
+ zone_span_writeunlock(zone);
+ totalram_pages += nr_pages;
+ }
+}
+
+static void __meminit 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_val(*pte))
+ return;
+ }
+
+ /* free a pte talbe */
+ free_pagetable(pmd_page(*pmd), 0);
+ spin_lock(&init_mm.page_table_lock);
+ pmd_clear(pmd);
+ spin_unlock(&init_mm.page_table_lock);
+}
+
+static void __meminit 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_val(*pmd))
+ return;
+ }
+
+ /* free a pmd talbe */
+ free_pagetable(pud_page(*pud), 0);
+ spin_lock(&init_mm.page_table_lock);
+ pud_clear(pud);
+ spin_unlock(&init_mm.page_table_lock);
+}
+
+/* Return true if pgd is changed, otherwise return false. */
+static bool __meminit 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_val(*pud))
+ return false;
+ }
+
+ /* free a pud table */
+ free_pagetable(pgd_page(*pgd), 0);
+ spin_lock(&init_mm.page_table_lock);
+ pgd_clear(pgd);
+ spin_unlock(&init_mm.page_table_lock);
+
+ return true;
+}
+
+static void __meminit
+remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
+ bool direct)
+{
+ unsigned long next, pages = 0;
+ pte_t *pte;
+ void *page_addr;
+ phys_addr_t phys_addr;
+
+ 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;
+
+ /*
+ * We mapped [0,1G) memory as identity mapping when
+ * initializing, in arch/x86/kernel/head_64.S. These
+ * pagetables cannot be removed.
+ */
+ phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
+ if (phys_addr < (phys_addr_t)0x40000000)
+ return;
+
+ if (IS_ALIGNED(addr, PAGE_SIZE) &&
+ IS_ALIGNED(next, PAGE_SIZE)) {
+ /*
+ * Do not free direct mapping pages since they were
+ * freed when offlining, or simplely not in use.
+ */
+ if (!direct)
+ free_pagetable(pte_page(*pte), 0);
+
+ spin_lock(&init_mm.page_table_lock);
+ pte_clear(&init_mm, addr, pte);
+ spin_unlock(&init_mm.page_table_lock);
+
+ /* For non-direct mapping, pages means nothing. */
+ pages++;
+ } else {
+ /*
+ * If we are here, we are freeing vmemmap pages since
+ * direct mapped memory ranges to be freed are aligned.
+ *
+ * If we are not removing the whole page, it means
+ * other page structs in this page are being used and
+ * we canot remove them. So fill the unused page_structs
+ * with 0xFD, and remove the page when it is wholly
+ * filled with 0xFD.
+ */
+ memset((void *)addr, PAGE_INUSE, next - addr);
+
+ page_addr = page_address(pte_page(*pte));
+ if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
+ free_pagetable(pte_page(*pte), 0);
+
+ spin_lock(&init_mm.page_table_lock);
+ pte_clear(&init_mm, addr, pte);
+ spin_unlock(&init_mm.page_table_lock);
+ }
+ }
+ }
+
+ /* Call free_pte_table() in remove_pmd_table(). */
+ flush_tlb_all();
+ if (direct)
+ update_page_count(PG_LEVEL_4K, -pages);
+}
+
+static void __meminit
+remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
+ bool direct)
+{
+ unsigned long next, pages = 0;
+ pte_t *pte_base;
+ pmd_t *pmd;
+ void *page_addr;
+
+ 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_large(*pmd)) {
+ if (IS_ALIGNED(addr, PMD_SIZE) &&
+ IS_ALIGNED(next, PMD_SIZE)) {
+ if (!direct)
+ free_pagetable(pmd_page(*pmd),
+ get_order(PMD_SIZE));
+
+ spin_lock(&init_mm.page_table_lock);
+ pmd_clear(pmd);
+ spin_unlock(&init_mm.page_table_lock);
+ pages++;
+ } else {
+ /* If here, we are freeing vmemmap pages. */
+ memset((void *)addr, PAGE_INUSE, next - addr);
+
+ page_addr = page_address(pmd_page(*pmd));
+ if (!memchr_inv(page_addr, PAGE_INUSE,
+ PMD_SIZE)) {
+ free_pagetable(pmd_page(*pmd),
+ get_order(PMD_SIZE));
+
+ spin_lock(&init_mm.page_table_lock);
+ pmd_clear(pmd);
+ spin_unlock(&init_mm.page_table_lock);
+ }
+ }
+
+ continue;
+ }
+
+ pte_base = (pte_t *)pmd_page_vaddr(*pmd);
+ remove_pte_table(pte_base, addr, next, direct);
+ free_pte_table(pte_base, pmd);
+ }
+
+ /* Call free_pmd_table() in remove_pud_table(). */
+ if (direct)
+ update_page_count(PG_LEVEL_2M, -pages);
+}
+
+static void __meminit
+remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
+ bool direct)
+{
+ unsigned long next, pages = 0;
+ pmd_t *pmd_base;
+ pud_t *pud;
+ void *page_addr;
+
+ 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_large(*pud)) {
+ if (IS_ALIGNED(addr, PUD_SIZE) &&
+ IS_ALIGNED(next, PUD_SIZE)) {
+ if (!direct)
+ free_pagetable(pud_page(*pud),
+ get_order(PUD_SIZE));
+
+ spin_lock(&init_mm.page_table_lock);
+ pud_clear(pud);
+ spin_unlock(&init_mm.page_table_lock);
+ pages++;
+ } else {
+ /* If here, we are freeing vmemmap pages. */
+ memset((void *)addr, PAGE_INUSE, next - addr);
+
+ page_addr = page_address(pud_page(*pud));
+ if (!memchr_inv(page_addr, PAGE_INUSE,
+ PUD_SIZE)) {
+ free_pagetable(pud_page(*pud),
+ get_order(PUD_SIZE));
+
+ spin_lock(&init_mm.page_table_lock);
+ pud_clear(pud);
+ spin_unlock(&init_mm.page_table_lock);
+ }
+ }
+
+ continue;
+ }
+
+ pmd_base = (pmd_t *)pud_page_vaddr(*pud);
+ remove_pmd_table(pmd_base, addr, next, direct);
+ free_pmd_table(pmd_base, pud);
+ }
+
+ if (direct)
+ update_page_count(PG_LEVEL_1G, -pages);
+}
+
+/* start and end are both virtual address. */
+static void __meminit
+remove_pagetable(unsigned long start, unsigned long end, bool direct)
+{
+ unsigned long next;
+ pgd_t *pgd;
+ pud_t *pud;
+ bool pgd_changed = false;
+
+ for (; start < end; start = next) {
+ next = pgd_addr_end(start, end);
+
+ pgd = pgd_offset_k(start);
+ if (!pgd_present(*pgd))
+ continue;
+
+ pud = (pud_t *)pgd_page_vaddr(*pgd);
+ remove_pud_table(pud, start, next, direct);
+ if (free_pud_table(pud, pgd))
+ pgd_changed = true;
+ }
+
+ if (pgd_changed)
+ sync_global_pgds(start, end - 1);
+
+ flush_tlb_all();
+}
+
#ifdef CONFIG_MEMORY_HOTREMOVE
int __ref arch_remove_memory(u64 start, u64 size)
{
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index a1b1c88f9ca..ca1f1c2bb7b 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -529,21 +529,13 @@ out_unlock:
return do_split;
}
-static int split_large_page(pte_t *kpte, unsigned long address)
+int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase)
{
unsigned long pfn, pfninc = 1;
unsigned int i, level;
- pte_t *pbase, *tmp;
+ pte_t *tmp;
pgprot_t ref_prot;
- struct page *base;
-
- if (!debug_pagealloc)
- spin_unlock(&cpa_lock);
- base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
- if (!debug_pagealloc)
- spin_lock(&cpa_lock);
- if (!base)
- return -ENOMEM;
+ struct page *base = virt_to_page(pbase);
spin_lock(&pgd_lock);
/*
@@ -551,10 +543,11 @@ static int split_large_page(pte_t *kpte, unsigned long address)
* up for us already:
*/
tmp = lookup_address(address, &level);
- if (tmp != kpte)
- goto out_unlock;
+ if (tmp != kpte) {
+ spin_unlock(&pgd_lock);
+ return 1;
+ }
- pbase = (pte_t *)page_address(base);
paravirt_alloc_pte(&init_mm, page_to_pfn(base));
ref_prot = pte_pgprot(pte_clrhuge(*kpte));
/*
@@ -601,17 +594,27 @@ static int split_large_page(pte_t *kpte, unsigned long address)
* going on.
*/
__flush_tlb_all();
+ spin_unlock(&pgd_lock);
- base = NULL;
+ return 0;
+}
-out_unlock:
- /*
- * If we dropped out via the lookup_address check under
- * pgd_lock then stick the page back into the pool:
- */
- if (base)
+static int split_large_page(pte_t *kpte, unsigned long address)
+{
+ pte_t *pbase;
+ struct page *base;
+
+ if (!debug_pagealloc)
+ spin_unlock(&cpa_lock);
+ base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
+ if (!debug_pagealloc)
+ spin_lock(&cpa_lock);
+ if (!base)
+ return -ENOMEM;
+
+ pbase = (pte_t *)page_address(base);
+ if (__split_large_page(kpte, address, pbase))
__free_page(base);
- spin_unlock(&pgd_lock);
return 0;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-27 15:51:59 +0000