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Subject[PATCH -v2 01/13] x86, mm: Add global page_size_mask
Date
detect if need to use 1G or 2M and store them in page_size_mask.

Only probe them one time.

Suggested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
arch/x86/include/asm/pgtable.h | 1 +
arch/x86/kernel/setup.c | 1 +
arch/x86/mm/init.c | 66 +++++++++++++++++++---------------------
3 files changed, 33 insertions(+), 35 deletions(-)
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 49afb3f..e47e4db 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -597,6 +597,7 @@ static inline int pgd_none(pgd_t pgd)
#ifndef __ASSEMBLY__

extern int direct_gbpages;
+void probe_page_size_mask(void);

/* local pte updates need not use xchg for locking */
static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index f4b9b80..d6e8c03 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -912,6 +912,7 @@ void __init setup_arch(char **cmdline_p)
setup_real_mode();

init_gbpages();
+ probe_page_size_mask();

/* max_pfn_mapped is updated here */
max_low_pfn_mapped = init_memory_mapping(0, max_low_pfn<<PAGE_SHIFT);
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index e0e6990..838e9bc 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -35,8 +35,10 @@ struct map_range {
unsigned page_size_mask;
};

-static void __init find_early_table_space(struct map_range *mr, unsigned long end,
- int use_pse, int use_gbpages)
+static int page_size_mask;
+
+static void __init find_early_table_space(struct map_range *mr,
+ unsigned long end)
{
unsigned long puds, pmds, ptes, tables, start = 0, good_end = end;
phys_addr_t base;
@@ -44,7 +46,7 @@ static void __init find_early_table_space(struct map_range *mr, unsigned long en
puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);

- if (use_gbpages) {
+ if (page_size_mask & (1 << PG_LEVEL_1G)) {
unsigned long extra;

extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
@@ -54,7 +56,7 @@ static void __init find_early_table_space(struct map_range *mr, unsigned long en

tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);

- if (use_pse) {
+ if (page_size_mask & (1 << PG_LEVEL_2M)) {
unsigned long extra;

extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
@@ -90,6 +92,30 @@ static void __init find_early_table_space(struct map_range *mr, unsigned long en
(pgt_buf_top << PAGE_SHIFT) - 1);
}

+void probe_page_size_mask(void)
+{
+#if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK)
+ /*
+ * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
+ * This will simplify cpa(), which otherwise needs to support splitting
+ * large pages into small in interrupt context, etc.
+ */
+ if (direct_gbpages)
+ page_size_mask |= 1 << PG_LEVEL_1G;
+ if (cpu_has_pse)
+ page_size_mask |= 1 << PG_LEVEL_2M;
+#endif
+
+ /* Enable PSE if available */
+ if (cpu_has_pse)
+ set_in_cr4(X86_CR4_PSE);
+
+ /* Enable PGE if available */
+ if (cpu_has_pge) {
+ set_in_cr4(X86_CR4_PGE);
+ __supported_pte_mask |= _PAGE_GLOBAL;
+ }
+}
void __init native_pagetable_reserve(u64 start, u64 end)
{
memblock_reserve(start, end - start);
@@ -125,45 +151,15 @@ static int __meminit save_mr(struct map_range *mr, int nr_range,
unsigned long __init_refok init_memory_mapping(unsigned long start,
unsigned long end)
{
- unsigned long page_size_mask = 0;
unsigned long start_pfn, end_pfn;
unsigned long ret = 0;
unsigned long pos;
-
struct map_range mr[NR_RANGE_MR];
int nr_range, i;
- int use_pse, use_gbpages;

printk(KERN_INFO "init_memory_mapping: [mem %#010lx-%#010lx]\n",
start, end - 1);

-#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
- /*
- * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
- * This will simplify cpa(), which otherwise needs to support splitting
- * large pages into small in interrupt context, etc.
- */
- use_pse = use_gbpages = 0;
-#else
- use_pse = cpu_has_pse;
- use_gbpages = direct_gbpages;
-#endif
-
- /* Enable PSE if available */
- if (cpu_has_pse)
- set_in_cr4(X86_CR4_PSE);
-
- /* Enable PGE if available */
- if (cpu_has_pge) {
- set_in_cr4(X86_CR4_PGE);
- __supported_pte_mask |= _PAGE_GLOBAL;
- }
-
- if (use_gbpages)
- page_size_mask |= 1 << PG_LEVEL_1G;
- if (use_pse)
- page_size_mask |= 1 << PG_LEVEL_2M;
-
memset(mr, 0, sizeof(mr));
nr_range = 0;

@@ -267,7 +263,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
* nodes are discovered.
*/
if (!after_bootmem)
- find_early_table_space(&mr[0], end, use_pse, use_gbpages);
+ find_early_table_space(&mr[0], end);

for (i = 0; i < nr_range; i++)
ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
--
1.7.7


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