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Subject[PATCH v7u1 09/31] x86, 64bit: #PF handler set page to cover 2M only
Date
Now #PF hanlder could map 1G per #PF, That causes same problem that
is fixed by
x86, mm: Only direct map addresses that are marked as E820_RAM

only add one 2M mapping instead of 1G accessing one time for dynamically
per #PF.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
---
arch/x86/kernel/head64.c | 42 +++++++++++++++++++++++++-----------------
1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 25591f9..a3fc233 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -52,15 +52,15 @@ int __init early_make_pgtable(unsigned long address)
unsigned long physaddr = address - __PAGE_OFFSET;
unsigned long i;
pgdval_t pgd, *pgd_p;
- pudval_t *pud_p;
+ pudval_t pud, *pud_p;
pmdval_t pmd, *pmd_p;

/* Invalid address or early pgt is done ? */
if (physaddr >= MAXMEM || read_cr3() != __pa(early_level4_pgt))
return -1;

- i = (address >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1);
- pgd_p = &early_level4_pgt[i].pgd;
+again:
+ pgd_p = &early_level4_pgt[pgd_index(address)].pgd;
pgd = *pgd_p;

/*
@@ -68,29 +68,37 @@ int __init early_make_pgtable(unsigned long address)
* critical -- __PAGE_OFFSET would point us back into the dynamic
* range and we might end up looping forever...
*/
- if (pgd && next_early_pgt < EARLY_DYNAMIC_PAGE_TABLES) {
+ if (pgd)
pud_p = (pudval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
- } else {
- if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES-1)
+ else {
+ if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
reset_early_page_tables();
+ goto again;
+ }

pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++];
for (i = 0; i < PTRS_PER_PUD; i++)
pud_p[i] = 0;
-
*pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
}
- i = (address >> PUD_SHIFT) & (PTRS_PER_PUD - 1);
- pud_p += i;
-
- pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++];
- pmd = (physaddr & PUD_MASK) + (__PAGE_KERNEL_LARGE & ~_PAGE_GLOBAL);
- for (i = 0; i < PTRS_PER_PMD; i++) {
- pmd_p[i] = pmd;
- pmd += PMD_SIZE;
- }
+ pud_p += pud_index(address);
+ pud = *pud_p;

- *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
+ if (pud)
+ pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
+ else {
+ if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
+ reset_early_page_tables();
+ goto again;
+ }
+
+ pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++];
+ for (i = 0; i < PTRS_PER_PMD; i++)
+ pmd_p[i] = 0;
+ *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
+ }
+ pmd = (physaddr & PMD_MASK) + (__PAGE_KERNEL_LARGE & ~_PAGE_GLOBAL);
+ pmd_p[pmd_index(address)] = pmd;

return 0;
}
--
1.7.10.4


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