Implement pud_free_pmd_page() and pmd_free_pte_page().
Implementation requires,
1) Clearing off the current pud/pmd entry
2) Invalidate TLB which could have previously
valid but not stale entry
3) Freeing of the un-used next level page tables
Signed-off-by: Chintan Pandya <[email protected]>
---
arch/arm64/mm/mmu.c | 38 ++++++++++++++++++++++++++++++++++----
1 file changed, 34 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index da98828..5f2da5c 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -45,6 +45,7 @@
#include <asm/memblock.h>
#include <asm/mmu_context.h>
#include <asm/ptdump.h>
+#include <asm/tlbflush.h>
#define NO_BLOCK_MAPPINGS BIT(0)
#define NO_CONT_MAPPINGS BIT(1)
@@ -973,12 +974,41 @@ int pmd_clear_huge(pmd_t *pmdp)
return 1;
}
-int pud_free_pmd_page(pud_t *pud, unsigned long addr)
+int pmd_free_pte_page(pmd_t *pmdp, unsigned long addr)
{
- return pud_none(*pud);
+ pte_t *table;
+ pmd_t pmd;
+
+ pmd = READ_ONCE(*pmdp);
+ if (pmd_present(pmd)) {
+ table = __va(pmd_page_paddr(pmd));
+ pmd_clear(pmdp);
+ __flush_tlb_kernel_pgtable(addr);
+ pte_free_kernel(NULL, table);
+ }
+ return 1;
}
-int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
+int pud_free_pmd_page(pud_t *pudp, unsigned long addr)
{
- return pmd_none(*pmd);
+ pmd_t *table;
+ pmd_t *entry;
+ pud_t pud;
+ unsigned long next, end;
+
+ pud = READ_ONCE(*pudp);
+ if (pud_present(pud)) {
+ table = __va(pud_page_paddr(pud));
+ entry = table;
+ next = addr;
+ end = addr + PUD_SIZE;
+ do {
+ pmd_free_pte_page(entry, next);
+ } while (entry++, next += PMD_SIZE, next != end);
+
+ pud_clear(pudp);
+ __flush_tlb_kernel_pgtable(addr);
+ pmd_free(NULL, table);
+ }
+ return 1;
}
--
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Center, Inc., is a member of Code Aurora Forum, a Linux Foundation
Collaborative Project
