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Diffstat (limited to 'arch/arm64/mm/mmu.c')
-rw-r--r--arch/arm64/mm/mmu.c31
1 files changed, 29 insertions, 2 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index ba00d0205447..d2e9dec38a15 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1025,7 +1025,7 @@ static void free_empty_pud_table(p4d_t *p4dp, unsigned long addr,
if (CONFIG_PGTABLE_LEVELS <= 3)
return;
- if (!pgtable_range_aligned(start, end, floor, ceiling, PGDIR_MASK))
+ if (!pgtable_range_aligned(start, end, floor, ceiling, P4D_MASK))
return;
/*
@@ -1048,8 +1048,8 @@ static void free_empty_p4d_table(pgd_t *pgdp, unsigned long addr,
unsigned long end, unsigned long floor,
unsigned long ceiling)
{
- unsigned long next;
p4d_t *p4dp, p4d;
+ unsigned long i, next, start = addr;
do {
next = p4d_addr_end(addr, end);
@@ -1061,6 +1061,27 @@ static void free_empty_p4d_table(pgd_t *pgdp, unsigned long addr,
WARN_ON(!p4d_present(p4d));
free_empty_pud_table(p4dp, addr, next, floor, ceiling);
} while (addr = next, addr < end);
+
+ if (!pgtable_l5_enabled())
+ return;
+
+ if (!pgtable_range_aligned(start, end, floor, ceiling, PGDIR_MASK))
+ return;
+
+ /*
+ * Check whether we can free the p4d page if the rest of the
+ * entries are empty. Overlap with other regions have been
+ * handled by the floor/ceiling check.
+ */
+ p4dp = p4d_offset(pgdp, 0UL);
+ for (i = 0; i < PTRS_PER_P4D; i++) {
+ if (!p4d_none(READ_ONCE(p4dp[i])))
+ return;
+ }
+
+ pgd_clear(pgdp);
+ __flush_tlb_kernel_pgtable(start);
+ free_hotplug_pgtable_page(virt_to_page(p4dp));
}
static void free_empty_tables(unsigned long addr, unsigned long end,
@@ -1145,6 +1166,12 @@ int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot)
return 1;
}
+#ifndef __PAGETABLE_P4D_FOLDED
+void p4d_clear_huge(p4d_t *p4dp)
+{
+}
+#endif
+
int pud_clear_huge(pud_t *pudp)
{
if (!pud_sect(READ_ONCE(*pudp)))