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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2024-06-14 12:59:02 +0300 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-06-17 17:46:22 +0200 |
| commit | d88e7b3e35cff2c318042990d70828f64c3ae296 (patch) | |
| tree | 3f0f608d97a95e8dce83b8ef6fe4510efab06e38 /arch/x86/mm | |
| parent | 26ba7353caaa7140561d3f7693a77a3eb68c722c (diff) | |
| download | linux-d88e7b3e35cff2c318042990d70828f64c3ae296.tar.gz linux-d88e7b3e35cff2c318042990d70828f64c3ae296.tar.bz2 linux-d88e7b3e35cff2c318042990d70828f64c3ae296.zip | |
x86/mm: Introduce kernel_ident_mapping_free()
The helper complements kernel_ident_mapping_init(): it frees the identity
mapping that was previously allocated. It will be used in the error path to free
a partially allocated mapping or if the mapping is no longer needed.
The caller provides a struct x86_mapping_info with the free_pgd_page() callback
hooked up and the pgd_t to free.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Kai Huang <kai.huang@intel.com>
Tested-by: Tao Liu <ltao@redhat.com>
Link: https://lore.kernel.org/r/20240614095904.1345461-18-kirill.shutemov@linux.intel.com
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/ident_map.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c index 968d7005f4a7..c45127265f2f 100644 --- a/arch/x86/mm/ident_map.c +++ b/arch/x86/mm/ident_map.c @@ -4,6 +4,79 @@ * included by both the compressed kernel and the regular kernel. */ +static void free_pte(struct x86_mapping_info *info, pmd_t *pmd) +{ + pte_t *pte = pte_offset_kernel(pmd, 0); + + info->free_pgt_page(pte, info->context); +} + +static void free_pmd(struct x86_mapping_info *info, pud_t *pud) +{ + pmd_t *pmd = pmd_offset(pud, 0); + int i; + + for (i = 0; i < PTRS_PER_PMD; i++) { + if (!pmd_present(pmd[i])) + continue; + + if (pmd_leaf(pmd[i])) + continue; + + free_pte(info, &pmd[i]); + } + + info->free_pgt_page(pmd, info->context); +} + +static void free_pud(struct x86_mapping_info *info, p4d_t *p4d) +{ + pud_t *pud = pud_offset(p4d, 0); + int i; + + for (i = 0; i < PTRS_PER_PUD; i++) { + if (!pud_present(pud[i])) + continue; + + if (pud_leaf(pud[i])) + continue; + + free_pmd(info, &pud[i]); + } + + info->free_pgt_page(pud, info->context); +} + +static void free_p4d(struct x86_mapping_info *info, pgd_t *pgd) +{ + p4d_t *p4d = p4d_offset(pgd, 0); + int i; + + for (i = 0; i < PTRS_PER_P4D; i++) { + if (!p4d_present(p4d[i])) + continue; + + free_pud(info, &p4d[i]); + } + + if (pgtable_l5_enabled()) + info->free_pgt_page(p4d, info->context); +} + +void kernel_ident_mapping_free(struct x86_mapping_info *info, pgd_t *pgd) +{ + int i; + + for (i = 0; i < PTRS_PER_PGD; i++) { + if (!pgd_present(pgd[i])) + continue; + + free_p4d(info, &pgd[i]); + } + + info->free_pgt_page(pgd, info->context); +} + static void ident_pmd_init(struct x86_mapping_info *info, pmd_t *pmd_page, unsigned long addr, unsigned long end) { |