FEAT_D128 halves PTRS_PER_PXX thus shrinking the VA range coverage for each page table level. Hence in order to preserve all existing VA range configurations, some geometry now need to become 5-level. Since fixmap is used to build and manipulate page tables early on during boot the mapping must also gain that additional level which was not required earlier. Enable fixmap with 5 level page table when required. This creates table entries at the PGD level. Add a fallback stub for pgd_page_paddr() when (PGTBALE_LEVELS <= 4) which helps in intercepting any unintended usage. Cc: Catalin Marinas Cc: Will Deacon Cc: Ryan Roberts Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- arch/arm64/include/asm/pgtable.h | 1 + arch/arm64/mm/fixmap.c | 18 +++++++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 2b457db19be0..7a5d6a14bb52 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -1178,6 +1178,7 @@ static inline p4d_t *p4d_offset_kimg(pgd_t *pgdp, u64 addr) #else static inline bool pgtable_l5_enabled(void) { return false; } +#define pgd_page_paddr(pgd) ({ BUILD_BUG(); 0; }) #define p4d_index(addr) (((addr) >> P4D_SHIFT) & (PTRS_PER_P4D - 1)) diff --git a/arch/arm64/mm/fixmap.c b/arch/arm64/mm/fixmap.c index 2a0fe0b0f771..5512521fef8f 100644 --- a/arch/arm64/mm/fixmap.c +++ b/arch/arm64/mm/fixmap.c @@ -34,6 +34,7 @@ static_assert(NR_BM_PMD_TABLES == 1); static pte_t bm_pte[NR_BM_PTE_TABLES][PTRS_PER_PTE] __bss_pgtbl; static pmd_t bm_pmd[PTRS_PER_PMD] __bss_pgtbl __maybe_unused; static pud_t bm_pud[PTRS_PER_PUD] __bss_pgtbl __maybe_unused; +static p4d_t bm_p4d[PTRS_PER_P4D] __bss_pgtbl __maybe_unused; static inline pte_t *fixmap_pte(unsigned long addr) { @@ -95,6 +96,19 @@ static void __init early_fixmap_init_pud(p4d_t *p4dp, unsigned long addr, early_fixmap_init_pmd(pudp, addr, end); } +static void __init early_fixmap_init_p4d(pgd_t *pgdp, unsigned long addr, + unsigned long end) +{ + pgd_t pgd = pgdp_get(pgdp); + p4d_t *p4dp; + + if (pgd_none(pgd)) + __pgd_populate(pgdp, __pa_symbol(bm_p4d), + PGD_TYPE_TABLE | PGD_TABLE_AF); + p4dp = p4d_offset_kimg(pgdp, addr); + early_fixmap_init_pud(p4dp, addr, end); +} + /* * The p*d_populate functions call virt_to_phys implicitly so they can't be used * directly on kernel symbols (bm_p*d). This function is called too early to use @@ -107,9 +121,7 @@ void __init early_fixmap_init(void) unsigned long end = FIXADDR_TOP; pgd_t *pgdp = pgd_offset_k(addr); - p4d_t *p4dp = p4d_offset_kimg(pgdp, addr); - - early_fixmap_init_pud(p4dp, addr, end); + early_fixmap_init_p4d(pgdp, addr, end); } /* -- 2.43.0