diff options
Diffstat (limited to 'arch/arm64/kernel/head.S')
-rw-r--r-- | arch/arm64/kernel/head.S | 122 |
1 files changed, 80 insertions, 42 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 67e86a0f57ac..66f01869e97c 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -148,6 +148,26 @@ preserve_boot_args: ENDPROC(preserve_boot_args) /* + * Macro to arrange a physical address in a page table entry, taking care of + * 52-bit addresses. + * + * Preserves: phys + * Returns: pte + */ + .macro phys_to_pte, phys, pte +#ifdef CONFIG_ARM64_PA_BITS_52 + /* + * We assume \phys is 64K aligned and this is guaranteed by only + * supporting this configuration with 64K pages. + */ + orr \pte, \phys, \phys, lsr #36 + and \pte, \pte, #PTE_ADDR_MASK +#else + mov \pte, \phys +#endif + .endm + +/* * Macro to create a table entry to the next page. * * tbl: page table address @@ -156,14 +176,16 @@ ENDPROC(preserve_boot_args) * ptrs: #imm pointers per table page * * Preserves: virt - * Corrupts: tmp1, tmp2 + * Corrupts: ptrs, tmp1, tmp2 * Returns: tbl -> next level table page address */ .macro create_table_entry, tbl, virt, shift, ptrs, tmp1, tmp2 - lsr \tmp1, \virt, #\shift - and \tmp1, \tmp1, #\ptrs - 1 // table index - add \tmp2, \tbl, #PAGE_SIZE + add \tmp1, \tbl, #PAGE_SIZE + phys_to_pte \tmp1, \tmp2 orr \tmp2, \tmp2, #PMD_TYPE_TABLE // address of next table and entry type + lsr \tmp1, \virt, #\shift + sub \ptrs, \ptrs, #1 + and \tmp1, \tmp1, \ptrs // table index str \tmp2, [\tbl, \tmp1, lsl #3] add \tbl, \tbl, #PAGE_SIZE // next level table page .endm @@ -173,15 +195,17 @@ ENDPROC(preserve_boot_args) * block entry in the next level (tbl) for the given virtual address. * * Preserves: tbl, next, virt - * Corrupts: tmp1, tmp2 + * Corrupts: ptrs_per_pgd, tmp1, tmp2 */ - .macro create_pgd_entry, tbl, virt, tmp1, tmp2 - create_table_entry \tbl, \virt, PGDIR_SHIFT, PTRS_PER_PGD, \tmp1, \tmp2 + .macro create_pgd_entry, tbl, virt, ptrs_per_pgd, tmp1, tmp2 + create_table_entry \tbl, \virt, PGDIR_SHIFT, \ptrs_per_pgd, \tmp1, \tmp2 #if SWAPPER_PGTABLE_LEVELS > 3 - create_table_entry \tbl, \virt, PUD_SHIFT, PTRS_PER_PUD, \tmp1, \tmp2 + mov \ptrs_per_pgd, PTRS_PER_PUD + create_table_entry \tbl, \virt, PUD_SHIFT, \ptrs_per_pgd, \tmp1, \tmp2 #endif #if SWAPPER_PGTABLE_LEVELS > 2 - create_table_entry \tbl, \virt, SWAPPER_TABLE_SHIFT, PTRS_PER_PTE, \tmp1, \tmp2 + mov \ptrs_per_pgd, PTRS_PER_PTE + create_table_entry \tbl, \virt, SWAPPER_TABLE_SHIFT, \ptrs_per_pgd, \tmp1, \tmp2 #endif .endm @@ -190,16 +214,17 @@ ENDPROC(preserve_boot_args) * virtual range (inclusive). * * Preserves: tbl, flags - * Corrupts: phys, start, end, pstate + * Corrupts: phys, start, end, tmp, pstate */ - .macro create_block_map, tbl, flags, phys, start, end - lsr \phys, \phys, #SWAPPER_BLOCK_SHIFT + .macro create_block_map, tbl, flags, phys, start, end, tmp lsr \start, \start, #SWAPPER_BLOCK_SHIFT and \start, \start, #PTRS_PER_PTE - 1 // table index - orr \phys, \flags, \phys, lsl #SWAPPER_BLOCK_SHIFT // table entry + bic \phys, \phys, #SWAPPER_BLOCK_SIZE - 1 lsr \end, \end, #SWAPPER_BLOCK_SHIFT and \end, \end, #PTRS_PER_PTE - 1 // table end index -9999: str \phys, [\tbl, \start, lsl #3] // store the entry +9999: phys_to_pte \phys, \tmp + orr \tmp, \tmp, \flags // table entry + str \tmp, [\tbl, \start, lsl #3] // store the entry add \start, \start, #1 // next entry add \phys, \phys, #SWAPPER_BLOCK_SIZE // next block cmp \start, \end @@ -244,26 +269,13 @@ __create_page_tables: adrp x0, idmap_pg_dir adrp x3, __idmap_text_start // __pa(__idmap_text_start) -#ifndef CONFIG_ARM64_VA_BITS_48 -#define EXTRA_SHIFT (PGDIR_SHIFT + PAGE_SHIFT - 3) -#define EXTRA_PTRS (1 << (48 - EXTRA_SHIFT)) - - /* - * If VA_BITS < 48, it may be too small to allow for an ID mapping to be - * created that covers system RAM if that is located sufficiently high - * in the physical address space. So for the ID map, use an extended - * virtual range in that case, by configuring an additional translation - * level. - * First, we have to verify our assumption that the current value of - * VA_BITS was chosen such that all translation levels are fully - * utilised, and that lowering T0SZ will always result in an additional - * translation level to be configured. - */ -#if VA_BITS != EXTRA_SHIFT -#error "Mismatch between VA_BITS and page size/number of translation levels" -#endif - /* + * VA_BITS may be too small to allow for an ID mapping to be created + * that covers system RAM if that is located sufficiently high in the + * physical address space. So for the ID map, use an extended virtual + * range in that case, and configure an additional translation level + * if needed. + * * Calculate the maximum allowed value for TCR_EL1.T0SZ so that the * entire ID map region can be mapped. As T0SZ == (64 - #bits used), * this number conveniently equals the number of leading zeroes in @@ -272,21 +284,44 @@ __create_page_tables: adrp x5, __idmap_text_end clz x5, x5 cmp x5, TCR_T0SZ(VA_BITS) // default T0SZ small enough? - b.ge 1f // .. then skip additional level + b.ge 1f // .. then skip VA range extension adr_l x6, idmap_t0sz str x5, [x6] dmb sy dc ivac, x6 // Invalidate potentially stale cache line - create_table_entry x0, x3, EXTRA_SHIFT, EXTRA_PTRS, x5, x6 -1: +#if (VA_BITS < 48) +#define EXTRA_SHIFT (PGDIR_SHIFT + PAGE_SHIFT - 3) +#define EXTRA_PTRS (1 << (PHYS_MASK_SHIFT - EXTRA_SHIFT)) + + /* + * If VA_BITS < 48, we have to configure an additional table level. + * First, we have to verify our assumption that the current value of + * VA_BITS was chosen such that all translation levels are fully + * utilised, and that lowering T0SZ will always result in an additional + * translation level to be configured. + */ +#if VA_BITS != EXTRA_SHIFT +#error "Mismatch between VA_BITS and page size/number of translation levels" #endif - create_pgd_entry x0, x3, x5, x6 + mov x4, EXTRA_PTRS + create_table_entry x0, x3, EXTRA_SHIFT, x4, x5, x6 +#else + /* + * If VA_BITS == 48, we don't have to configure an additional + * translation level, but the top-level table has more entries. + */ + mov x4, #1 << (PHYS_MASK_SHIFT - PGDIR_SHIFT) + str_l x4, idmap_ptrs_per_pgd, x5 +#endif +1: + ldr_l x4, idmap_ptrs_per_pgd + create_pgd_entry x0, x3, x4, x5, x6 mov x5, x3 // __pa(__idmap_text_start) adr_l x6, __idmap_text_end // __pa(__idmap_text_end) - create_block_map x0, x7, x3, x5, x6 + create_block_map x0, x7, x3, x5, x6, x4 /* * Map the kernel image (starting with PHYS_OFFSET). @@ -294,12 +329,13 @@ __create_page_tables: adrp x0, swapper_pg_dir mov_q x5, KIMAGE_VADDR + TEXT_OFFSET // compile time __va(_text) add x5, x5, x23 // add KASLR displacement - create_pgd_entry x0, x5, x3, x6 + mov x4, PTRS_PER_PGD + create_pgd_entry x0, x5, x4, x3, x6 adrp x6, _end // runtime __pa(_end) adrp x3, _text // runtime __pa(_text) sub x6, x6, x3 // _end - _text add x6, x6, x5 // runtime __va(_end) - create_block_map x0, x7, x3, x5, x6 + create_block_map x0, x7, x3, x5, x6, x4 /* * Since the page tables have been populated with non-cacheable @@ -679,8 +715,10 @@ ENTRY(__enable_mmu) update_early_cpu_boot_status 0, x1, x2 adrp x1, idmap_pg_dir adrp x2, swapper_pg_dir - msr ttbr0_el1, x1 // load TTBR0 - msr ttbr1_el1, x2 // load TTBR1 + phys_to_ttbr x1, x3 + phys_to_ttbr x2, x4 + msr ttbr0_el1, x3 // load TTBR0 + msr ttbr1_el1, x4 // load TTBR1 isb msr sctlr_el1, x0 isb |