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author | Kristina Martsenko <kristina.martsenko@arm.com> | 2017-12-13 20:07:24 +0300 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2017-12-22 20:37:33 +0300 |
commit | fa2a8445b1d3810c52f2a6b3a006456bd1aacb7e (patch) | |
tree | 61ab6a749b01e7ad21b5a96ecf1be2011bc13223 /arch/arm64/kernel | |
parent | 75387b92635e7dca410c1ef92cfe510019248f76 (diff) | |
download | linux-fa2a8445b1d3810c52f2a6b3a006456bd1aacb7e.tar.xz |
arm64: allow ID map to be extended to 52 bits
Currently, when using VA_BITS < 48, if the ID map text happens to be
placed in physical memory above VA_BITS, we increase the VA size (up to
48) and create a new table level, in order to map in the ID map text.
This is okay because the system always supports 48 bits of VA.
This patch extends the code such that if the system supports 52 bits of
VA, and the ID map text is placed that high up, then we increase the VA
size accordingly, up to 52.
One difference from the current implementation is that so far the
condition of VA_BITS < 48 has meant that the top level table is always
"full", with the maximum number of entries, and an extra table level is
always needed. Now, when VA_BITS = 48 (and using 64k pages), the top
level table is not full, and we simply need to increase the number of
entries in it, instead of creating a new table level.
Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[catalin.marinas@arm.com: reduce arguments to __create_hyp_mappings()]
[catalin.marinas@arm.com: reworked/renamed __cpu_uses_extended_idmap_level()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r-- | arch/arm64/kernel/head.S | 76 |
1 files changed, 45 insertions, 31 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index eeec0001e204..66f01869e97c 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -176,7 +176,7 @@ 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 @@ -184,7 +184,8 @@ ENDPROC(preserve_boot_args) phys_to_pte \tmp1, \tmp2 orr \tmp2, \tmp2, #PMD_TYPE_TABLE // address of next table and entry type lsr \tmp1, \virt, #\shift - and \tmp1, \tmp1, #\ptrs - 1 // table index + 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 @@ -194,15 +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 @@ -266,26 +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 @@ -294,18 +284,41 @@ __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, x4 @@ -316,7 +329,8 @@ __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 |