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author | Sascha Hauer <s.hauer@pengutronix.de> | 2018-03-08 13:55:04 +0100 |
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committer | Sascha Hauer <s.hauer@pengutronix.de> | 2018-03-23 07:43:27 +0100 |
commit | 71494946d5beb75c82dc69f8e0509afe5d3f7dec (patch) | |
tree | f74d9a724ea58098ac28cba0a92255dc46135cb1 | |
parent | 77446c78219e5432f6690001c404a40819cc7e16 (diff) | |
download | barebox-71494946d5beb75c82dc69f8e0509afe5d3f7dec.tar.gz barebox-71494946d5beb75c82dc69f8e0509afe5d3f7dec.tar.xz |
ARM: aarch64: mmu: Fix adding additional page table levels
When we create a higher level page table we have to initialize it
with the settings from the previous lower level page table so that
we do not modify unrelated mappings. split_block() is taken from
U-Boot code and does this job.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
-rw-r--r-- | arch/arm/cpu/mmu_64.c | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/arch/arm/cpu/mmu_64.c b/arch/arm/cpu/mmu_64.c index baa443f9e2..2934ad12cd 100644 --- a/arch/arm/cpu/mmu_64.c +++ b/arch/arm/cpu/mmu_64.c @@ -123,10 +123,8 @@ static uint64_t *get_level_table(uint64_t *pte) { uint64_t *table = (uint64_t *)(*pte & XLAT_ADDR_MASK); - if (pte_type(pte) != PTE_TYPE_TABLE) { - table = create_table(); - set_table(pte, table); - } + if (pte_type(pte) != PTE_TYPE_TABLE) + BUG(); return table; } @@ -154,6 +152,36 @@ static __maybe_unused uint64_t *find_pte(uint64_t addr) return pte; } +#define MAX_PTE_ENTRIES 512 + +/* Splits a block PTE into table with subpages spanning the old block */ +static void split_block(uint64_t *pte, int level) +{ + uint64_t old_pte = *pte; + uint64_t *new_table; + uint64_t i = 0; + int levelshift; + + if ((*pte & PTE_TYPE_MASK) == PTE_TYPE_TABLE) + return; + + /* level describes the parent level, we need the child ones */ + levelshift = level2shift(level + 1); + + new_table = create_table(); + + for (i = 0; i < MAX_PTE_ENTRIES; i++) { + new_table[i] = old_pte | (i << levelshift); + + /* Level 3 block PTEs have the table type */ + if ((level + 1) == 3) + new_table[i] |= PTE_TYPE_TABLE; + } + + /* Set the new table into effect */ + set_table(pte, new_table); +} + static void map_region(uint64_t virt, uint64_t phys, uint64_t size, uint64_t attr) { uint64_t block_size; @@ -191,7 +219,8 @@ static void map_region(uint64_t virt, uint64_t phys, uint64_t size, uint64_t att phys += block_size; size -= block_size; break; - + } else { + split_block(pte, level); } table = get_level_table(pte); |