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author | Alexandre Ghiti <alexghiti@rivosinc.com> | 2022-12-01 14:51:28 +0100 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-31 13:32:38 +0100 |
commit | 6392d71b4bf9b11ed51d3fcfba1764e01663df67 (patch) | |
tree | fc04dc5668fa7cb4c7d0895f481e5ac517662e00 /arch/riscv/include | |
parent | dd203468f07194a5a6e3999f01c3a22d579e9aee (diff) | |
download | linux-6392d71b4bf9b11ed51d3fcfba1764e01663df67.tar.gz |
riscv: Fix P4D_SHIFT definition for 3-level page table mode
[ Upstream commit 71fc3621efc38ace9640ee6a0db3300900689592 ] RISC-V kernels support 3,4,5-level page tables at runtime by folding upper levels. In case of a 3-level page table, PGDIR is folded into P4D which in turn is folded into PUD: PGDIR_SHIFT value is correctly set to the same value as PUD_SHIFT, but P4D_SHIFT is not, then any use of P4D_SHIFT will access invalid address bits (all set to 1). Fix this by dynamically defining P4D_SHIFT value, like we already do for PGDIR_SHIFT. Fixes: d10efa21a937 ("riscv: mm: Control p4d's folding by pgtable_l5_enabled") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20221201135128.1482189-2-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/riscv/include')
-rw-r--r-- | arch/riscv/include/asm/pgtable-64.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h index dc42375c2357..42a042c0e13e 100644 --- a/arch/riscv/include/asm/pgtable-64.h +++ b/arch/riscv/include/asm/pgtable-64.h @@ -25,7 +25,11 @@ extern bool pgtable_l5_enabled; #define PGDIR_MASK (~(PGDIR_SIZE - 1)) /* p4d is folded into pgd in case of 4-level page table */ -#define P4D_SHIFT 39 +#define P4D_SHIFT_L3 30 +#define P4D_SHIFT_L4 39 +#define P4D_SHIFT_L5 39 +#define P4D_SHIFT (pgtable_l5_enabled ? P4D_SHIFT_L5 : \ + (pgtable_l4_enabled ? P4D_SHIFT_L4 : P4D_SHIFT_L3)) #define P4D_SIZE (_AC(1, UL) << P4D_SHIFT) #define P4D_MASK (~(P4D_SIZE - 1)) |