diff options
| author | Palmer Dabbelt | 2024-05-16 13:00:00 -0700 |
|---|---|---|
| committer | Palmer Dabbelt | 2024-05-22 16:12:47 -0700 |
| commit | 12cf29c6f900f04cd34e8867d4421aba49cd6a5d (patch) | |
| tree | bb772156df7d8afbb24e7e32f3ad56a82d6a5bf3 /arch | |
| parent | 2aff5f955bbae311ca4b66e1dbd934e8f346d1f1 (diff) | |
| parent | ad5643cf2f699989daa85d909403febd6712fccb (diff) | |
Merge patch series "riscv: access_ok() optimization"
Samuel Holland <samuel.holland@sifive.com> says:
This series optimizes access_ok() by defining TASK_SIZE_MAX. At Alex's
suggestion, I also tried making TASK_SIZE constant (specifically by
making PGDIR_SHIFT a variable instead of a ternary expression, then
replacing the load with an immediate using ALTERNATIVE). This appeared
to slightly improve performance on some implementations (C906) but
regressed it on others (FU740). So I am leaving further optimizations to
a later series.
* b4-shazam-merge:
riscv: Define TASK_SIZE_MAX for __access_ok()
riscv: Remove PGDIR_SIZE_L3 and TASK_SIZE_MIN
Link: https://lore.kernel.org/r/20240327143858.711792-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/riscv/include/asm/pgtable-64.h | 2 | ||||
| -rw-r--r-- | arch/riscv/include/asm/pgtable.h | 3 |
2 files changed, 1 insertions, 4 deletions
diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h index 221a5c1ee287..8c36a8818432 100644 --- a/arch/riscv/include/asm/pgtable-64.h +++ b/arch/riscv/include/asm/pgtable-64.h @@ -16,8 +16,6 @@ extern bool pgtable_l5_enabled; #define PGDIR_SHIFT_L3 30 #define PGDIR_SHIFT_L4 39 #define PGDIR_SHIFT_L5 48 -#define PGDIR_SIZE_L3 (_AC(1, UL) << PGDIR_SHIFT_L3) - #define PGDIR_SHIFT (pgtable_l5_enabled ? PGDIR_SHIFT_L5 : \ (pgtable_l4_enabled ? PGDIR_SHIFT_L4 : PGDIR_SHIFT_L3)) /* Size of region mapped by a page global directory */ diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 55a7c3ec246b..aad8b8ca51f1 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -880,7 +880,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte) */ #ifdef CONFIG_64BIT #define TASK_SIZE_64 (PGDIR_SIZE * PTRS_PER_PGD / 2) -#define TASK_SIZE_MIN (PGDIR_SIZE_L3 * PTRS_PER_PGD / 2) +#define TASK_SIZE_MAX LONG_MAX #ifdef CONFIG_COMPAT #define TASK_SIZE_32 (_AC(0x80000000, UL) - PAGE_SIZE) @@ -892,7 +892,6 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte) #else #define TASK_SIZE FIXADDR_START -#define TASK_SIZE_MIN TASK_SIZE #endif #else /* CONFIG_MMU */ |