[PATCH V3 4/4] riscv: mm: Optimize TASK_SIZE definition

guoren
2023-12-22T11:57:36Z

From: Guo Ren <guoren@linux.alibaba.com>

Unify the TASK_SIZE definition with VA_BITS for better readability.
Add COMPAT mode user address space info in the comment.

Reviewed-by: Leonardo Bras <leobras@redhat.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
arch/riscv/include/asm/pgtable.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index e415582276ec..271565e1956f 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -866,6 +866,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
* Note that PGDIR_SIZE must evenly divide TASK_SIZE.
* Task size is:
* - 0x9fc00000 (~2.5GB) for RV32.
+ * - 0x80000000 ( 2GB) for RV64 compat mode
* - 0x4000000000 ( 256GB) for RV64 using SV39 mmu
* - 0x800000000000 ( 128TB) for RV64 using SV48 mmu
* - 0x100000000000000 ( 64PB) for RV64 using SV57 mmu
@@ -877,10 +878,10 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
* Similarly for SV57, bits 63–57 must be equal to bit 56.
*/
#ifdef CONFIG_64BIT
-#define TASK_SIZE_64 (PGDIR_SIZE * PTRS_PER_PGD / 2)
+#define TASK_SIZE_64 (UL(1) << (VA_BITS - 1))

#ifdef CONFIG_COMPAT
-#define TASK_SIZE_32 (_AC(0x80000000, UL))
+#define TASK_SIZE_32 (UL(1) << (VA_BITS_SV32 - 1))
#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
TASK_SIZE_32 : TASK_SIZE_64)
#else
--
2.40.1