[PATCH v9 3/4] RISC-V: mm: Update pgtable comment documentation

Charlie Jenkins charlie at rivosinc.com
Tue Aug 8 18:51:09 PDT 2023


sv57 is supported in the kernel so pgtable.h should reflect that.

Signed-off-by: Charlie Jenkins <charlie at rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti at rivosinc.com>
---
 arch/riscv/include/asm/pgtable.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 2611c1324a7c..76907b95109a 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -849,14 +849,16 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
  * Task size is:
- * -     0x9fc00000 (~2.5GB) for RV32.
- * -   0x4000000000 ( 256GB) for RV64 using SV39 mmu
- * - 0x800000000000 ( 128TB) for RV64 using SV48 mmu
+ * -        0x9fc00000	(~2.5GB) for RV32.
+ * -      0x4000000000	( 256GB) for RV64 using SV39 mmu
+ * -    0x800000000000	( 128TB) for RV64 using SV48 mmu
+ * - 0x100000000000000	(  64PB) for RV64 using SV57 mmu
  *
  * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V
  * Instruction Set Manual Volume II: Privileged Architecture" states that
  * "load and store effective addresses, which are 64bits, must have bits
  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
+ * 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)
-- 
2.34.1




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