Merge patch series "Improve PTDUMP and introduce new fields"

Yu Chien Peter Lin <peterlin@andestech.com> says:

This patchset enhances PTDUMP by providing additional information
from pagetable entries.

The first patch fixes the RSW field, while the second and third
patches introduce the PBMT and NAPOT fields, respectively, for
RV64 systems.

* b4-shazam-merge:
  riscv: Introduce NAPOT field to PTDUMP
  riscv: Introduce PBMT field to PTDUMP
  riscv: Improve PTDUMP to show RSW with non-zero value

Link: https://lore.kernel.org/r/20230921025022.3989723-1-peterlin@andestech.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

2 files changed, 36 insertions, 21 deletions

diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h
index f896708e8331..179bd4afece4 100644
--- a/arch/riscv/include/asm/pgtable-bits.h
+++ b/arch/riscv/include/asm/pgtable-bits.h
@@ -16,9 +16,9 @@
 #define _PAGE_GLOBAL    (1 << 5)    /* Global */
 #define _PAGE_ACCESSED  (1 << 6)    /* Set by hardware on any access */
 #define _PAGE_DIRTY     (1 << 7)    /* Set by hardware on any write */
-#define _PAGE_SOFT      (1 << 8)    /* Reserved for software */
+#define _PAGE_SOFT      (3 << 8)    /* Reserved for software */
 
-#define _PAGE_SPECIAL   _PAGE_SOFT
+#define _PAGE_SPECIAL   (1 << 8)    /* RSW: 0x1 */
 #define _PAGE_TABLE     _PAGE_PRESENT
 
 /*
diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c
index e9090b38f811..657c27bc07a7 100644
--- a/arch/riscv/mm/ptdump.c
+++ b/arch/riscv/mm/ptdump.c
@@ -129,55 +129,55 @@ static struct ptd_mm_info efi_ptd_info = {
 /* Page Table Entry */
 struct prot_bits {
 	u64 mask;
-	u64 val;
 	const char *set;
 	const char *clear;
 };
 
 static const struct prot_bits pte_bits[] = {
 	{
+#ifdef CONFIG_64BIT
+		.mask = _PAGE_NAPOT,
+		.set = "N",
+		.clear = ".",
+	}, {
+		.mask = _PAGE_MTMASK_SVPBMT,
+		.set = "MT(%s)",
+		.clear = "  ..  ",
+	}, {
+#endif
 		.mask = _PAGE_SOFT,
-		.val = _PAGE_SOFT,
-		.set = "RSW",
-		.clear = "   ",
+		.set = "RSW(%d)",
+		.clear = "  ..  ",
 	}, {
 		.mask = _PAGE_DIRTY,
-		.val = _PAGE_DIRTY,
 		.set = "D",
 		.clear = ".",
 	}, {
 		.mask = _PAGE_ACCESSED,
-		.val = _PAGE_ACCESSED,
 		.set = "A",
 		.clear = ".",
 	}, {
 		.mask = _PAGE_GLOBAL,
-		.val = _PAGE_GLOBAL,
 		.set = "G",
 		.clear = ".",
 	}, {
 		.mask = _PAGE_USER,
-		.val = _PAGE_USER,
 		.set = "U",
 		.clear = ".",
 	}, {
 		.mask = _PAGE_EXEC,
-		.val = _PAGE_EXEC,
 		.set = "X",
 		.clear = ".",
 	}, {
 		.mask = _PAGE_WRITE,
-		.val = _PAGE_WRITE,
 		.set = "W",
 		.clear = ".",
 	}, {
 		.mask = _PAGE_READ,
-		.val = _PAGE_READ,
 		.set = "R",
 		.clear = ".",
 	}, {
 		.mask = _PAGE_PRESENT,
-		.val = _PAGE_PRESENT,
 		.set = "V",
 		.clear = ".",
 	}
@@ -208,15 +208,30 @@ static void dump_prot(struct pg_state *st)
 	unsigned int i;
 
 	for (i = 0; i < ARRAY_SIZE(pte_bits); i++) {
-		const char *s;
+		char s[7];
+		unsigned long val;
 
-		if ((st->current_prot & pte_bits[i].mask) == pte_bits[i].val)
-			s = pte_bits[i].set;
-		else
-			s = pte_bits[i].clear;
+		val = st->current_prot & pte_bits[i].mask;
+		if (val) {
+			if (pte_bits[i].mask == _PAGE_SOFT)
+				sprintf(s, pte_bits[i].set, val >> 8);
+#ifdef CONFIG_64BIT
+			else if (pte_bits[i].mask == _PAGE_MTMASK_SVPBMT) {
+				if (val == _PAGE_NOCACHE_SVPBMT)
+					sprintf(s, pte_bits[i].set, "NC");
+				else if (val == _PAGE_IO_SVPBMT)
+					sprintf(s, pte_bits[i].set, "IO");
+				else
+					sprintf(s, pte_bits[i].set, "??");
+			}
+#endif
+			else
+				sprintf(s, "%s", pte_bits[i].set);
+		} else {
+			sprintf(s, "%s", pte_bits[i].clear);
+		}
 
-		if (s)
-			pt_dump_seq_printf(st->seq, " %s", s);
+		pt_dump_seq_printf(st->seq, " %s", s);
 	}
 }