[PATCH v3 2/3] riscv: ptdump: Use per-level attribute bits for parsing

["Dylan.Wu" <fredwudi0305@gmail.com>]

Rename the ptdump data structures with a ptdump_ prefix for clarity
and to avoid namespace collisions when other modules (like KVM) define
their own instances:
  - struct prot_bits   -> struct ptdump_prot_bits
  - struct pg_level    -> struct ptdump_pg_level
  - struct pg_state    -> struct ptdump_pg_state

Add bits/num fields to struct ptdump_pg_level so each page table level
can have its own set of attribute bits, and add a pg_level pointer to
struct ptdump_pg_state so the attribute parsing logic can use per-level
bits instead of a global array.

Update dump_prot() to use the per-level bits from the pg_level pointer
rather than the global pte_bits array. Rename the pg_level[] instance
to kernel_pg_levels[] to distinguish it from future gstage instances.

No functional changes in the output.

Assisted-by: YuanSheng: deepseek-v4-pro
Co-developed-by: Quan Zhou <zhouquan@iscas.ac.cn>
Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn>
Signed-off-by: Dylan.Wu <fredwudi0305@gmail.com>
---
 arch/riscv/include/asm/ptdump.h |  9 +++--
 arch/riscv/mm/ptdump.c          | 62 ++++++++++++++++++++-------------
 2 files changed, 44 insertions(+), 27 deletions(-)

diff --git a/arch/riscv/include/asm/ptdump.h b/arch/riscv/include/asm/ptdump.h
index 90dce9f64..53b0e52f0 100644
--- a/arch/riscv/include/asm/ptdump.h
+++ b/arch/riscv/include/asm/ptdump.h
@@ -10,18 +10,20 @@ struct addr_marker {
 	const char *name;
 };
 
-struct prot_bits {
+struct ptdump_prot_bits {
 	u64 mask;
 	const char *set;
 	const char *clear;
 };
 
-struct pg_level {
+struct ptdump_pg_level {
+	const struct ptdump_prot_bits *bits;
+	size_t num;
 	const char *name;
 	u64 mask;
 };
 
-struct pg_state {
+struct ptdump_pg_state {
 	struct ptdump_state ptdump;
 	struct seq_file *seq;
 	const struct addr_marker *marker;
@@ -32,6 +34,7 @@ struct pg_state {
 	u64 current_prot;
 	bool check_wx;
 	unsigned long wx_pages;
+	const struct ptdump_pg_level *pg_level;
 };
 
 void note_page(struct ptdump_state *pt_st, unsigned long addr,
diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c
index d9a955b8a..c67fbbf5f 100644
--- a/arch/riscv/mm/ptdump.c
+++ b/arch/riscv/mm/ptdump.c
@@ -102,7 +102,7 @@ static struct ptd_mm_info efi_ptd_info = {
 };
 #endif
 
-static const struct prot_bits pte_bits[] = {
+static const struct ptdump_prot_bits pte_bits[] = {
 	{
 #ifdef CONFIG_64BIT
 		.mask = _PAGE_NAPOT,
@@ -152,46 +152,58 @@ static const struct prot_bits pte_bits[] = {
 	}
 };
 
-static struct pg_level pg_level[] = {
+static struct ptdump_pg_level kernel_pg_levels[] = {
 	{ /* pgd */
+		.bits = pte_bits,
+		.num = ARRAY_SIZE(pte_bits),
 		.name = "PGD",
 	}, { /* p4d */
+		.bits = pte_bits,
+		.num = ARRAY_SIZE(pte_bits),
 		.name = (CONFIG_PGTABLE_LEVELS > 4) ? "P4D" : "PGD",
 	}, { /* pud */
+		.bits = pte_bits,
+		.num = ARRAY_SIZE(pte_bits),
 		.name = (CONFIG_PGTABLE_LEVELS > 3) ? "PUD" : "PGD",
 	}, { /* pmd */
+		.bits = pte_bits,
+		.num = ARRAY_SIZE(pte_bits),
 		.name = (CONFIG_PGTABLE_LEVELS > 2) ? "PMD" : "PGD",
 	}, { /* pte */
+		.bits = pte_bits,
+		.num = ARRAY_SIZE(pte_bits),
 		.name = "PTE",
 	},
 };
 
-static void dump_prot(struct pg_state *st)
+static void dump_prot(struct ptdump_pg_state *st)
 {
+	const struct ptdump_pg_level *lvl = &st->pg_level[st->level];
+	const struct ptdump_prot_bits *bits = lvl->bits;
 	unsigned int i;
 
-	for (i = 0; i < ARRAY_SIZE(pte_bits); i++) {
+	for (i = 0; i < lvl->num; i++) {
 		char s[7];
 		unsigned long val;
 
-		val = st->current_prot & pte_bits[i].mask;
+		val = st->current_prot & bits[i].mask;
 		if (val) {
-			if (pte_bits[i].mask == _PAGE_SOFT)
-				snprintf(s, sizeof(s), pte_bits[i].set, val >> 8);
+			if (bits[i].mask == _PAGE_SOFT)
+				snprintf(s, sizeof(s), bits[i].set, val >> 8);
 #ifdef CONFIG_64BIT
-			else if (pte_bits[i].mask == _PAGE_MTMASK_SVPBMT) {
+			else if (bits[i].mask == _PAGE_MTMASK_SVPBMT) {
 				if (val == _PAGE_NOCACHE_SVPBMT)
-					snprintf(s, sizeof(s), pte_bits[i].set, "NC");
+					snprintf(s, sizeof(s), bits[i].set, "NC");
 				else if (val == _PAGE_IO_SVPBMT)
-					snprintf(s, sizeof(s), pte_bits[i].set, "IO");
+					snprintf(s, sizeof(s), bits[i].set, "IO");
 				else
-					snprintf(s, sizeof(s), pte_bits[i].set, "??");
+					snprintf(s, sizeof(s), bits[i].set, "??");
 			}
 #endif
 			else
-				strscpy(s, pte_bits[i].set);
+				strscpy(s, bits[i].set);
 		} else {
-			strscpy(s, pte_bits[i].clear);
+			strscpy(s, bits[i].clear);
 		}
 
 		pt_dump_seq_printf(st->seq, " %s", s);
@@ -203,7 +215,7 @@ static void dump_prot(struct pg_state *st)
 #else
 #define ADDR_FORMAT	"0x%08lx"
 #endif
-static void dump_addr(struct pg_state *st, unsigned long addr)
+static void dump_addr(struct ptdump_pg_state *st, unsigned long addr)
 {
 	static const char units[] = "KMGTPE";
 	const char *unit = units;
@@ -221,10 +233,10 @@ static void dump_addr(struct pg_state *st, unsigned long addr)
 	}
 
 	pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
-			   pg_level[st->level].name);
+			   kernel_pg_levels[st->level].name);
 }
 
-static void note_prot_wx(struct pg_state *st, unsigned long addr)
+static void note_prot_wx(struct ptdump_pg_state *st, unsigned long addr)
 {
 	if (!st->check_wx)
 		return;
@@ -242,12 +254,12 @@ static void note_prot_wx(struct pg_state *st, unsigned long addr)
 void note_page(struct ptdump_state *pt_st, unsigned long addr,
 	      int level, u64 val)
 {
-	struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
+	struct ptdump_pg_state *st = container_of(pt_st, struct ptdump_pg_state, ptdump);
 	u64 pa = PFN_PHYS(pte_pfn(__pte(val)));
 	u64 prot = 0;
 
 	if (level >= 0)
-		prot = val & pg_level[level].mask;
+		prot = val & kernel_pg_levels[level].mask;
 
 	if (st->level == -1) {
 		st->level = level;
@@ -316,10 +328,11 @@ static void note_page_flush(struct ptdump_state *pt_st)
 
 static void ptdump_walk(struct seq_file *s, struct ptd_mm_info *pinfo)
 {
-	struct pg_state st = {
+	struct ptdump_pg_state st = {
 		.seq = s,
 		.marker = pinfo->markers,
 		.level = -1,
+		.pg_level = kernel_pg_levels,
 		.ptdump = {
 			.note_page_pte = note_page_pte,
 			.note_page_pmd = note_page_pmd,
@@ -339,13 +352,14 @@ static void ptdump_walk(struct seq_file *s, struct ptd_mm_info *pinfo)
 
 bool ptdump_check_wx(void)
 {
-	struct pg_state st = {
+	struct ptdump_pg_state st = {
 		.seq = NULL,
 		.marker = (struct addr_marker[]) {
 			{0, NULL},
 			{-1, NULL},
 		},
 		.level = -1,
+		.pg_level = kernel_pg_levels,
 		.check_wx = true,
 		.ptdump = {
 			.note_page_pte = note_page_pte,
@@ -410,12 +424,12 @@ static int __init ptdump_init(void)
 
 	kernel_ptd_info.base_addr = KERN_VIRT_START;
 
-	pg_level[1].name = pgtable_l5_enabled ? "P4D" : "PGD";
-	pg_level[2].name = pgtable_l4_enabled ? "PUD" : "PGD";
+	kernel_pg_levels[1].name = pgtable_l5_enabled ? "P4D" : "PGD";
+	kernel_pg_levels[2].name = pgtable_l4_enabled ? "PUD" : "PGD";
 
-	for (i = 0; i < ARRAY_SIZE(pg_level); i++)
+	for (i = 0; i < ARRAY_SIZE(kernel_pg_levels); i++)
 		for (j = 0; j < ARRAY_SIZE(pte_bits); j++)
-			pg_level[i].mask |= pte_bits[j].mask;
+			kernel_pg_levels[i].mask |= pte_bits[j].mask;
 
 	debugfs_create_file("kernel_page_tables", 0400, NULL, &kernel_ptd_info,
 			    &ptdump_fops);
-- 
2.34.1