Unverified Commit d5d2c264 authored by Yu Chien Peter Lin's avatar Yu Chien Peter Lin Committed by Palmer Dabbelt
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riscv: Improve PTDUMP to show RSW with non-zero value 



RSW field can be used to encode 2 bits of software
defined information. Currently, PTDUMP only prints
"RSW" when its value is 1 or 3.

To fix this issue and improve the debugging experience
with PTDUMP, we redefine _PAGE_SPECIAL to its original
value and use _PAGE_SOFT as the RSW mask, allow it to
print the RSW with any non-zero value.

This patch also removes the val from the struct prot_bits
as it is no longer needed.

Signed-off-by: default avatarYu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
Tested-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230921025022.3989723-2-peterlin@andestech.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 0bb80ecc

arch/riscv/include/asm/pgtable-bits.h

+2 −2
Original line number Diff line number Diff line
@@ -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



/*

arch/riscv/mm/ptdump.c

+15 −20
Original line number Diff line number Diff line
@@ -129,7 +129,6 @@ static struct ptd_mm_info efi_ptd_info = { 
/* Page Table Entry */

struct prot_bits {

	u64 mask;

	u64 val;

	const char *set;

	const char *clear;

};
@@ -137,47 +136,38 @@ struct prot_bits { 
static const struct prot_bits pte_bits[] = {

	{

		.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 = ".",

	}
@@ -208,14 +198,19 @@ 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;

		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);

			else

			s = pte_bits[i].clear;

				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);

	}

}