riscv: Fix accessing pfn bits in PTEs for non-32bit
From: Heiko Stuebner <heiko@...> Date: Sun, 6 Jun 2021 09:04:02 +0000
Commit-Message
On rv32 the PFN part of PTEs is defined to use bits [xlen-1:10] while on rv64 it is defined to use bits [53:10], leaving [63:54] as reserved. With upcoming optional extensions like svpbmt these previously reserved bits will get used so simply right-shifting the PTE to get the PFN won't be enough. So introduce a _PAGE_PFN_MASK constant to mask the correct bits for both rv32 and rv64 before shifting. Signed-off-by: Heiko Stuebner <heiko@...> Reviewed-by: Philipp Tomsich <philipp.tomsich@...>
Patch-Comment
arch/riscv/include/asm/pgtable-32.h | 8 ++++++++ arch/riscv/include/asm/pgtable-64.h | 14 +++++++++++--- arch/riscv/include/asm/pgtable-bits.h | 6 ------ arch/riscv/include/asm/pgtable.h | 8 +++++--- 4 files changed, 24 insertions(+), 12 deletions(-)
Statistics
- 24 lines added
- 12 lines removed
Changes
--------------------- arch/riscv/include/asm/pgtable-32.h ----------------------
index 5b2e79e5bfa5..e266a4fe7f43 100644
@@ -7,6 +7,7 @@
#define _ASM_RISCV_PGTABLE_32_H
#include <asm-generic/pgtable-nopmd.h>
+#include <linux/bits.h>
#include <linux/const.h>
/* Size of region mapped by a page global directory */
@@ -16,4 +17,11 @@
#define MAX_POSSIBLE_PHYSMEM_BITS 34
+/*
+ * rv32 PTE format:
+ * | XLEN-1 10 | 9 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
+ * PFN reserved for SW D A G U X W R V
+ */
+#define _PAGE_PFN_MASK GENMASK(31, 10)
+
#endif /* _ASM_RISCV_PGTABLE_32_H */
--------------------- arch/riscv/include/asm/pgtable-64.h ----------------------
index 7e246e9f8d70..15f3ad5aee4f 100644
@@ -6,6 +6,7 @@
#ifndef _ASM_RISCV_PGTABLE_64_H
#define _ASM_RISCV_PGTABLE_64_H
+#include <linux/bits.h>
#include <linux/const.h>
extern bool pgtable_l4_enabled;
@@ -65,6 +66,13 @@ typedef struct {
#define PTRS_PER_PMD (PAGE_SIZE / sizeof(pmd_t))
+/*
+ * rv64 PTE format:
+ * | 63 | 62 61 | 60 54 | 53 10 | 9 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
+ * N MT RSV PFN reserved for SW D A G U X W R V
+ */
+#define _PAGE_PFN_MASK GENMASK(53, 10)
+
static inline int pud_present(pud_t pud)
{
return (pud_val(pud) & _PAGE_PRESENT);
@@ -108,12 +116,12 @@ static inline unsigned long _pud_pfn(pud_t pud)
static inline pmd_t *pud_pgtable(pud_t pud)
{
+ return (pmd_t *)pfn_to_virt(__page_val_to_pfn(pud_val(pud)));
}
static inline struct page *pud_page(pud_t pud)
{
+ return pfn_to_page(__page_val_to_pfn(pud_val(pud)));
}
#define mm_p4d_folded mm_p4d_folded
@@ -143,7 +151,7 @@ static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot)
static inline unsigned long _pmd_pfn(pmd_t pmd)
{
+ return __page_val_to_pfn(pmd_val(pmd));
}
#define mk_pmd(page, prot) pfn_pmd(page_to_pfn(page), prot)
-------------------- arch/riscv/include/asm/pgtable-bits.h ---------------------
index a6b0c89824c2..e571fa954afc 100644
@@ -6,12 +6,6 @@
#ifndef _ASM_RISCV_PGTABLE_BITS_H
#define _ASM_RISCV_PGTABLE_BITS_H
#define _PAGE_ACCESSED_OFFSET 6
#define _PAGE_PRESENT (1 << 0)
----------------------- arch/riscv/include/asm/pgtable.h -----------------------
index 046b44225623..faba543e2b08 100644
@@ -108,6 +108,8 @@
#include <asm/tlbflush.h>
#include <linux/mm_types.h>
+#define __page_val_to_pfn(_val) (((_val) & _PAGE_PFN_MASK) >> _PAGE_PFN_SHIFT)
+
#ifdef CONFIG_64BIT
#include <asm/pgtable-64.h>
#else
@@ -261,12 +263,12 @@ static inline unsigned long _pgd_pfn(pgd_t pgd)
static inline struct page *pmd_page(pmd_t pmd)
{
+ return pfn_to_page(__page_val_to_pfn(pmd_val(pmd)));
}
static inline unsigned long pmd_page_vaddr(pmd_t pmd)
{
+ return (unsigned long)pfn_to_virt(__page_val_to_pfn(pmd_val(pmd)));
}
static inline pte_t pmd_pte(pmd_t pmd)
@@ -282,7 +284,7 @@ static inline pte_t pud_pte(pud_t pud)
/* Yields the page frame number (PFN) of a page table entry */
static inline unsigned long pte_pfn(pte_t pte)
{
+ return __page_val_to_pfn(pte_val(pte));
}
#define pte_page(x) pfn_to_page(pte_pfn(x))