2023-09-15 03:43:12

by Linus Walleij

[permalink] [raw]
Subject: [PATCH] ARC: mm: Make virt_to_pfn() a static inline

Making virt_to_pfn() a static inline taking a strongly typed
(const void *) makes the contract of a passing a pointer of that
type to the function explicit and exposes any misuse of the
macro virt_to_pfn() acting polymorphic and accepting many types
such as (void *), (unitptr_t) or (unsigned long) as arguments
without warnings.

In order to do this we move the virt_to_phys() and
below the definition of the __pa() and __va() macros so it
compiles. The macro version was also able to do recursive
symbol resolution.

Signed-off-by: Linus Walleij <[email protected]>
---
arch/arc/include/asm/page.h | 21 ++++++++++++---------
arch/arc/include/asm/pgtable-levels.h | 2 +-
2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/arch/arc/include/asm/page.h b/arch/arc/include/asm/page.h
index 02b53ad811fb..def0dfb95b43 100644
--- a/arch/arc/include/asm/page.h
+++ b/arch/arc/include/asm/page.h
@@ -84,15 +84,6 @@ typedef struct {

typedef struct page *pgtable_t;

-/*
- * Use virt_to_pfn with caution:
- * If used in pte or paddr related macros, it could cause truncation
- * in PAE40 builds
- * As a rule of thumb, only use it in helpers starting with virt_
- * You have been warned !
- */
-#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
-
/*
* When HIGHMEM is enabled we have holes in the memory map so we need
* pfn_valid() that takes into account the actual extents of the physical
@@ -122,6 +113,18 @@ extern int pfn_valid(unsigned long pfn);
#define __pa(vaddr) ((unsigned long)(vaddr))
#define __va(paddr) ((void *)((unsigned long)(paddr)))

+/*
+ * Use virt_to_pfn with caution:
+ * If used in pte or paddr related macros, it could cause truncation
+ * in PAE40 builds
+ * As a rule of thumb, only use it in helpers starting with virt_
+ * You have been warned !
+ */
+static inline unsigned long virt_to_pfn(const void *kaddr)
+{
+ return __pa(kaddr) >> PAGE_SHIFT;
+}
+
#define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr))
#define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr))

diff --git a/arch/arc/include/asm/pgtable-levels.h b/arch/arc/include/asm/pgtable-levels.h
index fc417c75c24d..86e148226463 100644
--- a/arch/arc/include/asm/pgtable-levels.h
+++ b/arch/arc/include/asm/pgtable-levels.h
@@ -159,7 +159,7 @@
#define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0)
#define pmd_page_vaddr(pmd) (pmd_val(pmd) & PAGE_MASK)
#define pmd_pfn(pmd) ((pmd_val(pmd) & PAGE_MASK) >> PAGE_SHIFT)
-#define pmd_page(pmd) virt_to_page(pmd_page_vaddr(pmd))
+#define pmd_page(pmd) virt_to_page((void *)pmd_page_vaddr(pmd))
#define set_pmd(pmdp, pmd) (*(pmdp) = pmd)
#define pmd_pgtable(pmd) ((pgtable_t) pmd_page(pmd))


---
base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d
change-id: 20230913-virt-to-phys-arc-b0b613c689b0

Best regards,
--
Linus Walleij <[email protected]>