[PATCH v3 0/2] csky: Convert memory accessors to static inlines

[PATCH v3 0/2] csky: Convert memory accessors to static inlines

[Linus Walleij]

This converts the virt_to_pfn and pfn_to_virt macros
into static inlines so we get proper type checking on
the pointers passed in.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
Changes in v3:
- Do not return const void * from pfn_to_virt(), return
  void * so we don't case a mess.
- Link to v2: https://lore.kernel.org/r/20230809-csky-virt-to-phys-v2-0-2697c93f60cf@linaro.org

Changes in v2:
- Fix compilation error on pfn_to_virt() by more casting.
- Return const void * rather than just void * from pfn_to_virt()
- Link to v1: https://lore.kernel.org/r/20230808-csky-virt-to-phys-v1-0-ac727f8def2f@linaro.org

---
Linus Walleij (2):
      csky: Cast argument to virt_to_pfn() to (void *)
      csky: Make pfn accessors static inlines

 arch/arc/include/asm/page.h  |  2 +-
 arch/csky/include/asm/page.h | 13 ++++++++++---
 2 files changed, 11 insertions(+), 4 deletions(-)
---
base-commit: 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5
change-id: 20230808-csky-virt-to-phys-3d80c17211f9

Best regards,
-- 
Linus Walleij <linus.walleij@linaro.org>

[PATCH v3 1/2] csky: Cast argument to virt_to_pfn() to (void *)

[Linus Walleij]

The virt_to_pfn() function takes a (void *) as argument, fix
this up to avoid exploiting the unintended polymorphism of
virt_to_pfn.

Acked-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 arch/arc/include/asm/page.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arc/include/asm/page.h b/arch/arc/include/asm/page.h
index e43fe27ec54d..02b53ad811fb 100644
--- a/arch/arc/include/asm/page.h
+++ b/arch/arc/include/asm/page.h
@@ -108,7 +108,7 @@ extern int pfn_valid(unsigned long pfn);
 
 #else /* CONFIG_HIGHMEM */
 
-#define ARCH_PFN_OFFSET		virt_to_pfn(CONFIG_LINUX_RAM_BASE)
+#define ARCH_PFN_OFFSET		virt_to_pfn((void *)CONFIG_LINUX_RAM_BASE)
 
 #endif /* CONFIG_HIGHMEM */
 

-- 
2.34.1

[PATCH v3 2/2] csky: Make pfn accessors static inlines

[Linus Walleij]

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.

For symmetry to the same thing with pfn_to_virt().

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

Acked-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 arch/csky/include/asm/page.h | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/csky/include/asm/page.h b/arch/csky/include/asm/page.h
index b23e3006a9e0..4a0502e324a6 100644
--- a/arch/csky/include/asm/page.h
+++ b/arch/csky/include/asm/page.h
@@ -34,9 +34,6 @@
 
 #include <linux/pfn.h>
 
-#define virt_to_pfn(kaddr)      (__pa(kaddr) >> PAGE_SHIFT)
-#define pfn_to_virt(pfn)        __va((pfn) << PAGE_SHIFT)
-
 #define virt_addr_valid(kaddr)  ((void *)(kaddr) >= (void *)PAGE_OFFSET && \
 			(void *)(kaddr) < high_memory)
 
@@ -80,6 +77,16 @@ extern unsigned long va_pa_offset;
 
 #define __pa_symbol(x)	__pa(RELOC_HIDE((unsigned long)(x), 0))
 
+static inline unsigned long virt_to_pfn(const void *kaddr)
+{
+	return __pa(kaddr) >> PAGE_SHIFT;
+}
+
+static inline void * pfn_to_virt(unsigned long pfn)
+{
+	return (void *)((unsigned long)__va(pfn) << PAGE_SHIFT);
+}
+
 #define MAP_NR(x)	PFN_DOWN((unsigned long)(x) - PAGE_OFFSET - \
 				 PHYS_OFFSET_OFFSET)
 #define virt_to_page(x)	(mem_map + MAP_NR(x))

-- 
2.34.1