2023-08-08 19:53:04

by Linus Walleij

Subject: [PATCH] Hexagon: Make pfn accessors statics inlines

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 do the same with pfn_to_virt().

For compiletime resolution of __pa() we need PAGE_OFFSET which
was not available to __pa() and resolved by the preprocessor
wherever __pa() was used. Fix this by explicitly including
<asm/mem-layout.h> where required, following the pattern of the
architectures page.h file.

Signed-off-by: Linus Walleij <[email protected]>
---
arch/hexagon/include/asm/page.h | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h
index 9c03b9965f07..b3d4a2c065be 100644
--- a/arch/hexagon/include/asm/page.h
+++ b/arch/hexagon/include/asm/page.h
@@ -78,6 +78,9 @@ typedef struct page *pgtable_t;
#define __pgd(x) ((pgd_t) { (x) })
#define __pgprot(x) ((pgprot_t) { (x) })

+/* Needed for PAGE_OFFSET used in the macro right below */
+#include <asm/mem-layout.h>
+
/*
* We need a __pa and a __va routine for kernel space.
* MIPS says they're only used during mem_init.
@@ -125,8 +128,16 @@ static inline void clear_page(void *page)
*/
#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)

-#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
-#define pfn_to_virt(pfn) __va((pfn) << PAGE_SHIFT)
+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 __va(pfn) << PAGE_SHIFT;
+}
+

#define page_to_virt(page) __va(page_to_phys(page))


---
base-commit: 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5
change-id: 20230808-hexagon-virt-to-pfn-457bd51a5744

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

2023-08-09 17:23:42

by Brian Cain

Subject: RE: [PATCH] Hexagon: Make pfn accessors statics inlines

> -----Original Message-----
> From: Linus Walleij <[email protected]>
> Sent: Tuesday, August 8, 2023 3:30 AM
> To: Brian Cain <[email protected]>
> Cc: [email protected]; [email protected]; Linus Walleij
> <[email protected]>
> Subject: [PATCH] Hexagon: Make pfn accessors statics inlines
>
> WARNING: This email originated from outside of Qualcomm. Please be wary of
> any links or attachments, and do not enable macros.
>
> 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 do the same with pfn_to_virt().
>
> For compiletime resolution of __pa() we need PAGE_OFFSET which
> was not available to __pa() and resolved by the preprocessor
> wherever __pa() was used. Fix this by explicitly including
> <asm/mem-layout.h> where required, following the pattern of the
> architectures page.h file.
>
> Signed-off-by: Linus Walleij <[email protected]>
> ---
> arch/hexagon/include/asm/page.h | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/arch/hexagon/include/asm/page.h
> b/arch/hexagon/include/asm/page.h
> index 9c03b9965f07..b3d4a2c065be 100644
> --- a/arch/hexagon/include/asm/page.h
> +++ b/arch/hexagon/include/asm/page.h
> @@ -78,6 +78,9 @@ typedef struct page *pgtable_t;
> #define __pgd(x) ((pgd_t) { (x) })
> #define __pgprot(x) ((pgprot_t) { (x) })
>
> +/* Needed for PAGE_OFFSET used in the macro right below */
> +#include <asm/mem-layout.h>
> +
> /*
> * We need a __pa and a __va routine for kernel space.
> * MIPS says they're only used during mem_init.
> @@ -125,8 +128,16 @@ static inline void clear_page(void *page)
> */
> #define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
>
> -#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
> -#define pfn_to_virt(pfn) __va((pfn) << PAGE_SHIFT)
> +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 __va(pfn) << PAGE_SHIFT;
> +}
> +
>
> #define page_to_virt(page) __va(page_to_phys(page))
>
>
> ---
> base-commit: 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5
> change-id: 20230808-hexagon-virt-to-pfn-457bd51a5744
>
> Best regards,
> --
> Linus Walleij <[email protected]>

Acked-by: Brian Cain <[email protected]>