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| author | Linus Walleij <linus.walleij@linaro.org> | 2022-06-02 10:18:32 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2023-05-29 11:27:08 +0200 |
| commit | a9ff6961601d9aa0c42b6eb7d850371f31b1f5e6 (patch) | |
| tree | 4f685558e06fb4667cb7634285d4d5eff4d1e7d8 /arch/arm/mm/cache-v4wb.S | |
| parent | asm-generic/page.h: Make pfn accessors static inlines (diff) | |
| download | linux-a9ff6961601d9aa0c42b6eb7d850371f31b1f5e6.tar.xz linux-a9ff6961601d9aa0c42b6eb7d850371f31b1f5e6.zip | |
ARM: 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.
Doing this is a bit intrusive: virt_to_pfn() requires
PHYS_PFN_OFFSET and PAGE_SHIFT to be defined, and this is defined in
<asm/page.h>, so this must be included *before* <asm/memory.h>.
The use of macros were obscuring the unclear inclusion order here,
as the macros would eventually be resolved, but a static inline
like this cannot be compiled with unresolved macros.
The naive solution to include <asm/page.h> at the top of
<asm/memory.h> does not work, because <asm/memory.h> sometimes
includes <asm/page.h> at the end of itself, which would create a
confusing inclusion loop. So instead, take the approach to always
unconditionally include <asm/page.h> at the end of <asm/memory.h>
arch/arm uses <asm/memory.h> explicitly in a lot of places,
however it turns out that if we just unconditionally include
<asm/memory.h> into <asm/page.h> and switch all inclusions of
<asm/memory.h> to <asm/page.h> instead, we enforce the right
order and <asm/memory.h> will always have access to the
definitions.
Put an inclusion guard in place making it impossible to include
<asm/memory.h> explicitly.
Link: https://lore.kernel.org/linux-mm/20220701160004.2ffff4e5ab59a55499f4c736@linux-foundation.org/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'arch/arm/mm/cache-v4wb.S')
| -rw-r--r-- | arch/arm/mm/cache-v4wb.S | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/arm/mm/cache-v4wb.S b/arch/arm/mm/cache-v4wb.S index 905ac2fa2b1e..ad382cee0fdb 100644 --- a/arch/arm/mm/cache-v4wb.S +++ b/arch/arm/mm/cache-v4wb.S @@ -7,7 +7,6 @@ #include <linux/linkage.h> #include <linux/init.h> #include <asm/assembler.h> -#include <asm/memory.h> #include <asm/page.h> #include "proc-macros.S" |