linux/arch/arm/mach-rockchip
Linus Walleij a9ff696160 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>
2023-05-29 11:27:08 +02:00
..
core.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
headsmp.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
platsmp.c ARM: rockchip: fix typos in comments 2022-04-04 10:43:20 +02:00
pm.c ARM: rockchip: Add missing of_node_put() in rockchip_suspend_init() 2022-06-17 19:05:51 +02:00
pm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
rockchip.c ARM: rockchip: Replace <linux/clk-provider.h> by <linux/of_clk.h> 2020-04-13 09:40:45 +02:00
sleep.S ARM: mm: Make virt_to_pfn() a static inline 2023-05-29 11:27:08 +02:00