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a9ff696160
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>
33 lines
800 B
ArmAsm
33 lines
800 B
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (c) 2003 ARM Limited
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* Copyright (c) u-boot contributors
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* Copyright (c) 2012 Pavel Machek <pavel@denx.de>
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*/
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#include <linux/linkage.h>
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#include <linux/init.h>
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#include <asm/page.h>
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#include <asm/assembler.h>
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.arch armv7-a
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.arm
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ENTRY(secondary_trampoline)
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/* CPU1 will always fetch from 0x0 when it is brought out of reset.
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* Thus, we can just subtract the PAGE_OFFSET to get the physical
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* address of &cpu1start_addr. This would not work for platforms
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* where the physical memory does not start at 0x0.
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*/
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ARM_BE8(setend be)
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adr r0, 1f
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ldmia r0, {r1, r2}
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sub r2, r2, #PAGE_OFFSET
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ldr r3, [r2]
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ldr r4, [r3]
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ARM_BE8(rev r4, r4)
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bx r4
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.align
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1: .long .
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.long socfpga_cpu1start_addr
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ENTRY(secondary_trampoline_end)
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