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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>
32 lines
806 B
ArmAsm
32 lines
806 B
ArmAsm
/* SPDX-License-Identifier: GPL-2.0+
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*
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* Shared SCU setup for mach-shmobile
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*
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* Copyright (C) 2012 Bastian Hecht
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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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/*
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* Boot code for secondary CPUs.
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*
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* First we turn on L1 cache coherency for our CPU. Then we jump to
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* secondary_startup that invalidates the cache and hands over control
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* to the common ARM startup code.
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*/
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ENTRY(shmobile_boot_scu)
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@ r0 = SCU base address
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mrc p15, 0, r1, c0, c0, 5 @ read MPIDR
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and r1, r1, #3 @ mask out cpu ID
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lsl r1, r1, #3 @ we will shift by cpu_id * 8 bits
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ldr r2, [r0, #8] @ SCU Power Status Register
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mov r3, #3
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lsl r3, r3, r1
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bic r2, r2, r3 @ Clear bits of our CPU (Run Mode)
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str r2, [r0, #8] @ write back
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b secondary_startup
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ENDPROC(shmobile_boot_scu)
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