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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>
122 lines
3.1 KiB
C
122 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/ftrace.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/mm_types.h>
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#include <linux/pgtable.h>
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#include <asm/bugs.h>
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#include <asm/cacheflush.h>
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#include <asm/idmap.h>
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#include <asm/page.h>
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#include <asm/smp_plat.h>
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#include <asm/suspend.h>
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#include <asm/tlbflush.h>
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extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid);
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extern void cpu_resume_mmu(void);
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#ifdef CONFIG_MMU
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int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
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{
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struct mm_struct *mm = current->active_mm;
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u32 __mpidr = cpu_logical_map(smp_processor_id());
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int ret;
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if (!idmap_pgd)
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return -EINVAL;
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/*
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* Function graph tracer state gets incosistent when the kernel
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* calls functions that never return (aka suspend finishers) hence
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* disable graph tracing during their execution.
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*/
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pause_graph_tracing();
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/*
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* Provide a temporary page table with an identity mapping for
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* the MMU-enable code, required for resuming. On successful
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* resume (indicated by a zero return code), we need to switch
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* back to the correct page tables.
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*/
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ret = __cpu_suspend(arg, fn, __mpidr);
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unpause_graph_tracing();
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if (ret == 0) {
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cpu_switch_mm(mm->pgd, mm);
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local_flush_bp_all();
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local_flush_tlb_all();
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check_other_bugs();
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}
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return ret;
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}
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#else
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int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
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{
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u32 __mpidr = cpu_logical_map(smp_processor_id());
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int ret;
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pause_graph_tracing();
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ret = __cpu_suspend(arg, fn, __mpidr);
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unpause_graph_tracing();
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return ret;
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}
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#define idmap_pgd NULL
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#endif
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/*
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* This is called by __cpu_suspend() to save the state, and do whatever
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* flushing is required to ensure that when the CPU goes to sleep we have
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* the necessary data available when the caches are not searched.
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*/
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void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
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{
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u32 *ctx = ptr;
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*save_ptr = virt_to_phys(ptr);
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/* This must correspond to the LDM in cpu_resume() assembly */
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*ptr++ = virt_to_phys(idmap_pgd);
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*ptr++ = sp;
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*ptr++ = virt_to_phys(cpu_do_resume);
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cpu_do_suspend(ptr);
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flush_cache_louis();
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/*
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* flush_cache_louis does not guarantee that
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* save_ptr and ptr are cleaned to main memory,
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* just up to the Level of Unification Inner Shareable.
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* Since the context pointer and context itself
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* are to be retrieved with the MMU off that
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* data must be cleaned from all cache levels
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* to main memory using "area" cache primitives.
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*/
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__cpuc_flush_dcache_area(ctx, ptrsz);
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__cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr));
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outer_clean_range(*save_ptr, *save_ptr + ptrsz);
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outer_clean_range(virt_to_phys(save_ptr),
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virt_to_phys(save_ptr) + sizeof(*save_ptr));
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}
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extern struct sleep_save_sp sleep_save_sp;
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static int cpu_suspend_alloc_sp(void)
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{
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void *ctx_ptr;
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/* ctx_ptr is an array of physical addresses */
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ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL);
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if (WARN_ON(!ctx_ptr))
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return -ENOMEM;
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sleep_save_sp.save_ptr_stash = ctx_ptr;
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sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
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sync_cache_w(&sleep_save_sp);
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return 0;
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}
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early_initcall(cpu_suspend_alloc_sp);
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