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de8e71ca4f
Only use the preallocated page table during the resume, not while suspending. This avoids the overhead of having to switch unnecessarily to the resume page table in the suspend path. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
52 lines
1.3 KiB
C
52 lines
1.3 KiB
C
#include <linux/init.h>
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#include <asm/pgalloc.h>
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#include <asm/pgtable.h>
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#include <asm/memory.h>
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#include <asm/suspend.h>
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#include <asm/tlbflush.h>
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static pgd_t *suspend_pgd;
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extern int __cpu_suspend(int, long, unsigned long, int (*)(unsigned long));
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extern void cpu_resume_turn_mmu_on(void);
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/*
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* Hide the first two arguments to __cpu_suspend - these are an implementation
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* detail which platform code shouldn't have to know about.
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*/
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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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int ret;
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if (!suspend_pgd)
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return -EINVAL;
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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(virt_to_phys(suspend_pgd),
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PHYS_OFFSET - PAGE_OFFSET, arg, fn);
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if (ret == 0) {
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cpu_switch_mm(mm->pgd, mm);
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local_flush_tlb_all();
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}
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return ret;
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}
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static int __init cpu_suspend_init(void)
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{
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suspend_pgd = pgd_alloc(&init_mm);
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if (suspend_pgd) {
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unsigned long addr = virt_to_phys(cpu_resume_turn_mmu_on);
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identity_mapping_add(suspend_pgd, addr, addr + SECTION_SIZE);
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}
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return suspend_pgd ? 0 : -ENOMEM;
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}
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core_initcall(cpu_suspend_init);
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