8e6f83bbdf
We need to ensure that state is pushed out from the L2 cache when suspending so that the resume paths can access their data before the MMU and caches have been re-initialized. Add the necessary calls to __cpu_suspend_save(). 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>
73 lines
1.9 KiB
C
73 lines
1.9 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(unsigned long, int (*)(unsigned long));
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extern void cpu_resume_mmu(void);
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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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*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(suspend_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_all();
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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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/*
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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(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_mmu);
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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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