Preallocate a page table and setup an identity mapping for the MMU enable code. This means we don't have to "borrow" a page table to do this, avoiding complexities with L2 cache coherency. 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>tirimbino
Russell King
14 years ago
parent
f5fa68d967
commit
e8ce0eb5e2
@ -1,22 +1,7 @@ |
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#ifndef __ASM_ARM_SUSPEND_H |
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#define __ASM_ARM_SUSPEND_H |
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#include <asm/memory.h> |
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#include <asm/tlbflush.h> |
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extern void cpu_resume(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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static inline int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) |
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{ |
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extern int __cpu_suspend(int, long, unsigned long, |
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int (*)(unsigned long)); |
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int ret = __cpu_suspend(0, PHYS_OFFSET - PAGE_OFFSET, arg, fn); |
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flush_tlb_all(); |
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return ret; |
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} |
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extern int cpu_suspend(unsigned long, int (*)(unsigned long)); |
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#endif |
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@ -0,0 +1,48 @@ |
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#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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* Temporarily switch the page tables to our suspend page |
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* tables, which contain the temporary identity mapping |
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* required for resuming. |
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*/ |
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cpu_switch_mm(suspend_pgd, mm); |
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ret = __cpu_suspend(0, PHYS_OFFSET - PAGE_OFFSET, arg, fn); |
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cpu_switch_mm(mm->pgd, mm); |
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local_flush_tlb_all(); |
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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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