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author | Arnd Bergmann <arnd@arndb.de> | 2011-10-08 21:07:42 +0200 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2011-10-08 21:07:42 +0200 |
commit | 71f2c153755442c05d15cd025484f676a5f3541f (patch) | |
tree | fe48af6ddc33da7a0aaf1a16ed9feeafa4a8e1e1 /arch/arm/kernel/suspend.c | |
parent | Merge branch 'sirf/cleanup' into next/cleanup (diff) | |
parent | Merge branch 'for_3_2/for-rmk/arm_cpu_pm' of git://gitorious.org/omap-sw-develoment/linux-omap-dev into devel-stable (diff) | |
download | linux-dev-71f2c153755442c05d15cd025484f676a5f3541f.tar.xz linux-dev-71f2c153755442c05d15cd025484f676a5f3541f.zip |
Merge branch 'depends/rmk/devel-stable' into next/cleanup
Diffstat (limited to 'arch/arm/kernel/suspend.c')
-rw-r--r-- | arch/arm/kernel/suspend.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c new file mode 100644 index 000000000000..93a22d282c16 --- /dev/null +++ b/arch/arm/kernel/suspend.c @@ -0,0 +1,72 @@ +#include <linux/init.h> + +#include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/memory.h> +#include <asm/suspend.h> +#include <asm/tlbflush.h> + +static pgd_t *suspend_pgd; + +extern int __cpu_suspend(unsigned long, int (*)(unsigned long)); +extern void cpu_resume_mmu(void); + +/* + * This is called by __cpu_suspend() to save the state, and do whatever + * flushing is required to ensure that when the CPU goes to sleep we have + * the necessary data available when the caches are not searched. + */ +void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) +{ + *save_ptr = virt_to_phys(ptr); + + /* This must correspond to the LDM in cpu_resume() assembly */ + *ptr++ = virt_to_phys(suspend_pgd); + *ptr++ = sp; + *ptr++ = virt_to_phys(cpu_do_resume); + + cpu_do_suspend(ptr); + + flush_cache_all(); + outer_clean_range(*save_ptr, *save_ptr + ptrsz); + outer_clean_range(virt_to_phys(save_ptr), + virt_to_phys(save_ptr) + sizeof(*save_ptr)); +} + +/* + * Hide the first two arguments to __cpu_suspend - these are an implementation + * detail which platform code shouldn't have to know about. + */ +int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) +{ + struct mm_struct *mm = current->active_mm; + int ret; + + if (!suspend_pgd) + return -EINVAL; + + /* + * Provide a temporary page table with an identity mapping for + * the MMU-enable code, required for resuming. On successful + * resume (indicated by a zero return code), we need to switch + * back to the correct page tables. + */ + ret = __cpu_suspend(arg, fn); + if (ret == 0) { + cpu_switch_mm(mm->pgd, mm); + local_flush_tlb_all(); + } + + return ret; +} + +static int __init cpu_suspend_init(void) +{ + suspend_pgd = pgd_alloc(&init_mm); + if (suspend_pgd) { + unsigned long addr = virt_to_phys(cpu_resume_mmu); + identity_mapping_add(suspend_pgd, addr, addr + SECTION_SIZE); + } + return suspend_pgd ? 0 : -ENOMEM; +} +core_initcall(cpu_suspend_init); |