projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| fb4a9602 | 1 | #include <linux/percpu.h> |
| 95322526 LP |
2 | #include <linux/slab.h> |
| 3 | #include <asm/cacheflush.h> | |
| 4 | #include <asm/cpu_ops.h> | |
| 5 | #include <asm/debug-monitors.h> | |
| 6 | #include <asm/pgtable.h> | |
| 7 | #include <asm/memory.h> | |
| 8 | #include <asm/smp_plat.h> | |
| 9 | #include <asm/suspend.h> | |
| 10 | #include <asm/tlbflush.h> | |
| 11 | ||
| 12 | extern int __cpu_suspend(unsigned long); | |
| 13 | /* | |
| 14 | * This is called by __cpu_suspend() to save the state, and do whatever | |
| 15 | * flushing is required to ensure that when the CPU goes to sleep we have | |
| 16 | * the necessary data available when the caches are not searched. | |
| 17 | * | |
| 18 | * @arg: Argument to pass to suspend operations | |
| 19 | * @ptr: CPU context virtual address | |
| 20 | * @save_ptr: address of the location where the context physical address | |
| 21 | * must be saved | |
| 22 | */ | |
| 23 | int __cpu_suspend_finisher(unsigned long arg, struct cpu_suspend_ctx *ptr, | |
| 24 | phys_addr_t *save_ptr) | |
| 25 | { | |
| 26 | int cpu = smp_processor_id(); | |
| 27 | ||
| 28 | *save_ptr = virt_to_phys(ptr); | |
| 29 | ||
| 30 | cpu_do_suspend(ptr); | |
| 31 | /* | |
| 32 | * Only flush the context that must be retrieved with the MMU | |
| 33 | * off. VA primitives ensure the flush is applied to all | |
| 34 | * cache levels so context is pushed to DRAM. | |
| 35 | */ | |
| 36 | __flush_dcache_area(ptr, sizeof(*ptr)); | |
| 37 | __flush_dcache_area(save_ptr, sizeof(*save_ptr)); | |
| 38 | ||
| 39 | return cpu_ops[cpu]->cpu_suspend(arg); | |
| 40 | } | |
| 41 | ||
| 65c021bb LP |
42 | /* |
| 43 | * This hook is provided so that cpu_suspend code can restore HW | |
| 44 | * breakpoints as early as possible in the resume path, before reenabling | |
| 45 | * debug exceptions. Code cannot be run from a CPU PM notifier since by the | |
| 46 | * time the notifier runs debug exceptions might have been enabled already, | |
| 47 | * with HW breakpoints registers content still in an unknown state. | |
| 48 | */ | |
| 49 | void (*hw_breakpoint_restore)(void *); | |
| 50 | void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *)) | |
| 51 | { | |
| 52 | /* Prevent multiple restore hook initializations */ | |
| 53 | if (WARN_ON(hw_breakpoint_restore)) | |
| 54 | return; | |
| 55 | hw_breakpoint_restore = hw_bp_restore; | |
| 56 | } | |
| 57 | ||
| 95322526 LP |
58 | /** |
| 59 | * cpu_suspend | |
| 60 | * | |
| 61 | * @arg: argument to pass to the finisher function | |
| 62 | */ | |
| 63 | int cpu_suspend(unsigned long arg) | |
| 64 | { | |
| 65 | struct mm_struct *mm = current->active_mm; | |
| 66 | int ret, cpu = smp_processor_id(); | |
| 67 | unsigned long flags; | |
| 68 | ||
| 69 | /* | |
| 70 | * If cpu_ops have not been registered or suspend | |
| 71 | * has not been initialized, cpu_suspend call fails early. | |
| 72 | */ | |
| 73 | if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend) | |
| 74 | return -EOPNOTSUPP; | |
| 75 | ||
| 76 | /* | |
| 77 | * From this point debug exceptions are disabled to prevent | |
| 78 | * updates to mdscr register (saved and restored along with | |
| 79 | * general purpose registers) from kernel debuggers. | |
| 80 | */ | |
| 81 | local_dbg_save(flags); | |
| 82 | ||
| 83 | /* | |
| 84 | * mm context saved on the stack, it will be restored when | |
| 85 | * the cpu comes out of reset through the identity mapped | |
| 86 | * page tables, so that the thread address space is properly | |
| 87 | * set-up on function return. | |
| 88 | */ | |
| 89 | ret = __cpu_suspend(arg); | |
| 90 | if (ret == 0) { | |
| 91 | cpu_switch_mm(mm->pgd, mm); | |
| 92 | flush_tlb_all(); | |
| fb4a9602 LP |
93 | |
| 94 | /* | |
| 95 | * Restore per-cpu offset before any kernel | |
| 96 | * subsystem relying on it has a chance to run. | |
| 97 | */ | |
| 98 | set_my_cpu_offset(per_cpu_offset(cpu)); | |
| 99 | ||
| 65c021bb LP |
100 | /* |
| 101 | * Restore HW breakpoint registers to sane values | |
| 102 | * before debug exceptions are possibly reenabled | |
| 103 | * through local_dbg_restore. | |
| 104 | */ | |
| 105 | if (hw_breakpoint_restore) | |
| 106 | hw_breakpoint_restore(NULL); | |
| 95322526 LP |
107 | } |
| 108 | ||
| 109 | /* | |
| 110 | * Restore pstate flags. OS lock and mdscr have been already | |
| 111 | * restored, so from this point onwards, debugging is fully | |
| 112 | * renabled if it was enabled when core started shutdown. | |
| 113 | */ | |
| 114 | local_dbg_restore(flags); | |
| 115 | ||
| 116 | return ret; | |
| 117 | } | |
| 118 | ||
| 119 | extern struct sleep_save_sp sleep_save_sp; | |
| 120 | extern phys_addr_t sleep_idmap_phys; | |
| 121 | ||
| 122 | static int cpu_suspend_init(void) | |
| 123 | { | |
| 124 | void *ctx_ptr; | |
| 125 | ||
| 126 | /* ctx_ptr is an array of physical addresses */ | |
| 127 | ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(phys_addr_t), GFP_KERNEL); | |
| 128 | ||
| 129 | if (WARN_ON(!ctx_ptr)) | |
| 130 | return -ENOMEM; | |
| 131 | ||
| 132 | sleep_save_sp.save_ptr_stash = ctx_ptr; | |
| 133 | sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr); | |
| 134 | sleep_idmap_phys = virt_to_phys(idmap_pg_dir); | |
| 135 | __flush_dcache_area(&sleep_save_sp, sizeof(struct sleep_save_sp)); | |
| 136 | __flush_dcache_area(&sleep_idmap_phys, sizeof(sleep_idmap_phys)); | |
| 137 | ||
| 138 | return 0; | |
| 139 | } | |
| 140 | early_initcall(cpu_suspend_init); |