diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/suspend_64.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/kernel/suspend_64.c b/arch/x86/kernel/suspend_64.c index 2e5efaaf880..569f1b540e3 100644 --- a/arch/x86/kernel/suspend_64.c +++ b/arch/x86/kernel/suspend_64.c @@ -19,6 +19,21 @@ extern const void __nosave_begin, __nosave_end; struct saved_context saved_context; +/** + * __save_processor_state - save CPU registers before creating a + * hibernation image and before restoring the memory state from it + * @ctxt - structure to store the registers contents in + * + * NOTE: If there is a CPU register the modification of which by the + * boot kernel (ie. the kernel used for loading the hibernation image) + * might affect the operations of the restored target kernel (ie. the one + * saved in the hibernation image), then its contents must be saved by this + * function. In other words, if kernel A is hibernated and different + * kernel B is used for loading the hibernation image into memory, the + * kernel A's __save_processor_state() function must save all registers + * needed by kernel A, so that it can operate correctly after the resume + * regardless of what kernel B does in the meantime. + */ void __save_processor_state(struct saved_context *ctxt) { kernel_fpu_begin(); @@ -69,6 +84,11 @@ static void do_fpu_end(void) kernel_fpu_end(); } +/** + * __restore_processor_state - restore the contents of CPU registers saved + * by __save_processor_state() + * @ctxt - structure to load the registers contents from + */ void __restore_processor_state(struct saved_context *ctxt) { /* |