diff options
author | James Morse <james.morse@arm.com> | 2016-04-27 17:47:06 +0100 |
---|---|---|
committer | Will Deacon <will.deacon@arm.com> | 2016-04-28 12:05:46 +0100 |
commit | adc9b2dfd00924e9e9b98613f36a6cb8c51f0dc6 (patch) | |
tree | 127168cb8901a501fa01f87491e18566f81f5630 /arch/arm64/kernel/suspend.c | |
parent | 67f6919766620e7ea7aab11a6a3470dc7b451359 (diff) |
arm64: kernel: Rework finisher callback out of __cpu_suspend_enter()
Hibernate could make use of the cpu_suspend() code to save/restore cpu
state, however it needs to be able to return '0' from the 'finisher'.
Rework cpu_suspend() so that the finisher is called from C code,
independently from the save/restore of cpu state. Space to save the context
in is allocated in the caller's stack frame, and passed into
__cpu_suspend_enter().
Hibernate's use of this API will look like a copy of the cpu_suspend()
function.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/suspend.c')
-rw-r--r-- | arch/arm64/kernel/suspend.c | 72 |
1 files changed, 42 insertions, 30 deletions
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index 66055392f445..0d52ec972a38 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -10,22 +10,22 @@ #include <asm/suspend.h> #include <asm/tlbflush.h> -extern int __cpu_suspend_enter(unsigned long arg, int (*fn)(unsigned long)); + /* * This is called by __cpu_suspend_enter() 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. * - * ptr: CPU context virtual address + * ptr: sleep_stack_data containing cpu state virtual address. * save_ptr: address of the location where the context physical address * must be saved */ -void notrace __cpu_suspend_save(struct cpu_suspend_ctx *ptr, +void notrace __cpu_suspend_save(struct sleep_stack_data *ptr, phys_addr_t *save_ptr) { *save_ptr = virt_to_phys(ptr); - cpu_do_suspend(ptr); + cpu_do_suspend(&ptr->system_regs); /* * Only flush the context that must be retrieved with the MMU * off. VA primitives ensure the flush is applied to all @@ -51,6 +51,30 @@ void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *)) hw_breakpoint_restore = hw_bp_restore; } +void notrace __cpu_suspend_exit(void) +{ + /* + * We are resuming from reset with the idmap active in TTBR0_EL1. + * We must uninstall the idmap and restore the expected MMU + * state before we can possibly return to userspace. + */ + cpu_uninstall_idmap(); + + /* + * Restore per-cpu offset before any kernel + * subsystem relying on it has a chance to run. + */ + set_my_cpu_offset(per_cpu_offset(smp_processor_id())); + + /* + * Restore HW breakpoint registers to sane values + * before debug exceptions are possibly reenabled + * through local_dbg_restore. + */ + if (hw_breakpoint_restore) + hw_breakpoint_restore(NULL); +} + /* * cpu_suspend * @@ -60,8 +84,9 @@ void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *)) */ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) { - int ret; + int ret = 0; unsigned long flags; + struct sleep_stack_data state; /* * From this point debug exceptions are disabled to prevent @@ -77,34 +102,21 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) */ pause_graph_tracing(); - /* - * mm context saved on the stack, it will be restored when - * the cpu comes out of reset through the identity mapped - * page tables, so that the thread address space is properly - * set-up on function return. - */ - ret = __cpu_suspend_enter(arg, fn); - if (ret == 0) { - /* - * We are resuming from reset with the idmap active in TTBR0_EL1. - * We must uninstall the idmap and restore the expected MMU - * state before we can possibly return to userspace. - */ - cpu_uninstall_idmap(); - - /* - * Restore per-cpu offset before any kernel - * subsystem relying on it has a chance to run. - */ - set_my_cpu_offset(per_cpu_offset(smp_processor_id())); + if (__cpu_suspend_enter(&state)) { + /* Call the suspend finisher */ + ret = fn(arg); /* - * Restore HW breakpoint registers to sane values - * before debug exceptions are possibly reenabled - * through local_dbg_restore. + * Never gets here, unless the suspend finisher fails. + * Successful cpu_suspend() should return from cpu_resume(), + * returning through this code path is considered an error + * If the return value is set to 0 force ret = -EOPNOTSUPP + * to make sure a proper error condition is propagated */ - if (hw_breakpoint_restore) - hw_breakpoint_restore(NULL); + if (!ret) + ret = -EOPNOTSUPP; + } else { + __cpu_suspend_exit(); } unpause_graph_tracing(); |