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Diffstat (limited to 'arch/arm64/kernel/suspend.c')
-rw-r--r--arch/arm64/kernel/suspend.c102
1 files changed, 44 insertions, 58 deletions
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c
index 66055392f445..b616e365cee3 100644
--- a/arch/arm64/kernel/suspend.c
+++ b/arch/arm64/kernel/suspend.c
@@ -10,30 +10,11 @@
#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
- * save_ptr: address of the location where the context physical address
- * must be saved
+ * This is allocated by cpu_suspend_init(), and used to store a pointer to
+ * the 'struct sleep_stack_data' the contains a particular CPUs state.
*/
-void notrace __cpu_suspend_save(struct cpu_suspend_ctx *ptr,
- phys_addr_t *save_ptr)
-{
- *save_ptr = virt_to_phys(ptr);
-
- cpu_do_suspend(ptr);
- /*
- * Only flush the context that must be retrieved with the MMU
- * off. VA primitives ensure the flush is applied to all
- * cache levels so context is pushed to DRAM.
- */
- __flush_dcache_area(ptr, sizeof(*ptr));
- __flush_dcache_area(save_ptr, sizeof(*save_ptr));
-}
+unsigned long *sleep_save_stash;
/*
* This hook is provided so that cpu_suspend code can restore HW
@@ -51,6 +32,30 @@ 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 +65,9 @@ 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 +83,21 @@ 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();
+ if (__cpu_suspend_enter(&state)) {
+ /* Call the suspend finisher */
+ ret = fn(arg);
/*
- * Restore per-cpu offset before any kernel
- * subsystem relying on it has a chance to run.
+ * 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
*/
- 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);
+ if (!ret)
+ ret = -EOPNOTSUPP;
+ } else {
+ __cpu_suspend_exit();
}
unpause_graph_tracing();
@@ -119,22 +112,15 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
return ret;
}
-struct sleep_save_sp sleep_save_sp;
-
static int __init cpu_suspend_init(void)
{
- void *ctx_ptr;
-
/* ctx_ptr is an array of physical addresses */
- ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(phys_addr_t), GFP_KERNEL);
+ sleep_save_stash = kcalloc(mpidr_hash_size(), sizeof(*sleep_save_stash),
+ GFP_KERNEL);
- if (WARN_ON(!ctx_ptr))
+ if (WARN_ON(!sleep_save_stash))
return -ENOMEM;
- sleep_save_sp.save_ptr_stash = ctx_ptr;
- sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
- __flush_dcache_area(&sleep_save_sp, sizeof(struct sleep_save_sp));
-
return 0;
}
early_initcall(cpu_suspend_init);