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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/mips/kernel/pm.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/kernel/pm.c')
-rw-r--r-- | arch/mips/kernel/pm.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/arch/mips/kernel/pm.c b/arch/mips/kernel/pm.c new file mode 100644 index 000000000..486ed2bf2 --- /dev/null +++ b/arch/mips/kernel/pm.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2014 Imagination Technologies Ltd. + * + * CPU PM notifiers for saving/restoring general CPU state. + */ + +#include <linux/cpu_pm.h> +#include <linux/init.h> + +#include <asm/dsp.h> +#include <asm/fpu.h> +#include <asm/mmu_context.h> +#include <asm/pm.h> +#include <asm/watch.h> + +/* Used by PM helper macros in asm/pm.h */ +struct mips_static_suspend_state mips_static_suspend_state; + +/** + * mips_cpu_save() - Save general CPU state. + * Ensures that general CPU context is saved, notably FPU and DSP. + */ +static int mips_cpu_save(void) +{ + /* Save FPU state */ + lose_fpu(1); + + /* Save DSP state */ + save_dsp(current); + + return 0; +} + +/** + * mips_cpu_restore() - Restore general CPU state. + * Restores important CPU context. + */ +static void mips_cpu_restore(void) +{ + unsigned int cpu = smp_processor_id(); + + /* Restore ASID */ + if (current->mm) + write_c0_entryhi(cpu_asid(cpu, current->mm)); + + /* Restore DSP state */ + restore_dsp(current); + + /* Restore UserLocal */ + if (cpu_has_userlocal) + write_c0_userlocal(current_thread_info()->tp_value); + + /* Restore watch registers */ + __restore_watch(current); +} + +/** + * mips_pm_notifier() - Notifier for preserving general CPU context. + * @self: Notifier block. + * @cmd: CPU PM event. + * @v: Private data (unused). + * + * This is called when a CPU power management event occurs, and is used to + * ensure that important CPU context is preserved across a CPU power down. + */ +static int mips_pm_notifier(struct notifier_block *self, unsigned long cmd, + void *v) +{ + int ret; + + switch (cmd) { + case CPU_PM_ENTER: + ret = mips_cpu_save(); + if (ret) + return NOTIFY_STOP; + break; + case CPU_PM_ENTER_FAILED: + case CPU_PM_EXIT: + mips_cpu_restore(); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block mips_pm_notifier_block = { + .notifier_call = mips_pm_notifier, +}; + +static int __init mips_pm_init(void) +{ + return cpu_pm_register_notifier(&mips_pm_notifier_block); +} +arch_initcall(mips_pm_init); |