[PATCH v3 1/1] arm64: kernel: remove ARM64_CPU_SUSPEND config option
Bartlomiej Zolnierkiewicz
b.zolnierkie at samsung.com
Fri Jan 30 08:18:27 PST 2015
Hi,
On Monday, January 26, 2015 06:33:44 PM Lorenzo Pieralisi wrote:
> ARM64_CPU_SUSPEND config option was introduced to make code providing
> context save/restore selectable only on platforms requiring power
> management capabilities.
>
> Currently ARM64_CPU_SUSPEND depends on the PM_SLEEP config option which
> in turn is set by the SUSPEND config option.
>
> The introduction of CPU_IDLE for arm64 requires that code configured
> by ARM64_CPU_SUSPEND (context save/restore) should be compiled in
> in order to enable the CPU idle driver to rely on CPU operations
> carrying out context save/restore.
>
> The ARM64_CPUIDLE config option (ARM64 generic idle driver) is therefore
> forced to select ARM64_CPU_SUSPEND, even if there may be (ie PM_SLEEP)
> failed dependencies, which is not a clean way of handling the kernel
> configuration option.
>
> For these reasons, this patch removes the ARM64_CPU_SUSPEND config option
> and makes the context save/restore dependent on CPU_PM, which is selected
> whenever either SUSPEND or CPU_IDLE are configured, cleaning up dependencies
> in the process.
>
> This way, code previously configured through ARM64_CPU_SUSPEND is
> compiled in whenever a power management subsystem requires it to be
> present in the kernel (SUSPEND || CPU_IDLE), which is the behaviour
> expected on ARM64 kernels.
>
> The cpu_suspend and cpu_init_idle CPU operations are added only if
> CPU_IDLE is selected, since they are CPU_IDLE specific methods and
> should be grouped and defined accordingly.
>
> PSCI CPU operations are updated to reflect the introduced changes.
cpu_suspend CPU operation is currently CPU_IDLE specific but I wonder
whether this is correct in the context of PSCI?
[ On 32-bit ARM PSCI cpu_suspend operation can be used in suspend code-path
(please take a look at arch/arm/mach-highbank/pm.c), on 64-bit ARM PSCI
this is not possible currently. ]
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
> Cc: Arnd Bergmann <arnd at arndb.de>
> Cc: Will Deacon <will.deacon at arm.com>
> Cc: Krzysztof Kozlowski <k.kozlowski at samsung.com>
> Cc: Daniel Lezcano <daniel.lezcano at linaro.org>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Mark Rutland <mark.rutland at arm.com>
> ---
> arch/arm64/Kconfig | 3 ---
> arch/arm64/include/asm/cpu_ops.h | 8 ++++----
> arch/arm64/include/asm/cpuidle.h | 6 ++++++
> arch/arm64/include/asm/suspend.h | 2 --
> arch/arm64/kernel/Makefile | 2 +-
> arch/arm64/kernel/asm-offsets.c | 2 +-
> arch/arm64/kernel/cpuidle.c | 20 ++++++++++++++++++++
> arch/arm64/kernel/hw_breakpoint.c | 2 +-
> arch/arm64/kernel/psci.c | 2 --
> arch/arm64/kernel/suspend.c | 21 ---------------------
> arch/arm64/mm/proc.S | 2 +-
> drivers/cpuidle/Kconfig.arm64 | 1 -
> drivers/cpuidle/cpuidle-arm64.c | 1 -
> 13 files changed, 34 insertions(+), 38 deletions(-)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index b1f9a20..9ac078f 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -627,9 +627,6 @@ source "kernel/power/Kconfig"
> config ARCH_SUSPEND_POSSIBLE
> def_bool y
>
> -config ARM64_CPU_SUSPEND
> - def_bool PM_SLEEP
> -
> endmenu
>
> menu "CPU Power Management"
> diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h
> index 6f8e2ef..da301ee 100644
> --- a/arch/arm64/include/asm/cpu_ops.h
> +++ b/arch/arm64/include/asm/cpu_ops.h
> @@ -28,8 +28,6 @@ struct device_node;
> * enable-method property.
> * @cpu_init: Reads any data necessary for a specific enable-method from the
> * devicetree, for a given cpu node and proposed logical id.
> - * @cpu_init_idle: Reads any data necessary to initialize CPU idle states from
> - * devicetree, for a given cpu node and proposed logical id.
> * @cpu_prepare: Early one-time preparation step for a cpu. If there is a
> * mechanism for doing so, tests whether it is possible to boot
> * the given CPU.
> @@ -42,6 +40,8 @@ struct device_node;
> * @cpu_die: Makes a cpu leave the kernel. Must not fail. Called from the
> * cpu being killed.
> * @cpu_kill: Ensures a cpu has left the kernel. Called from another cpu.
> + * @cpu_init_idle: Reads any data necessary to initialize CPU idle states from
> + * devicetree, for a given cpu node and proposed logical id.
> * @cpu_suspend: Suspends a cpu and saves the required context. May fail owing
> * to wrong parameters or error conditions. Called from the
> * CPU being suspended. Must be called with IRQs disabled.
> @@ -49,7 +49,6 @@ struct device_node;
> struct cpu_operations {
> const char *name;
> int (*cpu_init)(struct device_node *, unsigned int);
> - int (*cpu_init_idle)(struct device_node *, unsigned int);
> int (*cpu_prepare)(unsigned int);
> int (*cpu_boot)(unsigned int);
> void (*cpu_postboot)(void);
> @@ -58,7 +57,8 @@ struct cpu_operations {
> void (*cpu_die)(unsigned int cpu);
> int (*cpu_kill)(unsigned int cpu);
> #endif
> -#ifdef CONFIG_ARM64_CPU_SUSPEND
> +#ifdef CONFIG_CPU_IDLE
> + int (*cpu_init_idle)(struct device_node *, unsigned int);
> int (*cpu_suspend)(unsigned long);
> #endif
> };
> diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h
> index b52a993..0710654 100644
> --- a/arch/arm64/include/asm/cpuidle.h
> +++ b/arch/arm64/include/asm/cpuidle.h
> @@ -3,11 +3,17 @@
>
> #ifdef CONFIG_CPU_IDLE
> extern int cpu_init_idle(unsigned int cpu);
> +extern int cpu_suspend(unsigned long arg);
> #else
> static inline int cpu_init_idle(unsigned int cpu)
> {
> return -EOPNOTSUPP;
> }
> +
> +static inline int cpu_suspend(unsigned long arg)
> +{
> + return -EOPNOTSUPP;
> +}
> #endif
>
> #endif
> diff --git a/arch/arm64/include/asm/suspend.h b/arch/arm64/include/asm/suspend.h
> index 456d67c..003802f 100644
> --- a/arch/arm64/include/asm/suspend.h
> +++ b/arch/arm64/include/asm/suspend.h
> @@ -23,6 +23,4 @@ struct sleep_save_sp {
>
> extern int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long));
> extern void cpu_resume(void);
> -extern int cpu_suspend(unsigned long);
> -
> #endif
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index eaa77ed..0622599 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -27,7 +27,7 @@ arm64-obj-$(CONFIG_SMP) += smp.o smp_spin_table.o topology.o
> arm64-obj-$(CONFIG_PERF_EVENTS) += perf_regs.o
> arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o
> arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
> -arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND) += sleep.o suspend.o
> +arm64-obj-$(CONFIG_CPU_PM) += sleep.o suspend.o
> arm64-obj-$(CONFIG_CPU_IDLE) += cpuidle.o
> arm64-obj-$(CONFIG_JUMP_LABEL) += jump_label.o
> arm64-obj-$(CONFIG_KGDB) += kgdb.o
> diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
> index 9a9fce0..a2ae194 100644
> --- a/arch/arm64/kernel/asm-offsets.c
> +++ b/arch/arm64/kernel/asm-offsets.c
> @@ -152,7 +152,7 @@ int main(void)
> DEFINE(KVM_VTTBR, offsetof(struct kvm, arch.vttbr));
> DEFINE(KVM_VGIC_VCTRL, offsetof(struct kvm, arch.vgic.vctrl_base));
> #endif
> -#ifdef CONFIG_ARM64_CPU_SUSPEND
> +#ifdef CONFIG_CPU_PM
> DEFINE(CPU_SUSPEND_SZ, sizeof(struct cpu_suspend_ctx));
> DEFINE(CPU_CTX_SP, offsetof(struct cpu_suspend_ctx, sp));
> DEFINE(MPIDR_HASH_MASK, offsetof(struct mpidr_hash, mask));
> diff --git a/arch/arm64/kernel/cpuidle.c b/arch/arm64/kernel/cpuidle.c
> index 19d17f5..5c08966 100644
> --- a/arch/arm64/kernel/cpuidle.c
> +++ b/arch/arm64/kernel/cpuidle.c
> @@ -29,3 +29,23 @@ int cpu_init_idle(unsigned int cpu)
> of_node_put(cpu_node);
> return ret;
> }
> +
> +/**
> + * cpu_suspend() - function to enter a low-power idle state
> + * @arg: argument to pass to CPU suspend operations
> + *
> + * Return: 0 on success, -EOPNOTSUPP if CPU suspend hook not initialized, CPU
> + * operations back-end error code otherwise.
> + */
> +int cpu_suspend(unsigned long arg)
> +{
> + int cpu = smp_processor_id();
> +
> + /*
> + * If cpu_ops have not been registered or suspend
> + * has not been initialized, cpu_suspend call fails early.
> + */
> + if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend)
> + return -EOPNOTSUPP;
> + return cpu_ops[cpu]->cpu_suspend(arg);
> +}
> diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
> index df1cf15..98bbe06 100644
> --- a/arch/arm64/kernel/hw_breakpoint.c
> +++ b/arch/arm64/kernel/hw_breakpoint.c
> @@ -894,7 +894,7 @@ static struct notifier_block hw_breakpoint_reset_nb = {
> .notifier_call = hw_breakpoint_reset_notify,
> };
>
> -#ifdef CONFIG_ARM64_CPU_SUSPEND
> +#ifdef CONFIG_CPU_PM
> extern void cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *));
> #else
> static inline void cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *))
> diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> index f1dbca7..3425f31 100644
> --- a/arch/arm64/kernel/psci.c
> +++ b/arch/arm64/kernel/psci.c
> @@ -540,8 +540,6 @@ const struct cpu_operations cpu_psci_ops = {
> .name = "psci",
> #ifdef CONFIG_CPU_IDLE
> .cpu_init_idle = cpu_psci_cpu_init_idle,
> -#endif
> -#ifdef CONFIG_ARM64_CPU_SUSPEND
> .cpu_suspend = cpu_psci_cpu_suspend,
> #endif
> #ifdef CONFIG_SMP
> diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c
> index 2d6b606..d7daf45 100644
> --- a/arch/arm64/kernel/suspend.c
> +++ b/arch/arm64/kernel/suspend.c
> @@ -1,7 +1,6 @@
> #include <linux/percpu.h>
> #include <linux/slab.h>
> #include <asm/cacheflush.h>
> -#include <asm/cpu_ops.h>
> #include <asm/debug-monitors.h>
> #include <asm/pgtable.h>
> #include <asm/memory.h>
> @@ -51,26 +50,6 @@ void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *))
> hw_breakpoint_restore = hw_bp_restore;
> }
>
> -/**
> - * cpu_suspend() - function to enter a low-power state
> - * @arg: argument to pass to CPU suspend operations
> - *
> - * Return: 0 on success, -EOPNOTSUPP if CPU suspend hook not initialized, CPU
> - * operations back-end error code otherwise.
> - */
> -int cpu_suspend(unsigned long arg)
> -{
> - int cpu = smp_processor_id();
> -
> - /*
> - * If cpu_ops have not been registered or suspend
> - * has not been initialized, cpu_suspend call fails early.
> - */
> - if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend)
> - return -EOPNOTSUPP;
> - return cpu_ops[cpu]->cpu_suspend(arg);
> -}
> -
> /*
> * __cpu_suspend
> *
> diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
> index 4e778b1..1257835 100644
> --- a/arch/arm64/mm/proc.S
> +++ b/arch/arm64/mm/proc.S
> @@ -102,7 +102,7 @@ ENTRY(cpu_do_idle)
> ret
> ENDPROC(cpu_do_idle)
>
> -#ifdef CONFIG_ARM64_CPU_SUSPEND
> +#ifdef CONFIG_CPU_PM
> /**
> * cpu_do_suspend - save CPU registers context
> *
> diff --git a/drivers/cpuidle/Kconfig.arm64 b/drivers/cpuidle/Kconfig.arm64
> index d0a08ed..6effb36 100644
> --- a/drivers/cpuidle/Kconfig.arm64
> +++ b/drivers/cpuidle/Kconfig.arm64
> @@ -4,7 +4,6 @@
>
> config ARM64_CPUIDLE
> bool "Generic ARM64 CPU idle Driver"
> - select ARM64_CPU_SUSPEND
> select DT_IDLE_STATES
> help
> Select this to enable generic cpuidle driver for ARM64.
> diff --git a/drivers/cpuidle/cpuidle-arm64.c b/drivers/cpuidle/cpuidle-arm64.c
> index 80704b9..39a2c62 100644
> --- a/drivers/cpuidle/cpuidle-arm64.c
> +++ b/drivers/cpuidle/cpuidle-arm64.c
> @@ -19,7 +19,6 @@
> #include <linux/of.h>
>
> #include <asm/cpuidle.h>
> -#include <asm/suspend.h>
>
> #include "dt_idle_states.h"
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