* [PATCH v3 0/1] arm64: kernel: ARM64_CPU_SUSPEND clean-up
@ 2015-01-26 18:33 Lorenzo Pieralisi
2015-01-26 18:33 ` [PATCH v3 1/1] arm64: kernel: remove ARM64_CPU_SUSPEND config option Lorenzo Pieralisi
0 siblings, 1 reply; 5+ messages in thread
From: Lorenzo Pieralisi @ 2015-01-26 18:33 UTC (permalink / raw)
To: linux-arm-kernel
v2 => v3
- Fixed defconfig compilation issue by moving the cpu_suspend
interface to arch/arm64/kernel/cpuidle.c
- Added cover letter description/reason for the clean-up
- Rebased against 3.19-rc6
v2:
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-December/311468.html
v1 => v2
- Rebased on top of
commit e5e62d475274 ("arm64: psci: Fix build breakage without PM_SLEEP")
The arm64 config option ARM64_CPU_SUSPEND was introduced so that code
required to save/restore CPU context could be selectively compiled in
the kernel.
Since ARM64_CPU_SUSPEND selected code is needed only if CONFIG_SUSPEND or
CONFIG_CPU_IDLE are selected in turn, and the CPU_PM config option already
represents those config cases, this patch removes the ARM64_CPU_SUSPEND config
option and reshuffles the code so that it is compiled by the kernel subsystem
only when it is needed.
On arm64 systems, the current arch API used by the CPUidle driver is:
cpu_suspend(index)
where index corresponds to the idle state index that should be entered
upon cpu_suspend() call. Since the cpu_suspend() function is the CPUidle
interface to arch code, it should be compiled in only if CPU_IDLE is
enabled, so the respective code is moved to the CPUidle specific compilation
unit. Since the ARM64_CPU_SUSPEND is removed, and it was used to selectively
compile CPU operations like cpu_suspend() (which in turn represents the
glue code used by the cpu_suspend() interface), the preprocessor macros
should be changed and updated to the current usage, which means that
the cpu_suspend CPU operation is compiled in only if CPU_IDLE is enabled
in the kernel.
A subsequent patch series will rename the cpu_suspend function, the
cpu_suspend CPU operations hook and the functions implementing save/restore
code so that the naming scheme would become more coherent and the CPUidle
arch interfaces for arm and arm64 kernel could follow the same naming
scheme, when it is settled in stone.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Lorenzo Pieralisi (1):
arm64: kernel: remove ARM64_CPU_SUSPEND config option
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(-)
--
2.2.1
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v3 1/1] arm64: kernel: remove ARM64_CPU_SUSPEND config option 2015-01-26 18:33 [PATCH v3 0/1] arm64: kernel: ARM64_CPU_SUSPEND clean-up Lorenzo Pieralisi @ 2015-01-26 18:33 ` Lorenzo Pieralisi 2015-01-30 16:18 ` Bartlomiej Zolnierkiewicz 0 siblings, 1 reply; 5+ messages in thread From: Lorenzo Pieralisi @ 2015-01-26 18:33 UTC (permalink / raw) To: linux-arm-kernel 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. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@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" -- 2.2.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v3 1/1] arm64: kernel: remove ARM64_CPU_SUSPEND config option 2015-01-26 18:33 ` [PATCH v3 1/1] arm64: kernel: remove ARM64_CPU_SUSPEND config option Lorenzo Pieralisi @ 2015-01-30 16:18 ` Bartlomiej Zolnierkiewicz 2015-01-30 17:01 ` Lorenzo Pieralisi 0 siblings, 1 reply; 5+ messages in thread From: Bartlomiej Zolnierkiewicz @ 2015-01-30 16:18 UTC (permalink / raw) To: linux-arm-kernel 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@arm.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Mark Rutland <mark.rutland@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" ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v3 1/1] arm64: kernel: remove ARM64_CPU_SUSPEND config option 2015-01-30 16:18 ` Bartlomiej Zolnierkiewicz @ 2015-01-30 17:01 ` Lorenzo Pieralisi 2015-01-30 17:38 ` Bartlomiej Zolnierkiewicz 0 siblings, 1 reply; 5+ messages in thread From: Lorenzo Pieralisi @ 2015-01-30 17:01 UTC (permalink / raw) To: linux-arm-kernel On Fri, Jan 30, 2015 at 04:18:27PM +0000, Bartlomiej Zolnierkiewicz wrote: > > 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 arm64 cpu_suspend() is the function interfacing the idle driver to the arch code, I will rename it in a subsequent clean-up that will include cpu_ops.cpu_suspend too (ie cpu_enter_idle). PSCI implements the cpu_ops.cpu_suspend operation through the PSCI CPU suspend call. > > [ 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. ] I did not merge that code, and in that context PSCI CPU suspend has been used to enter what I guess what the deepest idle state, it slipped my review, it is a valid usage, should have been documented though before implementing it that way. On arm64 we are defining a specific system suspend interface to give system suspend a clearer semantics: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-January/318540.html Does this answer your question ? Thanks, Lorenzo > > Best regards, > -- > Bartlomiej Zolnierkiewicz > Samsung R&D Institute Poland > Samsung Electronics > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > Cc: Arnd Bergmann <arnd@arndb.de> > > Cc: Will Deacon <will.deacon@arm.com> > > Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> > > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > > Cc: Catalin Marinas <catalin.marinas@arm.com> > > Cc: Mark Rutland <mark.rutland@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" > > > ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v3 1/1] arm64: kernel: remove ARM64_CPU_SUSPEND config option 2015-01-30 17:01 ` Lorenzo Pieralisi @ 2015-01-30 17:38 ` Bartlomiej Zolnierkiewicz 0 siblings, 0 replies; 5+ messages in thread From: Bartlomiej Zolnierkiewicz @ 2015-01-30 17:38 UTC (permalink / raw) To: linux-arm-kernel On Friday, January 30, 2015 05:01:18 PM Lorenzo Pieralisi wrote: > On Fri, Jan 30, 2015 at 04:18:27PM +0000, Bartlomiej Zolnierkiewicz wrote: > > > > 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 arm64 cpu_suspend() is the function interfacing the idle driver to > the arch code, I will rename it in a subsequent clean-up that will > include cpu_ops.cpu_suspend too (ie cpu_enter_idle). > > PSCI implements the cpu_ops.cpu_suspend operation through the PSCI CPU > suspend call. > > > > > [ 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. ] > > I did not merge that code, and in that context PSCI CPU suspend has been > used to enter what I guess what the deepest idle state, it slipped my > review, it is a valid usage, should have been documented though before > implementing it that way. > > On arm64 we are defining a specific system suspend interface to give > system suspend a clearer semantics: > > http://lists.infradead.org/pipermail/linux-arm-kernel/2015-January/318540.html > > Does this answer your question ? Yes. Thank you! Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2015-01-30 17:38 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2015-01-26 18:33 [PATCH v3 0/1] arm64: kernel: ARM64_CPU_SUSPEND clean-up Lorenzo Pieralisi 2015-01-26 18:33 ` [PATCH v3 1/1] arm64: kernel: remove ARM64_CPU_SUSPEND config option Lorenzo Pieralisi 2015-01-30 16:18 ` Bartlomiej Zolnierkiewicz 2015-01-30 17:01 ` Lorenzo Pieralisi 2015-01-30 17:38 ` Bartlomiej Zolnierkiewicz
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