From mboxrd@z Thu Jan 1 00:00:00 1970 From: lorenzo.pieralisi@arm.com (Lorenzo Pieralisi) Date: Fri, 30 Jan 2015 17:01:18 +0000 Subject: [PATCH v3 1/1] arm64: kernel: remove ARM64_CPU_SUSPEND config option In-Reply-To: <1598265.lHdhMYsZXo@amdc1032> References: <1422297224-27834-1-git-send-email-lorenzo.pieralisi@arm.com> <1422297224-27834-2-git-send-email-lorenzo.pieralisi@arm.com> <1598265.lHdhMYsZXo@amdc1032> Message-ID: <20150130170118.GA11122@red-moon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > > Cc: Arnd Bergmann > > Cc: Will Deacon > > Cc: Krzysztof Kozlowski > > Cc: Daniel Lezcano > > Cc: Catalin Marinas > > Cc: Mark Rutland > > --- > > 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 > > #include > > #include > > -#include > > #include > > #include > > #include > > @@ -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 > > > > #include > > -#include > > > > #include "dt_idle_states.h" > > >