[PATCH v3] [RFC] arm: use PSCI if available
Marc Zyngier
marc.zyngier at arm.com
Wed Mar 27 09:35:13 EDT 2013
On 27/03/13 12:50, Stefano Stabellini wrote:
> Check for the presence of PSCI before setting smp_ops, use PSCI if it is
> available.
>
> This is useful because at least when running on Xen it's possible to have a
> PSCI node for example on a Versatile Express or an Exynos5 machine. In these
> cases the PSCI SMP calls should be the ones to be called.
>
> Remove virt_smp_ops and platsmp.c from mach-virt because they aren't needed
> anymore.
>
>
>
> This patch was originally part of this series:
>
> http://marc.info/?l=linux-arm-kernel&m=136430903110734&w=2
>
> I am keeping it separate now since it is the only non-obvious change and
> it is not Xen related.
>
>
>
>
> Changes in v3:
> - move the call to psci_init to setup_arch;
> - export psci_smp_ops from psci.h;
> - introduce psci_smp_available;
> - introduce stub functions for psci_init and psci_smp_available ifndef
> CONFIG_ARM_PSCI;
> - only compile psci_smp functions ifdef CONFIG_SMP.
>
>
> Signed-off-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
> CC: will.deacon at arm.com
> CC: arnd at arndb.de
> CC: marc.zyngier at arm.com
> CC: linux at arm.linux.org.uk
> CC: nico at linaro.org
> ---
> arch/arm/include/asm/psci.h | 9 ++++
> arch/arm/kernel/psci.c | 97 ++++++++++++++++++++++++++++++++++--------
> arch/arm/kernel/setup.c | 7 +++-
> arch/arm/mach-virt/Makefile | 1 -
> arch/arm/mach-virt/platsmp.c | 58 -------------------------
> arch/arm/mach-virt/virt.c | 3 -
> 6 files changed, 94 insertions(+), 81 deletions(-)
> delete mode 100644 arch/arm/mach-virt/platsmp.c
>
> diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
> index ce0dbe7..ddef231 100644
> --- a/arch/arm/include/asm/psci.h
> +++ b/arch/arm/include/asm/psci.h
> @@ -32,5 +32,14 @@ struct psci_operations {
> };
>
> extern struct psci_operations psci_ops;
> +extern struct smp_operations psci_smp_ops;
> +
> +#ifdef CONFIG_ARM_PSCI
> +int psci_init(void);
> +bool psci_smp_available(void);
> +#else
> +static inline int psci_init(void) { return -ENODEV; }
> +static inline bool psci_smp_available(void) { return false; }
> +#endif
>
> #endif /* __ASM_ARM_PSCI_H */
> diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
> index 3653164..90f0839 100644
> --- a/arch/arm/kernel/psci.c
> +++ b/arch/arm/kernel/psci.c
> @@ -16,6 +16,7 @@
> #define pr_fmt(fmt) "psci: " fmt
>
> #include <linux/init.h>
> +#include <linux/irqchip/arm-gic.h>
> #include <linux/of.h>
>
> #include <asm/compiler.h>
> @@ -23,8 +24,9 @@
> #include <asm/opcodes-sec.h>
> #include <asm/opcodes-virt.h>
> #include <asm/psci.h>
> +#include <asm/smp_plat.h>
>
> -struct psci_operations psci_ops;
> +extern void secondary_startup(void);
>
> static int (*invoke_psci_fn)(u32, u32, u32, u32);
>
> @@ -36,7 +38,11 @@ enum psci_function {
> PSCI_FN_MAX,
> };
>
> -static u32 psci_function_id[PSCI_FN_MAX];
> +struct psci_function_desc {
> + enum psci_function func;
> + bool valid;
> +};
> +static struct psci_function_desc psci_function_id[PSCI_FN_MAX];
>
> #define PSCI_RET_SUCCESS 0
> #define PSCI_RET_EOPNOTSUPP -1
> @@ -116,7 +122,10 @@ static int psci_cpu_suspend(struct psci_power_state state,
> int err;
> u32 fn, power_state;
>
> - fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
> + if (!psci_function_id[PSCI_FN_CPU_SUSPEND].valid)
> + return -ENOSYS;
> +
> + fn = psci_function_id[PSCI_FN_CPU_SUSPEND].func;
> power_state = psci_power_state_pack(state);
> err = invoke_psci_fn(fn, power_state, entry_point, 0);
> return psci_to_linux_errno(err);
> @@ -127,7 +136,10 @@ static int psci_cpu_off(struct psci_power_state state)
> int err;
> u32 fn, power_state;
>
> - fn = psci_function_id[PSCI_FN_CPU_OFF];
> + if (!psci_function_id[PSCI_FN_CPU_OFF].valid)
> + return -ENOSYS;
> +
> + fn = psci_function_id[PSCI_FN_CPU_OFF].func;
> power_state = psci_power_state_pack(state);
> err = invoke_psci_fn(fn, power_state, 0, 0);
> return psci_to_linux_errno(err);
> @@ -138,7 +150,10 @@ static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
> int err;
> u32 fn;
>
> - fn = psci_function_id[PSCI_FN_CPU_ON];
> + if (!psci_function_id[PSCI_FN_CPU_ON].valid)
> + return -ENOSYS;
> +
> + fn = psci_function_id[PSCI_FN_CPU_ON].func;
> err = invoke_psci_fn(fn, cpuid, entry_point, 0);
> return psci_to_linux_errno(err);
> }
> @@ -148,25 +163,64 @@ static int psci_migrate(unsigned long cpuid)
> int err;
> u32 fn;
>
> - fn = psci_function_id[PSCI_FN_MIGRATE];
> + if (!psci_function_id[PSCI_FN_MIGRATE].valid)
> + return -ENOSYS;
> +
> + fn = psci_function_id[PSCI_FN_MIGRATE].func;
> err = invoke_psci_fn(fn, cpuid, 0, 0);
> return psci_to_linux_errno(err);
> }
>
> +struct psci_operations psci_ops = {
> + .cpu_suspend = psci_cpu_suspend,
> + .cpu_off = psci_cpu_off,
> + .cpu_on = psci_cpu_on,
> + .migrate = psci_migrate,
> +};
> +
> +#ifdef CONFIG_SMP
> +static void __init psci_smp_init_cpus(void)
> +{
> +}
> +
> +static void __init psci_smp_prepare_cpus(unsigned int max_cpus)
> +{
> +}
> +
> +static int __cpuinit psci_boot_secondary(unsigned int cpu,
> + struct task_struct *idle)
> +{
> + return psci_cpu_on(cpu_logical_map(cpu), __pa(secondary_startup));
> +}
> +
> +static void __cpuinit psci_secondary_init(unsigned int cpu)
> +{
> + gic_secondary_init(0);
> +}
So here we end-up with a dependency between SMP, PSCI, and GIC.
I really can't see that being a good idea, even I like the general
direction of this series.
M.
--
Jazz is not dead. It just smells funny...
More information about the linux-arm-kernel
mailing list