| Message ID | 1436350417-6712-5-git-send-email-jszhang@marvell.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jul 08, 2015 at 06:13:37PM +0800, Jisheng Zhang wrote: > This patch implements cpuidle_ops using psci. After this patch, we can use > cpuidle-arm.c with psci backend for both arm and arm64. I really don't see the point of most of the patches in this series. To summarise, what you're doing is: 1. Renaming arch/arm/kernel/psci_smp.c to arch/arm/kernel/psci.c 2. Adding a #ifdef CONFIG_SMP around _all_ the code in psci.c 3. Adding cpuidle code with an #ifdef CONFIG_CPU_IDLE around all the CPU idle code. So, we end up with a file which contains: /* header */ #include statements /* some commentry relevant to SMP code */ #ifdef CONFIG_CPU_IDLE ... cpu idle code ... #endif #ifdef CONFIG_SMP ... smp code ... #endif which (a) is a mess, and (b) is unnecessary. The only relevant bits which are shared are the #include statements. Please try this alternative approach: 1. Leave psci_smp.c alone. 2. Add arch/arm/kernel/psci_cpuidle.c containing the #include statements you need, and the CPU idle code. I think such an approach will reduce your patch series to two patches, one moving the ARM64 code, and one adding the cpuidle code.
Dear Russell, On Wed, 8 Jul 2015 11:34:29 +0100 Russell King - ARM Linux <linux@arm.linux.org.uk> wrote: > On Wed, Jul 08, 2015 at 06:13:37PM +0800, Jisheng Zhang wrote: > > This patch implements cpuidle_ops using psci. After this patch, we can use > > cpuidle-arm.c with psci backend for both arm and arm64. > > I really don't see the point of most of the patches in this series. > > To summarise, what you're doing is: > > 1. Renaming arch/arm/kernel/psci_smp.c to arch/arm/kernel/psci.c > 2. Adding a #ifdef CONFIG_SMP around _all_ the code in psci.c > 3. Adding cpuidle code with an #ifdef CONFIG_CPU_IDLE around all the > CPU idle code. > > So, we end up with a file which contains: > > /* > header > */ > #include statements > > /* > some commentry relevant to SMP code > */ > #ifdef CONFIG_CPU_IDLE > ... cpu idle code ... > #endif > #ifdef CONFIG_SMP > ... smp code ... > #endif > > which (a) is a mess, and (b) is unnecessary. The only relevant bits which > are shared are the #include statements. > > Please try this alternative approach: > > 1. Leave psci_smp.c alone. > 2. Add arch/arm/kernel/psci_cpuidle.c containing the #include statements > you need, and the CPU idle code. > > I think such an approach will reduce your patch series to two patches, > one moving the ARM64 code, and one adding the cpuidle code. > Good idea! Will refine the patches as you suggested. Thanks a lot for your review, Jisheng
Dear Russell, On Wed, 8 Jul 2015 19:38:42 +0800 Jisheng Zhang <jszhang@marvell.com> wrote: > Dear Russell, > > On Wed, 8 Jul 2015 11:34:29 +0100 > Russell King - ARM Linux <linux@arm.linux.org.uk> wrote: > > > On Wed, Jul 08, 2015 at 06:13:37PM +0800, Jisheng Zhang wrote: > > > This patch implements cpuidle_ops using psci. After this patch, we can use > > > cpuidle-arm.c with psci backend for both arm and arm64. > > > > I really don't see the point of most of the patches in this series. > > > > To summarise, what you're doing is: > > > > 1. Renaming arch/arm/kernel/psci_smp.c to arch/arm/kernel/psci.c > > 2. Adding a #ifdef CONFIG_SMP around _all_ the code in psci.c > > 3. Adding cpuidle code with an #ifdef CONFIG_CPU_IDLE around all the > > CPU idle code. > > > > So, we end up with a file which contains: > > > > /* > > header > > */ > > #include statements > > > > /* > > some commentry relevant to SMP code > > */ > > #ifdef CONFIG_CPU_IDLE > > ... cpu idle code ... > > #endif > > #ifdef CONFIG_SMP > > ... smp code ... > > #endif > > > > which (a) is a mess, and (b) is unnecessary. The only relevant bits which > > are shared are the #include statements. > > > > Please try this alternative approach: > > > > 1. Leave psci_smp.c alone. > > 2. Add arch/arm/kernel/psci_cpuidle.c containing the #include statements > > you need, and the CPU idle code. After more consideration, I have one concern. Currently, cpuidle_ops is defined as the following, > struct cpuidle_ops { > int (*suspend)(int cpu, unsigned long arg); the cpu may not be necessary, because to-be-suspended cpu is always the calling cpu itself. > int (*init)(struct device_node *, int cpu); the device_node here may not be necessary either, because we can get the node via. of_get_cpu_node. So if we refine cpuidle_ops defintion, the code would be as simple as static struct cpuidle_ops psci_cpuidle_ops __initdata = { .suspend = cpu_psci_cpu_suspend, .init = cpu_psci_cpu_init_idle, }; CPUIDLE_METHOD_OF_DECLARE(psci_idle, "psci", &psci_cpuidle_ops); I'm not sure a new psci_cpuidle.c only with above 5 lines is acceptable or not. Thanks, Jisheng > > > > I think such an approach will reduce your patch series to two patches, > > one moving the ARM64 code, and one adding the cpuidle code. > > > > Good idea! Will refine the patches as you suggested. >
diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c index 7f6ff02..c5b94f5 100644 --- a/arch/arm/kernel/psci.c +++ b/arch/arm/kernel/psci.c @@ -13,6 +13,7 @@ * Author: Will Deacon <will.deacon@arm.com> */ +#include <linux/cpuidle.h> #include <linux/init.h> #include <linux/smp.h> #include <linux/of.h> @@ -21,6 +22,7 @@ #include <uapi/linux/psci.h> +#include <asm/cpuidle.h> #include <asm/psci.h> #include <asm/smp_plat.h> @@ -47,6 +49,24 @@ * */ +#ifdef CONFIG_CPU_IDLE +static int psci_cpuidle_suspend(int cpu, unsigned long arg) +{ + return cpu_psci_cpu_suspend(arg); +} + +static int psci_cpuidle_init(struct device_node *node, int cpu) +{ + return cpu_psci_cpu_init_idle(cpu); +} + +static struct cpuidle_ops psci_cpuidle_ops __initdata = { + .suspend = psci_cpuidle_suspend, + .init = psci_cpuidle_init, +}; +CPUIDLE_METHOD_OF_DECLARE(psci_idle, "psci", &psci_cpuidle_ops); +#endif + #ifdef CONFIG_SMP extern void secondary_startup(void);
This patch implements cpuidle_ops using psci. After this patch, we can use cpuidle-arm.c with psci backend for both arm and arm64. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> --- arch/arm/kernel/psci.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)