Hi Nicolas, On Thu, Jul 3, 2014 at 6:59 PM, Nicolas Pitre <nicolas.pitre@xxxxxxxxxx> wrote: > On Thu, 3 Jul 2014, Abhilash Kesavan wrote: > >> Use the MCPM layer to handle core suspend/resume on Exynos5420. >> Also, restore the entry address setup code post-resume. >> >> Signed-off-by: Abhilash Kesavan <a.kesavan@xxxxxxxxxxx> >> --- >> Changes in v2: >> - Made use of the MCPM suspend/powered_up call-backs >> Changes in v3: >> - Used the residency value to indicate the entered state >> Changes in v4: >> - Checked if MCPM has been enabled to prevent build error >> >> This has been tested both on an SMDK5420 and Peach Pit Chromebook on >> 3.16-rc3/next-20140702. >> >> Here are the dependencies (some of these patches did not apply cleanly): >> 1) Cleanup patches for mach-exynos >> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33772 >> >> 2) PMU cleanup and refactoring for using DT >> https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg671625.html >> >> 3) Exynos5420 PMU/S2R Series >> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33898 >> >> 4) MCPM boot CPU CCI enablement patches >> www.spinics.net/lists/linux-samsung-soc/msg32923.html >> >> 5) Exynos5420 CPUIdle Series which populates MCPM suspend/powered_up >> call-backs. >> www.gossamer-threads.com/lists/linux/kernel/1945347 >> https://patchwork.kernel.org/patch/4357461/ >> >> 6) Exynos5420 MCPM cluster power down support >> http://www.spinics.net/lists/arm-kernel/msg339988.html >> >> 7) TPM reset mask patch >> http://www.spinics.net/lists/arm-kernel/msg341884.html >> >> arch/arm/include/asm/mcpm.h | 6 ++++ >> arch/arm/mach-exynos/mcpm-exynos.c | 50 ++++++++++++++++++++++++---------- >> arch/arm/mach-exynos/pm.c | 38 ++++++++++++++++++++++++-- >> arch/arm/mach-exynos/regs-pmu.h | 1 + >> drivers/cpuidle/cpuidle-big_little.c | 2 +- >> 5 files changed, 79 insertions(+), 18 deletions(-) >> >> diff --git a/arch/arm/include/asm/mcpm.h b/arch/arm/include/asm/mcpm.h >> index ff73aff..051fbf1 100644 >> --- a/arch/arm/include/asm/mcpm.h >> +++ b/arch/arm/include/asm/mcpm.h >> @@ -272,4 +272,10 @@ void __init mcpm_smp_set_ops(void); >> #define MCPM_SYNC_CLUSTER_SIZE \ >> (MCPM_SYNC_CLUSTER_INBOUND + __CACHE_WRITEBACK_GRANULE) >> >> +/* Definitions for various MCPM scenarios that might need special handling */ >> +#define MCPM_CPU_IDLE 0x0 >> +#define MCPM_CPU_SUSPEND 0x1 >> +#define MCPM_CPU_SWITCH 0x2 >> +#define MCPM_CPU_HOTPLUG 0x3 > > Please, let's avoid going that route. There is no such special handling > needed if the API is sufficient. And the provided API allows you to > suspend a CPU or shut it down. It shouldn't matter at that level if > this is due to a cluster switch or a hotplug event. Do you really need > something else? No, just one local flag for suspend should be enough for me. Will remove these. > > [...] >> @@ -129,7 +132,7 @@ static int exynos_power_up(unsigned int cpu, unsigned int cluster) >> * and can only be executed on processors like A15 and A7 that hit the cache >> * with the C bit clear in the SCTLR register. >> */ >> -static void exynos_power_down(void) >> +static void exynos_mcpm_power_down(u64 residency) >> { >> unsigned int mpidr, cpu, cluster; >> bool last_man = false, skip_wfi = false; >> @@ -150,7 +153,12 @@ static void exynos_power_down(void) >> BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP); >> cpu_use_count[cpu][cluster]--; >> if (cpu_use_count[cpu][cluster] == 0) { >> - exynos_cpu_power_down(cpunr); >> + /* >> + * Bypass power down for CPU0 during suspend. This is being >> + * taken care by the SYS_PWR_CFG bit in CORE0_SYS_PWR_REG. >> + */ >> + if ((cpunr != 0) || (residency != MCPM_CPU_SUSPEND)) >> + exynos_cpu_power_down(cpunr); >> >> if (exynos_cluster_unused(cluster)) { >> exynos_cluster_power_down(cluster); >> @@ -209,6 +217,11 @@ static void exynos_power_down(void) >> /* Not dead at this point? Let our caller cope. */ >> } >> >> +static void exynos_power_down(void) >> +{ >> + exynos_mcpm_power_down(MCPM_CPU_SWITCH | MCPM_CPU_HOTPLUG); >> +} > > To distinguish between a suspend and a power-down, you can simply use > exynos_power_down() as your common handler, and have > exynos_mcpm_power_down() and exynos_mcpm_suspend() as wrappers around it > passing the appropriate private flags with local meanings. My patch is in line with your explanation, except it makes use of the new MCPM flags. I will clean those out and just use one flag for suspend instead. Please check the v5 patch that I will post in a bit in case I have missed something. Regards, Abhilash > > > Nicolas > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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