On wto, 2014-08-05 at 16:46 +0200, Daniel Lezcano wrote: > On 08/05/2014 12:43 PM, Krzysztof Kozlowski wrote: > > Cleanup a little the SMP/hotplug code for Exynos by: > > 1. Moving completely all functions from hotplug.c into the platsmp.c; > > 2. Deleting the hotplug.c file. > > > > After recent cleanups (e.g. 75ad2ab28f0f "ARM: EXYNOS: use > > v7_exit_coherency_flush macro for cache disabling") there was only CPU > > power down related code in hotplug.c file. Keeping this file does not > > give any benefits. > > > > The commit only moves code around with one additional observable change: > > the hotplug.c was compiled with custom CFLAGS (-march=armv7-a). These > > CFLAGS are not necessary any more. > > What is the benefit of moving this code around ? > > Usually the cpu hotplug code is located in hotplug.c for most of the > platforms, so why moving pm code inside platsmp ? The benefits are: 1. Less dependencies, cleaner code because platsmp.c is the only user of code located in hotplug.c. So the exynos_cpu_die() had to be declared in common.h. 2. Less dependencies between modules after adding patch 3/3 [1] which introduces exynos_set_delayed_reset_assertion() function. The exynos_set_delayed_reset_assertion() is called by: - cpu_leave_power (hotplug.c) - platform_do_lowpower (hotplug.c) - exynos_boot_secondary (platsmp.c) so merging everything into one file seemed simpler and cleaner. However I do not insist on such solution. I'm merely interested in getting the third patch into the kernel :) . [1] http://www.spinics.net/lists/arm-kernel/msg352890.html Best regards, Krzysztof > > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx> > > Reviewed-by: Tomasz Figa <t.figa@xxxxxxxxxxx> > > > > --- > > Changes since v4: > > 1. Rebase on linux-next-20140804. > > 2. Add Reviewed-by Tomasz Figa. > > --- > > arch/arm/mach-exynos/Makefile | 3 -- > > arch/arm/mach-exynos/common.h | 2 - > > arch/arm/mach-exynos/hotplug.c | 91 ------------------------------------------ > > arch/arm/mach-exynos/platsmp.c | 74 ++++++++++++++++++++++++++++++++++ > > 4 files changed, 74 insertions(+), 96 deletions(-) > > delete mode 100644 arch/arm/mach-exynos/hotplug.c > > > > diff --git a/arch/arm/mach-exynos/Makefile b/arch/arm/mach-exynos/Makefile > > index 788f26d21141..0095de99d703 100644 > > --- a/arch/arm/mach-exynos/Makefile > > +++ b/arch/arm/mach-exynos/Makefile > > @@ -21,9 +21,6 @@ obj-$(CONFIG_PM_GENERIC_DOMAINS) += pm_domains.o > > > > obj-$(CONFIG_SMP) += platsmp.o headsmp.o > > > > -obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o > > -CFLAGS_hotplug.o += -march=armv7-a > > - > > plus_sec := $(call as-instr,.arch_extension sec,+sec) > > AFLAGS_exynos-smc.o :=-Wa,-march=armv7-a$(plus_sec) > > > > diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h > > index 47b904b3b973..3d3e6af9d015 100644 > > --- a/arch/arm/mach-exynos/common.h > > +++ b/arch/arm/mach-exynos/common.h > > @@ -130,8 +130,6 @@ extern void exynos_cpu_resume(void); > > > > extern struct smp_operations exynos_smp_ops; > > > > -extern void exynos_cpu_die(unsigned int cpu); > > - > > /* PMU(Power Management Unit) support */ > > > > #define PMU_TABLE_END (-1U) > > diff --git a/arch/arm/mach-exynos/hotplug.c b/arch/arm/mach-exynos/hotplug.c > > deleted file mode 100644 > > index 4d86961a7957..000000000000 > > --- a/arch/arm/mach-exynos/hotplug.c > > +++ /dev/null > > @@ -1,91 +0,0 @@ > > -/* > > - * Cloned from linux/arch/arm/mach-realview/hotplug.c > > - * > > - * Copyright (C) 2002 ARM Ltd. > > - * All Rights Reserved > > - * > > - * This program is free software; you can redistribute it and/or modify > > - * it under the terms of the GNU General Public License version 2 as > > - * published by the Free Software Foundation. > > -*/ > > - > > -#include <linux/kernel.h> > > -#include <linux/errno.h> > > -#include <linux/smp.h> > > -#include <linux/io.h> > > - > > -#include <asm/cacheflush.h> > > -#include <asm/cp15.h> > > -#include <asm/smp_plat.h> > > - > > -#include "common.h" > > -#include "regs-pmu.h" > > - > > -static inline void cpu_leave_lowpower(void) > > -{ > > - unsigned int v; > > - > > - asm volatile( > > - "mrc p15, 0, %0, c1, c0, 0\n" > > - " orr %0, %0, %1\n" > > - " mcr p15, 0, %0, c1, c0, 0\n" > > - " mrc p15, 0, %0, c1, c0, 1\n" > > - " orr %0, %0, %2\n" > > - " mcr p15, 0, %0, c1, c0, 1\n" > > - : "=&r" (v) > > - : "Ir" (CR_C), "Ir" (0x40) > > - : "cc"); > > -} > > - > > -static inline void platform_do_lowpower(unsigned int cpu, int *spurious) > > -{ > > - u32 mpidr = cpu_logical_map(cpu); > > - u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); > > - > > - for (;;) { > > - > > - /* Turn the CPU off on next WFI instruction. */ > > - exynos_cpu_power_down(core_id); > > - > > - wfi(); > > - > > - if (pen_release == core_id) { > > - /* > > - * OK, proper wakeup, we're done > > - */ > > - break; > > - } > > - > > - /* > > - * Getting here, means that we have come out of WFI without > > - * having been woken up - this shouldn't happen > > - * > > - * Just note it happening - when we're woken, we can report > > - * its occurrence. > > - */ > > - (*spurious)++; > > - } > > -} > > - > > -/* > > - * platform-specific code to shutdown a CPU > > - * > > - * Called with IRQs disabled > > - */ > > -void __ref exynos_cpu_die(unsigned int cpu) > > -{ > > - int spurious = 0; > > - > > - v7_exit_coherency_flush(louis); > > - > > - platform_do_lowpower(cpu, &spurious); > > - > > - /* > > - * bring this CPU back into the world of cache > > - * coherency, and then restore interrupts > > - */ > > - cpu_leave_lowpower(); > > - > > - if (spurious) > > - pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); > > -} > > diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c > > index a9f1cf759949..a809f76c8160 100644 > > --- a/arch/arm/mach-exynos/platsmp.c > > +++ b/arch/arm/mach-exynos/platsmp.c > > @@ -22,6 +22,7 @@ > > #include <linux/of_address.h> > > > > #include <asm/cacheflush.h> > > +#include <asm/cp15.h> > > #include <asm/smp_plat.h> > > #include <asm/smp_scu.h> > > #include <asm/firmware.h> > > @@ -33,6 +34,54 @@ > > > > extern void exynos4_secondary_startup(void); > > > > +#ifdef CONFIG_HOTPLUG_CPU > > +static inline void cpu_leave_lowpower(void) > > +{ > > + unsigned int v; > > + > > + asm volatile( > > + "mrc p15, 0, %0, c1, c0, 0\n" > > + " orr %0, %0, %1\n" > > + " mcr p15, 0, %0, c1, c0, 0\n" > > + " mrc p15, 0, %0, c1, c0, 1\n" > > + " orr %0, %0, %2\n" > > + " mcr p15, 0, %0, c1, c0, 1\n" > > + : "=&r" (v) > > + : "Ir" (CR_C), "Ir" (0x40) > > + : "cc"); > > +} > > + > > +static inline void platform_do_lowpower(unsigned int cpu, int *spurious) > > +{ > > + u32 mpidr = cpu_logical_map(cpu); > > + u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); > > + > > + for (;;) { > > + > > + /* Turn the CPU off on next WFI instruction. */ > > + exynos_cpu_power_down(core_id); > > + > > + wfi(); > > + > > + if (pen_release == core_id) { > > + /* > > + * OK, proper wakeup, we're done > > + */ > > + break; > > + } > > + > > + /* > > + * Getting here, means that we have come out of WFI without > > + * having been woken up - this shouldn't happen > > + * > > + * Just note it happening - when we're woken, we can report > > + * its occurrence. > > + */ > > + (*spurious)++; > > + } > > +} > > +#endif /* CONFIG_HOTPLUG_CPU */ > > + > > /** > > * exynos_core_power_down : power down the specified cpu > > * @cpu : the cpu to power down > > @@ -318,6 +367,31 @@ static void __init exynos_smp_prepare_cpus(unsigned int max_cpus) > > } > > } > > > > +#ifdef CONFIG_HOTPLUG_CPU > > +/* > > + * platform-specific code to shutdown a CPU > > + * > > + * Called with IRQs disabled > > + */ > > +static void __ref exynos_cpu_die(unsigned int cpu) > > +{ > > + int spurious = 0; > > + > > + v7_exit_coherency_flush(louis); > > + > > + platform_do_lowpower(cpu, &spurious); > > + > > + /* > > + * bring this CPU back into the world of cache > > + * coherency, and then restore interrupts > > + */ > > + cpu_leave_lowpower(); > > + > > + if (spurious) > > + pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); > > +} > > +#endif /* CONFIG_HOTPLUG_CPU */ > > + > > struct smp_operations exynos_smp_ops __initdata = { > > .smp_init_cpus = exynos_smp_init_cpus, > > .smp_prepare_cpus = exynos_smp_prepare_cpus, > > > > -- 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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