diff options
| -rw-r--r-- | arch/arm/mach-zynq/Makefile | 3 | ||||
| -rw-r--r-- | arch/arm/mach-zynq/common.h | 3 | ||||
| -rw-r--r-- | arch/arm/mach-zynq/hotplug.c | 104 | ||||
| -rw-r--r-- | arch/arm/mach-zynq/platsmp.c | 3 |
4 files changed, 113 insertions, 0 deletions
diff --git a/arch/arm/mach-zynq/Makefile b/arch/arm/mach-zynq/Makefile index b595d22134ec..1b25d92ebf22 100644 --- a/arch/arm/mach-zynq/Makefile +++ b/arch/arm/mach-zynq/Makefile @@ -4,4 +4,7 @@ # Common support obj-y := common.o slcr.o +CFLAGS_REMOVE_hotplug.o =-march=armv6k +CFLAGS_hotplug.o =-Wa,-march=armv7-a -mcpu=cortex-a9 +obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o obj-$(CONFIG_SMP) += headsmp.o platsmp.o diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h index fd308f8b18d9..fbbd0e21c404 100644 --- a/arch/arm/mach-zynq/common.h +++ b/arch/arm/mach-zynq/common.h @@ -34,4 +34,7 @@ extern struct smp_operations zynq_smp_ops __initdata; extern void __iomem *zynq_slcr_base; extern void __iomem *zynq_scu_base; +/* Hotplug */ +extern void zynq_platform_cpu_die(unsigned int cpu); + #endif diff --git a/arch/arm/mach-zynq/hotplug.c b/arch/arm/mach-zynq/hotplug.c new file mode 100644 index 000000000000..c89672bd1de2 --- /dev/null +++ b/arch/arm/mach-zynq/hotplug.c @@ -0,0 +1,104 @@ +/* + * Copyright (C) 2012-2013 Xilinx + * + * based on 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 <asm/cacheflush.h> +#include <asm/cp15.h> +#include "common.h" + +static inline void zynq_cpu_enter_lowpower(void) +{ + unsigned int v; + + flush_cache_all(); + asm volatile( + " mcr p15, 0, %1, c7, c5, 0\n" + " dsb\n" + /* + * Turn off coherency + */ + " mrc p15, 0, %0, c1, c0, 1\n" + " bic %0, %0, #0x40\n" + " mcr p15, 0, %0, c1, c0, 1\n" + " mrc p15, 0, %0, c1, c0, 0\n" + " bic %0, %0, %2\n" + " mcr p15, 0, %0, c1, c0, 0\n" + : "=&r" (v) + : "r" (0), "Ir" (CR_C) + : "cc"); +} + +static inline void zynq_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, #0x40\n" + " mcr p15, 0, %0, c1, c0, 1\n" + : "=&r" (v) + : "Ir" (CR_C) + : "cc"); +} + +static inline void zynq_platform_do_lowpower(unsigned int cpu, int *spurious) +{ + /* + * there is no power-control hardware on this platform, so all + * we can do is put the core into WFI; this is safe as the calling + * code will have already disabled interrupts + */ + for (;;) { + dsb(); + wfi(); + + /* + * 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 zynq_platform_cpu_die(unsigned int cpu) +{ + int spurious = 0; + + /* + * we're ready for shutdown now, so do it + */ + zynq_cpu_enter_lowpower(); + zynq_platform_do_lowpower(cpu, &spurious); + + /* + * bring this CPU back into the world of cache + * coherency, and then restore interrupts + */ + zynq_cpu_leave_lowpower(); + + if (spurious) + pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); +} diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c index cdfd888ca783..3072cbd7ec6f 100644 --- a/arch/arm/mach-zynq/platsmp.c +++ b/arch/arm/mach-zynq/platsmp.c @@ -146,4 +146,7 @@ struct smp_operations zynq_smp_ops __initdata = { .smp_prepare_cpus = zynq_smp_prepare_cpus, .smp_secondary_init = zynq_secondary_init, .smp_boot_secondary = zynq_boot_secondary, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_die = zynq_platform_cpu_die, +#endif }; |