diff options
Diffstat (limited to 'arch/arm/mach-vexpress')
| -rw-r--r-- | arch/arm/mach-vexpress/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/ct-ca9x4.c | 2 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/hotplug.c | 128 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/include/mach/smp.h | 5 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/platsmp.c | 74 |
5 files changed, 159 insertions, 51 deletions
diff --git a/arch/arm/mach-vexpress/Makefile b/arch/arm/mach-vexpress/Makefile index 1b71b77ade22..2c0ac7de2814 100644 --- a/arch/arm/mach-vexpress/Makefile +++ b/arch/arm/mach-vexpress/Makefile @@ -5,4 +5,5 @@ obj-y := v2m.o obj-$(CONFIG_ARCH_VEXPRESS_CA9X4) += ct-ca9x4.o obj-$(CONFIG_SMP) += platsmp.o headsmp.o +obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o diff --git a/arch/arm/mach-vexpress/ct-ca9x4.c b/arch/arm/mach-vexpress/ct-ca9x4.c index 26a02eb57571..f4455e3ed6a4 100644 --- a/arch/arm/mach-vexpress/ct-ca9x4.c +++ b/arch/arm/mach-vexpress/ct-ca9x4.c @@ -53,7 +53,9 @@ static struct map_desc ct_ca9x4_io_desc[] __initdata = { static void __init ct_ca9x4_map_io(void) { +#ifdef CONFIG_LOCAL_TIMERS twd_base = MMIO_P2V(A9_MPCORE_TWD); +#endif v2m_map_io(ct_ca9x4_io_desc, ARRAY_SIZE(ct_ca9x4_io_desc)); } diff --git a/arch/arm/mach-vexpress/hotplug.c b/arch/arm/mach-vexpress/hotplug.c new file mode 100644 index 000000000000..ea4cbfb90a66 --- /dev/null +++ b/arch/arm/mach-vexpress/hotplug.c @@ -0,0 +1,128 @@ +/* + * 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> + +extern volatile int pen_release; + +static inline void cpu_enter_lowpower(void) +{ + unsigned int v; + + flush_cache_all(); + asm volatile( + "mcr p15, 0, %1, c7, c5, 0\n" + " mcr p15, 0, %1, c7, c10, 4\n" + /* + * Turn off coherency + */ + " mrc p15, 0, %0, c1, c0, 1\n" + " bic %0, %0, %3\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), "Ir" (0x40) + : "cc"); +} + +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) +{ + /* + * 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 (;;) { + /* + * here's the WFI + */ + asm(".word 0xe320f003\n" + : + : + : "memory", "cc"); + + if (pen_release == cpu) { + /* + * 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)++; + } +} + +int platform_cpu_kill(unsigned int cpu) +{ + return 1; +} + +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +void platform_cpu_die(unsigned int cpu) +{ + int spurious = 0; + + /* + * we're ready for shutdown now, so do it + */ + cpu_enter_lowpower(); + 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); +} + +int platform_cpu_disable(unsigned int cpu) +{ + /* + * we don't allow CPU 0 to be shutdown (it is still too special + * e.g. clock tick interrupts) + */ + return cpu == 0 ? -EPERM : 0; +} diff --git a/arch/arm/mach-vexpress/include/mach/smp.h b/arch/arm/mach-vexpress/include/mach/smp.h index 5a6da4fd247e..4c05e4a9713a 100644 --- a/arch/arm/mach-vexpress/include/mach/smp.h +++ b/arch/arm/mach-vexpress/include/mach/smp.h @@ -2,13 +2,12 @@ #define __MACH_SMP_H #include <asm/hardware/gic.h> -#include <asm/smp_mpidr.h> /* * We use IRQ1 as the IPI */ -static inline void smp_cross_call(const struct cpumask *mask) +static inline void smp_cross_call(const struct cpumask *mask, int ipi) { - gic_raise_softirq(mask, 1); + gic_raise_softirq(mask, ipi); } #endif diff --git a/arch/arm/mach-vexpress/platsmp.c b/arch/arm/mach-vexpress/platsmp.c index 670970699ba9..8ce9fef29555 100644 --- a/arch/arm/mach-vexpress/platsmp.c +++ b/arch/arm/mach-vexpress/platsmp.c @@ -17,7 +17,6 @@ #include <linux/io.h> #include <asm/cacheflush.h> -#include <asm/localtimer.h> #include <asm/smp_scu.h> #include <asm/unified.h> @@ -35,6 +34,19 @@ extern void vexpress_secondary_startup(void); */ volatile int __cpuinitdata pen_release = -1; +/* + * Write pen_release in a way that is guaranteed to be visible to all + * observers, irrespective of whether they're taking part in coherency + * or not. This is necessary for the hotplug code to work reliably. + */ +static void write_pen_release(int val) +{ + pen_release = val; + smp_wmb(); + __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); + outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); +} + static void __iomem *scu_base_addr(void) { return MMIO_P2V(A9_MPCORE_SCU); @@ -44,8 +56,6 @@ static DEFINE_SPINLOCK(boot_lock); void __cpuinit platform_secondary_init(unsigned int cpu) { - trace_hardirqs_off(); - /* * if any interrupts are already enabled for the primary * core (e.g. timer irq), then they will not have been enabled @@ -57,8 +67,7 @@ void __cpuinit platform_secondary_init(unsigned int cpu) * let the primary processor know we're out of the * pen, then head off into the C entry point */ - pen_release = -1; - smp_wmb(); + write_pen_release(-1); /* * Synchronise with the boot thread. @@ -83,16 +92,14 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) * since we haven't sent them a soft interrupt, they shouldn't * be there. */ - pen_release = cpu; - __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); - outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); + write_pen_release(cpu); /* * Send the secondary CPU a soft interrupt, thereby causing * the boot monitor to read the system wide flags register, * and branch to the address found there. */ - smp_cross_call(cpumask_of(cpu)); + smp_cross_call(cpumask_of(cpu), 1); timeout = jiffies + (1 * HZ); while (time_before(jiffies, timeout)) { @@ -124,13 +131,6 @@ void __init smp_init_cpus(void) ncores = scu_base ? scu_get_core_count(scu_base) : 1; /* sanity check */ - if (ncores == 0) { - printk(KERN_ERR - "vexpress: strange CM count of 0? Default to 1\n"); - - ncores = 1; - } - if (ncores > NR_CPUS) { printk(KERN_WARNING "vexpress: no. of cores (%d) greater than configured " @@ -143,20 +143,10 @@ void __init smp_init_cpus(void) set_cpu_possible(i, true); } -void __init smp_prepare_cpus(unsigned int max_cpus) +void __init platform_smp_prepare_cpus(unsigned int max_cpus) { - unsigned int ncores = num_possible_cpus(); - unsigned int cpu = smp_processor_id(); int i; - smp_store_cpu_info(cpu); - - /* - * are we trying to boot more cores than exist? - */ - if (max_cpus > ncores) - max_cpus = ncores; - /* * Initialise the present map, which describes the set of CPUs * actually populated at the present time. @@ -164,27 +154,15 @@ void __init smp_prepare_cpus(unsigned int max_cpus) for (i = 0; i < max_cpus; i++) set_cpu_present(i, true); + scu_enable(scu_base_addr()); + /* - * Initialise the SCU if there are more than one CPU and let - * them know where to start. + * Write the address of secondary startup into the + * system-wide flags register. The boot monitor waits + * until it receives a soft interrupt, and then the + * secondary CPU branches to this address. */ - if (max_cpus > 1) { - /* - * Enable the local timer or broadcast device for the - * boot CPU, but only if we have more than one CPU. - */ - percpu_timer_setup(); - - scu_enable(scu_base_addr()); - - /* - * Write the address of secondary startup into the - * system-wide flags register. The boot monitor waits - * until it receives a soft interrupt, and then the - * secondary CPU branches to this address. - */ - writel(~0, MMIO_P2V(V2M_SYS_FLAGSCLR)); - writel(BSYM(virt_to_phys(vexpress_secondary_startup)), - MMIO_P2V(V2M_SYS_FLAGSSET)); - } + writel(~0, MMIO_P2V(V2M_SYS_FLAGSCLR)); + writel(BSYM(virt_to_phys(vexpress_secondary_startup)), + MMIO_P2V(V2M_SYS_FLAGSSET)); } |
