From: Zhang Zhuoyu <[email protected]> This implements CPU hotplug for ls1. When cpu is down, it will be put in WFI state. When cpu is up, it will be waked by a IPI interrupt and reinitialized.
Signed-off-by: Zhang Zhuoyu <[email protected]> Signed-off-by: Chenhui Zhao <[email protected]> --- arch/arm/mach-imx/common.h | 4 ++ arch/arm/mach-imx/hotplug.c | 90 +++++++++++++++++++++++++++++++++++++++++++ arch/arm/mach-imx/platsmp.c | 22 ++++++++-- arch/arm/mach-imx/src.c | 21 ++++++++++ 4 files changed, 132 insertions(+), 5 deletions(-) diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h index 203ee73..2ca32fe 100644 --- a/arch/arm/mach-imx/common.h +++ b/arch/arm/mach-imx/common.h @@ -115,6 +115,7 @@ void tzic_handle_irq(struct pt_regs *); extern void imx_enable_cpu(int cpu, bool enable); extern void imx_set_cpu_jump(int cpu, void *jump_addr); extern u32 imx_get_cpu_arg(int cpu); +extern u32 ls1_get_cpu_arg(int cpu); extern void imx_set_cpu_arg(int cpu, u32 arg); extern void v7_cpu_resume(void); #ifdef CONFIG_SMP @@ -145,6 +146,9 @@ extern void imx6q_set_chicken_bit(void); extern void imx_cpu_die(unsigned int cpu); extern int imx_cpu_kill(unsigned int cpu); +extern void ls1021a_cpu_die(unsigned int cpu); +extern int ls1021a_cpu_kill(unsigned int cpu); + #ifdef CONFIG_PM extern void imx6q_pm_init(void); extern void imx5_pm_init(void); diff --git a/arch/arm/mach-imx/hotplug.c b/arch/arm/mach-imx/hotplug.c index 3daf1ed..646034f 100644 --- a/arch/arm/mach-imx/hotplug.c +++ b/arch/arm/mach-imx/hotplug.c @@ -14,6 +14,9 @@ #include <linux/jiffies.h> #include <asm/cp15.h> #include <asm/proc-fns.h> +#include<asm/smp.h> +#include<asm/smp_plat.h> +#include<asm/cacheflush.h> #include "common.h" @@ -38,6 +41,22 @@ static inline void cpu_enter_lowpower(void) : "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"); +} + /* * platform-specific code to shutdown a CPU * @@ -66,3 +85,74 @@ int imx_cpu_kill(unsigned int cpu) imx_set_cpu_arg(cpu, 0); return 1; } + +static inline void ls1_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 (;;) { + wfi(); + + if (pen_release == cpu_logical_map(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)++; + } +} + +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +void __ref ls1021a_cpu_die(unsigned int cpu) +{ + int spurious = 0; + + v7_exit_coherency_flush(louis); + + /*we're ready for shutdown now, so do it*/ + ls1_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); + + /* + * Do not return to the idle loop - jump back to the secondary + * cpu initialisation. There's some initialisation which needs + * to be repeated to undo the effects of taking the CPU offline. + */ + __asm__("mov sp, %0\n" + " mov fp, #0\n" + " b ls1021a_secondary_startup" + : + : "r" (task_stack_page(current) + THREAD_SIZE - 8)); +} + +int ls1021a_cpu_kill(unsigned int cpu) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(50); + + while (ls1_get_cpu_arg(cpu)) + if (time_after(jiffies, timeout)) + return 0; + return 1; +} diff --git a/arch/arm/mach-imx/platsmp.c b/arch/arm/mach-imx/platsmp.c index 5225b69..d262b32 100644 --- a/arch/arm/mach-imx/platsmp.c +++ b/arch/arm/mach-imx/platsmp.c @@ -29,6 +29,7 @@ u32 g_diag_reg; static void __iomem *scu_base; +void __iomem *dcfg_base; static struct map_desc scu_io_desc __initdata = { /* .virtual and .pfn are run-time assigned */ @@ -196,19 +197,26 @@ static void __init ls1021a_smp_init_cpus(void) set_cpu_possible(i, false); } +void ls1021a_set_secondary_entry(void) +{ + unsigned long paddr; + + if (dcfg_base) { + paddr = virt_to_phys(ls1021a_secondary_startup); + writel_relaxed(cpu_to_be32(paddr), + dcfg_base + DCFG_CCSR_SCRATCHRW1); + } +} + static void __init ls1021a_smp_prepare_cpus(unsigned int max_cpus) { struct device_node *np; - void __iomem *dcfg_base; - unsigned long paddr; np = of_find_compatible_node(NULL, NULL, "fsl,ls1021a-dcfg"); dcfg_base = of_iomap(np, 0); WARN_ON(!dcfg_base); - paddr = virt_to_phys(ls1021a_secondary_startup); - writel_relaxed(cpu_to_be32(paddr), dcfg_base + DCFG_CCSR_SCRATCHRW1); - + ls1021a_set_secondary_entry(); } struct smp_operations ls1021a_smp_ops __initdata = { @@ -216,4 +224,8 @@ struct smp_operations ls1021a_smp_ops __initdata = { .smp_prepare_cpus = ls1021a_smp_prepare_cpus, .smp_boot_secondary = ls1021a_boot_secondary, .smp_secondary_init = ls1021a_secondary_init, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_die = ls1021a_cpu_die, + .cpu_kill = ls1021a_cpu_kill, +#endif }; diff --git a/arch/arm/mach-imx/src.c b/arch/arm/mach-imx/src.c index 10a6b1a..49508d6 100644 --- a/arch/arm/mach-imx/src.c +++ b/arch/arm/mach-imx/src.c @@ -30,6 +30,8 @@ #define BP_SRC_SCR_CORE1_RST 14 #define BP_SRC_SCR_CORE1_ENABLE 22 +#define CCSR_TWAITSR0 0x04C + static void __iomem *src_base; static DEFINE_SPINLOCK(scr_lock); @@ -114,6 +116,25 @@ void imx_set_cpu_arg(int cpu, u32 arg) writel_relaxed(arg, src_base + SRC_GPR1 + cpu * 8 + 4); } +u32 ls1_get_cpu_arg(int cpu) +{ + struct device_node *np; + void __iomem *ls1_rcpm_base; + + np = of_find_compatible_node(NULL, NULL, "fsl,qoriq-rcpm-2.1"); + if (!np) { + pr_err("%s(): Can not find the RCPM node.\n", __func__); + return -ENODEV; + } + + ls1_rcpm_base = of_iomap(np, 0); + of_node_put(np); + WARN_ON(!ls1_rcpm_base); + + cpu = cpu_logical_map(cpu); + return readl_relaxed(ls1_rcpm_base + CCSR_TWAITSR0) & (1 << cpu); +} + void imx_src_prepare_restart(void) { u32 val; -- 1.7.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
