diff options
Diffstat (limited to 'arch/arm/mach-vexpress/tc2_pm.c')
| -rw-r--r-- | arch/arm/mach-vexpress/tc2_pm.c | 121 |
1 files changed, 68 insertions, 53 deletions
diff --git a/arch/arm/mach-vexpress/tc2_pm.c b/arch/arm/mach-vexpress/tc2_pm.c index e6eb48192912..29e7785a54bc 100644 --- a/arch/arm/mach-vexpress/tc2_pm.c +++ b/arch/arm/mach-vexpress/tc2_pm.c @@ -12,10 +12,12 @@ * published by the Free Software Foundation. */ +#include <linux/delay.h> #include <linux/init.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/of_address.h> +#include <linux/of_irq.h> #include <linux/spinlock.h> #include <linux/errno.h> #include <linux/irqchip/arm-gic.h> @@ -31,11 +33,17 @@ #include "spc.h" /* SCC conf registers */ +#define RESET_CTRL 0x018 +#define RESET_A15_NCORERESET(cpu) (1 << (2 + (cpu))) +#define RESET_A7_NCORERESET(cpu) (1 << (16 + (cpu))) + #define A15_CONF 0x400 #define A7_CONF 0x500 #define SYS_INFO 0x700 #define SPC_BASE 0xb00 +static void __iomem *scc; + /* * We can't use regular spinlocks. In the switcher case, it is possible * for an outbound CPU to call power_down() after its inbound counterpart @@ -156,32 +164,7 @@ static void tc2_pm_down(u64 residency) : : "r" (0x400) ); } - /* - * We need to disable and flush the whole (L1 and L2) cache. - * Let's do it in the safest possible way i.e. with - * no memory access within the following sequence - * including the stack. - * - * Note: fp is preserved to the stack explicitly prior doing - * this since adding it to the clobber list is incompatible - * with having CONFIG_FRAME_POINTER=y. - */ - asm volatile( - "str fp, [sp, #-4]! \n\t" - "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t" - "bic r0, r0, #"__stringify(CR_C)" \n\t" - "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t" - "isb \n\t" - "bl v7_flush_dcache_all \n\t" - "clrex \n\t" - "mrc p15, 0, r0, c1, c0, 1 @ get AUXCR \n\t" - "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" - "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t" - "isb \n\t" - "dsb \n\t" - "ldr fp, [sp], #4" - : : : "r0","r1","r2","r3","r4","r5","r6","r7", - "r9","r10","lr","memory"); + v7_exit_coherency_flush(all); cci_disable_port_by_cpu(mpidr); @@ -197,26 +180,7 @@ static void tc2_pm_down(u64 residency) arch_spin_unlock(&tc2_pm_lock); - /* - * We need to disable and flush only the L1 cache. - * Let's do it in the safest possible way as above. - */ - asm volatile( - "str fp, [sp, #-4]! \n\t" - "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t" - "bic r0, r0, #"__stringify(CR_C)" \n\t" - "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t" - "isb \n\t" - "bl v7_flush_dcache_louis \n\t" - "clrex \n\t" - "mrc p15, 0, r0, c1, c0, 1 @ get AUXCR \n\t" - "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" - "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t" - "isb \n\t" - "dsb \n\t" - "ldr fp, [sp], #4" - : : : "r0","r1","r2","r3","r4","r5","r6","r7", - "r9","r10","lr","memory"); + v7_exit_coherency_flush(louis); } __mcpm_cpu_down(cpu, cluster); @@ -233,6 +197,55 @@ static void tc2_pm_power_down(void) tc2_pm_down(0); } +static int tc2_core_in_reset(unsigned int cpu, unsigned int cluster) +{ + u32 mask = cluster ? + RESET_A7_NCORERESET(cpu) + : RESET_A15_NCORERESET(cpu); + + return !(readl_relaxed(scc + RESET_CTRL) & mask); +} + +#define POLL_MSEC 10 +#define TIMEOUT_MSEC 1000 + +static int tc2_pm_power_down_finish(unsigned int cpu, unsigned int cluster) +{ + unsigned tries; + + pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); + BUG_ON(cluster >= TC2_CLUSTERS || cpu >= TC2_MAX_CPUS_PER_CLUSTER); + + for (tries = 0; tries < TIMEOUT_MSEC / POLL_MSEC; ++tries) { + /* + * Only examine the hardware state if the target CPU has + * caught up at least as far as tc2_pm_down(): + */ + if (ACCESS_ONCE(tc2_pm_use_count[cpu][cluster]) == 0) { + pr_debug("%s(cpu=%u, cluster=%u): RESET_CTRL = 0x%08X\n", + __func__, cpu, cluster, + readl_relaxed(scc + RESET_CTRL)); + + /* + * We need the CPU to reach WFI, but the power + * controller may put the cluster in reset and + * power it off as soon as that happens, before + * we have a chance to see STANDBYWFI. + * + * So we need to check for both conditions: + */ + if (tc2_core_in_reset(cpu, cluster) || + ve_spc_cpu_in_wfi(cpu, cluster)) + return 0; /* success: the CPU is halted */ + } + + /* Otherwise, wait and retry: */ + msleep(POLL_MSEC); + } + + return -ETIMEDOUT; /* timeout */ +} + static void tc2_pm_suspend(u64 residency) { unsigned int mpidr, cpu, cluster; @@ -275,10 +288,11 @@ static void tc2_pm_powered_up(void) } static const struct mcpm_platform_ops tc2_pm_power_ops = { - .power_up = tc2_pm_power_up, - .power_down = tc2_pm_power_down, - .suspend = tc2_pm_suspend, - .powered_up = tc2_pm_powered_up, + .power_up = tc2_pm_power_up, + .power_down = tc2_pm_power_down, + .power_down_finish = tc2_pm_power_down_finish, + .suspend = tc2_pm_suspend, + .powered_up = tc2_pm_powered_up, }; static bool __init tc2_pm_usage_count_init(void) @@ -311,8 +325,7 @@ static void __naked tc2_pm_power_up_setup(unsigned int affinity_level) static int __init tc2_pm_init(void) { - int ret; - void __iomem *scc; + int ret, irq; u32 a15_cluster_id, a7_cluster_id, sys_info; struct device_node *np; @@ -336,13 +349,15 @@ static int __init tc2_pm_init(void) tc2_nr_cpus[a15_cluster_id] = (sys_info >> 16) & 0xf; tc2_nr_cpus[a7_cluster_id] = (sys_info >> 20) & 0xf; + irq = irq_of_parse_and_map(np, 0); + /* * A subset of the SCC registers is also used to communicate * with the SPC (power controller). We need to be able to * drive it very early in the boot process to power up * processors, so we initialize the SPC driver here. */ - ret = ve_spc_init(scc + SPC_BASE, a15_cluster_id); + ret = ve_spc_init(scc + SPC_BASE, a15_cluster_id, irq); if (ret) return ret; |