diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/mach-sunxi/mc_smp.c | 190 |
1 files changed, 189 insertions, 1 deletions
diff --git a/arch/arm/mach-sunxi/mc_smp.c b/arch/arm/mach-sunxi/mc_smp.c index 92e3d7ba496a..fc0acfa07f74 100644 --- a/arch/arm/mach-sunxi/mc_smp.c +++ b/arch/arm/mach-sunxi/mc_smp.c @@ -15,6 +15,8 @@ #include <linux/cpu_pm.h> #include <linux/delay.h> #include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/irqchip/arm-gic.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_device.h> @@ -30,6 +32,9 @@ #define SUNXI_CPUS_PER_CLUSTER 4 #define SUNXI_NR_CLUSTERS 2 +#define POLL_USEC 100 +#define TIMEOUT_USEC 100000 + #define CPUCFG_CX_CTRL_REG0(c) (0x10 * (c)) #define CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE(n) BIT(n) #define CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE_ALL 0xf @@ -37,6 +42,9 @@ #define CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A15 BIT(0) #define CPUCFG_CX_CTRL_REG1(c) (0x10 * (c) + 0x4) #define CPUCFG_CX_CTRL_REG1_ACINACTM BIT(0) +#define CPUCFG_CX_STATUS(c) (0x30 + 0x4 * (c)) +#define CPUCFG_CX_STATUS_STANDBYWFI(n) BIT(16 + (n)) +#define CPUCFG_CX_STATUS_STANDBYWFIL2 BIT(0) #define CPUCFG_CX_RST_CTRL(c) (0x80 + 0x4 * (c)) #define CPUCFG_CX_RST_CTRL_DBG_SOC_RST BIT(24) #define CPUCFG_CX_RST_CTRL_ETM_RST(n) BIT(20 + (n)) @@ -121,7 +129,7 @@ static int sunxi_cpu_powerup(unsigned int cpu, unsigned int cluster) { u32 reg; - pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); + pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu); if (cpu >= SUNXI_CPUS_PER_CLUSTER || cluster >= SUNXI_NR_CLUSTERS) return -EINVAL; @@ -390,8 +398,188 @@ out: return 0; } +#ifdef CONFIG_HOTPLUG_CPU +static void sunxi_cluster_cache_disable(void) +{ + unsigned int cluster = MPIDR_AFFINITY_LEVEL(read_cpuid_mpidr(), 1); + u32 reg; + + pr_debug("%s: cluster %u\n", __func__, cluster); + + sunxi_cluster_cache_disable_without_axi(); + + /* last man standing, assert ACINACTM */ + reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster)); + reg |= CPUCFG_CX_CTRL_REG1_ACINACTM; + writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster)); +} + +static void sunxi_mc_smp_cpu_die(unsigned int l_cpu) +{ + unsigned int mpidr, cpu, cluster; + bool last_man; + + mpidr = cpu_logical_map(l_cpu); + cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); + pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu); + + spin_lock(&boot_lock); + sunxi_mc_smp_cpu_table[cluster][cpu]--; + if (sunxi_mc_smp_cpu_table[cluster][cpu] == 1) { + /* A power_up request went ahead of us. */ + pr_debug("%s: aborting due to a power up request\n", + __func__); + spin_unlock(&boot_lock); + return; + } else if (sunxi_mc_smp_cpu_table[cluster][cpu] > 1) { + pr_err("Cluster %d CPU%d boots multiple times\n", + cluster, cpu); + BUG(); + } + + last_man = sunxi_mc_smp_cluster_is_down(cluster); + spin_unlock(&boot_lock); + + gic_cpu_if_down(0); + if (last_man) + sunxi_cluster_cache_disable(); + else + v7_exit_coherency_flush(louis); + + for (;;) + wfi(); +} + +static int sunxi_cpu_powerdown(unsigned int cpu, unsigned int cluster) +{ + u32 reg; + + pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu); + if (cpu >= SUNXI_CPUS_PER_CLUSTER || cluster >= SUNXI_NR_CLUSTERS) + return -EINVAL; + + /* gate processor power */ + reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + reg |= PRCM_PWROFF_GATING_REG_CORE(cpu); + writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + udelay(20); + + /* close power switch */ + sunxi_cpu_power_switch_set(cpu, cluster, false); + + return 0; +} + +static int sunxi_cluster_powerdown(unsigned int cluster) +{ + u32 reg; + + pr_debug("%s: cluster %u\n", __func__, cluster); + if (cluster >= SUNXI_NR_CLUSTERS) + return -EINVAL; + + /* assert cluster resets or system will hang */ + pr_debug("%s: assert cluster reset\n", __func__); + reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + reg &= ~CPUCFG_CX_RST_CTRL_DBG_SOC_RST; + reg &= ~CPUCFG_CX_RST_CTRL_H_RST; + reg &= ~CPUCFG_CX_RST_CTRL_L2_RST; + writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + + /* gate cluster power */ + pr_debug("%s: gate cluster power\n", __func__); + reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + reg |= PRCM_PWROFF_GATING_REG_CLUSTER; + writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + udelay(20); + + return 0; +} + +static int sunxi_mc_smp_cpu_kill(unsigned int l_cpu) +{ + unsigned int mpidr, cpu, cluster; + unsigned int tries, count; + int ret = 0; + u32 reg; + + mpidr = cpu_logical_map(l_cpu); + cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); + + /* This should never happen */ + if (WARN_ON(cluster >= SUNXI_NR_CLUSTERS || + cpu >= SUNXI_CPUS_PER_CLUSTER)) + return 0; + + /* wait for CPU core to die and enter WFI */ + count = TIMEOUT_USEC / POLL_USEC; + spin_lock_irq(&boot_lock); + for (tries = 0; tries < count; tries++) { + spin_unlock_irq(&boot_lock); + usleep_range(POLL_USEC / 2, POLL_USEC); + spin_lock_irq(&boot_lock); + + /* + * If the user turns off a bunch of cores at the same + * time, the kernel might call cpu_kill before some of + * them are ready. This is because boot_lock serializes + * both cpu_die and cpu_kill callbacks. Either one could + * run first. We should wait for cpu_die to complete. + */ + if (sunxi_mc_smp_cpu_table[cluster][cpu]) + continue; + + reg = readl(cpucfg_base + CPUCFG_CX_STATUS(cluster)); + if (reg & CPUCFG_CX_STATUS_STANDBYWFI(cpu)) + break; + } + + if (tries >= count) { + ret = ETIMEDOUT; + goto out; + } + + /* power down CPU core */ + sunxi_cpu_powerdown(cpu, cluster); + + if (!sunxi_mc_smp_cluster_is_down(cluster)) + goto out; + + /* wait for cluster L2 WFI */ + ret = readl_poll_timeout(cpucfg_base + CPUCFG_CX_STATUS(cluster), reg, + reg & CPUCFG_CX_STATUS_STANDBYWFIL2, + POLL_USEC, TIMEOUT_USEC); + if (ret) { + /* + * Ignore timeout on the cluster. Leaving the cluster on + * will not affect system execution, just use a bit more + * power. But returning an error here will only confuse + * the user as the CPU has already been shutdown. + */ + ret = 0; + goto out; + } + + /* Power down cluster */ + sunxi_cluster_powerdown(cluster); + +out: + spin_unlock_irq(&boot_lock); + pr_debug("%s: cluster %u cpu %u powerdown: %d\n", + __func__, cluster, cpu, ret); + return !ret; +} + +#endif + static const struct smp_operations sunxi_mc_smp_smp_ops __initconst = { .smp_boot_secondary = sunxi_mc_smp_boot_secondary, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_die = sunxi_mc_smp_cpu_die, + .cpu_kill = sunxi_mc_smp_cpu_kill, +#endif }; static bool __init sunxi_mc_smp_cpu_table_init(void) |