diff options
Diffstat (limited to 'arch/arm/mach-vexpress/dcscb.c')
| -rw-r--r-- | arch/arm/mach-vexpress/dcscb.c | 197 |
1 files changed, 67 insertions, 130 deletions
diff --git a/arch/arm/mach-vexpress/dcscb.c b/arch/arm/mach-vexpress/dcscb.c index 30b9933..5cedcf5 100644 --- a/arch/arm/mach-vexpress/dcscb.c +++ b/arch/arm/mach-vexpress/dcscb.c @@ -12,7 +12,6 @@ #include <linux/init.h> #include <linux/kernel.h> #include <linux/io.h> -#include <linux/spinlock.h> #include <linux/errno.h> #include <linux/of_address.h> #include <linux/vexpress.h> @@ -36,163 +35,102 @@ #define KFC_CFG_W 0x2c #define DCS_CFG_R 0x30 -/* - * We can't use regular spinlocks. In the switcher case, it is possible - * for an outbound CPU to call power_down() while its inbound counterpart - * is already live using the same logical CPU number which trips lockdep - * debugging. - */ -static arch_spinlock_t dcscb_lock = __ARCH_SPIN_LOCK_UNLOCKED; - static void __iomem *dcscb_base; -static int dcscb_use_count[4][2]; static int dcscb_allcpus_mask[2]; -static int dcscb_power_up(unsigned int cpu, unsigned int cluster) +static int dcscb_cpu_powerup(unsigned int cpu, unsigned int cluster) { unsigned int rst_hold, cpumask = (1 << cpu); - unsigned int all_mask; pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); - if (cpu >= 4 || cluster >= 2) + if (cluster >= 2 || !(cpumask & dcscb_allcpus_mask[cluster])) return -EINVAL; - all_mask = dcscb_allcpus_mask[cluster]; + rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4); + rst_hold &= ~(cpumask | (cpumask << 4)); + writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4); + return 0; +} - /* - * Since this is called with IRQs enabled, and no arch_spin_lock_irq - * variant exists, we need to disable IRQs manually here. - */ - local_irq_disable(); - arch_spin_lock(&dcscb_lock); - - dcscb_use_count[cpu][cluster]++; - if (dcscb_use_count[cpu][cluster] == 1) { - rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4); - if (rst_hold & (1 << 8)) { - /* remove cluster reset and add individual CPU's reset */ - rst_hold &= ~(1 << 8); - rst_hold |= all_mask; - } - rst_hold &= ~(cpumask | (cpumask << 4)); - writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4); - } else if (dcscb_use_count[cpu][cluster] != 2) { - /* - * The only possible values are: - * 0 = CPU down - * 1 = CPU (still) up - * 2 = CPU requested to be up before it had a chance - * to actually make itself down. - * Any other value is a bug. - */ - BUG(); - } +static int dcscb_cluster_powerup(unsigned int cluster) +{ + unsigned int rst_hold; - arch_spin_unlock(&dcscb_lock); - local_irq_enable(); + pr_debug("%s: cluster %u\n", __func__, cluster); + if (cluster >= 2) + return -EINVAL; + /* remove cluster reset and add individual CPU's reset */ + rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4); + rst_hold &= ~(1 << 8); + rst_hold |= dcscb_allcpus_mask[cluster]; + writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4); return 0; } -static void dcscb_power_down(void) +static void dcscb_cpu_powerdown_prepare(unsigned int cpu, unsigned int cluster) { - unsigned int mpidr, cpu, cluster, rst_hold, cpumask, all_mask; - bool last_man = false, skip_wfi = false; - - mpidr = read_cpuid_mpidr(); - cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); - cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); - cpumask = (1 << cpu); + unsigned int rst_hold; pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); - BUG_ON(cpu >= 4 || cluster >= 2); - - all_mask = dcscb_allcpus_mask[cluster]; - - __mcpm_cpu_going_down(cpu, cluster); - - arch_spin_lock(&dcscb_lock); - BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP); - dcscb_use_count[cpu][cluster]--; - if (dcscb_use_count[cpu][cluster] == 0) { - rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4); - rst_hold |= cpumask; - if (((rst_hold | (rst_hold >> 4)) & all_mask) == all_mask) { - rst_hold |= (1 << 8); - last_man = true; - } - writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4); - } else if (dcscb_use_count[cpu][cluster] == 1) { - /* - * A power_up request went ahead of us. - * Even if we do not want to shut this CPU down, - * the caller expects a certain state as if the WFI - * was aborted. So let's continue with cache cleaning. - */ - skip_wfi = true; - } else - BUG(); - - if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) { - arch_spin_unlock(&dcscb_lock); - - /* Flush all cache levels for this cluster. */ - v7_exit_coherency_flush(all); - - /* - * A full outer cache flush could be needed at this point - * on platforms with such a cache, depending on where the - * outer cache sits. In some cases the notion of a "last - * cluster standing" would need to be implemented if the - * outer cache is shared across clusters. In any case, when - * the outer cache needs flushing, there is no concurrent - * access to the cache controller to worry about and no - * special locking besides what is already provided by the - * MCPM state machinery is needed. - */ - - /* - * Disable cluster-level coherency by masking - * incoming snoops and DVM messages: - */ - cci_disable_port_by_cpu(mpidr); - - __mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN); - } else { - arch_spin_unlock(&dcscb_lock); - - /* Disable and flush the local CPU cache. */ - v7_exit_coherency_flush(louis); - } + BUG_ON(cluster >= 2 || !((1 << cpu) & dcscb_allcpus_mask[cluster])); - __mcpm_cpu_down(cpu, cluster); + rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4); + rst_hold |= (1 << cpu); + writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4); +} - /* Now we are prepared for power-down, do it: */ - dsb(); - if (!skip_wfi) - wfi(); +static void dcscb_cluster_powerdown_prepare(unsigned int cluster) +{ + unsigned int rst_hold; - /* Not dead at this point? Let our caller cope. */ + pr_debug("%s: cluster %u\n", __func__, cluster); + BUG_ON(cluster >= 2); + + rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4); + rst_hold |= (1 << 8); + writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4); } -static const struct mcpm_platform_ops dcscb_power_ops = { - .power_up = dcscb_power_up, - .power_down = dcscb_power_down, -}; +static void dcscb_cpu_cache_disable(void) +{ + /* Disable and flush the local CPU cache. */ + v7_exit_coherency_flush(louis); +} -static void __init dcscb_usage_count_init(void) +static void dcscb_cluster_cache_disable(void) { - unsigned int mpidr, cpu, cluster; + /* Flush all cache levels for this cluster. */ + v7_exit_coherency_flush(all); - mpidr = read_cpuid_mpidr(); - cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); - cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); + /* + * A full outer cache flush could be needed at this point + * on platforms with such a cache, depending on where the + * outer cache sits. In some cases the notion of a "last + * cluster standing" would need to be implemented if the + * outer cache is shared across clusters. In any case, when + * the outer cache needs flushing, there is no concurrent + * access to the cache controller to worry about and no + * special locking besides what is already provided by the + * MCPM state machinery is needed. + */ - pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); - BUG_ON(cpu >= 4 || cluster >= 2); - dcscb_use_count[cpu][cluster] = 1; + /* + * Disable cluster-level coherency by masking + * incoming snoops and DVM messages: + */ + cci_disable_port_by_cpu(read_cpuid_mpidr()); } +static const struct mcpm_platform_ops dcscb_power_ops = { + .cpu_powerup = dcscb_cpu_powerup, + .cluster_powerup = dcscb_cluster_powerup, + .cpu_powerdown_prepare = dcscb_cpu_powerdown_prepare, + .cluster_powerdown_prepare = dcscb_cluster_powerdown_prepare, + .cpu_cache_disable = dcscb_cpu_cache_disable, + .cluster_cache_disable = dcscb_cluster_cache_disable, +}; + extern void dcscb_power_up_setup(unsigned int affinity_level); static int __init dcscb_init(void) @@ -213,7 +151,6 @@ static int __init dcscb_init(void) cfg = readl_relaxed(dcscb_base + DCS_CFG_R); dcscb_allcpus_mask[0] = (1 << (((cfg >> 16) >> (0 << 2)) & 0xf)) - 1; dcscb_allcpus_mask[1] = (1 << (((cfg >> 16) >> (1 << 2)) & 0xf)) - 1; - dcscb_usage_count_init(); ret = mcpm_platform_register(&dcscb_power_ops); if (!ret) |
