diff options
Diffstat (limited to 'arch/arm/mach-vexpress')
| -rw-r--r-- | arch/arm/mach-vexpress/Kconfig | 9 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/core.h | 2 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/dcscb.c | 253 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/dcscb_setup.S | 38 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/platsmp.c | 20 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/v2m.c | 1 |
7 files changed, 324 insertions, 0 deletions
diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig index 5907e10c37fd..b8bbabec6310 100644 --- a/arch/arm/mach-vexpress/Kconfig +++ b/arch/arm/mach-vexpress/Kconfig @@ -57,4 +57,13 @@ config ARCH_VEXPRESS_CORTEX_A5_A9_ERRATA config ARCH_VEXPRESS_CA9X4 bool "Versatile Express Cortex-A9x4 tile" +config ARCH_VEXPRESS_DCSCB + bool "Dual Cluster System Control Block (DCSCB) support" + depends on MCPM + select ARM_CCI + help + Support for the Dual Cluster System Configuration Block (DCSCB). + This is needed to provide CPU and cluster power management + on RTSM implementing big.LITTLE. + endmenu diff --git a/arch/arm/mach-vexpress/Makefile b/arch/arm/mach-vexpress/Makefile index 42703e8b4d3b..48ba89a8149f 100644 --- a/arch/arm/mach-vexpress/Makefile +++ b/arch/arm/mach-vexpress/Makefile @@ -6,5 +6,6 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include \ obj-y := v2m.o obj-$(CONFIG_ARCH_VEXPRESS_CA9X4) += ct-ca9x4.o +obj-$(CONFIG_ARCH_VEXPRESS_DCSCB) += dcscb.o dcscb_setup.o obj-$(CONFIG_SMP) += platsmp.o obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o diff --git a/arch/arm/mach-vexpress/core.h b/arch/arm/mach-vexpress/core.h index f134cd4a85f1..bde4374ab6d5 100644 --- a/arch/arm/mach-vexpress/core.h +++ b/arch/arm/mach-vexpress/core.h @@ -6,6 +6,8 @@ void vexpress_dt_smp_map_io(void); +bool vexpress_smp_init_ops(void); + extern struct smp_operations vexpress_smp_ops; extern void vexpress_cpu_die(unsigned int cpu); diff --git a/arch/arm/mach-vexpress/dcscb.c b/arch/arm/mach-vexpress/dcscb.c new file mode 100644 index 000000000000..16d57a8a9d5a --- /dev/null +++ b/arch/arm/mach-vexpress/dcscb.c @@ -0,0 +1,253 @@ +/* + * arch/arm/mach-vexpress/dcscb.c - Dual Cluster System Configuration Block + * + * Created by: Nicolas Pitre, May 2012 + * Copyright: (C) 2012-2013 Linaro Limited + * + * 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/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> +#include <linux/arm-cci.h> + +#include <asm/mcpm.h> +#include <asm/proc-fns.h> +#include <asm/cacheflush.h> +#include <asm/cputype.h> +#include <asm/cp15.h> + + +#define RST_HOLD0 0x0 +#define RST_HOLD1 0x4 +#define SYS_SWRESET 0x8 +#define RST_STAT0 0xc +#define RST_STAT1 0x10 +#define EAG_CFG_R 0x20 +#define EAG_CFG_W 0x24 +#define KFC_CFG_R 0x28 +#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) +{ + unsigned int rst_hold, cpumask = (1 << cpu); + unsigned int all_mask = dcscb_allcpus_mask[cluster]; + + pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); + if (cpu >= 4 || cluster >= 2) + return -EINVAL; + + /* + * 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(); + } + + arch_spin_unlock(&dcscb_lock); + local_irq_enable(); + + return 0; +} + +static void dcscb_power_down(void) +{ + 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); + all_mask = dcscb_allcpus_mask[cluster]; + + pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); + BUG_ON(cpu >= 4 || cluster >= 2); + + __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. + * + * A15/A7 can hit in the cache with SCTLR.C=0, so we don't need + * a preliminary flush here for those CPUs. At least, that's + * the theory -- without the extra flush, Linux explodes on + * RTSM (to be investigated). + */ + flush_cache_all(); + set_cr(get_cr() & ~CR_C); + flush_cache_all(); + + /* + * This is a harmless no-op. On platforms with a real + * outer cache this might either be needed or not, + * depending on where the outer cache sits. + */ + outer_flush_all(); + + /* Disable local coherency by clearing the ACTLR "SMP" bit: */ + set_auxcr(get_auxcr() & ~(1 << 6)); + + /* + * 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); + + /* + * Flush the local CPU cache. + * + * A15/A7 can hit in the cache with SCTLR.C=0, so we don't need + * a preliminary flush here for those CPUs. At least, that's + * the theory -- without the extra flush, Linux explodes on + * RTSM (to be investigated). + */ + flush_cache_louis(); + set_cr(get_cr() & ~CR_C); + flush_cache_louis(); + + /* Disable local coherency by clearing the ACTLR "SMP" bit: */ + set_auxcr(get_auxcr() & ~(1 << 6)); + } + + __mcpm_cpu_down(cpu, cluster); + + /* Now we are prepared for power-down, do it: */ + dsb(); + if (!skip_wfi) + wfi(); + + /* Not dead at this point? Let our caller cope. */ +} + +static const struct mcpm_platform_ops dcscb_power_ops = { + .power_up = dcscb_power_up, + .power_down = dcscb_power_down, +}; + +static void __init dcscb_usage_count_init(void) +{ + unsigned int mpidr, cpu, cluster; + + mpidr = read_cpuid_mpidr(); + cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); + + pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); + BUG_ON(cpu >= 4 || cluster >= 2); + dcscb_use_count[cpu][cluster] = 1; +} + +extern void dcscb_power_up_setup(unsigned int affinity_level); + +static int __init dcscb_init(void) +{ + struct device_node *node; + unsigned int cfg; + int ret; + + if (!cci_probed()) + return -ENODEV; + + node = of_find_compatible_node(NULL, NULL, "arm,rtsm,dcscb"); + if (!node) + return -ENODEV; + dcscb_base = of_iomap(node, 0); + if (!dcscb_base) + return -EADDRNOTAVAIL; + 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) + ret = mcpm_sync_init(dcscb_power_up_setup); + if (ret) { + iounmap(dcscb_base); + return ret; + } + + pr_info("VExpress DCSCB support installed\n"); + + /* + * Future entries into the kernel can now go + * through the cluster entry vectors. + */ + vexpress_flags_set(virt_to_phys(mcpm_entry_point)); + + return 0; +} + +early_initcall(dcscb_init); diff --git a/arch/arm/mach-vexpress/dcscb_setup.S b/arch/arm/mach-vexpress/dcscb_setup.S new file mode 100644 index 000000000000..4bb7fbe0f621 --- /dev/null +++ b/arch/arm/mach-vexpress/dcscb_setup.S @@ -0,0 +1,38 @@ +/* + * arch/arm/include/asm/dcscb_setup.S + * + * Created by: Dave Martin, 2012-06-22 + * Copyright: (C) 2012-2013 Linaro Limited + * + * 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/linkage.h> + + +ENTRY(dcscb_power_up_setup) + + cmp r0, #0 @ check affinity level + beq 2f + +/* + * Enable cluster-level coherency, in preparation for turning on the MMU. + * The ACTLR SMP bit does not need to be set here, because cpu_resume() + * already restores that. + * + * A15/A7 may not require explicit L2 invalidation on reset, dependent + * on hardware integration decisions. + * For now, this code assumes that L2 is either already invalidated, + * or invalidation is not required. + */ + + b cci_enable_port_for_self + +2: @ Implementation-specific local CPU setup operations should go here, + @ if any. In this case, there is nothing to do. + + bx lr + +ENDPROC(dcscb_power_up_setup) diff --git a/arch/arm/mach-vexpress/platsmp.c b/arch/arm/mach-vexpress/platsmp.c index dc1ace55d557..993c9ae5dc5e 100644 --- a/arch/arm/mach-vexpress/platsmp.c +++ b/arch/arm/mach-vexpress/platsmp.c @@ -12,9 +12,11 @@ #include <linux/errno.h> #include <linux/smp.h> #include <linux/io.h> +#include <linux/of.h> #include <linux/of_fdt.h> #include <linux/vexpress.h> +#include <asm/mcpm.h> #include <asm/smp_scu.h> #include <asm/mach/map.h> @@ -203,3 +205,21 @@ struct smp_operations __initdata vexpress_smp_ops = { .cpu_die = vexpress_cpu_die, #endif }; + +bool __init vexpress_smp_init_ops(void) +{ +#ifdef CONFIG_MCPM + /* + * The best way to detect a multi-cluster configuration at the moment + * is to look for the presence of a CCI in the system. + * Override the default vexpress_smp_ops if so. + */ + struct device_node *node; + node = of_find_compatible_node(NULL, NULL, "arm,cci-400"); + if (node && of_device_is_available(node)) { + mcpm_smp_set_ops(); + return true; + } +#endif + return false; +} diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c index d6016970e2fe..95a469e23e37 100644 --- a/arch/arm/mach-vexpress/v2m.c +++ b/arch/arm/mach-vexpress/v2m.c @@ -455,6 +455,7 @@ static const char * const v2m_dt_match[] __initconst = { DT_MACHINE_START(VEXPRESS_DT, "ARM-Versatile Express") .dt_compat = v2m_dt_match, .smp = smp_ops(vexpress_smp_ops), + .smp_init = smp_init_ops(vexpress_smp_init_ops), .map_io = v2m_dt_map_io, .init_early = v2m_dt_init_early, .init_time = v2m_dt_timer_init, |