diff options
Diffstat (limited to 'arch/arm/mach-vexpress/dcscb.c')
| -rw-r--r-- | arch/arm/mach-vexpress/dcscb.c | 253 |
1 files changed, 0 insertions, 253 deletions
diff --git a/arch/arm/mach-vexpress/dcscb.c b/arch/arm/mach-vexpress/dcscb.c deleted file mode 100644 index 16d57a8a9d5a..000000000000 --- a/arch/arm/mach-vexpress/dcscb.c +++ /dev/null @@ -1,253 +0,0 @@ -/* - * 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); |