--- /dev/null
+ARM Versatile Express Serial Configuration Controller
+-----------------------------------------------------
+
+Test chips for ARM Versatile Express platform implement SCC (Serial
+Configuration Controller) interface, used to set initial conditions
+for the test chip.
+
+In some cases its registers are also mapped in normal address space
+and can be used to obtain runtime information about the chip internals
+(like silicon temperature sensors) and as interface to other subsystems
+like platform configuration control and power management.
+
+Required properties:
+
+- compatible value: "arm,vexpress-scc,<model>", "arm,vexpress-scc";
+ where <model> is the full tile model name (as used
+ in the tile's Technical Reference Manual),
+ eg. for Coretile Express A15x2 A7x3 (V2P-CA15_A7):
+ compatible = "arm,vexpress-scc,v2p-ca15_a7", "arm,vexpress-scc";
+
+Optional properties:
+
+- reg: when the SCC is memory mapped, physical address and size of the
+ registers window
+- interrupts: when the SCC can generate a system-level interrupt
+
+Example:
+
+ scc@7fff0000 {
+ compatible = "arm,vexpress-scc,v2p-ca15_a7", "arm,vexpress-scc";
+ reg = <0 0x7fff0000 0 0x1000>;
+ interrupts = <0 95 4>;
+ };
F: drivers/cpufreq/arm_big_little.c
F: drivers/cpufreq/arm_big_little_dt.c
+CPUIDLE DRIVER - ARM BIG LITTLE
+M: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+M: Daniel Lezcano <daniel.lezcano@linaro.org>
+L: linux-pm@vger.kernel.org
+L: linux-arm-kernel@lists.infradead.org
+T: git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
+S: Maintained
+F: drivers/cpuidle/cpuidle-big_little.c
+
CPUIDLE DRIVERS
M: Rafael J. Wysocki <rjw@sisk.pl>
M: Daniel Lezcano <daniel.lezcano@linaro.org>
clock-names = "apb_pclk";
};
+ scc@7fff0000 {
+ compatible = "arm,vexpress-scc,v2p-ca15_a7", "arm,vexpress-scc";
+ reg = <0 0x7fff0000 0 0x1000>;
+ interrupts = <0 95 4>;
+ };
+
timer {
compatible = "arm,armv7-timer";
interrupts = <1 13 0xf08>,
This is needed to provide CPU and cluster power management
on RTSM implementing big.LITTLE.
+config ARCH_VEXPRESS_TC2_PM
+ bool "Versatile Express TC2 power management"
+ depends on MCPM
+ select ARM_CCI
+ help
+ Support for CPU and cluster power management on Versatile Express
+ with a TC2 (A15x2 A7x3) big.LITTLE core tile.
+
endmenu
obj-y := v2m.o
obj-$(CONFIG_ARCH_VEXPRESS_CA9X4) += ct-ca9x4.o
obj-$(CONFIG_ARCH_VEXPRESS_DCSCB) += dcscb.o dcscb_setup.o
+obj-$(CONFIG_ARCH_VEXPRESS_TC2_PM) += tc2_pm.o spc.o
obj-$(CONFIG_SMP) += platsmp.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
/*
* 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).
+ * To do so we do:
+ * - Clear the SCTLR.C bit to prevent further cache allocations
+ * - Flush the whole cache
+ * - Clear the ACTLR "SMP" bit to disable local coherency
+ *
+ * Let's do it in the safest possible way i.e. with
+ * no memory access within the following sequence
+ * including to the stack.
*/
- flush_cache_all();
- set_cr(get_cr() & ~CR_C);
- flush_cache_all();
+ asm volatile(
+ "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 "
+ : : : "r0","r1","r2","r3","r4","r5","r6","r7",
+ "r9","r10","r11","lr","memory");
/*
* This is a harmless no-op. On platforms with a real
*/
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:
/*
* 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).
+ * Let's do it in the safest possible way as above.
*/
- 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));
+ asm volatile(
+ "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 "
+ : : : "r0","r1","r2","r3","r4","r5","r6","r7",
+ "r9","r10","r11","lr","memory");
}
__mcpm_cpu_down(cpu, cluster);
--- /dev/null
+/*
+ * Versatile Express Serial Power Controller (SPC) support
+ *
+ * Copyright (C) 2013 ARM Ltd.
+ *
+ * Authors: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
+ * Achin Gupta <achin.gupta@arm.com>
+ * Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * 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.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include <asm/cacheflush.h>
+
+#define SPCLOG "vexpress-spc: "
+
+/* SPC wake-up IRQs status and mask */
+#define WAKE_INT_MASK 0x24
+#define WAKE_INT_RAW 0x28
+#define WAKE_INT_STAT 0x2c
+/* SPC power down registers */
+#define A15_PWRDN_EN 0x30
+#define A7_PWRDN_EN 0x34
+/* SPC per-CPU mailboxes */
+#define A15_BX_ADDR0 0x68
+#define A7_BX_ADDR0 0x78
+
+/* wake-up interrupt masks */
+#define GBL_WAKEUP_INT_MSK (0x3 << 10)
+
+/* TC2 static dual-cluster configuration */
+#define MAX_CLUSTERS 2
+
+struct ve_spc_drvdata {
+ void __iomem *baseaddr;
+ /*
+ * A15s cluster identifier
+ * It corresponds to A15 processors MPIDR[15:8] bitfield
+ */
+ u32 a15_clusid;
+};
+
+static struct ve_spc_drvdata *info;
+
+static inline bool cluster_is_a15(u32 cluster)
+{
+ return cluster == info->a15_clusid;
+}
+
+/**
+ * ve_spc_global_wakeup_irq()
+ *
+ * Function to set/clear global wakeup IRQs. Not protected by locking since
+ * it might be used in code paths where normal cacheable locks are not
+ * working. Locking must be provided by the caller to ensure atomicity.
+ *
+ * @set: if true, global wake-up IRQs are set, if false they are cleared
+ */
+void ve_spc_global_wakeup_irq(bool set)
+{
+ u32 reg;
+
+ reg = readl_relaxed(info->baseaddr + WAKE_INT_MASK);
+
+ if (set)
+ reg |= GBL_WAKEUP_INT_MSK;
+ else
+ reg &= ~GBL_WAKEUP_INT_MSK;
+
+ writel_relaxed(reg, info->baseaddr + WAKE_INT_MASK);
+}
+
+/**
+ * ve_spc_cpu_wakeup_irq()
+ *
+ * Function to set/clear per-CPU wake-up IRQs. Not protected by locking since
+ * it might be used in code paths where normal cacheable locks are not
+ * working. Locking must be provided by the caller to ensure atomicity.
+ *
+ * @cluster: mpidr[15:8] bitfield describing cluster affinity level
+ * @cpu: mpidr[7:0] bitfield describing cpu affinity level
+ * @set: if true, wake-up IRQs are set, if false they are cleared
+ */
+void ve_spc_cpu_wakeup_irq(u32 cluster, u32 cpu, bool set)
+{
+ u32 mask, reg;
+
+ if (cluster >= MAX_CLUSTERS)
+ return;
+
+ mask = 1 << cpu;
+
+ if (!cluster_is_a15(cluster))
+ mask <<= 4;
+
+ reg = readl_relaxed(info->baseaddr + WAKE_INT_MASK);
+
+ if (set)
+ reg |= mask;
+ else
+ reg &= ~mask;
+
+ writel_relaxed(reg, info->baseaddr + WAKE_INT_MASK);
+}
+
+/**
+ * ve_spc_set_resume_addr() - set the jump address used for warm boot
+ *
+ * @cluster: mpidr[15:8] bitfield describing cluster affinity level
+ * @cpu: mpidr[7:0] bitfield describing cpu affinity level
+ * @addr: physical resume address
+ */
+void ve_spc_set_resume_addr(u32 cluster, u32 cpu, u32 addr)
+{
+ void __iomem *baseaddr;
+
+ if (cluster >= MAX_CLUSTERS)
+ return;
+
+ if (cluster_is_a15(cluster))
+ baseaddr = info->baseaddr + A15_BX_ADDR0 + (cpu << 2);
+ else
+ baseaddr = info->baseaddr + A7_BX_ADDR0 + (cpu << 2);
+
+ writel_relaxed(addr, baseaddr);
+}
+
+/**
+ * ve_spc_powerdown()
+ *
+ * Function to enable/disable cluster powerdown. Not protected by locking
+ * since it might be used in code paths where normal cacheable locks are not
+ * working. Locking must be provided by the caller to ensure atomicity.
+ *
+ * @cluster: mpidr[15:8] bitfield describing cluster affinity level
+ * @enable: if true enables powerdown, if false disables it
+ */
+void ve_spc_powerdown(u32 cluster, bool enable)
+{
+ u32 pwdrn_reg;
+
+ if (cluster >= MAX_CLUSTERS)
+ return;
+
+ pwdrn_reg = cluster_is_a15(cluster) ? A15_PWRDN_EN : A7_PWRDN_EN;
+ writel_relaxed(enable, info->baseaddr + pwdrn_reg);
+}
+
+int __init ve_spc_init(void __iomem *baseaddr, u32 a15_clusid)
+{
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info) {
+ pr_err(SPCLOG "unable to allocate mem\n");
+ return -ENOMEM;
+ }
+
+ info->baseaddr = baseaddr;
+ info->a15_clusid = a15_clusid;
+
+ /*
+ * Multi-cluster systems may need this data when non-coherent, during
+ * cluster power-up/power-down. Make sure driver info reaches main
+ * memory.
+ */
+ sync_cache_w(info);
+ sync_cache_w(&info);
+
+ return 0;
+}
--- /dev/null
+/*
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2012 ARM Limited
+ */
+
+
+#ifndef __SPC_H_
+#define __SPC_H_
+
+int __init ve_spc_init(void __iomem *base, u32 a15_clusid);
+void ve_spc_global_wakeup_irq(bool set);
+void ve_spc_cpu_wakeup_irq(u32 cluster, u32 cpu, bool set);
+void ve_spc_set_resume_addr(u32 cluster, u32 cpu, u32 addr);
+void ve_spc_powerdown(u32 cluster, bool enable);
+
+#endif
--- /dev/null
+/*
+ * arch/arm/mach-vexpress/tc2_pm.c - TC2 power management support
+ *
+ * Created by: Nicolas Pitre, October 2012
+ * Copyright: (C) 2012-2013 Linaro Limited
+ *
+ * Some portions of this file were originally written by Achin Gupta
+ * Copyright: (C) 2012 ARM 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/io.h>
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/irqchip/arm-gic.h>
+
+#include <asm/mcpm.h>
+#include <asm/proc-fns.h>
+#include <asm/cacheflush.h>
+#include <asm/cputype.h>
+#include <asm/cp15.h>
+
+#include <linux/arm-cci.h>
+
+#include "spc.h"
+
+/* SCC conf registers */
+#define A15_CONF 0x400
+#define A7_CONF 0x500
+#define SYS_INFO 0x700
+#define SPC_BASE 0xb00
+
+/*
+ * 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
+ * is already live using the same logical CPU number which trips lockdep
+ * debugging.
+ */
+static arch_spinlock_t tc2_pm_lock = __ARCH_SPIN_LOCK_UNLOCKED;
+
+#define TC2_CLUSTERS 2
+#define TC2_MAX_CPUS_PER_CLUSTER 3
+
+static unsigned int tc2_nr_cpus[TC2_CLUSTERS];
+
+/* Keep per-cpu usage count to cope with unordered up/down requests */
+static int tc2_pm_use_count[TC2_MAX_CPUS_PER_CLUSTER][TC2_CLUSTERS];
+
+#define tc2_cluster_unused(cluster) \
+ (!tc2_pm_use_count[0][cluster] && \
+ !tc2_pm_use_count[1][cluster] && \
+ !tc2_pm_use_count[2][cluster])
+
+static int tc2_pm_power_up(unsigned int cpu, unsigned int cluster)
+{
+ pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+ if (cluster >= TC2_CLUSTERS || cpu >= tc2_nr_cpus[cluster])
+ 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(&tc2_pm_lock);
+
+ if (tc2_cluster_unused(cluster))
+ ve_spc_powerdown(cluster, false);
+
+ tc2_pm_use_count[cpu][cluster]++;
+ if (tc2_pm_use_count[cpu][cluster] == 1) {
+ ve_spc_set_resume_addr(cluster, cpu,
+ virt_to_phys(mcpm_entry_point));
+ ve_spc_cpu_wakeup_irq(cluster, cpu, true);
+ } else if (tc2_pm_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(&tc2_pm_lock);
+ local_irq_enable();
+
+ return 0;
+}
+
+static void tc2_pm_down(u64 residency)
+{
+ unsigned int mpidr, cpu, cluster;
+ bool last_man = false, skip_wfi = false;
+
+ 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(cluster >= TC2_CLUSTERS || cpu >= TC2_MAX_CPUS_PER_CLUSTER);
+
+ __mcpm_cpu_going_down(cpu, cluster);
+
+ arch_spin_lock(&tc2_pm_lock);
+ BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
+ tc2_pm_use_count[cpu][cluster]--;
+ if (tc2_pm_use_count[cpu][cluster] == 0) {
+ ve_spc_cpu_wakeup_irq(cluster, cpu, true);
+ if (tc2_cluster_unused(cluster)) {
+ ve_spc_powerdown(cluster, true);
+ ve_spc_global_wakeup_irq(true);
+ last_man = true;
+ }
+ } else if (tc2_pm_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(&tc2_pm_lock);
+
+ if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A15) {
+ /*
+ * On the Cortex-A15 we need to disable
+ * L2 prefetching before flushing the cache.
+ */
+ asm volatile(
+ "mcr p15, 1, %0, c15, c0, 3 \n\t"
+ "isb \n\t"
+ "dsb "
+ : : "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.
+ */
+ asm volatile(
+ "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 "
+ : : : "r0","r1","r2","r3","r4","r5","r6","r7",
+ "r9","r10","r11","lr","memory");
+
+ cci_disable_port_by_cpu(mpidr);
+
+ __mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
+ } else {
+ /*
+ * If last man then undo any setup done previously.
+ */
+ if (last_man) {
+ ve_spc_powerdown(cluster, false);
+ ve_spc_global_wakeup_irq(false);
+ }
+
+ 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(
+ "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 "
+ : : : "r0","r1","r2","r3","r4","r5","r6","r7",
+ "r9","r10","r11","lr","memory");
+ }
+
+ __mcpm_cpu_down(cpu, cluster);
+
+ /* Now we are prepared for power-down, do it: */
+ if (!skip_wfi)
+ wfi();
+
+ /* Not dead at this point? Let our caller cope. */
+}
+
+static void tc2_pm_power_down(void)
+{
+ tc2_pm_down(0);
+}
+
+static void tc2_pm_suspend(u64 residency)
+{
+ unsigned int mpidr, cpu, cluster;
+
+ mpidr = read_cpuid_mpidr();
+ cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+ cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+ ve_spc_set_resume_addr(cluster, cpu, virt_to_phys(mcpm_entry_point));
+ gic_cpu_if_down();
+ tc2_pm_down(residency);
+}
+
+static void tc2_pm_powered_up(void)
+{
+ unsigned int mpidr, cpu, cluster;
+ unsigned long flags;
+
+ 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(cluster >= TC2_CLUSTERS || cpu >= TC2_MAX_CPUS_PER_CLUSTER);
+
+ local_irq_save(flags);
+ arch_spin_lock(&tc2_pm_lock);
+
+ if (tc2_cluster_unused(cluster)) {
+ ve_spc_powerdown(cluster, false);
+ ve_spc_global_wakeup_irq(false);
+ }
+
+ if (!tc2_pm_use_count[cpu][cluster])
+ tc2_pm_use_count[cpu][cluster] = 1;
+
+ ve_spc_cpu_wakeup_irq(cluster, cpu, false);
+ ve_spc_set_resume_addr(cluster, cpu, 0);
+
+ arch_spin_unlock(&tc2_pm_lock);
+ local_irq_restore(flags);
+}
+
+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,
+};
+
+static bool __init tc2_pm_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);
+ if (cluster >= TC2_CLUSTERS || cpu >= tc2_nr_cpus[cluster]) {
+ pr_err("%s: boot CPU is out of bound!\n", __func__);
+ return false;
+ }
+ tc2_pm_use_count[cpu][cluster] = 1;
+ return true;
+}
+
+/*
+ * Enable cluster-level coherency, in preparation for turning on the MMU.
+ */
+static void __naked tc2_pm_power_up_setup(unsigned int affinity_level)
+{
+ asm volatile (" \n"
+" cmp r0, #1 \n"
+" bxne lr \n"
+" b cci_enable_port_for_self ");
+}
+
+static int __init tc2_pm_init(void)
+{
+ int ret;
+ void __iomem *scc;
+ u32 a15_cluster_id, a7_cluster_id, sys_info;
+ struct device_node *np;
+
+ /*
+ * The power management-related features are hidden behind
+ * SCC registers. We need to extract runtime information like
+ * cluster ids and number of CPUs really available in clusters.
+ */
+ np = of_find_compatible_node(NULL, NULL,
+ "arm,vexpress-scc,v2p-ca15_a7");
+ scc = of_iomap(np, 0);
+ if (!scc)
+ return -ENODEV;
+
+ a15_cluster_id = readl_relaxed(scc + A15_CONF) & 0xf;
+ a7_cluster_id = readl_relaxed(scc + A7_CONF) & 0xf;
+ if (a15_cluster_id >= TC2_CLUSTERS || a7_cluster_id >= TC2_CLUSTERS)
+ return -EINVAL;
+
+ sys_info = readl_relaxed(scc + SYS_INFO);
+ tc2_nr_cpus[a15_cluster_id] = (sys_info >> 16) & 0xf;
+ tc2_nr_cpus[a7_cluster_id] = (sys_info >> 20) & 0xf;
+
+ /*
+ * 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);
+ if (ret)
+ return ret;
+
+ if (!cci_probed())
+ return -ENODEV;
+
+ if (!tc2_pm_usage_count_init())
+ return -EINVAL;
+
+ ret = mcpm_platform_register(&tc2_pm_power_ops);
+ if (!ret) {
+ mcpm_sync_init(tc2_pm_power_up_setup);
+ pr_info("TC2 power management initialized\n");
+ }
+ return ret;
+}
+
+early_initcall(tc2_pm_init);
help
Select this to enable cpuidle on Xilinx Zynq processors.
+config CPU_IDLE_BIG_LITTLE
+ bool "Support for ARM big.LITTLE processors"
+ depends on ARCH_VEXPRESS_TC2_PM
+ select ARM_CPU_SUSPEND
+ select CPU_IDLE_MULTIPLE_DRIVERS
+ help
+ Select this option to enable CPU idle driver for big.LITTLE based
+ ARM systems. Driver manages CPUs coordination through MCPM and
+ define different C-states for little and big cores through the
+ multiple CPU idle drivers infrastructure.
endif
config ARCH_NEEDS_CPU_IDLE_COUPLED
obj-$(CONFIG_CPU_IDLE_CALXEDA) += cpuidle-calxeda.o
obj-$(CONFIG_ARCH_KIRKWOOD) += cpuidle-kirkwood.o
obj-$(CONFIG_CPU_IDLE_ZYNQ) += cpuidle-zynq.o
+obj-$(CONFIG_CPU_IDLE_BIG_LITTLE) += cpuidle-big_little.o
--- /dev/null
+/*
+ * Copyright (c) 2013 ARM/Linaro
+ *
+ * Authors: Daniel Lezcano <daniel.lezcano@linaro.org>
+ * Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ * Nicolas Pitre <nicolas.pitre@linaro.org>
+ *
+ * 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.
+ *
+ * Maintainer: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ * Maintainer: Daniel Lezcano <daniel.lezcano@linaro.org>
+ */
+#include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include <asm/cpu.h>
+#include <asm/cputype.h>
+#include <asm/cpuidle.h>
+#include <asm/mcpm.h>
+#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+
+static int bl_enter_powerdown(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx);
+
+/*
+ * NB: Owing to current menu governor behaviour big and LITTLE
+ * index 1 states have to define exit_latency and target_residency for
+ * cluster state since, when all CPUs in a cluster hit it, the cluster
+ * can be shutdown. This means that when a single CPU enters this state
+ * the exit_latency and target_residency values are somewhat overkill.
+ * There is no notion of cluster states in the menu governor, so CPUs
+ * have to define CPU states where possibly the cluster will be shutdown
+ * depending on the state of other CPUs. idle states entry and exit happen
+ * at random times; however the cluster state provides target_residency
+ * values as if all CPUs in a cluster enter the state at once; this is
+ * somewhat optimistic and behaviour should be fixed either in the governor
+ * or in the MCPM back-ends.
+ * To make this driver 100% generic the number of states and the exit_latency
+ * target_residency values must be obtained from device tree bindings.
+ *
+ * exit_latency: refers to the TC2 vexpress test chip and depends on the
+ * current cluster operating point. It is the time it takes to get the CPU
+ * up and running when the CPU is powered up on cluster wake-up from shutdown.
+ * Current values for big and LITTLE clusters are provided for clusters
+ * running at default operating points.
+ *
+ * target_residency: it is the minimum amount of time the cluster has
+ * to be down to break even in terms of power consumption. cluster
+ * shutdown has inherent dynamic power costs (L2 writebacks to DRAM
+ * being the main factor) that depend on the current operating points.
+ * The current values for both clusters are provided for a CPU whose half
+ * of L2 lines are dirty and require cleaning to DRAM, and takes into
+ * account leakage static power values related to the vexpress TC2 testchip.
+ */
+static struct cpuidle_driver bl_idle_little_driver = {
+ .name = "little_idle",
+ .owner = THIS_MODULE,
+ .states[0] = ARM_CPUIDLE_WFI_STATE,
+ .states[1] = {
+ .enter = bl_enter_powerdown,
+ .exit_latency = 700,
+ .target_residency = 2500,
+ .flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_TIMER_STOP,
+ .name = "C1",
+ .desc = "ARM little-cluster power down",
+ },
+ .state_count = 2,
+};
+
+static struct cpuidle_driver bl_idle_big_driver = {
+ .name = "big_idle",
+ .owner = THIS_MODULE,
+ .states[0] = ARM_CPUIDLE_WFI_STATE,
+ .states[1] = {
+ .enter = bl_enter_powerdown,
+ .exit_latency = 500,
+ .target_residency = 2000,
+ .flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_TIMER_STOP,
+ .name = "C1",
+ .desc = "ARM big-cluster power down",
+ },
+ .state_count = 2,
+};
+
+/*
+ * notrace prevents trace shims from getting inserted where they
+ * should not. Global jumps and ldrex/strex must not be inserted
+ * in power down sequences where caches and MMU may be turned off.
+ */
+static int notrace bl_powerdown_finisher(unsigned long arg)
+{
+ /* MCPM works with HW CPU identifiers */
+ unsigned int mpidr = read_cpuid_mpidr();
+ unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+ unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+
+ mcpm_set_entry_vector(cpu, cluster, cpu_resume);
+
+ /*
+ * Residency value passed to mcpm_cpu_suspend back-end
+ * has to be given clear semantics. Set to 0 as a
+ * temporary value.
+ */
+ mcpm_cpu_suspend(0);
+
+ /* return value != 0 means failure */
+ return 1;
+}
+
+/**
+ * bl_enter_powerdown - Programs CPU to enter the specified state
+ * @dev: cpuidle device
+ * @drv: The target state to be programmed
+ * @idx: state index
+ *
+ * Called from the CPUidle framework to program the device to the
+ * specified target state selected by the governor.
+ */
+static int bl_enter_powerdown(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx)
+{
+ cpu_pm_enter();
+
+ cpu_suspend(0, bl_powerdown_finisher);
+
+ /* signals the MCPM core that CPU is out of low power state */
+ mcpm_cpu_powered_up();
+
+ cpu_pm_exit();
+
+ return idx;
+}
+
+static int __init bl_idle_driver_init(struct cpuidle_driver *drv, int cpu_id)
+{
+ struct cpuinfo_arm *cpu_info;
+ struct cpumask *cpumask;
+ unsigned long cpuid;
+ int cpu;
+
+ cpumask = kzalloc(cpumask_size(), GFP_KERNEL);
+ if (!cpumask)
+ return -ENOMEM;
+
+ for_each_possible_cpu(cpu) {
+ cpu_info = &per_cpu(cpu_data, cpu);
+ cpuid = is_smp() ? cpu_info->cpuid : read_cpuid_id();
+
+ /* read cpu id part number */
+ if ((cpuid & 0xFFF0) == cpu_id)
+ cpumask_set_cpu(cpu, cpumask);
+ }
+
+ drv->cpumask = cpumask;
+
+ return 0;
+}
+
+static int __init bl_idle_init(void)
+{
+ int ret;
+
+ /*
+ * Initialize the driver just for a compliant set of machines
+ */
+ if (!of_machine_is_compatible("arm,vexpress,v2p-ca15_a7"))
+ return -ENODEV;
+ /*
+ * For now the differentiation between little and big cores
+ * is based on the part number. A7 cores are considered little
+ * cores, A15 are considered big cores. This distinction may
+ * evolve in the future with a more generic matching approach.
+ */
+ ret = bl_idle_driver_init(&bl_idle_little_driver,
+ ARM_CPU_PART_CORTEX_A7);
+ if (ret)
+ return ret;
+
+ ret = bl_idle_driver_init(&bl_idle_big_driver, ARM_CPU_PART_CORTEX_A15);
+ if (ret)
+ goto out_uninit_little;
+
+ ret = cpuidle_register(&bl_idle_little_driver, NULL);
+ if (ret)
+ goto out_uninit_big;
+
+ ret = cpuidle_register(&bl_idle_big_driver, NULL);
+ if (ret)
+ goto out_unregister_little;
+
+ return 0;
+
+out_unregister_little:
+ cpuidle_unregister(&bl_idle_little_driver);
+out_uninit_big:
+ kfree(bl_idle_big_driver.cpumask);
+out_uninit_little:
+ kfree(bl_idle_little_driver.cpumask);
+
+ return ret;
+}
+device_initcall(bl_idle_init);
writel_relaxed(1, base + GIC_CPU_CTRL);
}
+void gic_cpu_if_down(void)
+{
+ void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
+ writel_relaxed(0, cpu_base + GIC_CPU_CTRL);
+}
+
#ifdef CONFIG_CPU_PM
/*
* Saves the GIC distributor registers during suspend or idle. Must be called
void gic_init_bases(unsigned int, int, void __iomem *, void __iomem *,
u32 offset, struct device_node *);
void gic_cascade_irq(unsigned int gic_nr, unsigned int irq);
+void gic_cpu_if_down(void);
static inline void gic_init(unsigned int nr, int start,
void __iomem *dist , void __iomem *cpu)
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / commitdiff