diff options
| -rw-r--r-- | Documentation/devicetree/bindings/arm/vexpress-scc.txt | 33 | ||||
| -rw-r--r-- | MAINTAINERS | 9 | ||||
| -rw-r--r-- | arch/arm/boot/dts/vexpress-v2p-ca15_a7.dts | 6 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/Kconfig | 8 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/dcscb.c | 58 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/spc.c | 180 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/spc.h | 24 | ||||
| -rw-r--r-- | arch/arm/mach-vexpress/tc2_pm.c | 346 | ||||
| -rw-r--r-- | drivers/cpuidle/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/cpuidle/Makefile | 1 | ||||
| -rw-r--r-- | drivers/cpuidle/cpuidle-big_little.c | 209 | ||||
| -rw-r--r-- | drivers/irqchip/irq-gic.c | 6 | ||||
| -rw-r--r-- | include/linux/irqchip/arm-gic.h | 1 |
14 files changed, 871 insertions, 21 deletions
diff --git a/Documentation/devicetree/bindings/arm/vexpress-scc.txt b/Documentation/devicetree/bindings/arm/vexpress-scc.txt new file mode 100644 index 0000000..ae5043e4 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/vexpress-scc.txt @@ -0,0 +1,33 @@ +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>; + }; diff --git a/MAINTAINERS b/MAINTAINERS index 229c66b..a0001ef 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2268,6 +2268,15 @@ F: drivers/cpufreq/arm_big_little.h 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> diff --git a/arch/arm/boot/dts/vexpress-v2p-ca15_a7.dts b/arch/arm/boot/dts/vexpress-v2p-ca15_a7.dts index d2803be..759b0cd 100644 --- a/arch/arm/boot/dts/vexpress-v2p-ca15_a7.dts +++ b/arch/arm/boot/dts/vexpress-v2p-ca15_a7.dts @@ -125,6 +125,12 @@ 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>, diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig index b8bbabe..c700e62 100644 --- a/arch/arm/mach-vexpress/Kconfig +++ b/arch/arm/mach-vexpress/Kconfig @@ -66,4 +66,12 @@ config ARCH_VEXPRESS_DCSCB 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 diff --git a/arch/arm/mach-vexpress/Makefile b/arch/arm/mach-vexpress/Makefile index 48ba89a..36ea824 100644 --- a/arch/arm/mach-vexpress/Makefile +++ b/arch/arm/mach-vexpress/Makefile @@ -7,5 +7,6 @@ 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_ARCH_VEXPRESS_TC2_PM) += tc2_pm.o spc.o obj-$(CONFIG_SMP) += platsmp.o obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o diff --git a/arch/arm/mach-vexpress/dcscb.c b/arch/arm/mach-vexpress/dcscb.c index 16d57a8..85fffa7 100644 --- a/arch/arm/mach-vexpress/dcscb.c +++ b/arch/arm/mach-vexpress/dcscb.c @@ -136,14 +136,29 @@ static void dcscb_power_down(void) /* * 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 @@ -152,9 +167,6 @@ static void dcscb_power_down(void) */ 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: @@ -167,18 +179,22 @@ static void dcscb_power_down(void) /* * 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); diff --git a/arch/arm/mach-vexpress/spc.c b/arch/arm/mach-vexpress/spc.c new file mode 100644 index 0000000..eefb029 --- /dev/null +++ b/arch/arm/mach-vexpress/spc.c @@ -0,0 +1,180 @@ +/* + * 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; +} diff --git a/arch/arm/mach-vexpress/spc.h b/arch/arm/mach-vexpress/spc.h new file mode 100644 index 0000000..5f7e4a4 --- /dev/null +++ b/arch/arm/mach-vexpress/spc.h @@ -0,0 +1,24 @@ +/* + * 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 diff --git a/arch/arm/mach-vexpress/tc2_pm.c b/arch/arm/mach-vexpress/tc2_pm.c new file mode 100644 index 0000000..68adb40 --- /dev/null +++ b/arch/arm/mach-vexpress/tc2_pm.c @@ -0,0 +1,346 @@ +/* + * 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); diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig index 0e2cd5c..0f86587 100644 --- a/drivers/cpuidle/Kconfig +++ b/drivers/cpuidle/Kconfig @@ -42,6 +42,16 @@ config CPU_IDLE_ZYNQ 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 diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile index 8767a7b..3b6445c 100644 --- a/drivers/cpuidle/Makefile +++ b/drivers/cpuidle/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o obj-$(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 diff --git a/drivers/cpuidle/cpuidle-big_little.c b/drivers/cpuidle/cpuidle-big_little.c new file mode 100644 index 0000000..b45fc62 --- /dev/null +++ b/drivers/cpuidle/cpuidle-big_little.c @@ -0,0 +1,209 @@ +/* + * 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); diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index ee7c503..d0e9480 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -453,6 +453,12 @@ static void gic_cpu_init(struct gic_chip_data *gic) 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 diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h index 3e203eb..0e5d9ec 100644 --- a/include/linux/irqchip/arm-gic.h +++ b/include/linux/irqchip/arm-gic.h @@ -66,6 +66,7 @@ extern struct irq_chip gic_arch_extn; 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) |