diff options
author | Jon Medhurst <tixy@linaro.org> | 2013-05-09 14:06:56 +0100 |
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committer | Jon Medhurst <tixy@linaro.org> | 2013-05-09 14:06:56 +0100 |
commit | 3bc528d32c5c98a496c3473353e701a6e23c0cb3 (patch) | |
tree | b76e5ff2770d6259f3e1e4b29f52f36ede6c4214 /arch | |
parent | 7d101db765ff1df9ef09503d80a725d8b4880d85 (diff) | |
parent | 23c5ac41ee7db68b1d64e75e641f026e8f1afe97 (diff) |
Merge branch 'tracking-armlt-dcscb' into lsk-3.9-vexpress
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm/include/asm/cp15.h | 14 | ||||
-rw-r--r-- | arch/arm/mach-vexpress/Kconfig | 9 | ||||
-rw-r--r-- | arch/arm/mach-vexpress/Makefile | 2 | ||||
-rw-r--r-- | arch/arm/mach-vexpress/dcscb.c | 256 | ||||
-rw-r--r-- | arch/arm/mach-vexpress/dcscb_setup.S | 80 |
5 files changed, 361 insertions, 0 deletions
diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h index 5ef4d8015a6..ce4d01c03e6 100644 --- a/arch/arm/include/asm/cp15.h +++ b/arch/arm/include/asm/cp15.h @@ -59,6 +59,20 @@ static inline void set_cr(unsigned int val) isb(); } +static inline unsigned int get_auxcr(void) +{ + unsigned int val; + asm("mrc p15, 0, %0, c1, c0, 1 @ get AUXCR" : "=r" (val)); + return val; +} + +static inline void set_auxcr(unsigned int val) +{ + asm volatile("mcr p15, 0, %0, c1, c0, 1 @ set AUXCR" + : : "r" (val)); + isb(); +} + #ifndef CONFIG_SMP extern void adjust_cr(unsigned long mask, unsigned long set); #endif diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig index 52d315b792c..49e97ef3933 100644 --- a/arch/arm/mach-vexpress/Kconfig +++ b/arch/arm/mach-vexpress/Kconfig @@ -52,4 +52,13 @@ 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. + endmenu diff --git a/arch/arm/mach-vexpress/Makefile b/arch/arm/mach-vexpress/Makefile index 80b64971fbd..f5b78d49246 100644 --- a/arch/arm/mach-vexpress/Makefile +++ b/arch/arm/mach-vexpress/Makefile @@ -6,5 +6,7 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include \ obj-y := v2m.o reset.o obj-$(CONFIG_ARCH_VEXPRESS_CA9X4) += ct-ca9x4.o +obj-$(CONFIG_ARCH_VEXPRESS_DCSCB) += dcscb.o dcscb_setup.o +CFLAGS_REMOVE_dcscb.o = -pg obj-$(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 new file mode 100644 index 00000000000..0dc3caca227 --- /dev/null +++ b/arch/arm/mach-vexpress/dcscb.c @@ -0,0 +1,256 @@ +/* + * 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> +#include <asm/psci.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() after 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_mcpm_cpu_mask[2]; + +static int dcscb_power_up(unsigned int cpu, unsigned int cluster) +{ + unsigned int rst_hold, cpumask = (1 << cpu); + unsigned int mcpm_mask = dcscb_mcpm_cpu_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 |= mcpm_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, mcpm_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); + mcpm_mask = dcscb_mcpm_cpu_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)) & mcpm_mask) == mcpm_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 (maybe not needed anymore, 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: + */ + disable_cci(cluster); + + __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 (maybe not needed anymore, 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: */ + if (!skip_wfi) { + dsb(); + 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; + + ret = psci_probe(); + if (!ret) { + pr_debug("psci found. Aborting native init\n"); + 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_mcpm_cpu_mask[0] = (1 << (((cfg >> 16) >> (0 << 2)) & 0xf)) - 1; + dcscb_mcpm_cpu_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; + } + + /* + * 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 00000000000..93bd13f458a --- /dev/null +++ b/arch/arm/mach-vexpress/dcscb_setup.S @@ -0,0 +1,80 @@ +/* + * 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> +#include <asm/mcpm.h> + + +#define SLAVE_SNOOPCTL_OFFSET 0 +#define SNOOPCTL_SNOOP_ENABLE (1 << 0) +#define SNOOPCTL_DVM_ENABLE (1 << 1) + +#define CCI_STATUS_OFFSET 0xc +#define STATUS_CHANGE_PENDING (1 << 0) + +#define CCI_SLAVE_OFFSET(n) (0x1000 + 0x1000 * (n)) + +#define RTSM_CCI_PHYS_BASE 0x2c090000 +#define RTSM_CCI_SLAVE_A15 3 +#define RTSM_CCI_SLAVE_A7 4 + +#define RTSM_CCI_A15_OFFSET CCI_SLAVE_OFFSET(RTSM_CCI_SLAVE_A15) +#define RTSM_CCI_A7_OFFSET CCI_SLAVE_OFFSET(RTSM_CCI_SLAVE_A7) + + +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. + */ + + mrc p15, 0, r0, c0, c0, 5 @ MPIDR + ubfx r0, r0, #8, #4 @ cluster + + @ A15/A7 may not require explicit L2 invalidation on reset, dependent + @ on hardware integration desicions. + @ For now, this code assumes that L2 is either already invalidated, or + @ invalidation is not required. + + ldr r3, =RTSM_CCI_PHYS_BASE + RTSM_CCI_A15_OFFSET + cmp r0, #0 @ A15 cluster? + addne r3, r3, #RTSM_CCI_A7_OFFSET - RTSM_CCI_A15_OFFSET + + @ r3 now points to the correct CCI slave register block + + ldr r0, [r3, #SLAVE_SNOOPCTL_OFFSET] + orr r0, r0, #SNOOPCTL_SNOOP_ENABLE | SNOOPCTL_DVM_ENABLE + str r0, [r3, #SLAVE_SNOOPCTL_OFFSET] @ enable CCI snoops + + @ Wait for snoop control change to complete: + + ldr r3, =RTSM_CCI_PHYS_BASE + +1: ldr r0, [r3, #CCI_STATUS_OFFSET] + tst r0, #STATUS_CHANGE_PENDING + bne 1b + + dsb @ Synchronise side-effects of enabling CCI + + bx lr + +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) |