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authorNicolas Pitre <nicolas.pitre@linaro.org>2012-10-19 20:48:50 -0400
committerJon Medhurst <tixy@linaro.org>2013-05-03 13:46:59 +0100
commit5215cc6c44ce1b882b1e63d7ff2e76234b943417 (patch)
tree94490f8ef93af06a2b7f3d7755dc753be01a75d7
parenteedf05bea83c12b323719560bfa42c10491d9b4e (diff)
downloadvexpress-lsk-5215cc6c44ce1b882b1e63d7ff2e76234b943417.tar.gz
ARM: TC2: basic PM support
Signed-off-by: Nicolas Pitre <nico@linaro.org>
-rw-r--r--arch/arm/mach-vexpress/Kconfig8
-rw-r--r--arch/arm/mach-vexpress/Makefile1
-rw-r--r--arch/arm/mach-vexpress/tc2_pm.c234
-rw-r--r--arch/arm/mach-vexpress/tc2_pm_setup.S88
4 files changed, 331 insertions, 0 deletions
diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig
index 2dec389c58b..5a99485138c 100644
--- a/arch/arm/mach-vexpress/Kconfig
+++ b/arch/arm/mach-vexpress/Kconfig
@@ -66,4 +66,12 @@ config ARCH_VEXPRESS_TC2_PM
config ARCH_VEXPRESS_CA9X4
bool "Versatile Express Cortex-A9x4 tile"
+config ARCH_VEXPRESS_TC2
+ bool "TC2 cluster management"
+ depends on MCPM
+ select ARM_SPC
+ select ARM_CCI
+ help
+ Support for CPU and cluster power management on TC2.
+
endmenu
diff --git a/arch/arm/mach-vexpress/Makefile b/arch/arm/mach-vexpress/Makefile
index 03d9029dbd6..e3948d02d4f 100644
--- a/arch/arm/mach-vexpress/Makefile
+++ b/arch/arm/mach-vexpress/Makefile
@@ -6,6 +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-$(CONFIG_ARCH_VEXPRESS_TC2) += tc2_pm.o tc2_pm_setup.o
obj-$(CONFIG_SMP) += platsmp.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
obj-$(CONFIG_ARCH_VEXPRESS_TC2_PM) += cpuidle-tc2.o hotplug-asm.o tc2-sleep.o
diff --git a/arch/arm/mach-vexpress/tc2_pm.c b/arch/arm/mach-vexpress/tc2_pm.c
new file mode 100644
index 00000000000..4be2d73cb38
--- /dev/null
+++ b/arch/arm/mach-vexpress/tc2_pm.c
@@ -0,0 +1,234 @@
+/*
+ * arch/arm/mach-vexpress/tc2_pm.c - TC2 power management support
+ *
+ * Created by: Nicolas Pitre, October 2012
+ * Copyright: (C) 2012 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/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+
+#include <asm/mcpm.h>
+#include <asm/proc-fns.h>
+#include <asm/cacheflush.h>
+#include <asm/cputype.h>
+#include <asm/cp15.h>
+
+#include <mach/motherboard.h>
+
+#include <linux/vexpress.h>
+#include <linux/arm-cci.h>
+
+/*
+ * 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;
+
+static int tc2_pm_use_count[3][2];
+
+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 >= 2 || cpu >= vexpress_spc_get_nb_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_pm_use_count[0][cluster] &&
+ !tc2_pm_use_count[1][cluster] &&
+ !tc2_pm_use_count[2][cluster])
+ vexpress_spc_powerdown_enable(cluster, 0);
+
+ tc2_pm_use_count[cpu][cluster]++;
+ if (tc2_pm_use_count[cpu][cluster] == 1) {
+ vexpress_spc_write_bxaddr_reg(cluster, cpu,
+ virt_to_phys(mcpm_entry_point));
+ vexpress_spc_set_cpu_wakeup_irq(cpu, cluster, 1);
+ } 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_power_down(void)
+{
+ 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 >= 2 || cpu >= vexpress_spc_get_nb_cpus(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) {
+ vexpress_spc_set_cpu_wakeup_irq(cpu, cluster, 1);
+ if (!tc2_pm_use_count[0][cluster] &&
+ !tc2_pm_use_count[1][cluster] &&
+ !tc2_pm_use_count[2][cluster]) {
+ vexpress_spc_powerdown_enable(cluster, 1);
+ vexpress_spc_set_global_wakeup_intr(1);
+ 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);
+
+ set_cr(get_cr() & ~CR_C);
+ flush_cache_all();
+ asm volatile ("clrex");
+ set_auxcr(get_auxcr() & ~(1 << 6));
+
+ disable_cci(cluster);
+
+ /*
+ * Ensure that both C & I bits are disabled in the SCTLR
+ * before disabling ACE snoops. This ensures that no
+ * coherency traffic will originate from this cpu after
+ * ACE snoops are turned off.
+ */
+ cpu_proc_fin();
+
+ __mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
+ } else {
+ /*
+ * If last man then undo any setup done previously.
+ */
+ if (last_man) {
+ vexpress_spc_powerdown_enable(cluster, 0);
+ vexpress_spc_set_global_wakeup_intr(0);
+ }
+
+ arch_spin_unlock(&tc2_pm_lock);
+
+ set_cr(get_cr() & ~CR_C);
+ flush_cache_louis();
+ asm volatile ("clrex");
+ set_auxcr(get_auxcr() & ~(1 << 6));
+ }
+
+ __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_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 >= 2 || cpu >= vexpress_spc_get_nb_cpus(cluster));
+
+ local_irq_save(flags);
+ arch_spin_lock(&tc2_pm_lock);
+
+ if (!tc2_pm_use_count[0][cluster] &&
+ !tc2_pm_use_count[1][cluster] &&
+ !tc2_pm_use_count[2][cluster]) {
+ vexpress_spc_powerdown_enable(cluster, 0);
+ vexpress_spc_set_global_wakeup_intr(0);
+ }
+
+ if (!tc2_pm_use_count[cpu][cluster])
+ tc2_pm_use_count[cpu][cluster] = 1;
+
+ vexpress_spc_set_cpu_wakeup_irq(cpu, cluster, 0);
+ vexpress_spc_write_bxaddr_reg(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,
+ .powered_up = tc2_pm_powered_up,
+};
+
+static void __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);
+ BUG_ON(cpu >= 3 || cluster >= 2);
+ tc2_pm_use_count[cpu][cluster] = 1;
+}
+
+extern void tc2_pm_power_up_setup(unsigned int affinity_level);
+
+static int __init tc2_pm_init(void)
+{
+ int ret;
+
+ if (!vexpress_spc_check_loaded())
+ return -ENODEV;
+
+ tc2_pm_usage_count_init();
+
+ ret = mcpm_platform_register(&tc2_pm_power_ops);
+ if (!ret)
+ ret = mcpm_sync_init(tc2_pm_power_up_setup);
+ if (!ret)
+ pr_info("TC2 power management initialized\n");
+ return ret;
+}
+
+early_initcall(tc2_pm_init);
diff --git a/arch/arm/mach-vexpress/tc2_pm_setup.S b/arch/arm/mach-vexpress/tc2_pm_setup.S
new file mode 100644
index 00000000000..046890e5ff8
--- /dev/null
+++ b/arch/arm/mach-vexpress/tc2_pm_setup.S
@@ -0,0 +1,88 @@
+/*
+ * arch/arm/include/asm/tc2_pm_setup.S
+ *
+ * Created by: Nicolas Pitre, October 2012
+ ( (based on dcscb_setup.S by Dave Martin)
+ * Copyright: (C) 2012 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 SPC_PHYS_BASE 0x7FFF0000
+
+#define SNOOP_CTL_A15 0x404
+#define SNOOP_CTL_A7 0x504
+
+#define A15_SNOOP_MASK (0x3 << 7)
+#define A7_SNOOP_MASK (0x1 << 13)
+
+#define A15_BX_ADDR0 0xB68
+
+
+#define CCI_PHYS_BASE 0x2c090000
+
+#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 CCI_SLAVE_A15 3
+#define CCI_SLAVE_A7 4
+#define CCI_A15_OFFSET CCI_SLAVE_OFFSET(CCI_SLAVE_A15)
+#define CCI_A7_OFFSET CCI_SLAVE_OFFSET(CCI_SLAVE_A7)
+
+
+/*
+ * 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.
+ */
+
+ENTRY(tc2_pm_power_up_setup)
+
+ cmp r0, #0
+ beq 2f
+
+ @ Enable CCI snoops
+ mrc p15, 0, r0, c0, c0, 5 @ MPIDR
+ ubfx r0, r0, #8, #4 @ cluster
+ ldr r3, =CCI_PHYS_BASE + CCI_A15_OFFSET
+ cmp r0, #0 @ A15 cluster?
+ addne r3, r3, #CCI_A7_OFFSET - 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, =CCI_PHYS_BASE
+1: ldr r0, [r3, #CCI_STATUS_OFFSET]
+ tst r0, #STATUS_CHANGE_PENDING
+ bne 1b
+
+ bx lr
+
+2: @ Clear the BX addr register
+ ldr r3, =SPC_PHYS_BASE + A15_BX_ADDR0
+ mrc p15, 0, r0, c0, c0, 5 @ MPIDR
+ ubfx r1, r0, #8, #4 @ cluster
+ ubfx r0, r0, #0, #4 @ cpu
+ add r3, r3, r1, lsl #4
+ mov r1, #0
+ str r1, [r3, r0, lsl #2]
+ dsb
+
+ bx lr
+
+ENDPROC(tc2_pm_power_up_setup)