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authorNicolas Pitre <nico@linaro.org>2012-12-10 00:22:06 -0500
committerJon Medhurst <tixy@linaro.org>2013-05-03 13:47:01 +0100
commit17f705be668f23cd5efcab837515f4c97ba0b3fa (patch)
treebd19a8e5e1aeb77b708dbdba5e93e7b93e3abe6b
parent970395d745e01a4e9429228a2b2ed5f240628539 (diff)
downloadvexpress-lsk-17f705be668f23cd5efcab837515f4c97ba0b3fa.tar.gz
ARM: vexpress/tc2: implement PM suspend method
This is simplistic for the moment as the expected residency is used to prevent the shutting down of L2 and the cluster if the residency for the last man is lower than 5 ms. To make this right, the residency end time for each CPU would need to be recorded and taken into account. On a suspend, the firmware mailbox address has to be set prior entering low power mode. Signed-off-by: Nicolas Pitre <nico@linaro.org>
-rw-r--r--arch/arm/mach-vexpress/Kconfig25
-rw-r--r--arch/arm/mach-vexpress/Makefile2
-rw-r--r--arch/arm/mach-vexpress/cpuidle-tc2.c141
-rw-r--r--arch/arm/mach-vexpress/hotplug-asm.S28
-rw-r--r--arch/arm/mach-vexpress/tc2-sleep.S76
-rw-r--r--arch/arm/mach-vexpress/tc2_pm.c23
6 files changed, 50 insertions, 245 deletions
diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig
index 5a99485138c..bca54a33598 100644
--- a/arch/arm/mach-vexpress/Kconfig
+++ b/arch/arm/mach-vexpress/Kconfig
@@ -49,20 +49,6 @@ config ARCH_VEXPRESS_CORTEX_A5_A9_ERRATA
build a working kernel, you must also enable relevant core
tile support or Flattened Device Tree based support options.
-config ARCH_VEXPRESS_TC2_PM
- bool "Power Management Support for TC2 test-chip (EXPERIMENTAL)"
- depends on CPU_IDLE && PM
- select ARM_CPU_SUSPEND
- select ARCH_NEEDS_CPU_IDLE_COUPLED
- select ARM_SPC
- select ARM_CCI
- help
- Provides code that enables CPU idle power management on the
- TC2 testchip. It enables the CPU idle driver so that the kernel
- can enter cluster power down states provided by the power
- controller. Code is built on top of coupled C-state idle code
- since all CPUs need to be idle to enter cluster shutdown.
-
config ARCH_VEXPRESS_CA9X4
bool "Versatile Express Cortex-A9x4 tile"
@@ -74,4 +60,15 @@ config ARCH_VEXPRESS_TC2
help
Support for CPU and cluster power management on TC2.
+config VEXPRESS_TC2_CPUIDLE
+ bool "cpuidle support for TC2 test-chip (EXPERIMENTAL)"
+ depends on CPU_IDLE && PM && ARCH_VEXPRESS_TC2
+ select ARM_CPU_SUSPEND
+ select ARM_SPC
+ help
+ Provides code that enables CPU idle power management on the
+ TC2 testchip. It enables the CPU idle driver so that the kernel
+ can enter cluster power down states provided by the power
+ controller.
+
endmenu
diff --git a/arch/arm/mach-vexpress/Makefile b/arch/arm/mach-vexpress/Makefile
index e3948d02d4f..50a57510d76 100644
--- a/arch/arm/mach-vexpress/Makefile
+++ b/arch/arm/mach-vexpress/Makefile
@@ -9,4 +9,4 @@ 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-$(CONFIG_ARCH_VEXPRESS_TC2_PM) += cpuidle-tc2.o hotplug-asm.o tc2-sleep.o
+obj-$(CONFIG_VEXPRESS_TC2_CPUIDLE) += cpuidle-tc2.o
diff --git a/arch/arm/mach-vexpress/cpuidle-tc2.c b/arch/arm/mach-vexpress/cpuidle-tc2.c
index 3b73d4a5dc5..0a983dd531b 100644
--- a/arch/arm/mach-vexpress/cpuidle-tc2.c
+++ b/arch/arm/mach-vexpress/cpuidle-tc2.c
@@ -20,6 +20,7 @@
#include <linux/module.h>
#include <linux/tick.h>
#include <linux/vexpress.h>
+#include <asm/bL_entry.h>
#include <asm/cpuidle.h>
#include <asm/cputype.h>
#include <asm/idmap.h>
@@ -51,7 +52,7 @@ static int tc2_cpuidle_simple_enter(struct cpuidle_device *dev,
return index;
}
-static int tc2_enter_coupled(struct cpuidle_device *dev,
+static int tc2_enter_powerdown(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int idx);
static struct cpuidle_state tc2_cpuidle_set[] __initdata = {
@@ -65,11 +66,10 @@ static struct cpuidle_state tc2_cpuidle_set[] __initdata = {
.desc = "ARM WFI",
},
[1] = {
- .enter = tc2_enter_coupled,
+ .enter = tc2_enter_powerdown,
.exit_latency = 300,
.target_residency = 1000,
- .flags = CPUIDLE_FLAG_TIME_VALID |
- CPUIDLE_FLAG_COUPLED,
+ .flags = CPUIDLE_FLAG_TIME_VALID,
.name = "C1",
.desc = "ARM power down",
},
@@ -83,45 +83,21 @@ struct cpuidle_driver tc2_idle_driver = {
static DEFINE_PER_CPU(struct cpuidle_device, tc2_idle_dev);
-#define NR_CLUSTERS 2
-static cpumask_t cluster_mask = CPU_MASK_NONE;
-
-extern void disable_clean_inv_dcache(int);
-static atomic_t abort_barrier[NR_CLUSTERS];
-
-extern void tc2_cpu_resume(void);
-extern void disable_snoops(void);
-
-static int notrace tc2_coupled_finisher(unsigned long arg)
+static int notrace tc2_powerdown_finisher(unsigned long arg)
{
unsigned int mpidr = read_cpuid_mpidr();
- unsigned int cpu = smp_processor_id();
unsigned int cluster = (mpidr >> 8) & 0xf;
- unsigned int weight = cpumask_weight(topology_core_cpumask(cpu));
- u8 wfi_weight = 0;
-
- cpuidle_coupled_parallel_barrier((struct cpuidle_device *)arg,
- &abort_barrier[cluster]);
- if (mpidr & 0xf) {
- disable_clean_inv_dcache(0);
- wfi();
- /* not reached */
- }
-
- while (wfi_weight != (weight - 1)) {
- wfi_weight = vexpress_spc_wfi_cpustat(cluster);
- wfi_weight = hweight8(wfi_weight);
- }
+ unsigned int cpu = mpidr & 0xf;
- vexpress_spc_powerdown_enable(cluster, 1);
- disable_clean_inv_dcache(1);
- disable_cci(cluster);
- disable_snoops();
+ bL_set_entry_vector(cpu, cluster, cpu_resume);
+ vexpress_spc_write_bxaddr_reg(cluster, cpu,
+ virt_to_phys(bL_entry_point));
+ bL_cpu_power_down();
return 1;
}
/*
- * tc2_enter_coupled - Programs CPU to enter the specified state
+ * tc2_enter_powerdown - Programs CPU to enter the specified state
* @dev: cpuidle device
* @drv: The target state to be programmed
* @idx: state index
@@ -129,38 +105,33 @@ static int notrace tc2_coupled_finisher(unsigned long arg)
* Called from the CPUidle framework to program the device to the
* specified target state selected by the governor.
*/
-static int tc2_enter_coupled(struct cpuidle_device *dev,
+static int tc2_enter_powerdown(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int idx)
{
struct timespec ts_preidle, ts_postidle, ts_idle;
int ret;
- int cluster = (read_cpuid_mpidr() >> 8) & 0xf;
+
/* Used to keep track of the total time in idle */
getnstimeofday(&ts_preidle);
- if (!cpu_isset(cluster, cluster_mask)) {
- cpuidle_coupled_parallel_barrier(dev,
- &abort_barrier[cluster]);
- goto shallow_out;
- }
-
BUG_ON(!irqs_disabled());
cpu_pm_enter();
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
- ret = cpu_suspend((unsigned long) dev, tc2_coupled_finisher);
-
+ ret = cpu_suspend((unsigned long) dev, tc2_powerdown_finisher);
if (ret)
BUG();
+ bL_cpu_powered_up();
+
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
cpu_pm_exit();
-shallow_out:
getnstimeofday(&ts_postidle);
+ local_irq_enable();
ts_idle = timespec_sub(ts_postidle, ts_preidle);
dev->last_residency = ts_idle.tv_nsec / NSEC_PER_USEC +
@@ -168,46 +139,6 @@ shallow_out:
return idx;
}
-static int idle_mask_show(struct seq_file *f, void *p)
-{
- char buf[256];
- bitmap_scnlistprintf(buf, 256, cpumask_bits(&cluster_mask),
- NR_CLUSTERS);
-
- seq_printf(f, "%s\n", buf);
-
- return 0;
-}
-
-static int idle_mask_open(struct inode *inode, struct file *file)
-{
- return single_open(file, idle_mask_show, inode->i_private);
-}
-
-static const struct file_operations cpuidle_fops = {
- .open = idle_mask_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
-
-static int idle_debug_set(void *data, u64 val)
-{
- if (val >= (unsigned)NR_CLUSTERS && val != 0xff) {
- pr_warning("Wrong parameter passed\n");
- return -EINVAL;
- }
- cpuidle_pause_and_lock();
- if (val == 0xff)
- cpumask_clear(&cluster_mask);
- else
- cpumask_set_cpu(val, &cluster_mask);
-
- cpuidle_resume_and_unlock();
- return 0;
-}
-DEFINE_SIMPLE_ATTRIBUTE(idle_debug_fops, NULL, idle_debug_set, "%llu\n");
-
/*
* tc2_idle_init
*
@@ -218,7 +149,6 @@ int __init tc2_idle_init(void)
{
struct cpuidle_device *dev;
int i, cpu_id;
- struct dentry *idle_debug, *file_debug;
struct cpuidle_driver *drv = &tc2_idle_driver;
if (!vexpress_spc_check_loaded()) {
@@ -240,10 +170,7 @@ int __init tc2_idle_init(void)
pr_err("CPUidle for CPU%d registered\n", cpu_id);
dev = &per_cpu(tc2_idle_dev, cpu_id);
dev->cpu = cpu_id;
- dev->safe_state_index = 0;
- cpumask_copy(&dev->coupled_cpus,
- topology_core_cpumask(cpu_id));
dev->state_count = drv->state_count;
if (cpuidle_register_device(dev)) {
@@ -253,40 +180,6 @@ int __init tc2_idle_init(void)
}
}
- idle_debug = debugfs_create_dir("idle_debug", NULL);
-
- if (IS_ERR_OR_NULL(idle_debug)) {
- printk(KERN_INFO "Error in creating idle debugfs directory\n");
- return 0;
- }
-
- file_debug = debugfs_create_file("enable_idle", S_IRUGO | S_IWGRP,
- idle_debug, NULL, &idle_debug_fops);
-
- if (IS_ERR_OR_NULL(file_debug)) {
- printk(KERN_INFO "Error in creating enable_idle file\n");
- return 0;
- }
-
- file_debug = debugfs_create_file("enable_mask", S_IRUGO | S_IWGRP,
- idle_debug, NULL, &cpuidle_fops);
-
- if (IS_ERR_OR_NULL(file_debug))
- printk(KERN_INFO "Error in creating enable_mask file\n");
-
- /* enable all wake-up IRQs by default */
- vexpress_spc_set_wake_intr(0x7ff);
- vexpress_flags_set(virt_to_phys(tc2_cpu_resume));
-
- /*
- * Enable idle by default for all possible clusters.
- * This must be done after all other setup to prevent the
- * possibility of clusters being powered down before they
- * are fully configured.
- */
- for (i = 0; i < NR_CLUSTERS; i++)
- cpumask_set_cpu(i, &cluster_mask);
-
return 0;
}
diff --git a/arch/arm/mach-vexpress/hotplug-asm.S b/arch/arm/mach-vexpress/hotplug-asm.S
deleted file mode 100644
index f63472edcc4..00000000000
--- a/arch/arm/mach-vexpress/hotplug-asm.S
+++ /dev/null
@@ -1,28 +0,0 @@
-#include <linux/linkage.h>
-#include <asm/asm-offsets.h>
-
- .text
-ENTRY(disable_clean_inv_dcache)
- ARM( stmfd sp!, {r4-r5, r7, r9-r11, lr} )
- THUMB( stmfd sp!, {r4-r7, r9-r11, lr} )
-
- mrc p15, 0, r3, c1, c0, 0
- bic r3, #4 @ clear C bit
- mcr p15, 0, r3, c1, c0, 0
- dsb
- isb
- mov r12, r0
- cmp r12, #0
- bleq v7_flush_dcache_louis
- cmp r12, #0
- blne v7_flush_dcache_all
- clrex
- mrc p15, 0, r3, c1, c0, 1
- bic r3, #0x40 @ clear SMP bit
- mcr p15, 0, r3, c1, c0, 1
- isb
- dsb
- ARM( ldmfd sp!, {r4-r5, r7, r9-r11, lr} )
- THUMB( ldmfd sp!, {r4-r7, r9-r11, lr} )
- mov pc, lr
-ENDPROC(disable_clean_inv_dcache)
diff --git a/arch/arm/mach-vexpress/tc2-sleep.S b/arch/arm/mach-vexpress/tc2-sleep.S
deleted file mode 100644
index 9bf8348fcc8..00000000000
--- a/arch/arm/mach-vexpress/tc2-sleep.S
+++ /dev/null
@@ -1,76 +0,0 @@
-#include <linux/linkage.h>
-
-#define SPC_PHYS_BASE 0x7FFF0000
-#define A15_CONF 0x400
-
-ENTRY(tc2_cpu_resume)
- mrc p15, 0, r0, c0, c0, 5
- ands r0, r0, #0xff00
- ldr r1, =SPC_PHYS_BASE
- mov r2, #A15_CONF
- add r1, r1, r2
- ldr r1, [r1]
- and r1, r1, #0x7
- cmp r1, r0, lsr #8
- adr r0, value
- addne r0, r0, #16
- ldmia r0, {r1, r2, r3, r4} @ CCI address, SCC snoop control & val
- mvn r3, r3 @ undo actions done at shutdown
- ldr r0, [r2]
- and r5, r0, r3
- str r5, [r2]
- mov r0, #3 @ enable CCI for the cluster
- str r0, [r1]
- adr r1, cci_ctrl
- ldr r1, [r1]
-loop:
- ldr r0, [r1]
- ands r0, r0, #1
- bne loop
- mov r0, #0 @ disable power down enable
- str r0, [r4]
- b cpu_resume
-ENDPROC(tc2_cpu_resume)
-
-ENTRY(disable_snoops)
- mrc p15, 0, r0, c0, c0, 5
- ands r0, r0, #0xff00
- ldr r1, scc_ptr
- ldr r1, [r1]
- mov r2, #A15_CONF
- add r1, r1, r2
- ldr r1, [r1]
- and r1, r1, #0x7
- cmp r1, r0, lsr #8
- adr r0, vvalue
- addne r0, r0, #8
- ldmia r0, {r2, r3} @ CCI address, SCC snoop control & val
- ldr r1, scc_ptr
- ldr r1, [r1]
- add r2, r1, r2
- ldr r0, [r2]
- orr r0, r0, r3
- dsb
- isb
- str r0, [r2]
- wfi
-ENDPROC(disable_snoops)
-
-cci_ctrl:
- .long 0x2c09000c
-value:
- .long 0x2c094000
- .long 0x7fff0404
- .long 0x180
- .long 0x7fff0b30
- .long 0x2c095000
- .long 0x7fff0504
- .long 0x2000
- .long 0x7fff0b34
-vvalue:
- .long 0x404
- .long 0x180
- .long 0x504
- .long 0x2000
-scc_ptr:
- .long vscc
diff --git a/arch/arm/mach-vexpress/tc2_pm.c b/arch/arm/mach-vexpress/tc2_pm.c
index 8be975e4b31..a5e18df801d 100644
--- a/arch/arm/mach-vexpress/tc2_pm.c
+++ b/arch/arm/mach-vexpress/tc2_pm.c
@@ -80,7 +80,7 @@ static int tc2_pm_power_up(unsigned int cpu, unsigned int cluster)
return 0;
}
-static void tc2_pm_power_down(void)
+static void tc2_pm_down(u64 residency)
{
unsigned int mpidr, cpu, cluster;
bool last_man = false, skip_wfi = false;
@@ -101,7 +101,8 @@ static void tc2_pm_power_down(void)
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]) {
+ !tc2_pm_use_count[2][cluster] &&
+ (!residency || residency > 5000)) {
vexpress_spc_powerdown_enable(cluster, 1);
vexpress_spc_set_global_wakeup_intr(1);
last_man = true;
@@ -164,6 +165,23 @@ static void tc2_pm_power_down(void)
/* 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);
+ vexpress_spc_write_bxaddr_reg(cluster, cpu,
+ virt_to_phys(mcpm_entry_point));
+ tc2_pm_down(residency);
+}
+
static void tc2_pm_powered_up(void)
{
unsigned int mpidr, cpu, cluster;
@@ -199,6 +217,7 @@ static void tc2_pm_powered_up(void)
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,
};