ARM: vexpress/tc2: implement PM suspend method
authorNicolas Pitre <nico@linaro.org>
Mon, 10 Dec 2012 05:22:06 +0000 (00:22 -0500)
committerJon Medhurst <tixy@linaro.org>
Mon, 1 Jul 2013 10:05:13 +0000 (11:05 +0100)
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>
arch/arm/mach-vexpress/Kconfig
arch/arm/mach-vexpress/Makefile
arch/arm/mach-vexpress/cpuidle-tc2.c
arch/arm/mach-vexpress/hotplug-asm.S [deleted file]
arch/arm/mach-vexpress/tc2-sleep.S [deleted file]
arch/arm/mach-vexpress/tc2_pm.c

index 6e432b2c90cfd7f7ab1a8ff8950d14e045e9466d..ceb7ef03d0f9cf8c98d0580672593cd1df3237e6 100644 (file)
@@ -54,20 +54,6 @@ 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"
 
@@ -79,4 +65,15 @@ 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
index 9650cc4eec19c3dc0db5e78ae63a8fdc54bcf054..4745fd36e91231086fd4f42376d1149964081cdd 100644 (file)
@@ -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
index 3b73d4a5dc5f83897c3818b7585d7fd4508a2d51..0a983dd531b76940bf8681fe0b3119f9e1c54741 100644 (file)
@@ -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 (file)
index f63472e..0000000
+++ /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 (file)
index 9bf8348..0000000
+++ /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
index 8be975e4b31d88a08bbd6e5867d3cc7a26b2f4ba..a5e18df801db1262fbfb2518be80a13aa1d32cb7 100644 (file)
@@ -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,
 };