[PATCH V3 3/7] ARM: tegra30: cpuidle: add powered-down state for secondary CPUs
Joseph Lo
josephl at nvidia.com
Mon Oct 29 06:28:17 EDT 2012
This supports power-gated idle on secondary CPUs for Tegra30. The
secondary CPUs can go into powered-down state independently. When
CPU goes into this state, it saves it's contexts and puts itself
to flow controlled WFI state. After that, it will been power gated.
Be aware of that, you may see the legacy power state "LP2" in the
code which is exactly the same meaning of "CPU power down".
Based on the work by:
Scott Williams <scwilliams at nvidia.com>
Signed-off-by: Joseph Lo <josephl at nvidia.com>
---
V3:
* remove the redundant header file
* update the subject and the commit message
* rename the LP2 state to "powered-down"
* refine the function name from "tegra30_idle_enter_lp2_cpu_n" to
"tegra30_cpu_core_power_down"
V2:
* static initialization for idle states when PM_SLEEP is true or not
* using inline fuction to replace the empty fuction when #ifdef false
* convert the phy cpu number by cpu_logical_map
* update the usage of tegra_cpu_lp2_mask (only one copy in the IRAM)
* update the usage of data cache maintenance API for LP2
* disable L1 data cache
* v7_flush_dcache_louis
* exit SMP coherency
---
arch/arm/mach-tegra/Makefile | 1 +
arch/arm/mach-tegra/cpuidle-tegra30.c | 86 +++++++++++++++++++++++++++++++++
arch/arm/mach-tegra/pm.c | 75 ++++++++++++++++++++++++++++
arch/arm/mach-tegra/pm.h | 30 +++++++++++
arch/arm/mach-tegra/reset.h | 9 ++++
arch/arm/mach-tegra/sleep-tegra30.S | 22 ++++++++
arch/arm/mach-tegra/sleep.S | 29 +++++++++++
arch/arm/mach-tegra/sleep.h | 2 +
8 files changed, 254 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-tegra/pm.c
create mode 100644 arch/arm/mach-tegra/pm.h
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index 9b80c1e..6f224f7 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -8,6 +8,7 @@ obj-y += pmc.o
obj-y += flowctrl.o
obj-y += powergate.o
obj-y += apbio.o
+obj-y += pm.o
obj-$(CONFIG_CPU_IDLE) += cpuidle.o
obj-$(CONFIG_CPU_IDLE) += sleep.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra20_clocks.o
diff --git a/arch/arm/mach-tegra/cpuidle-tegra30.c b/arch/arm/mach-tegra/cpuidle-tegra30.c
index 37e7551..cc48d7f 100644
--- a/arch/arm/mach-tegra/cpuidle-tegra30.c
+++ b/arch/arm/mach-tegra/cpuidle-tegra30.c
@@ -22,21 +22,107 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
+#include <linux/clockchips.h>
#include <asm/cpuidle.h>
+#include <asm/proc-fns.h>
+#include <asm/suspend.h>
+#include <asm/smp_plat.h>
+
+#include "pm.h"
+#include "sleep.h"
+
+#ifdef CONFIG_PM_SLEEP
+static int tegra30_idle_lp2(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index);
+#endif
static struct cpuidle_driver tegra_idle_driver = {
.name = "tegra_idle",
.owner = THIS_MODULE,
.en_core_tk_irqen = 1,
+#ifdef CONFIG_PM_SLEEP
+ .state_count = 2,
+#else
.state_count = 1,
+#endif
.states = {
[0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
+#ifdef CONFIG_PM_SLEEP
+ [1] = {
+ .enter = tegra30_idle_lp2,
+ .exit_latency = 2000,
+ .target_residency = 2200,
+ .power_usage = 0,
+ .flags = CPUIDLE_FLAG_TIME_VALID,
+ .name = "powered-down",
+ .desc = "CPU power gated",
+ },
+#endif
},
};
static DEFINE_PER_CPU(struct cpuidle_device, tegra_idle_device);
+#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_SMP
+static bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
+
+ smp_wmb();
+
+ save_cpu_arch_register();
+
+ cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
+
+ restore_cpu_arch_register();
+
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
+
+ return true;
+}
+#else
+static inline bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ return true;
+}
+#endif
+
+static int __cpuinit tegra30_idle_lp2(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ u32 cpu = is_smp() ? cpu_logical_map(dev->cpu) : dev->cpu;
+ bool entered_lp2 = false;
+
+ local_fiq_disable();
+
+ tegra_set_cpu_in_lp2(cpu);
+ cpu_pm_enter();
+
+ if (cpu == 0)
+ cpu_do_idle();
+ else
+ entered_lp2 = tegra30_cpu_core_power_down(dev, drv, index);
+
+ cpu_pm_exit();
+ tegra_clear_cpu_in_lp2(cpu);
+
+ local_fiq_enable();
+
+ smp_rmb();
+
+ return (entered_lp2) ? index : 0;
+}
+#endif
+
int __init tegra30_cpuidle_init(void)
{
int ret;
diff --git a/arch/arm/mach-tegra/pm.c b/arch/arm/mach-tegra/pm.c
new file mode 100644
index 0000000..39ee557
--- /dev/null
+++ b/arch/arm/mach-tegra/pm.c
@@ -0,0 +1,75 @@
+/*
+ * CPU complex suspend & resume functions for Tegra SoCs
+ *
+ * Copyright (c) 2009-2012, NVIDIA Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/cpumask.h>
+
+#include <mach/iomap.h>
+
+#include "reset.h"
+
+#ifdef CONFIG_PM_SLEEP
+static unsigned int g_diag_reg;
+static DEFINE_SPINLOCK(tegra_lp2_lock);
+
+void save_cpu_arch_register(void)
+{
+ /* read diagnostic register */
+ asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc");
+ return;
+}
+
+void restore_cpu_arch_register(void)
+{
+ /* write diagnostic register */
+ asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc");
+ return;
+}
+
+void __cpuinit tegra_clear_cpu_in_lp2(int phy_cpu_id)
+{
+ u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
+
+ spin_lock(&tegra_lp2_lock);
+
+ BUG_ON(!(*cpu_in_lp2 & BIT(phy_cpu_id)));
+ *cpu_in_lp2 &= ~BIT(phy_cpu_id);
+
+ spin_unlock(&tegra_lp2_lock);
+}
+
+bool __cpuinit tegra_set_cpu_in_lp2(int phy_cpu_id)
+{
+ bool last_cpu = false;
+ cpumask_t *cpu_lp2_mask = tegra_cpu_lp2_mask;
+ u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
+
+ spin_lock(&tegra_lp2_lock);
+
+ BUG_ON((*cpu_in_lp2 & BIT(phy_cpu_id)));
+ *cpu_in_lp2 |= BIT(phy_cpu_id);
+
+ if ((phy_cpu_id == 0) && cpumask_equal(cpu_lp2_mask, cpu_online_mask))
+ last_cpu = true;
+
+ spin_unlock(&tegra_lp2_lock);
+ return last_cpu;
+}
+#endif
diff --git a/arch/arm/mach-tegra/pm.h b/arch/arm/mach-tegra/pm.h
new file mode 100644
index 0000000..bcfc45f
--- /dev/null
+++ b/arch/arm/mach-tegra/pm.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2010 Google, Inc.
+ * Copyright (c) 2010-2012 NVIDIA Corporation. All rights reserved.
+ *
+ * Author:
+ * Colin Cross <ccross at google.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _MACH_TEGRA_PM_H_
+#define _MACH_TEGRA_PM_H_
+
+void save_cpu_arch_register(void);
+void restore_cpu_arch_register(void);
+
+void tegra_clear_cpu_in_lp2(int phy_cpu_id);
+bool tegra_set_cpu_in_lp2(int phy_cpu_id);
+
+#endif /* _MACH_TEGRA_PM_H_ */
diff --git a/arch/arm/mach-tegra/reset.h b/arch/arm/mach-tegra/reset.h
index de88bf8..234cd6b 100644
--- a/arch/arm/mach-tegra/reset.h
+++ b/arch/arm/mach-tegra/reset.h
@@ -29,6 +29,8 @@
#ifndef __ASSEMBLY__
+#include <mach/irammap.h>
+
extern unsigned long __tegra_cpu_reset_handler_data[TEGRA_RESET_DATA_SIZE];
void __tegra_cpu_reset_handler_start(void);
@@ -36,6 +38,13 @@ void __tegra_cpu_reset_handler(void);
void __tegra_cpu_reset_handler_end(void);
void tegra_secondary_startup(void);
+#ifdef CONFIG_PM_SLEEP
+#define tegra_cpu_lp2_mask \
+ (IO_ADDRESS(TEGRA_IRAM_BASE + TEGRA_IRAM_RESET_HANDLER_OFFSET + \
+ ((u32)&__tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_LP2] - \
+ (u32)__tegra_cpu_reset_handler_start)))
+#endif
+
#define tegra_cpu_reset_handler_offset \
((u32)__tegra_cpu_reset_handler - \
(u32)__tegra_cpu_reset_handler_start)
diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
index be7614b..59984d7 100644
--- a/arch/arm/mach-tegra/sleep-tegra30.S
+++ b/arch/arm/mach-tegra/sleep-tegra30.S
@@ -17,6 +17,7 @@
#include <linux/linkage.h>
#include <asm/assembler.h>
+#include <asm/asm-offsets.h>
#include "sleep.h"
#include "flowctrl.h"
@@ -80,6 +81,7 @@ delay_1:
ldr r3, [r1] @ read CSR
str r3, [r1] @ clear CSR
tst r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN
+ moveq r3, #FLOW_CTRL_WAIT_FOR_INTERRUPT @ For LP2
movne r3, #FLOW_CTRL_WAITEVENT @ For hotplug
str r3, [r2]
ldr r0, [r2]
@@ -103,3 +105,23 @@ wfe_war:
ENDPROC(tegra30_cpu_shutdown)
#endif
+
+#ifdef CONFIG_PM_SLEEP
+/*
+ * tegra30_sleep_cpu_secondary_finish(unsigned long v2p)
+ *
+ * Enters LP2 on secondary CPU by exiting coherency and powergating the CPU.
+ */
+ENTRY(tegra30_sleep_cpu_secondary_finish)
+ mov r7, lr
+
+ /* Flush and disable the L1 data cache */
+ bl tegra_disable_clean_inv_dcache
+
+ /* Powergate this CPU. */
+ mov r0, #0 @ power mode flags (!hotplug)
+ bl tegra30_cpu_shutdown
+ mov r0, #1 @ never return here
+ mov pc, r7
+ENDPROC(tegra30_sleep_cpu_secondary_finish)
+#endif
diff --git a/arch/arm/mach-tegra/sleep.S b/arch/arm/mach-tegra/sleep.S
index ea81554..cba7a52 100644
--- a/arch/arm/mach-tegra/sleep.S
+++ b/arch/arm/mach-tegra/sleep.S
@@ -25,9 +25,38 @@
#include <linux/linkage.h>
#include <asm/assembler.h>
+#include <asm/cp15.h>
#include <mach/iomap.h>
#include "flowctrl.h"
#include "sleep.h"
+#ifdef CONFIG_PM_SLEEP
+/*
+ * tegra_disable_clean_inv_dcache
+ *
+ * disable, clean & invalidate the D-cache
+ *
+ * Corrupted registers: r1-r3, r6, r8, r9-r11
+ */
+ENTRY(tegra_disable_clean_inv_dcache)
+ stmfd sp!, {r0, r4-r5, r7, r9-r11, lr}
+ dmb @ ensure ordering
+
+ /* Disable the D-cache */
+ mrc p15, 0, r2, c1, c0, 0
+ bic r2, r2, #CR_C
+ mcr p15, 0, r2, c1, c0, 0
+ isb
+
+ /* Flush the D-cache */
+ bl v7_flush_dcache_louis
+
+ /* Trun off coherency */
+ exit_smp r4, r5
+
+ ldmfd sp!, {r0, r4-r5, r7, r9-r11, pc}
+ENDPROC(tegra_disable_clean_inv_dcache)
+
+#endif
diff --git a/arch/arm/mach-tegra/sleep.h b/arch/arm/mach-tegra/sleep.h
index c9dec37..220fbd1 100644
--- a/arch/arm/mach-tegra/sleep.h
+++ b/arch/arm/mach-tegra/sleep.h
@@ -82,5 +82,7 @@ static inline void tegra20_hotplug_init(void) {}
static inline void tegra30_hotplug_init(void) {}
#endif
+int tegra30_sleep_cpu_secondary_finish(unsigned long);
+
#endif
#endif
--
1.7.0.4
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