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authorArnd Bergmann <arnd@arndb.de>2013-06-20 02:06:36 +0200
committerArnd Bergmann <arnd@arndb.de>2013-06-20 02:06:36 +0200
commitd5a51af940efec07c969bdb5fe478bb518116404 (patch)
tree26291e51122081d929e3cac3d441ee5efbfa75d6 /kernel/cpu.c
parenta44bde66bec168889c95bd1d0d15834b02387901 (diff)
parentd75f3d92e86e65b3cb9725e65f7278cc303511db (diff)
Merge tag 'mxs-dt-3.11' of git://git.linaro.org/people/shawnguo/linux-2.6 into next/dt
From Shawn Guo: mxs device tree changes for 3.11: * A couple of new board support, cfa10055 and cfa10057 * A few updates on cfa10036 device tree source * Some auart pinctrl data addition * Adopt soc bus infrastructure for mach-mxs * tag 'mxs-dt-3.11' of git://git.linaro.org/people/shawnguo/linux-2.6: ARM: mxs: dt: Add Crystalfontz CFA-10057 device tree ARM: mxs: dt: Add the Crystalfontz CFA-10055 device tree ARM: cfa10049: Switch the chip select pin of the LCD controller ARM: cfa10036: Add USB0 OTG port ARM: dts: apf28dev: Add touchscreen support for APF28dev ARM: mxs: Fix UARTs on M28EVK ARM: cfa10036: dt: Change i2c0 clock frequency ARM: dts: cfa10036: Change the OLED display to SSD1306 ARM: mx28: add auart4 2 pins pinmux to imx28.dtsi ARM: mx28: add auart3 2 pins pinmux to imx28.dtsi ARM: mx28: add auart2 2 pins pinmux to imx28.dtsi ARM: mxs: Use soc bus infrastructure ARM: dts: mx28: Adjust the digctl compatible string ARM: mxs: Remove init_irq declaration in machine description Includes an update to 3.10-rc6 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c55
1 files changed, 23 insertions, 32 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index b5e4ab2d427e..198a38883e64 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -133,6 +133,27 @@ static void cpu_hotplug_done(void)
mutex_unlock(&cpu_hotplug.lock);
}
+/*
+ * Wait for currently running CPU hotplug operations to complete (if any) and
+ * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects
+ * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the
+ * hotplug path before performing hotplug operations. So acquiring that lock
+ * guarantees mutual exclusion from any currently running hotplug operations.
+ */
+void cpu_hotplug_disable(void)
+{
+ cpu_maps_update_begin();
+ cpu_hotplug_disabled = 1;
+ cpu_maps_update_done();
+}
+
+void cpu_hotplug_enable(void)
+{
+ cpu_maps_update_begin();
+ cpu_hotplug_disabled = 0;
+ cpu_maps_update_done();
+}
+
#else /* #if CONFIG_HOTPLUG_CPU */
static void cpu_hotplug_begin(void) {}
static void cpu_hotplug_done(void) {}
@@ -541,36 +562,6 @@ static int __init alloc_frozen_cpus(void)
core_initcall(alloc_frozen_cpus);
/*
- * Prevent regular CPU hotplug from racing with the freezer, by disabling CPU
- * hotplug when tasks are about to be frozen. Also, don't allow the freezer
- * to continue until any currently running CPU hotplug operation gets
- * completed.
- * To modify the 'cpu_hotplug_disabled' flag, we need to acquire the
- * 'cpu_add_remove_lock'. And this same lock is also taken by the regular
- * CPU hotplug path and released only after it is complete. Thus, we
- * (and hence the freezer) will block here until any currently running CPU
- * hotplug operation gets completed.
- */
-void cpu_hotplug_disable_before_freeze(void)
-{
- cpu_maps_update_begin();
- cpu_hotplug_disabled = 1;
- cpu_maps_update_done();
-}
-
-
-/*
- * When tasks have been thawed, re-enable regular CPU hotplug (which had been
- * disabled while beginning to freeze tasks).
- */
-void cpu_hotplug_enable_after_thaw(void)
-{
- cpu_maps_update_begin();
- cpu_hotplug_disabled = 0;
- cpu_maps_update_done();
-}
-
-/*
* When callbacks for CPU hotplug notifications are being executed, we must
* ensure that the state of the system with respect to the tasks being frozen
* or not, as reported by the notification, remains unchanged *throughout the
@@ -589,12 +580,12 @@ cpu_hotplug_pm_callback(struct notifier_block *nb,
case PM_SUSPEND_PREPARE:
case PM_HIBERNATION_PREPARE:
- cpu_hotplug_disable_before_freeze();
+ cpu_hotplug_disable();
break;
case PM_POST_SUSPEND:
case PM_POST_HIBERNATION:
- cpu_hotplug_enable_after_thaw();
+ cpu_hotplug_enable();
break;
default: