Attachment 160030 Details for Bug 249689 – description of patch on RHBZ

[patch] description of patch on RHBZ

Test_patch (text/plain), 6.55 KB, created by Jeremy Scherer on 2007-07-26 15:36:38 UTC

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Creator: Jeremy Scherer

Created: 2007-07-26 15:36:38 UTC

Size: 6.55 KB

patch

obsolete

>http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=455c017ae3934797653549704c286e7bcc3a9397#patch2
>
>From: Rafael J. Wysocki <rjw@sisk.pl>
>Date: Wed, 9 May 2007 09:35:11 +0000 (-0700)
>Subject: microcode: use suspend-related CPU hotplug notifications
>X-Git-Tag: v2.6.22-rc1~176
>X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=455c017ae3934797653549704c286e7bcc3a9397
>
>microcode: use suspend-related CPU hotplug notifications
>
>Make the microcode driver use the suspend-related CPU hotplug notifications
>to handle the CPU hotplug events occuring during system-wide suspend and
>resume transitions.  Remove the global variable suspend_cpu_hotplug
>previously used for this purpose.
>
>Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
>Cc: Gautham R Shenoy <ego@in.ibm.com>
>Cc: Pavel Machek <pavel@ucw.cz>
>Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
>---
>
>diff --git a/arch/i386/kernel/microcode.c b/arch/i386/kernel/microcode.c
>index 7d934e4..83f825f 100644
>--- a/arch/i386/kernel/microcode.c
>+++ b/arch/i386/kernel/microcode.c
>@@ -567,7 +567,7 @@ static int cpu_request_microcode(int cpu)
> 	return error;
> }
> 
>-static int apply_microcode_on_cpu(int cpu)
>+static int apply_microcode_check_cpu(int cpu)
> {
> 	struct cpuinfo_x86 *c = cpu_data + cpu;
> 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
>@@ -575,8 +575,9 @@ static int apply_microcode_on_cpu(int cpu)
> 	unsigned int val[2];
> 	int err = 0;
> 
>+	/* Check if the microcode is available */
> 	if (!uci->mc)
>-		return -EINVAL;
>+		return 0;
> 
> 	old = current->cpus_allowed;
> 	set_cpus_allowed(current, cpumask_of_cpu(cpu));
>@@ -614,7 +615,7 @@ static int apply_microcode_on_cpu(int cpu)
> 	return err;
> }
> 
>-static void microcode_init_cpu(int cpu)
>+static void microcode_init_cpu(int cpu, int resume)
> {
> 	cpumask_t old;
> 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
>@@ -624,8 +625,7 @@ static void microcode_init_cpu(int cpu)
> 	set_cpus_allowed(current, cpumask_of_cpu(cpu));
> 	mutex_lock(&microcode_mutex);
> 	collect_cpu_info(cpu);
>-	if (uci->valid && system_state == SYSTEM_RUNNING &&
>-	    !suspend_cpu_hotplug)
>+	if (uci->valid && system_state == SYSTEM_RUNNING && !resume)
> 		cpu_request_microcode(cpu);
> 	mutex_unlock(&microcode_mutex);
> 	set_cpus_allowed(current, old);
>@@ -702,7 +702,7 @@ static struct attribute_group mc_attr_group = {
> 	.name = "microcode",
> };
> 
>-static int mc_sysdev_add(struct sys_device *sys_dev)
>+static int __mc_sysdev_add(struct sys_device *sys_dev, int resume)
> {
> 	int err, cpu = sys_dev->id;
> 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
>@@ -711,39 +711,31 @@ static int mc_sysdev_add(struct sys_device *sys_dev)
> 		return 0;
> 
> 	pr_debug("Microcode:CPU %d added\n", cpu);
>-	/* If suspend_cpu_hotplug is set, the system is resuming and we should
>-	 * use the data from before the suspend.
>-	 */
>-	if (suspend_cpu_hotplug) {
>-		err = apply_microcode_on_cpu(cpu);
>-		if (err)
>-			microcode_fini_cpu(cpu);
>-	}
>-	if (!uci->valid)
>-		memset(uci, 0, sizeof(*uci));
>+	memset(uci, 0, sizeof(*uci));
> 
> 	err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
> 	if (err)
> 		return err;
> 
>-	if (!uci->valid)
>-		microcode_init_cpu(cpu);
>+	microcode_init_cpu(cpu, resume);
> 
> 	return 0;
> }
> 
>+static int mc_sysdev_add(struct sys_device *sys_dev)
>+{
>+	return __mc_sysdev_add(sys_dev, 0);
>+}
>+
> static int mc_sysdev_remove(struct sys_device *sys_dev)
> {
> 	int cpu = sys_dev->id;
> 
> 	if (!cpu_online(cpu))
> 		return 0;
>+
> 	pr_debug("Microcode:CPU %d removed\n", cpu);
>-	/* If suspend_cpu_hotplug is set, the system is suspending and we should
>-	 * keep the microcode in memory for the resume.
>-	 */
>-	if (!suspend_cpu_hotplug)
>-		microcode_fini_cpu(cpu);
>+	microcode_fini_cpu(cpu);
> 	sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
> 	return 0;
> }
>@@ -774,16 +766,34 @@ mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
> 
> 	sys_dev = get_cpu_sysdev(cpu);
> 	switch (action) {
>+	case CPU_UP_CANCELED_FROZEN:
>+		/* The CPU refused to come up during a system resume */
>+		microcode_fini_cpu(cpu);
>+		break;
> 	case CPU_ONLINE:
>-	case CPU_ONLINE_FROZEN:
> 	case CPU_DOWN_FAILED:
>-	case CPU_DOWN_FAILED_FROZEN:
> 		mc_sysdev_add(sys_dev);
> 		break;
>+	case CPU_ONLINE_FROZEN:
>+		/* System-wide resume is in progress, try to apply microcode */
>+		if (apply_microcode_check_cpu(cpu)) {
>+			/* The application of microcode failed */
>+			microcode_fini_cpu(cpu);
>+			__mc_sysdev_add(sys_dev, 1);
>+			break;
>+		}
>+	case CPU_DOWN_FAILED_FROZEN:
>+		if (sysfs_create_group(&sys_dev->kobj, &mc_attr_group))
>+			printk(KERN_ERR "Microcode: Failed to create the sysfs "
>+				"group for CPU%d\n", cpu);
>+		break;
> 	case CPU_DOWN_PREPARE:
>-	case CPU_DOWN_PREPARE_FROZEN:
> 		mc_sysdev_remove(sys_dev);
> 		break;
>+	case CPU_DOWN_PREPARE_FROZEN:
>+		/* Suspend is in progress, only remove the interface */
>+		sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
>+		break;
> 	}
> 	return NOTIFY_OK;
> }
>diff --git a/kernel/cpu.c b/kernel/cpu.c
>index 369d289..208cf34 100644
>--- a/kernel/cpu.c
>+++ b/kernel/cpu.c
>@@ -262,12 +262,6 @@ int __cpuinit cpu_up(unsigned int cpu)
> }
> 
> #ifdef CONFIG_SUSPEND_SMP
>-/* Needed to prevent the microcode driver from requesting firmware in its CPU
>- * hotplug notifier during the suspend/resume.
>- */
>-int suspend_cpu_hotplug;
>-EXPORT_SYMBOL(suspend_cpu_hotplug);
>-
> static cpumask_t frozen_cpus;
> 
> int disable_nonboot_cpus(void)
>@@ -275,7 +269,6 @@ int disable_nonboot_cpus(void)
> 	int cpu, first_cpu, error = 0;
> 
> 	mutex_lock(&cpu_add_remove_lock);
>-	suspend_cpu_hotplug = 1;
> 	first_cpu = first_cpu(cpu_online_map);
> 	/* We take down all of the non-boot CPUs in one shot to avoid races
> 	 * with the userspace trying to use the CPU hotplug at the same time
>@@ -302,7 +295,6 @@ int disable_nonboot_cpus(void)
> 	} else {
> 		printk(KERN_ERR "Non-boot CPUs are not disabled\n");
> 	}
>-	suspend_cpu_hotplug = 0;
> 	mutex_unlock(&cpu_add_remove_lock);
> 	return error;
> }
>@@ -317,7 +309,6 @@ void enable_nonboot_cpus(void)
> 	if (cpus_empty(frozen_cpus))
> 		goto out;
> 
>-	suspend_cpu_hotplug = 1;
> 	printk("Enabling non-boot CPUs ...\n");
> 	for_each_cpu_mask(cpu, frozen_cpus) {
> 		error = _cpu_up(cpu, 1);
>@@ -328,7 +319,6 @@ void enable_nonboot_cpus(void)
> 		printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error);
> 	}
> 	cpus_clear(frozen_cpus);
>-	suspend_cpu_hotplug = 0;
> out:
> 	mutex_unlock(&cpu_add_remove_lock);
> }
>
>

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Attachments on bug 249689: 160020 | 160023 | 160030 | 160033