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authorRafael J. Wysocki <rjw@sisk.pl>2007-04-01 23:49:49 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-04-02 10:06:09 -0700
commit1d64b9cb1dc2a7cd521444e3d908adeccd026356 (patch)
tree31c6c7751b656e74b5ee05159c85154f710e8956 /arch
parent0c84ce268b69855919b6ac7edc8f11caf21e9c88 (diff)
[PATCH] Fix microcode-related suspend problem
Fix the regression resulting from the recent change of suspend code ordering that causes systems based on Intel x86 CPUs using the microcode driver to hang during the resume. The problem occurs since the microcode driver uses request_firmware() in its CPU hotplug notifier, which is called after tasks has been frozen and hangs. It can be fixed by telling the microcode driver to use the microcode stored in memory during the resume instead of trying to load it from disk. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Adrian Bunk <bunk@stusta.de> Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Cc: Pavel Machek <pavel@ucw.cz> Cc: Maxim <maximlevitsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/kernel/microcode.c71
1 files changed, 67 insertions, 4 deletions
diff --git a/arch/i386/kernel/microcode.c b/arch/i386/kernel/microcode.c
index b8f16633a6e..cbe7ec8dbb9 100644
--- a/arch/i386/kernel/microcode.c
+++ b/arch/i386/kernel/microcode.c
@@ -567,6 +567,53 @@ static int cpu_request_microcode(int cpu)
return error;
}
+static int apply_microcode_on_cpu(int cpu)
+{
+ struct cpuinfo_x86 *c = cpu_data + cpu;
+ struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ cpumask_t old;
+ unsigned int val[2];
+ int err = 0;
+
+ if (!uci->mc)
+ return -EINVAL;
+
+ old = current->cpus_allowed;
+ set_cpus_allowed(current, cpumask_of_cpu(cpu));
+
+ /* Check if the microcode we have in memory matches the CPU */
+ if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
+ cpu_has(c, X86_FEATURE_IA64) || uci->sig != cpuid_eax(0x00000001))
+ err = -EINVAL;
+
+ if (!err && ((c->x86_model >= 5) || (c->x86 > 6))) {
+ /* get processor flags from MSR 0x17 */
+ rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
+ if (uci->pf != (1 << ((val[1] >> 18) & 7)))
+ err = -EINVAL;
+ }
+
+ if (!err) {
+ wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+ /* see notes above for revision 1.07. Apparent chip bug */
+ sync_core();
+ /* get the current revision from MSR 0x8B */
+ rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
+ if (uci->rev != val[1])
+ err = -EINVAL;
+ }
+
+ if (!err)
+ apply_microcode(cpu);
+ else
+ printk(KERN_ERR "microcode: Could not apply microcode to CPU%d:"
+ " sig=0x%x, pf=0x%x, rev=0x%x\n",
+ cpu, uci->sig, uci->pf, uci->rev);
+
+ set_cpus_allowed(current, old);
+ return err;
+}
+
static void microcode_init_cpu(int cpu)
{
cpumask_t old;
@@ -577,7 +624,8 @@ 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)
+ if (uci->valid && system_state == SYSTEM_RUNNING &&
+ !suspend_cpu_hotplug)
cpu_request_microcode(cpu);
mutex_unlock(&microcode_mutex);
set_cpus_allowed(current, old);
@@ -663,13 +711,24 @@ static int mc_sysdev_add(struct sys_device *sys_dev)
return 0;
pr_debug("Microcode:CPU %d added\n", cpu);
- memset(uci, 0, sizeof(*uci));
+ /* 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));
err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
if (err)
return err;
- microcode_init_cpu(cpu);
+ if (!uci->valid)
+ microcode_init_cpu(cpu);
+
return 0;
}
@@ -680,7 +739,11 @@ static int mc_sysdev_remove(struct sys_device *sys_dev)
if (!cpu_online(cpu))
return 0;
pr_debug("Microcode:CPU %d removed\n", cpu);
- microcode_fini_cpu(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);
sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
return 0;
}