Two miscellaneous MCE fixes

-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.10 (GNU/Linux)
 
 iQIcBAABAgAGBQJPX7q/AAoJEKurIx+X31iBIHIQAIjXmz+5cCp/sDjtcoiPvcvu
 0OLspJbT4jswGdiFP+Xvn7MEJH2Q+Bj8ejejCrpyXG4R1v/K9zmzDwyAGaJbLiGw
 T5I9L9/GesYhCoIzyT7IfyNCtjsXMRmdmxLbxvyWxXiw/tT355Reb8Pqsq3Xy9dA
 0swO69MC3oJcYG19pLgv+QrtZaK79aiJqe5YmDIIoLYo8jIhnza2bKn3CKvQLV34
 8jIKTyo31MOTVZW9qy+pt5kNrnUgtmMBtdEsfVQdrAxKyEXwBd0rFRLHZ0c8YQit
 QcI0/MyK5la3swtiGnEiJQOvGGP/VIfPklVdw3ahLAthYUC+mof6zDBqpSGheJBQ
 f0Tbm0k3uWzVVij6Au2i3xi+nKNiPtUlOCcE1EPFvOYh0QOSDy4TPdxRDCZHHPeA
 hc5nbLTqwxAc8BE3vnDySztCGoeA3/UEOba1Kc4meKyLma7pJ4eNEL9j40XInn/z
 JRNbfj4BuSgmpV5nZbsb9jU/f15OfOuwZ+UMz//PYuIEI6gK3aYXojc5x1Z++Dot
 G6GIF4zs1zkzOnvaNeB8KZkmtWvRl/7dZuEM5SMDU+V0lj5xDs3nM4AhYPYSAvX2
 knmj//Gr/NE/DpAH0+bZIqzz6eduGc8HV5Y0nWlWvPKO+qs4n9uE0/8VL+5lZcQ8
 kojVLi2WTLvhCsnxUV3z
 =G63l
 -----END PGP SIGNATURE-----

Merge tag 'mce-for-tip' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into x86/mce

Apply two miscellaneous MCE fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/mce.h

@@ -151,7 +151,7 @@ static inline void enable_p5_mce(void) {}
 
 void mce_setup(struct mce *m);
 void mce_log(struct mce *m);
-extern struct device *mce_device[CONFIG_NR_CPUS];
+DECLARE_PER_CPU(struct device *, mce_device);
 
 /*
  * Maximum banks number.

arch/x86/kernel/cpu/mcheck/mce.c

@@ -1614,6 +1614,12 @@ static int __mce_read_apei(char __user **ubuf, size_t usize)
 	/* Error or no more MCE record */
 	if (rc <= 0) {
 		mce_apei_read_done = 1;
+		/*
+		 * When ERST is disabled, mce_chrdev_read() should return
+		 * "no record" instead of "no device."
+		 */
+		if (rc == -ENODEV)
+			return 0;
 		return rc;
 	}
 	rc = -EFAULT;
@@ -1932,7 +1938,7 @@ static struct bus_type mce_subsys = {
 	.dev_name	= "machinecheck",
 };
 
-struct device *mce_device[CONFIG_NR_CPUS];
+DEFINE_PER_CPU(struct device *, mce_device);
 
 __cpuinitdata
 void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu);
@@ -2111,7 +2117,7 @@ static __cpuinit int mce_device_create(unsigned int cpu)
 			goto error2;
 	}
 	cpumask_set_cpu(cpu, mce_device_initialized);
-	mce_device[cpu] = dev;
+	per_cpu(mce_device, cpu) = dev;
 
 	return 0;
 error2:
@@ -2128,7 +2134,7 @@ error:
 
 static __cpuinit void mce_device_remove(unsigned int cpu)
 {
-	struct device *dev = mce_device[cpu];
+	struct device *dev = per_cpu(mce_device, cpu);
 	int i;
 
 	if (!cpumask_test_cpu(cpu, mce_device_initialized))
@@ -2142,7 +2148,7 @@ static __cpuinit void mce_device_remove(unsigned int cpu)
 
 	device_unregister(dev);
 	cpumask_clear_cpu(cpu, mce_device_initialized);
-	mce_device[cpu] = NULL;
+	per_cpu(mce_device, cpu) = NULL;
 }
 
 /* Make sure there are no machine checks on offlined CPUs. */

arch/x86/kernel/cpu/mcheck/mce_amd.c

@@ -523,7 +523,7 @@ static __cpuinit int threshold_create_bank(unsigned int cpu, unsigned int bank)
 {
 	int i, err = 0;
 	struct threshold_bank *b = NULL;
-	struct device *dev = mce_device[cpu];
+	struct device *dev = per_cpu(mce_device, cpu);
 	char name[32];
 
 	sprintf(name, "threshold_bank%i", bank);
@@ -587,7 +587,7 @@ static __cpuinit int threshold_create_bank(unsigned int cpu, unsigned int bank)
 		if (i == cpu)
 			continue;
 
-		dev = mce_device[i];
+		dev = per_cpu(mce_device, i);
 		if (dev)
 			err = sysfs_create_link(&dev->kobj,b->kobj, name);
 		if (err)
@@ -667,7 +667,8 @@ static void threshold_remove_bank(unsigned int cpu, int bank)
 #ifdef CONFIG_SMP
 	/* sibling symlink */
 	if (shared_bank[bank] && b->blocks->cpu != cpu) {
-		sysfs_remove_link(&mce_device[cpu]->kobj, name);
+		dev = per_cpu(mce_device, cpu);
+		sysfs_remove_link(&dev->kobj, name);
 		per_cpu(threshold_banks, cpu)[bank] = NULL;
 
 		return;
@@ -679,7 +680,7 @@ static void threshold_remove_bank(unsigned int cpu, int bank)
 		if (i == cpu)
 			continue;
 
-		dev = mce_device[i];
+		dev = per_cpu(mce_device, i);
 		if (dev)
 			sysfs_remove_link(&dev->kobj, name);
 		per_cpu(threshold_banks, i)[bank] = NULL;