x86-microcode: generic interface refactoring

This is the 1st patch in the series. Here the aim was to avoid any
significant changes, logically-wise.

So it's mainly about generic interface refactoring: e.g. make
microcode_{intel,amd}.c more about arch-specific details and less
about policies like make-sure-we-run-on-a-target-cpu
(no more set_cpus_allowed_ptr() here) and generic synchronization (no
more microcode_mutex here).

All in all, more line have been deleted than added.

4 files changed, 145 insertions(+), 198 deletions(-)
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/microcode.c

@@ -71,7 +71,7 @@
  *		Thanks to Stuart Swales for pointing out this bug.
  */
 
-/*#define DEBUG pr_debug */
+/* #define DEBUG pr_debug */
 #include <linux/capability.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -104,8 +104,7 @@ MODULE_LICENSE("GPL");
 struct microcode_ops *microcode_ops;
 
 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
-DEFINE_MUTEX(microcode_mutex);
-EXPORT_SYMBOL_GPL(microcode_mutex);
+static DEFINE_MUTEX(microcode_mutex);
 
 struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
 EXPORT_SYMBOL_GPL(ucode_cpu_info);
@@ -234,22 +233,6 @@ MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
 struct platform_device *microcode_pdev;
 EXPORT_SYMBOL_GPL(microcode_pdev);
 
-static void microcode_init_cpu(int cpu, int resume)
-{
-	cpumask_t old;
-	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
-
-	old = current->cpus_allowed;
-
-	set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
-	mutex_lock(&microcode_mutex);
-	microcode_ops->collect_cpu_info(cpu);
-	if (uci->valid && system_state == SYSTEM_RUNNING && !resume)
-		microcode_ops->cpu_request_microcode(cpu);
-	mutex_unlock(&microcode_mutex);
-	set_cpus_allowed_ptr(current, &old);
-}
-
 static ssize_t reload_store(struct sys_device *dev,
 			    struct sysdev_attribute *attr,
 			    const char *buf, size_t sz)
@@ -266,15 +249,16 @@ static ssize_t reload_store(struct sys_device *dev,
 		cpumask_t old = current->cpus_allowed;
 
 		get_online_cpus();
+		if (cpu_online(cpu)) {
 			set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
-
 			mutex_lock(&microcode_mutex);
 			if (uci->valid)
 				err = microcode_ops->cpu_request_microcode(cpu);
 			mutex_unlock(&microcode_mutex);
-		put_online_cpus();
 			set_cpus_allowed_ptr(current, &old);
 		}
+		put_online_cpus();
+	}
 	if (err)
 		return err;
 	return sz;
@@ -285,7 +269,7 @@ static ssize_t version_show(struct sys_device *dev,
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 
-	return sprintf(buf, "0x%x\n", uci->rev);
+	return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
 }
 
 static ssize_t pf_show(struct sys_device *dev,
@@ -293,7 +277,7 @@ static ssize_t pf_show(struct sys_device *dev,
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 
-	return sprintf(buf, "0x%x\n", uci->pf);
+	return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
 }
 
 static SYSDEV_ATTR(reload, 0200, NULL, reload_store);
@@ -312,7 +296,85 @@ static struct attribute_group mc_attr_group = {
 	.name = "microcode",
 };
 
-static int __mc_sysdev_add(struct sys_device *sys_dev, int resume)
+static void microcode_fini_cpu(int cpu)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+
+	mutex_lock(&microcode_mutex);
+	microcode_ops->microcode_fini_cpu(cpu);
+	uci->valid = 0;
+	mutex_unlock(&microcode_mutex);
+}
+
+static void collect_cpu_info(int cpu)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+
+	memset(uci, 0, sizeof(*uci));
+	if (!microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig))
+		uci->valid = 1;
+}
+
+static void microcode_resume_cpu(int cpu)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+	struct cpu_signature nsig;
+
+	pr_debug("microcode: CPU%d resumed\n", cpu);
+
+	if (!uci->mc.valid_mc)
+		return;
+
+	/*
+	 * Let's verify that the 'cached' ucode does belong
+	 * to this cpu (a bit of paranoia):
+	 */
+	if (microcode_ops->collect_cpu_info(cpu, &nsig)) {
+		microcode_fini_cpu(cpu);
+		return;
+	}
+
+	if (memcmp(&nsig, &uci->cpu_sig, sizeof(nsig))) {
+		microcode_fini_cpu(cpu);
+		/* Should we look for a new ucode here? */
+		return;
+	}
+
+	microcode_ops->apply_microcode(cpu);
+}
+
+void microcode_update_cpu(int cpu)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+
+	/* We should bind the task to the CPU */
+	BUG_ON(raw_smp_processor_id() != cpu);
+
+	mutex_lock(&microcode_mutex);
+	/*
+	 * Check if the system resume is in progress (uci->valid != NULL),
+	 * otherwise just request a firmware:
+	 */
+	if (uci->valid) {
+		microcode_resume_cpu(cpu);
+	} else {	
+		collect_cpu_info(cpu);
+		if (uci->valid && system_state == SYSTEM_RUNNING)
+			microcode_ops->cpu_request_microcode(cpu);
+	}
+	mutex_unlock(&microcode_mutex);
+}
+
+static void microcode_init_cpu(int cpu)
+{
+	cpumask_t old = current->cpus_allowed;
+
+	set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+	microcode_update_cpu(cpu);
+	set_cpus_allowed_ptr(current, &old);
+}
+
+static int mc_sysdev_add(struct sys_device *sys_dev)
 {
 	int err, cpu = sys_dev->id;
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
@@ -327,16 +389,10 @@ static int __mc_sysdev_add(struct sys_device *sys_dev, int resume)
 	if (err)
 		return err;
 
-	microcode_init_cpu(cpu, resume);
-
+	microcode_init_cpu(cpu);
 	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;
@@ -345,7 +401,7 @@ static int mc_sysdev_remove(struct sys_device *sys_dev)
 		return 0;
 
 	pr_debug("microcode: CPU%d removed\n", cpu);
-	microcode_ops->microcode_fini_cpu(cpu);
+	microcode_fini_cpu(cpu);
 	sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
 	return 0;
 }
@@ -376,33 +432,26 @@ 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_ops->microcode_fini_cpu(cpu);
-		break;
 	case CPU_ONLINE:
-	case CPU_DOWN_FAILED:
-		mc_sysdev_add(sys_dev);
-		break;
 	case CPU_ONLINE_FROZEN:
-		/* System-wide resume is in progress, try to apply microcode */
-		if (microcode_ops->apply_microcode_check_cpu(cpu)) {
-			/* The application of microcode failed */
-			microcode_ops->microcode_fini_cpu(cpu);
-			__mc_sysdev_add(sys_dev, 1);
-			break;
-		}
+		microcode_init_cpu(cpu);
+	case CPU_DOWN_FAILED:
 	case CPU_DOWN_FAILED_FROZEN:
+		pr_debug("microcode: CPU%d added\n", cpu);
 		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:
-		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);
+		pr_debug("microcode: CPU%d removed\n", cpu);
+		break;
+	case CPU_DEAD:
+	case CPU_UP_CANCELED_FROZEN:
+		/* The CPU refused to come up during a system resume */
+		microcode_fini_cpu(cpu);
 		break;
 	}
 	return NOTIFY_OK;

arch/x86/kernel/microcode_amd.c

@@ -59,38 +59,28 @@ MODULE_LICENSE("GPL v2");
 /* serialize access to the physical write */
 static DEFINE_SPINLOCK(microcode_update_lock);
 
-/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
-extern struct mutex (microcode_mutex);
-
 struct equiv_cpu_entry *equiv_cpu_table;
 
-extern struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
-
-static void collect_cpu_info_amd(int cpu)
+static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
 {
 	struct cpuinfo_x86 *c = &cpu_data(cpu);
-	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 
-	/* We should bind the task to the CPU */
-	BUG_ON(raw_smp_processor_id() != cpu);
-	uci->rev = 0;
-	uci->pf = 0;
-	uci->mc.mc_amd = NULL;
-	uci->valid = 1;
+	memset(csig, 0, sizeof(*csig));
 
 	if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 0x10) {
 		printk(KERN_ERR "microcode: CPU%d not a capable AMD processor\n",
 		       cpu);
-		uci->valid = 0;
-		return;
+		return -1;
 	}
 
 	asm volatile("movl %1, %%ecx; rdmsr"
-		     : "=a" (uci->rev)
+		     : "=a" (csig->rev)
 		     : "i" (0x0000008B) : "ecx");
 
 	printk(KERN_INFO "microcode: collect_cpu_info_amd : patch_id=0x%x\n",
-	       uci->rev);
+		csig->rev);
+
+	return 0;
 }
 
 static int get_matching_microcode_amd(void *mc, int cpu)
@@ -119,7 +109,7 @@ static int get_matching_microcode_amd(void *mc, int cpu)
 	if (equiv_cpu_table == NULL) {
 		printk(KERN_INFO "microcode: CPU%d microcode update with "
 		       "version 0x%x (current=0x%x)\n",
-		       cpu, mc_header->patch_id, uci->rev);
+		       cpu, mc_header->patch_id, uci->cpu_sig.rev);
 		goto out;
 	}
 
@@ -185,12 +175,12 @@ static int get_matching_microcode_amd(void *mc, int cpu)
 		pci_dev_put(sb_pci_dev);
 	}
 
-	if (mc_header->patch_id <= uci->rev)
+	if (mc_header->patch_id <= uci->cpu_sig.rev)
 		return 0;
 
 	printk(KERN_INFO "microcode: CPU%d found a matching microcode "
 	       "update with version 0x%x (current=0x%x)\n",
-	       cpu, mc_header->patch_id, uci->rev);
+	       cpu, mc_header->patch_id, uci->cpu_sig.rev);
 
 out:
 	new_mc = vmalloc(UCODE_MAX_SIZE);
@@ -250,9 +240,9 @@ static void apply_microcode_amd(int cpu)
 
 	printk(KERN_INFO "microcode: CPU%d updated from revision "
 	       "0x%x to 0x%x \n",
-	       cpu_num, uci->rev, uci->mc.mc_amd->hdr.patch_id);
+	       cpu_num, uci->cpu_sig.rev, uci->mc.mc_amd->hdr.patch_id);
 
-	uci->rev = rev;
+	uci->cpu_sig.rev = rev;
 }
 
 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
@@ -437,61 +427,18 @@ static int cpu_request_microcode_amd(int cpu)
 	return error;
 }
 
-static int apply_microcode_check_cpu_amd(int cpu)
-{
-	struct cpuinfo_x86 *c = &cpu_data(cpu);
-	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
-	unsigned int rev;
-	cpumask_t old;
-	int err = 0;
-
-	/* Check if the microcode is available */
-	if (!uci->mc.mc_amd)
-		return 0;
-
-	old = current->cpus_allowed;
-	set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
-
-	/* Check if the microcode we have in memory matches the CPU */
-	if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 16)
-		err = -EINVAL;
-
-	if (!err) {
-		asm volatile("movl %1, %%ecx; rdmsr"
-		     : "=a" (rev)
-		     : "i" (0x0000008B) : "ecx");
-
-		if (uci->rev != rev)
-			err = -EINVAL;
-	}
-
-	if (!err)
-		apply_microcode_amd(cpu);
-	else
-		printk(KERN_ERR "microcode: Could not apply microcode to CPU%d:"
-		       " rev=0x%x\n",
-		       cpu,  uci->rev);
-
-	set_cpus_allowed(current, old);
-	return err;
-}
-
 static void microcode_fini_cpu_amd(int cpu)
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 
-	mutex_lock(&microcode_mutex);
-	uci->valid = 0;
 	vfree(uci->mc.mc_amd);
 	uci->mc.mc_amd = NULL;
-	mutex_unlock(&microcode_mutex);
 }
 
 static struct microcode_ops microcode_amd_ops = {
 	.get_next_ucode                   = get_next_ucode_amd,
 	.get_matching_microcode           = get_matching_microcode_amd,
 	.microcode_sanity_check           = NULL,
-	.apply_microcode_check_cpu        = apply_microcode_check_cpu_amd,
 	.cpu_request_microcode            = cpu_request_microcode_amd,
 	.collect_cpu_info                 = collect_cpu_info_amd,
 	.apply_microcode                  = apply_microcode_amd,

arch/x86/kernel/microcode_intel.c

@@ -122,46 +122,37 @@ MODULE_LICENSE("GPL");
 /* serialize access to the physical write to MSR 0x79 */
 static DEFINE_SPINLOCK(microcode_update_lock);
 
-/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
-extern struct mutex microcode_mutex;
-
-extern struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
-
-static void collect_cpu_info(int cpu_num)
+static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
 {
 	struct cpuinfo_x86 *c = &cpu_data(cpu_num);
-	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 	unsigned int val[2];
 
-	/* We should bind the task to the CPU */
-	BUG_ON(raw_smp_processor_id() != cpu_num);
-	uci->pf = uci->rev = 0;
-	uci->mc.mc_intel = NULL;
-	uci->valid = 1;
+	memset(csig, 0, sizeof(*csig));
 
 	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
 	    cpu_has(c, X86_FEATURE_IA64)) {
 		printk(KERN_ERR "microcode: CPU%d not a capable Intel "
 			"processor\n", cpu_num);
-		uci->valid = 0;
-		return;
+		return -1;
 	}
 
-	uci->sig = cpuid_eax(0x00000001);
+	csig->sig = cpuid_eax(0x00000001);
 
 	if ((c->x86_model >= 5) || (c->x86 > 6)) {
 		/* get processor flags from MSR 0x17 */
 		rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
-		uci->pf = 1 << ((val[1] >> 18) & 7);
+		csig->pf = 1 << ((val[1] >> 18) & 7);
 	}
 
 	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], uci->rev);
+	rdmsr(MSR_IA32_UCODE_REV, val[0], csig->rev);
 	pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
-			uci->sig, uci->pf, uci->rev);
+			csig->sig, csig->pf, csig->rev);
+
+	return 0;
 }
 
 static inline int microcode_update_match(int cpu_num,
@@ -169,8 +160,8 @@ static inline int microcode_update_match(int cpu_num,
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 
-	if (!sigmatch(sig, uci->sig, pf, uci->pf)
-		|| mc_header->rev <= uci->rev)
+	if (!sigmatch(sig, uci->cpu_sig.sig, pf, uci->cpu_sig.pf)
+		|| mc_header->rev <= uci->cpu_sig.rev)
 		return 0;
 	return 1;
 }
@@ -289,7 +280,7 @@ static int get_matching_microcode(void *mc, int cpu)
 find:
 	pr_debug("microcode: CPU%d found a matching microcode update with"
 		 " version 0x%x (current=0x%x)\n",
-		 cpu, mc_header->rev, uci->rev);
+		 cpu, mc_header->rev, uci->cpu_sig.rev);
 	new_mc = vmalloc(total_size);
 	if (!new_mc) {
 		printk(KERN_ERR "microcode: error! Can not allocate memory\n");
@@ -335,16 +326,16 @@ static void apply_microcode(int cpu)
 	spin_unlock_irqrestore(&microcode_update_lock, flags);
 	if (val[1] != uci->mc.mc_intel->hdr.rev) {
 		printk(KERN_ERR "microcode: CPU%d update from revision "
-			"0x%x to 0x%x failed\n", cpu_num, uci->rev, val[1]);
+			"0x%x to 0x%x failed\n", cpu_num, uci->cpu_sig.rev, val[1]);
 		return;
 	}
 	printk(KERN_INFO "microcode: CPU%d updated from revision "
 	       "0x%x to 0x%x, date = %04x-%02x-%02x \n",
-		cpu_num, uci->rev, val[1],
+		cpu_num, uci->cpu_sig.rev, val[1],
 		uci->mc.mc_intel->hdr.date & 0xffff,
 		uci->mc.mc_intel->hdr.date >> 24,
 		(uci->mc.mc_intel->hdr.date >> 16) & 0xff);
-	uci->rev = val[1];
+	uci->cpu_sig.rev = val[1];
 }
 
 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
@@ -459,70 +450,18 @@ static int cpu_request_microcode(int cpu)
 	return error;
 }
 
-static int apply_microcode_check_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;
-
-	/* Check if the microcode is available */
-	if (!uci->mc.mc_intel)
-		return 0;
-
-	old = current->cpus_allowed;
-	set_cpus_allowed_ptr(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_ptr(current, &old);
-	return err;
-}
-
 static void microcode_fini_cpu(int cpu)
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 
-	mutex_lock(&microcode_mutex);
-	uci->valid = 0;
 	vfree(uci->mc.mc_intel);
 	uci->mc.mc_intel = NULL;
-	mutex_unlock(&microcode_mutex);
 }
 
 static struct microcode_ops microcode_intel_ops = {
 	.get_next_ucode                   = get_next_ucode,
 	.get_matching_microcode           = get_matching_microcode,
 	.microcode_sanity_check           = microcode_sanity_check,
-	.apply_microcode_check_cpu        = apply_microcode_check_cpu,
 	.cpu_request_microcode            = cpu_request_microcode,
 	.collect_cpu_info                 = collect_cpu_info,
 	.apply_microcode                  = apply_microcode,

include/asm-x86/microcode.h

+#ifndef ASM_X86__MICROCODE_H
+#define ASM_X86__MICROCODE_H
+
 extern int microcode_init(void *opaque, struct module *module);
 extern void microcode_exit(void);
 
+struct cpu_signature;
+
 struct microcode_ops {
 	long (*get_next_ucode)(void **mc, long offset);
 	long (*microcode_get_next_ucode)(void **mc, long offset);
 	int (*get_matching_microcode)(void *mc, int cpu);
-	int (*apply_microcode_check_cpu)(int cpu);
 	int (*microcode_sanity_check)(void *mc);
 	int (*cpu_request_microcode)(int cpu);
-	void (*collect_cpu_info)(int cpu_num);
+	int (*collect_cpu_info)(int cpu_num, struct cpu_signature *csig);
 	void (*apply_microcode)(int cpu);
 	void (*microcode_fini_cpu)(int cpu);
 	void (*clear_patch)(void *data);
@@ -75,13 +79,21 @@ struct microcode_amd {
 	unsigned int mpb[0];
 };
 
-struct ucode_cpu_info {
-	int valid;
+struct cpu_signature {
 	unsigned int sig;
 	unsigned int pf;
 	unsigned int rev;
+};
+
+struct ucode_cpu_info {
+	struct cpu_signature cpu_sig;
+	int valid;
 	union {
 		struct microcode_intel *mc_intel;
 		struct microcode_amd *mc_amd;
+		void *valid_mc;
 	} mc;
 };
+extern struct ucode_cpu_info ucode_cpu_info[];
+
+#endif /* ASM_X86__MICROCODE_H */