[PATCH 9/8] CPU: Introduce ARCH_HAS_CPU_AUTOPROBE and X86 parts

[Thomas Renninger]

On Tuesday, December 20, 2011 12:46:34 AM Andi Kleen wrote:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> 
> Don't try to describe the actual models for now.
> 
...
> +static const struct x86_cpu_id microcode_id[] = {
> +#ifdef CONFIG_MICROCODE_INTEL
> +       { X86_VENDOR_INTEL, X86_VENDOR_ANY, X86_MODEL_ANY, },
X86_VENDOR_ANY -> X86_FAMILY_ANY
> +#endif
> +#ifdef CONFIG_MICROCODE_AMD
> +       { X86_VENDOR_AMD, X86_VENDOR_ANY, X86_MODEL_ANY, },
X86_VENDOR_ANY -> X86_FAMILY_ANY

Otherwise the patchset worked for me as expected and
I got quite some (all expected?) drivers autoloaded on a
recent CPU as soon as I loaded the cpuid driver:

powernow_k8
mperf
crc32c_intel
ghash_clmulni_intel
aesni_intel
cryptd
aes_x86_64
microcode

Tested-by: Thomas Renninger <trenn@xxxxxxx>


Additionally I adopted the "use cpuid because cpu is a sysdev device"
approach to make use of the cpu device object (after Kay's "removal
of sysdev" patches).

Kay's and Andi's patches do not conflict and can go in together.
As soon as both are in, this on top patch cleans up X86 autoprobing
to use the cpu device object (instead of cpuid driver):

---
CPU: Introduce ARCH_HAS_CPU_AUTOPROBE and X86 parts

This patch is based on Andi Kleen's work:
Implement autoprobing/loading of modules serving CPU
specific features (x86cpu autoloading).

And Kay Siever's work to get rid of sysdev cpu structures
and making use of struct device instead.

Signed-off-by: Thomas Renninger <trenn@xxxxxxx>
CC: ak@xxxxxxxxxxxxxxx
CC: kay.sievers@xxxxxxxx
CC: hpa@xxxxxxxxx
CC: davej@xxxxxxxxxx
CC: kay.sievers@xxxxxxxx
CC: axboe@xxxxxxxxx
CC: hpa@xxxxxxxxx
CC: herbert@xxxxxxxxxxxxxxxxxxx
CC: ying.huang@xxxxxxxxx
CC: lenb@xxxxxxxxxx

---
 arch/x86/Kconfig            |    3 ++
 arch/x86/kernel/cpu/match.c |   43 ++++++++++++++++++++++++++++++++
 arch/x86/kernel/cpuid.c     |   58 --------------------------------------------
 drivers/base/cpu.c          |   11 ++++++++
 include/linux/cpu.h         |    7 +++++
 5 files changed, 65 insertions(+), 57 deletions(-)

Index: linux-3.2-rc6-master/arch/x86/kernel/cpuid.c
===================================================================
--- linux-3.2-rc6-master.orig/arch/x86/kernel/cpuid.c
+++ linux-3.2-rc6-master/arch/x86/kernel/cpuid.c
@@ -40,7 +40,6 @@
 #include <linux/notifier.h>
 #include <linux/uaccess.h>
 #include <linux/gfp.h>
-#include <linux/slab.h>
 
 #include <asm/processor.h>
 #include <asm/msr.h>
@@ -139,56 +138,13 @@ static const struct file_operations cpui
 	.open = cpuid_open,
 };
 
-static ssize_t print_cpu_modalias(struct device *dev,
-				  struct device_attribute *attr,
-				  char *bufptr)
-{
-	int size = PAGE_SIZE;
-	int i, n;
-	char *buf = bufptr;
-
-	n = snprintf(buf, size, "x86cpu:vendor:%04x:family:%04x:model:%04x:feature:",
-		boot_cpu_data.x86_vendor,
-		boot_cpu_data.x86,
-		boot_cpu_data.x86_model);
-	size -= n;
-	buf += n;
-	size -= 2;
-	for (i = 0; i < NCAPINTS*32; i++) {
-		if (boot_cpu_has(i)) {
-			n = snprintf(buf, size, ",%04x", i);
-			if (n < 0) {
-				WARN(1, "x86 features overflow page\n");
-				break;
-			}
-			size -= n;
-			buf += n;
-		}
-	}
-	*buf++ = ',';
-	*buf++ = '\n';
-	return buf - bufptr;
-}
-
-static DEVICE_ATTR(modalias, 0444, print_cpu_modalias, NULL);
-
 static __cpuinit int cpuid_device_create(int cpu)
 {
 	struct device *dev;
-	int err;
 
 	dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu), NULL,
 			    "cpu%d", cpu);
-	if (IS_ERR(dev))
-		return PTR_ERR(dev);
-
-	err = device_create_file(dev, &dev_attr_modalias);
-	if (err) {
-		/* keep device around on error. attribute is optional. */
-		err = 0;
-	}
-
-	return 0;
+	return IS_ERR(dev) ? PTR_ERR(dev) : 0;
 }
 
 static void cpuid_device_destroy(int cpu)
@@ -226,17 +182,6 @@ static char *cpuid_devnode(struct device
 	return kasprintf(GFP_KERNEL, "cpu/%u/cpuid", MINOR(dev->devt));
 }
 
-static int cpuid_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
-{
-	char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (buf) {
-		print_cpu_modalias(NULL, NULL, buf);
-		add_uevent_var(env, "MODALIAS=%s", buf);
-		kfree(buf);
-	}
-	return 0;
-}
-
 static int __init cpuid_init(void)
 {
 	int i, err = 0;
@@ -255,7 +200,6 @@ static int __init cpuid_init(void)
 		goto out_chrdev;
 	}
 	cpuid_class->devnode = cpuid_devnode;
-	cpuid_class->dev_uevent = cpuid_dev_uevent;
 	for_each_online_cpu(i) {
 		err = cpuid_device_create(i);CPU: Introduce ARCH_HAS_CPU_AUTOPROBE and X86 parts
 		if (err != 0)
Index: linux-3.2-rc6-master/arch/x86/Kconfig
===================================================================
--- linux-3.2-rc6-master.orig/arch/x86/Kconfig
+++ linux-3.2-rc6-master/arch/x86/Kconfig
@@ -185,6 +185,9 @@ config ARCH_HAS_DEFAULT_IDLE
 config ARCH_HAS_CACHE_LINE_SIZE
 	def_bool y
 
+config ARCH_HAS_CPU_AUTOPROBE
+	def_bool y
+
 config HAVE_SETUP_PER_CPU_AREA
 	def_bool y
 
Index: linux-3.2-rc6-master/drivers/base/cpu.c
===================================================================
--- linux-3.2-rc6-master.orig/drivers/base/cpu.c
+++ linux-3.2-rc6-master/drivers/base/cpu.c
@@ -10,6 +10,7 @@
 #include <linux/device.h>
 #include <linux/node.h>
 #include <linux/gfp.h>
+#include <linux/slab.h>
 
 #include "base.h"
 
@@ -221,6 +222,9 @@ int __cpuinit register_cpu(struct cpu *c
 	cpu->node_id = cpu_to_node(num);
 	cpu->dev.id = num;
 	cpu->dev.bus = &cpu_subsys;
+#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
+	cpu->dev.bus->uevent = arch_cpu_uevent;
+#endif
 	error = device_register(&cpu->dev);
 	if (!error && cpu->hotpluggable)
 		register_cpu_control(cpu);
@@ -245,6 +249,10 @@ struct device *get_cpu_device(unsigned c
 }
 EXPORT_SYMBOL_GPL(get_cpu_device);
 
+#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
+static DEVICE_ATTR(modalias, 0444, arch_print_cpu_modalias, NULL);
+#endif
+
 static struct attribute *cpu_root_attrs[] = {
 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 	&dev_attr_probe.attr,
@@ -255,6 +263,9 @@ static struct attribute *cpu_root_attrs[
 	&cpu_attrs[2].attr.attr,
 	&dev_attr_kernel_max.attr,
 	&dev_attr_offline.attr,
+#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
+	&dev_attr_modalias.attr,
+#endif
 	NULL
 };
 
Index: linux-3.2-rc6-master/arch/x86/kernel/cpu/match.c
===================================================================
--- linux-3.2-rc6-master.orig/arch/x86/kernel/cpu/match.c
+++ linux-3.2-rc6-master/arch/x86/kernel/cpu/match.c
@@ -2,6 +2,7 @@
 #include <asm/processor.h>
 #include <linux/cpu.h>
 #include <linux/module.h>
+#include <linux/slab.h>
 
 /**
  * x86_match_cpu - match current CPU again an array of x86_cpu_ids
@@ -46,3 +47,45 @@ const struct x86_cpu_id *x86_match_cpu(c
 	return NULL;
 }
 EXPORT_SYMBOL(x86_match_cpu);
+
+ssize_t arch_print_cpu_modalias(struct device *dev,
+				struct device_attribute *attr,
+				char *bufptr)
+{
+	int size = PAGE_SIZE;
+	int i, n;
+	char *buf = bufptr;
+
+	n = snprintf(buf, size, "x86cpu:vendor:%04x:family:%04x:model:%04x:feature:",
+		boot_cpu_data.x86_vendor,
+		boot_cpu_data.x86,
+		boot_cpu_data.x86_model);
+	size -= n;
+	buf += n;
+	size -= 2;
+	for (i = 0; i < NCAPINTS*32; i++) {
+		if (boot_cpu_has(i)) {
+			n = snprintf(buf, size, ",%04x", i);
+			if (n < 0) {
+				WARN(1, "x86 features overflow page\n");
+				break;
+			}
+			size -= n;
+			buf += n;
+		}
+	}
+	*buf++ = ',';
+	*buf++ = '\n';
+	return buf - bufptr;
+}
+
+int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (buf) {
+		arch_print_cpu_modalias(NULL, NULL, buf);
+		add_uevent_var(env, "MODALIAS=%s", buf);
+		kfree(buf);
+	}
+	return 0;
+}
Index: linux-3.2-rc6-master/include/linux/cpu.h
===================================================================
--- linux-3.2-rc6-master.orig/include/linux/cpu.h
+++ linux-3.2-rc6-master/include/linux/cpu.h
@@ -43,6 +43,13 @@ extern ssize_t arch_cpu_release(const ch
 #endif
 struct notifier_block;
 
+#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
+extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env);
+extern ssize_t arch_print_cpu_modalias(struct device *dev,
+				       struct device_attribute *attr,
+				       char *bufptr);
+#endif
+
 /*
  * CPU notifier priorities.
  */
--
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