PCI/sysfs: add per pci device msi[x] irq listing (v5)

This patch adds a per-pci-device subdirectory in sysfs called: /sys/bus/pci/devices/<device>/msi_irqs This sub-directory exports the set of msi vectors allocated by a given pci device, by creating a numbered sub-directory for each vector beneath msi_irqs. For each vector various attributes can be exported. Currently the only attribute is called mode, which tracks the operational mode of that vector (msi vs. msix) Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI/sysfs: add per pci device msi[x] irq listing (v5)
This patch adds a per-pci-device subdirectory in sysfs called: /sys/bus/pci/devices/<device>/msi_irqs This sub-directory exports the set of msi vectors allocated by a given pci device, by creating a numbered sub-directory for each vector beneath msi_irqs. For each vector various attributes can be exported. Currently the only attribute is called mode, which tracks the operational mode of that vector (msi vs. msix) Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Neil Horman · Jesse Barnes
1 parent 8e8da023f5
Showing 4 changed files with 133 additions and 0 deletions Side-by-side Diff
Documentation/ABI/testing/sysfs-bus-pci
drivers/pci/msi.c
include/linux/msi.h
include/linux/pci.h
@@ -66,6 +66,24 @@
 		re-discover previously removed devices.
 		Depends on CONFIG_HOTPLUG.
  
+What:		/sys/bus/pci/devices/.../msi_irqs/
+Date:		September, 2011
+Contact:	Neil Horman <nhorman@tuxdriver.com>
+Description:
+		The /sys/devices/.../msi_irqs directory contains a variable set
+		of sub-directories, with each sub-directory being named after a
+		corresponding msi irq vector allocated to that device.  Each
+		numbered sub-directory N contains attributes of that irq.
+		Note that this directory is not created for device drivers which
+		do not support msi irqs
+
+What:		/sys/bus/pci/devices/.../msi_irqs/<N>/mode
+Date:		September 2011
+Contact:	Neil Horman <nhorman@tuxdriver.com>
+Description:
+		This attribute indicates the mode that the irq vector named by
+		the parent directory is in (msi vs. msix)
+
 What:		/sys/bus/pci/devices/.../remove
 Date:		January 2009
 Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
@@ -323,6 +323,8 @@
 			if (list_is_last(&entry->list, &dev->msi_list))
 				iounmap(entry->mask_base);
 		}
+		kobject_del(&entry->kobj);
+		kobject_put(&entry->kobj);
 		list_del(&entry->list);
 		kfree(entry);
 	}
@@ -403,6 +405,98 @@
 }
 EXPORT_SYMBOL_GPL(pci_restore_msi_state);
  
+
+#define to_msi_attr(obj) container_of(obj, struct msi_attribute, attr)
+#define to_msi_desc(obj) container_of(obj, struct msi_desc, kobj)
+
+struct msi_attribute {
+	struct attribute        attr;
+	ssize_t (*show)(struct msi_desc *entry, struct msi_attribute *attr,
+			char *buf);
+	ssize_t (*store)(struct msi_desc *entry, struct msi_attribute *attr,
+			 const char *buf, size_t count);
+};
+
+static ssize_t show_msi_mode(struct msi_desc *entry, struct msi_attribute *atr,
+			     char *buf)
+{
+	return sprintf(buf, "%s\n", entry->msi_attrib.is_msix ? "msix" : "msi");
+}
+
+static ssize_t msi_irq_attr_show(struct kobject *kobj,
+				 struct attribute *attr, char *buf)
+{
+	struct msi_attribute *attribute = to_msi_attr(attr);
+	struct msi_desc *entry = to_msi_desc(kobj);
+
+	if (!attribute->show)
+		return -EIO;
+
+	return attribute->show(entry, attribute, buf);
+}
+
+static const struct sysfs_ops msi_irq_sysfs_ops = {
+	.show = msi_irq_attr_show,
+};
+
+static struct msi_attribute mode_attribute =
+	__ATTR(mode, S_IRUGO, show_msi_mode, NULL);
+
+
+struct attribute *msi_irq_default_attrs[] = {
+	&mode_attribute.attr,
+	NULL
+};
+
+void msi_kobj_release(struct kobject *kobj)
+{
+	struct msi_desc *entry = to_msi_desc(kobj);
+
+	pci_dev_put(entry->dev);
+}
+
+static struct kobj_type msi_irq_ktype = {
+	.release = msi_kobj_release,
+	.sysfs_ops = &msi_irq_sysfs_ops,
+	.default_attrs = msi_irq_default_attrs,
+};
+
+static int populate_msi_sysfs(struct pci_dev *pdev)
+{
+	struct msi_desc *entry;
+	struct kobject *kobj;
+	int ret;
+	int count = 0;
+
+	pdev->msi_kset = kset_create_and_add("msi_irqs", NULL, &pdev->dev.kobj);
+	if (!pdev->msi_kset)
+		return -ENOMEM;
+
+	list_for_each_entry(entry, &pdev->msi_list, list) {
+		kobj = &entry->kobj;
+		kobj->kset = pdev->msi_kset;
+		pci_dev_get(pdev);
+		ret = kobject_init_and_add(kobj, &msi_irq_ktype, NULL,
+				     "%u", entry->irq);
+		if (ret)
+			goto out_unroll;
+
+		count++;
+	}
+
+	return 0;
+
+out_unroll:
+	list_for_each_entry(entry, &pdev->msi_list, list) {
+		if (!count)
+			break;
+		kobject_del(&entry->kobj);
+		kobject_put(&entry->kobj);
+		count--;
+	}
+	return ret;
+}
+
 /**
  * msi_capability_init - configure device's MSI capability structure
  * @dev: pointer to the pci_dev data structure of MSI device function
@@ -454,6 +548,13 @@
 		return ret;
 	}
  
+	ret = populate_msi_sysfs(dev);
+	if (ret) {
+		msi_mask_irq(entry, mask, ~mask);
+		free_msi_irqs(dev);
+		return ret;
+	}
+
 	/* Set MSI enabled bits	 */
 	pci_intx_for_msi(dev, 0);
 	msi_set_enable(dev, pos, 1);
@@ -574,6 +675,12 @@
  
 	msix_program_entries(dev, entries);
  
+	ret = populate_msi_sysfs(dev);
+	if (ret) {
+		ret = 0;
+		goto error;
+	}
+
 	/* Set MSI-X enabled bits and unmask the function */
 	pci_intx_for_msi(dev, 0);
 	dev->msix_enabled = 1;
@@ -732,6 +839,8 @@
  
 	pci_msi_shutdown(dev);
 	free_msi_irqs(dev);
+	kset_unregister(dev->msi_kset);
+	dev->msi_kset = NULL;
 }
 EXPORT_SYMBOL(pci_disable_msi);
  
@@ -830,6 +939,8 @@
  
 	pci_msix_shutdown(dev);
 	free_msi_irqs(dev);
+	kset_unregister(dev->msi_kset);
+	dev->msi_kset = NULL;
 }
 EXPORT_SYMBOL(pci_disable_msix);
  
 #ifndef LINUX_MSI_H
 #define LINUX_MSI_H
  
+#include <linux/kobject.h>
 #include <linux/list.h>
  
 struct msi_msg {
@@ -44,6 +45,8 @@
  
 	/* Last set MSI message */
 	struct msi_msg msg;
+
+	struct kobject kobj;
 };
  
 /*
@@ -336,6 +336,7 @@
 	struct bin_attribute *res_attr_wc[DEVICE_COUNT_RESOURCE]; /* sysfs file for WC mapping of resources */
 #ifdef CONFIG_PCI_MSI
 	struct list_head msi_list;
+	struct kset *msi_kset;
 #endif
 	struct pci_vpd *vpd;
 #ifdef CONFIG_PCI_ATS
...	...	@@ -66,6 +66,24 @@
66	66	re-discover previously removed devices.
67	67	Depends on CONFIG_HOTPLUG.
68	68
	69	+What: /sys/bus/pci/devices/.../msi_irqs/
	70	+Date: September, 2011
	71	+Contact: Neil Horman <nhorman@tuxdriver.com>
	72	+Description:
	73	+ The /sys/devices/.../msi_irqs directory contains a variable set
	74	+ of sub-directories, with each sub-directory being named after a
	75	+ corresponding msi irq vector allocated to that device. Each
	76	+ numbered sub-directory N contains attributes of that irq.
	77	+ Note that this directory is not created for device drivers which
	78	+ do not support msi irqs
	79	+
	80	+What: /sys/bus/pci/devices/.../msi_irqs/<N>/mode
	81	+Date: September 2011
	82	+Contact: Neil Horman <nhorman@tuxdriver.com>
	83	+Description:
	84	+ This attribute indicates the mode that the irq vector named by
	85	+ the parent directory is in (msi vs. msix)
	86	+
69	87	What: /sys/bus/pci/devices/.../remove
70	88	Date: January 2009
71	89	Contact: Linux PCI developers <linux-pci@vger.kernel.org>
...	...	@@ -323,6 +323,8 @@
323	323	if (list_is_last(&entry->list, &dev->msi_list))
324	324	iounmap(entry->mask_base);
325	325	}
	326	+ kobject_del(&entry->kobj);
	327	+ kobject_put(&entry->kobj);
326	328	list_del(&entry->list);
327	329	kfree(entry);
328	330	}
...	...	@@ -403,6 +405,98 @@
403	405	}
404	406	EXPORT_SYMBOL_GPL(pci_restore_msi_state);
405	407
	408	+
	409	+#define to_msi_attr(obj) container_of(obj, struct msi_attribute, attr)
	410	+#define to_msi_desc(obj) container_of(obj, struct msi_desc, kobj)
	411	+
	412	+struct msi_attribute {
	413	+ struct attribute attr;
	414	+ ssize_t (show)(struct msi_desc entry, struct msi_attribute *attr,
	415	+ char *buf);
	416	+ ssize_t (store)(struct msi_desc entry, struct msi_attribute *attr,
	417	+ const char *buf, size_t count);
	418	+};
	419	+
	420	+static ssize_t show_msi_mode(struct msi_desc entry, struct msi_attribute atr,
	421	+ char *buf)
	422	+{
	423	+ return sprintf(buf, "%s\n", entry->msi_attrib.is_msix ? "msix" : "msi");
	424	+}
	425	+
	426	+static ssize_t msi_irq_attr_show(struct kobject *kobj,
	427	+ struct attribute attr, char buf)
	428	+{
	429	+ struct msi_attribute *attribute = to_msi_attr(attr);
	430	+ struct msi_desc *entry = to_msi_desc(kobj);
	431	+
	432	+ if (!attribute->show)
	433	+ return -EIO;
	434	+
	435	+ return attribute->show(entry, attribute, buf);
	436	+}
	437	+
	438	+static const struct sysfs_ops msi_irq_sysfs_ops = {
	439	+ .show = msi_irq_attr_show,
	440	+};
	441	+
	442	+static struct msi_attribute mode_attribute =
	443	+ __ATTR(mode, S_IRUGO, show_msi_mode, NULL);
	444	+
	445	+
	446	+struct attribute *msi_irq_default_attrs[] = {
	447	+ &mode_attribute.attr,
	448	+ NULL
	449	+};
	450	+
	451	+void msi_kobj_release(struct kobject *kobj)
	452	+{
	453	+ struct msi_desc *entry = to_msi_desc(kobj);
	454	+
	455	+ pci_dev_put(entry->dev);
	456	+}
	457	+
	458	+static struct kobj_type msi_irq_ktype = {
	459	+ .release = msi_kobj_release,
	460	+ .sysfs_ops = &msi_irq_sysfs_ops,
	461	+ .default_attrs = msi_irq_default_attrs,
	462	+};
	463	+
	464	+static int populate_msi_sysfs(struct pci_dev *pdev)
	465	+{
	466	+ struct msi_desc *entry;
	467	+ struct kobject *kobj;
	468	+ int ret;
	469	+ int count = 0;
	470	+
	471	+ pdev->msi_kset = kset_create_and_add("msi_irqs", NULL, &pdev->dev.kobj);
	472	+ if (!pdev->msi_kset)
	473	+ return -ENOMEM;
	474	+
	475	+ list_for_each_entry(entry, &pdev->msi_list, list) {
	476	+ kobj = &entry->kobj;
	477	+ kobj->kset = pdev->msi_kset;
	478	+ pci_dev_get(pdev);
	479	+ ret = kobject_init_and_add(kobj, &msi_irq_ktype, NULL,
	480	+ "%u", entry->irq);
	481	+ if (ret)
	482	+ goto out_unroll;
	483	+
	484	+ count++;
	485	+ }
	486	+
	487	+ return 0;
	488	+
	489	+out_unroll:
	490	+ list_for_each_entry(entry, &pdev->msi_list, list) {
	491	+ if (!count)
	492	+ break;
	493	+ kobject_del(&entry->kobj);
	494	+ kobject_put(&entry->kobj);
	495	+ count--;
	496	+ }
	497	+ return ret;
	498	+}
	499	+
406	500	/**
407	501	* msi_capability_init - configure device's MSI capability structure
408	502	* @dev: pointer to the pci_dev data structure of MSI device function
...	...	@@ -454,6 +548,13 @@
454	548	return ret;
455	549	}
456	550
	551	+ ret = populate_msi_sysfs(dev);
	552	+ if (ret) {
	553	+ msi_mask_irq(entry, mask, ~mask);
	554	+ free_msi_irqs(dev);
	555	+ return ret;
	556	+ }
	557	+
457	558	/* Set MSI enabled bits */
458	559	pci_intx_for_msi(dev, 0);
459	560	msi_set_enable(dev, pos, 1);
...	...	@@ -574,6 +675,12 @@
574	675
575	676	msix_program_entries(dev, entries);
576	677
	678	+ ret = populate_msi_sysfs(dev);
	679	+ if (ret) {
	680	+ ret = 0;
	681	+ goto error;
	682	+ }
	683	+
577	684	/* Set MSI-X enabled bits and unmask the function */
578	685	pci_intx_for_msi(dev, 0);
579	686	dev->msix_enabled = 1;
...	...	@@ -732,6 +839,8 @@
732	839
733	840	pci_msi_shutdown(dev);
734	841	free_msi_irqs(dev);
	842	+ kset_unregister(dev->msi_kset);
	843	+ dev->msi_kset = NULL;
735	844	}
736	845	EXPORT_SYMBOL(pci_disable_msi);
737	846
...	...	@@ -830,6 +939,8 @@
830	939
831	940	pci_msix_shutdown(dev);
832	941	free_msi_irqs(dev);
	942	+ kset_unregister(dev->msi_kset);
	943	+ dev->msi_kset = NULL;
833	944	}
834	945	EXPORT_SYMBOL(pci_disable_msix);
835	946
1	1	#ifndef LINUX_MSI_H
2	2	#define LINUX_MSI_H
3	3
	4	+#include <linux/kobject.h>
4	5	#include <linux/list.h>
5	6
6	7	struct msi_msg {
...	...	@@ -44,6 +45,8 @@
44	45
45	46	/* Last set MSI message */
46	47	struct msi_msg msg;
	48	+
	49	+ struct kobject kobj;
47	50	};
48	51
49	52	/*
...	...	@@ -336,6 +336,7 @@
336	336	struct bin_attribute res_attr_wc[DEVICE_COUNT_RESOURCE]; / sysfs file for WC mapping of resources */
337	337	#ifdef CONFIG_PCI_MSI
338	338	struct list_head msi_list;
	339	+ struct kset *msi_kset;
339	340	#endif
340	341	struct pci_vpd *vpd;
341	342	#ifdef CONFIG_PCI_ATS