From da8d1c8ba4dcb16d60be54b233deca9a7cac98dc Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Thu, 6 Oct 2011 14:08:18 -0400 Subject: [PATCH] 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//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 Signed-off-by: Jesse Barnes --- Documentation/ABI/testing/sysfs-bus-pci | 18 ++++ drivers/pci/msi.c | 111 ++++++++++++++++++++++++ include/linux/msi.h | 3 + include/linux/pci.h | 1 + 4 files changed, 133 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index 349ecf26ce10..34f51100f029 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -66,6 +66,24 @@ Description: re-discover previously removed devices. Depends on CONFIG_HOTPLUG. +What: /sys/bus/pci/devices/.../msi_irqs/ +Date: September, 2011 +Contact: Neil Horman +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//mode +Date: September 2011 +Contact: Neil Horman +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 diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 0e6d04d7ba4f..e6b6b9c67023 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -323,6 +323,8 @@ static void free_msi_irqs(struct pci_dev *dev) 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 @@ void pci_restore_msi_state(struct pci_dev *dev) } 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 @@ static int msi_capability_init(struct pci_dev *dev, int nvec) 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 @@ static int msix_capability_init(struct pci_dev *dev, 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 @@ void pci_disable_msi(struct pci_dev *dev) 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 @@ void pci_disable_msix(struct pci_dev *dev) pci_msix_shutdown(dev); free_msi_irqs(dev); + kset_unregister(dev->msi_kset); + dev->msi_kset = NULL; } EXPORT_SYMBOL(pci_disable_msix); diff --git a/include/linux/msi.h b/include/linux/msi.h index 05acced439a3..ce93a341337d 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -1,6 +1,7 @@ #ifndef LINUX_MSI_H #define LINUX_MSI_H +#include #include struct msi_msg { @@ -44,6 +45,8 @@ struct msi_desc { /* Last set MSI message */ struct msi_msg msg; + + struct kobject kobj; }; /* diff --git a/include/linux/pci.h b/include/linux/pci.h index 7cda65b5f798..84225c756bd1 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -336,6 +336,7 @@ struct pci_dev { 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 -- 2.34.1