I've made some more changes based on the feedback. I figured if the
sysfs entries were removed before the msi_desc structs were deleted
from msi_list then we wouldn't have to worry about synchronization.
How does it look? What's the decision on the directory name?
Thanks,
-- Vinnie
>From 89928bd9145228ed7691c593b4f0369dd12b3929 Mon Sep 17 00:00:00 2001
From: Vincent Rizza <vinnie@xxxxxxx>
Date: Thu, 13 Nov 2008 10:27:33 +1100
Subject: [PATCH] Add sysfs entry that displays MSI-X IRQs
Creates a sysfs entry for each MSI-X vector. The name of the entry is
based on the entry_nr attribute in msi_desc.msi_attrib. The file
contains the MSI-X vector number corresponding to that entry_nr value.
Signed-off-by: Vincent Rizza <vinnie@xxxxxxx>
Signed-off-by: Brett Grandbois <brettg@xxxxxxx>
Signed-off-by: Ken Sandars <ksandars@xxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-pci | 10 +++++
drivers/pci/msi.c | 62 +++++++++++++++++++++++++++++++
include/linux/msi.h | 4 ++
include/linux/pci.h | 1 +
4 files changed, 77 insertions(+), 0 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index ceddcff..9941233 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -9,3 +9,13 @@ Description:
that some devices may have malformatted data. If the
underlying VPD has a writable section then the
corresponding section of this file will be writable.
+
+What: /sys/bus/pci/devices/.../msix_irq/<IRQ vector number>
+Date: November 2008
+Contact: Vincent Rizza <vinnie@xxxxxxx>
+Description:
+ If a pci device uses any MSI-X IRQs a new directory
+ is created called "msix_irq". The directory contains a
+ file for each MSI-X IRQ used. The filename is the number
+ stored in msi_desc.msi_attrib.entry_nr. The files contain
+ the MSI-X vector corresponding to their entry_nr number.
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 74801f7..c2c43df 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -25,6 +25,31 @@
static int pci_msi_enable = 1;
+static ssize_t
+pci_msix_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ /* kobj = msix_dir. The parent kobj is needed to get pci_dev */
+ struct kobject *p_kobj = kobj->parent;
+ struct pci_dev *pdev = to_pci_dev(container_of(p_kobj, struct device,
+ kobj));
+ struct msi_desc *entry;
+ unsigned long msi_index;
+ int ret = 0;
+
+ ret = strict_strtoul(attr->attr.name, 10, &msi_index);
+ if (!ret) {
+ list_for_each_entry(entry, &pdev->msi_list, list) {
+ if (entry->msi_attrib.entry_nr == msi_index) {
+ ret = snprintf(buf, PAGE_SIZE, "%d\n",
+ entry->irq);
+ break;
+ }
+ }
+ }
+
+ return ret;
+}
+
/* Arch hooks */
int __attribute__ ((weak))
@@ -488,10 +513,32 @@ static int msix_capability_init(struct pci_dev *dev,
return avail;
}
+ /* create directory "msix_irq" */
+ dev->msix_dir = kobject_create_and_add("msix_irq", &dev->dev.kobj);
+ if (!dev->msix_dir) {
+ msi_free_irqs(dev);
+ return -ENOMEM;
+ }
+
i = 0;
list_for_each_entry(entry, &dev->msi_list, list) {
entries[i].vector = entry->irq;
set_irq_msi(entry->irq, entry);
+
+ snprintf(entry->msix_fname, sizeof(entry->msix_fname), "%d",
+ entry->msi_attrib.entry_nr);
+ entry->sysfs_entry.attr.name = (const char *) entry->msix_fname;
+ entry->sysfs_entry.attr.mode = 0444;
+ entry->sysfs_entry.show = pci_msix_show;
+
+ ret = sysfs_create_file(dev->msix_dir,
+ &entry->sysfs_entry.attr);
+ if (ret) {
+ /* Using name as a flag during clean-up */
+ entry->sysfs_entry.attr.name = NULL;
+ msi_free_irqs(dev);
+ return ret;
+ }
i++;
}
/* Set MSI-X enabled bits */
@@ -628,6 +675,14 @@ static int msi_free_irqs(struct pci_dev* dev)
list_for_each_entry(entry, &dev->msi_list, list) {
if (entry->irq)
BUG_ON(irq_has_action(entry->irq));
+ /*
+ * Only remove if it's been created. If the attribute's name is
+ * set then this particular "entry" corresponds to a sysfs
+ * file.
+ */
+ if (entry->sysfs_entry.attr.name)
+ sysfs_remove_file(&dev->dev.kobj,
+ &entry->sysfs_entry.attr);
}
arch_teardown_msi_irqs(dev);
@@ -645,6 +700,13 @@ static int msi_free_irqs(struct pci_dev* dev)
kfree(entry);
}
+ /* Also doesn't exist in MSI mode */
+ if (dev->msix_dir) {
+ sysfs_remove_dir(dev->msix_dir);
+ kobject_put(dev->msix_dir);
+ dev->msix_dir = NULL;
+ }
+
return 0;
}
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 8f29392..242e068 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -33,6 +33,10 @@ struct msi_desc {
void __iomem *mask_base;
struct pci_dev *dev;
+ struct kobj_attribute sysfs_entry;
+ /* filename = IRQ */
+ char msix_fname[16];
+
/* Last set MSI message */
struct msi_msg msg;
};
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c75b82b..6b818f7 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -234,6 +234,7 @@ 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 kobject *msix_dir;
#endif
struct pci_vpd *vpd;
};
--
1.5.4.5
