I've made quite a few changes again, got rid of the kobject and used
an attribute group. I also tried your tests Matthew and didn't oops
on either of them. I also wrote some code that open()'ed the file then
continuously read() from the file while I rmmod'ed the driver. After
the driver was removed the read() call was returning bad file
descriptor errors until I modprobe'ed the driver back in. I ran that
test for about 1 hour and the behaviour was the same each time.
Thanks,
-- Vinnie
>From 96ce20b78031515274f6f6e67fc02110bd94f15f 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 IRQ. The name of the entry is
based on the entry_nr attribute in msi_desc.msi_attrib. The file
contains the MSI-X IRQ number corresponding to that entry_nr value.
Signed-off-by: Vincent Rizza <vinnie@xxxxxxx>
Signed-off-by: Brett Grandbois <brettg@xxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-pci | 10 +++++
drivers/pci/msi.c | 60 +++++++++++++++++++++++++++++++
include/linux/msi.h | 5 +++
include/linux/pci.h | 2 +
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..9b868d4 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/.../irqs/<MSI-X entry_nr>
+Date: November 2008
+Contact: Vincent Rizza <vinnie@xxxxxxx>
+Description:
+ If a pci device uses any MSI-X IRQs a new directory is
+ created called "irqs". 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 IRQ corresponding to their entry_nr number.
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 74801f7..58991dc 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -25,6 +25,28 @@
static int pci_msi_enable = 1;
+static ssize_t
+pci_msix_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ 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))
@@ -494,6 +516,37 @@ static int msix_capability_init(struct pci_dev *dev,
set_irq_msi(entry->irq, entry);
i++;
}
+
+ dev->msix_dir.attrs = kzalloc(sizeof(struct attribute *) * (i + 1),
+ GFP_KERNEL);
+ if (!dev->msix_dir.attrs) {
+ msi_free_irqs(dev);
+ return -ENOMEM;
+ }
+
+ i = 0;
+ list_for_each_entry(entry, &dev->msi_list, list) {
+ 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;
+
+ dev->msix_dir.attrs[i] = &entry->sysfs_entry.attr;
+ i++;
+ }
+ /* NULL terminate to mark end of array */
+ dev->msix_dir.attrs[i] = NULL;
+
+ snprintf(dev->msix_gname, sizeof(dev->msix_gname), "%s", "irqs");
+ dev->msix_dir.name = (const char *) dev->msix_gname;
+ ret = sysfs_create_group(&dev->dev.kobj, &dev->msix_dir);
+ if (ret) {
+ dev->msix_dir.name = NULL;
+ msi_free_irqs(dev);
+ return ret;
+ }
+
/* Set MSI-X enabled bits */
pci_intx_for_msi(dev, 0);
msix_set_enable(dev, 1);
@@ -625,6 +678,13 @@ static int msi_free_irqs(struct pci_dev* dev)
{
struct msi_desc *entry, *tmp;
+ if (dev->msix_dir.attrs) {
+ if (dev->msix_dir.name)
+ sysfs_remove_group(&dev->dev.kobj, &dev->msix_dir);
+
+ kfree(dev->msix_dir.attrs);
+ }
+
list_for_each_entry(entry, &dev->msi_list, list) {
if (entry->irq)
BUG_ON(irq_has_action(entry->irq));
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 8f29392..9de7d9d 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -2,6 +2,7 @@
#define LINUX_MSI_H
#include <linux/list.h>
+#include <linux/device.h>
struct msi_msg {
u32 address_lo; /* low 32 bits of msi message address */
@@ -33,6 +34,10 @@ struct msi_desc {
void __iomem *mask_base;
struct pci_dev *dev;
+ struct device_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..6b5e393 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -234,6 +234,8 @@ 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 attribute_group msix_dir;
+ char msix_gname[8];
#endif
struct pci_vpd *vpd;
};
--
1.5.4.5
