[PATCH 4/5] PCI: Add max_vfs in sysfs per pci device where supports

Yinghai Lu
2012-10-03T17:52:09Z

only pci device that support sriov will have max_vfs show up in /sys

when user set value in /sys, driver ops set_max_vfs will be called to enable
VF there.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
drivers/pci/pci-sysfs.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/pci.h | 1 +
2 files changed, 52 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index fbbb97f..9b6f409 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -458,6 +458,52 @@ boot_vga_show(struct device *dev, struct device_attribute *attr, char *buf)
}
struct device_attribute vga_attr = __ATTR_RO(boot_vga);

+static ssize_t
+max_vfs_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ return sprintf(buf, "%u\n", pdev->max_vfs);
+}
+
+static void max_vfs_callback(struct device *dev)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ mutex_lock(&pci_remove_rescan_mutex);
+ if (pdev->is_added && dev->driver) {
+ struct pci_driver *pdrv;
+
+ pdrv = to_pci_driver(dev->driver);
+ if (pdrv->set_max_vfs)
+ pdrv->set_max_vfs(pdev);
+
+ }
+ mutex_unlock(&pci_remove_rescan_mutex);
+}
+static ssize_t
+max_vfs_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned long val;
+ int err;
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ if (kstrtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ pdev->max_vfs = val;
+
+ err = device_schedule_callback(dev, max_vfs_callback);
+
+ if (err)
+ return err;
+
+ return count;
+}
+struct device_attribute max_vfs_attr =
+ __ATTR(max_vfs, 0644, max_vfs_show, max_vfs_store);
+
static void
pci_config_pm_runtime_get(struct pci_dev *pdev)
{
@@ -1405,6 +1451,7 @@ late_initcall(pci_sysfs_init);

static struct attribute *pci_dev_dev_attrs[] = {
&vga_attr.attr,
+ &max_vfs_attr.attr,
NULL,
};

@@ -1418,6 +1465,10 @@ static umode_t pci_dev_attrs_are_visible(struct kobject *kobj,
if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
return 0;

+ if (a == &max_vfs_attr.attr)
+ if (!pdev->is_physfn)
+ return 0;
+
return a->mode;
}

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7d70a5e..f7423d4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -335,6 +335,7 @@ struct pci_dev {
unsigned int broken_intx_masking:1;
unsigned int io_window_1k:1; /* Intel P2P bridge 1K I/O windows */
pci_dev_flags_t dev_flags;
+ unsigned int max_vfs;
atomic_t enable_cnt; /* pci_enable_device has been called */

u32 saved_config_space[16]; /* config space saved at suspend time */
--
1.7.7