The original form of this patch was written by Matthew Wilcox,
and was enhanced to include links from the sysfs slots/ directory
pointing back at the device functions.
Cc: willy@xxxxxxxxxxxxxxx
Signed-off-by: Alex Chiang <achiang@xxxxxx>
---
Not sure why I've been sitting on this patch for so long, but
I think it would be a useful thing to have upstream.
Documentation/ABI/testing/sysfs-bus-pci | 40 ++++++++++++++++++++++++++
drivers/pci/pci-sysfs.c | 37 ++++++++++++++++++++++++
drivers/pci/slot.c | 48 ++++++++++++++++++++++++++++++++
3 files changed, 125 insertions(+)
---
diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 25be325..428676c 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -133,6 +133,46 @@ Description:
The symbolic link points to the PCI device sysfs entry of the
Physical Function this device associates with.
+
+What: /sys/bus/pci/slots/...
+Date: April 2005 (possibly older)
+KernelVersion: 2.6.12 (possibly older)
+Contact: linux-pci@xxxxxxxxxxxxxxx
+Description:
+ When the appropriate driver is loaded, it will create a
+ directory per claimed physical PCI slot in
+ /sys/bus/pci/slots/. The names of these directories are
+ specific to the driver, which in turn, are specific to the
+ platform, but in general, should match the label on the
+ machine's physical chassis.
+
+ The drivers that can create slot directories include the
+ PCI hotplug drivers, and as of 2.6.27, the pci_slot driver.
+
+ The slot directories contain, at a minimum, a file named
+ 'address' which contains the PCI bus:device:function tuple.
+ Other files may appear as well, but are specific to the
+ driver.
+
+What: /sys/bus/pci/slots/.../function[0-7]
+Date: March 2010
+KernelVersion: 2.6.35
+Contact: linux-pci@xxxxxxxxxxxxxxx
+Description:
+ If PCI slot directories (as described above) are created,
+ and the physical slot is actually populated with a device,
+ symbolic links in the slot directory pointing to the
+ device's PCI functions are created as well.
+
+What: /sys/bus/pci/devices/.../slot
+Date: March 2010
+KernelVersion: 2.6.35
+Contact: linux-pci@xxxxxxxxxxxxxxx
+Description:
+ If PCI slot directories (as described above) are created,
+ a symbolic link pointing to the slot directory will be
+ created as well.
+
What: /sys/bus/pci/slots/.../module
Date: June 2009
Contact: linux-pci@xxxxxxxxxxxxxxx
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 807224e..d234234 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1006,6 +1006,39 @@ error:
return retval;
}
+static void pci_remove_slot_links(struct pci_dev *dev)
+{
+ char func[10];
+ struct pci_slot *slot;
+
+ sysfs_remove_link(&dev->dev.kobj, "slot");
+ list_for_each_entry(slot, &dev->bus->slots, list) {
+ if (slot->number != PCI_SLOT(dev->devfn))
+ continue;
+ snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
+ sysfs_remove_link(&slot->kobj, func);
+ }
+}
+
+static int pci_create_slot_links(struct pci_dev *dev)
+{
+ int result = 0;
+ char func[10];
+ struct pci_slot *slot;
+
+ list_for_each_entry(slot, &dev->bus->slots, list) {
+ if (slot->number != PCI_SLOT(dev->devfn))
+ continue;
+ result = sysfs_create_link(&dev->dev.kobj, &slot->kobj, "slot");
+ if (result)
+ goto out;
+ snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
+ result = sysfs_create_link(&slot->kobj, &dev->dev.kobj, func);
+ }
+out:
+ return result;
+}
+
int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
{
int retval;
@@ -1067,6 +1100,8 @@ int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
if (retval)
goto err_vga_file;
+ pci_create_slot_links(pdev);
+
return 0;
err_vga_file:
@@ -1116,6 +1151,8 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
if (!sysfs_initialized)
return;
+ pci_remove_slot_links(pdev);
+
pci_remove_capabilities_sysfs(pdev);
if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index 49c9e6c..a8e22c6 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -96,6 +96,50 @@ static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
return bus_speed_read(slot->bus->cur_bus_speed, buf);
}
+static void remove_sysfs_files(struct pci_slot *slot)
+{
+ char func[10];
+ struct list_head *tmp;
+
+ list_for_each(tmp, &slot->bus->devices) {
+ struct pci_dev *dev = pci_dev_b(tmp);
+ if (PCI_SLOT(dev->devfn) != slot->number)
+ continue;
+ sysfs_remove_link(&dev->dev.kobj, "slot");
+
+ snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
+ sysfs_remove_link(&slot->kobj, func);
+ }
+}
+
+static int create_sysfs_files(struct pci_slot *slot)
+{
+ int result;
+ char func[10];
+ struct list_head *tmp;
+
+ list_for_each(tmp, &slot->bus->devices) {
+ struct pci_dev *dev = pci_dev_b(tmp);
+ if (PCI_SLOT(dev->devfn) != slot->number)
+ continue;
+
+ result = sysfs_create_link(&dev->dev.kobj, &slot->kobj, "slot");
+ if (result)
+ goto fail;
+
+ snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
+ result = sysfs_create_link(&slot->kobj, &dev->dev.kobj, func);
+ if (result)
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ remove_sysfs_files(slot);
+ return result;
+}
+
static void pci_slot_release(struct kobject *kobj)
{
struct pci_dev *dev;
@@ -108,6 +152,8 @@ static void pci_slot_release(struct kobject *kobj)
if (PCI_SLOT(dev->devfn) == slot->number)
dev->slot = NULL;
+ remove_sysfs_files(slot);
+
list_del(&slot->list);
kfree(slot);
@@ -299,6 +345,8 @@ placeholder:
INIT_LIST_HEAD(&slot->list);
list_add(&slot->list, &parent->slots);
+ create_sysfs_files(slot);
+
list_for_each_entry(dev, &parent->devices, bus_list)
if (PCI_SLOT(dev->devfn) == slot_nr)
dev->slot = slot;
--
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