[PATCH][focal/linux-azure] PCI/sysfs: Convert "config" to static attribute
Tim Gardner
tim.gardner at canonical.com
Mon Nov 29 14:31:38 UTC 2021
From: Krzysztof Wilczyński <kw at linux.com>
BugLink: https://bugs.launchpad.net/bugs/1952621
The "config" sysfs attribute allows access to either the legacy (PCI and
PCI-X Mode 1) or the extended (PCI-X Mode 2 and PCIe) device configuration
space. Previously it was dynamically created either when a device was
added (for hot-added devices) or via a late_initcall (for devices present
at boot):
pci_bus_add_devices
pci_bus_add_device
pci_create_sysfs_dev_files
if (!sysfs_initialized)
return
sysfs_create_bin_file # for hot-added devices
pci_sysfs_init # late_initcall
sysfs_initialized = 1
for_each_pci_dev(pdev)
pci_create_sysfs_dev_files(pdev) # for devices present at boot
And dynamically removed when the PCI device is stopped and removed:
pci_stop_bus_device
pci_stop_dev
pci_remove_sysfs_dev_files
sysfs_remove_bin_file
This attribute does not need to be created or removed dynamically, so we
can use a static attribute so the device model takes care of addition and
removal automatically.
Convert "config" to a static attribute and use the .is_bin_visible()
callback to set the correct object size (either 256 bytes or 4 KiB) at
runtime.
The pci_sysfs_init() scheme was added in the pre-git era by
https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/drivers/pci/pci-sysfs.c?id=f6d553444da2
[bhelgaas: commit log]
Suggested-by: Oliver O'Halloran <oohall at gmail.com>
Link: https://lore.kernel.org/r/CAOSf1CHss03DBSDO4PmTtMp0tCEu5kScn704ZEwLKGXQzBfqaA@mail.gmail.com
Link: https://lore.kernel.org/r/20210416205856.3234481-2-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw at linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
(cherry picked from commit e1d3f3268b0e512ceb811dd4765e476626bde71c)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
drivers/pci/pci-sysfs.c | 64 ++++++++++++++++-------------------------
1 file changed, 25 insertions(+), 39 deletions(-)
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index b78835742526b..399f441e81a4c 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -814,6 +814,29 @@ static ssize_t pci_write_config(struct file *filp, struct kobject *kobj,
return count;
}
+static BIN_ATTR(config, 0644, pci_read_config, pci_write_config, 0);
+
+static struct bin_attribute *pci_dev_config_attrs[] = {
+ &bin_attr_config,
+ NULL,
+};
+
+static umode_t pci_dev_config_attr_is_visible(struct kobject *kobj,
+ struct bin_attribute *a, int n)
+{
+ struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+
+ a->size = PCI_CFG_SPACE_SIZE;
+ if (pdev->cfg_size > PCI_CFG_SPACE_SIZE)
+ a->size = PCI_CFG_SPACE_EXP_SIZE;
+
+ return a->attr.mode;
+}
+
+static const struct attribute_group pci_dev_config_attr_group = {
+ .bin_attrs = pci_dev_config_attrs,
+ .is_bin_visible = pci_dev_config_attr_is_visible,
+};
#ifdef HAVE_PCI_LEGACY
/**
@@ -1283,26 +1306,6 @@ static ssize_t pci_read_rom(struct file *filp, struct kobject *kobj,
return count;
}
-static const struct bin_attribute pci_config_attr = {
- .attr = {
- .name = "config",
- .mode = 0644,
- },
- .size = PCI_CFG_SPACE_SIZE,
- .read = pci_read_config,
- .write = pci_write_config,
-};
-
-static const struct bin_attribute pcie_config_attr = {
- .attr = {
- .name = "config",
- .mode = 0644,
- },
- .size = PCI_CFG_SPACE_EXP_SIZE,
- .read = pci_read_config,
- .write = pci_write_config,
-};
-
static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
@@ -1354,16 +1357,9 @@ int __must_check pci_create_sysfs_dev_files(struct pci_dev *pdev)
if (!sysfs_initialized)
return -EACCES;
- if (pdev->cfg_size > PCI_CFG_SPACE_SIZE)
- retval = sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
- else
- retval = sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
- if (retval)
- goto err;
-
retval = pci_create_resource_files(pdev);
if (retval)
- goto err_config_file;
+ goto err;
/* If the device has a ROM, try to expose it in sysfs. */
rom_size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
@@ -1404,11 +1400,6 @@ int __must_check pci_create_sysfs_dev_files(struct pci_dev *pdev)
}
err_resource_files:
pci_remove_resource_files(pdev);
-err_config_file:
- if (pdev->cfg_size > PCI_CFG_SPACE_SIZE)
- sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
- else
- sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
err:
return retval;
}
@@ -1434,12 +1425,6 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
return;
pci_remove_capabilities_sysfs(pdev);
-
- if (pdev->cfg_size > PCI_CFG_SPACE_SIZE)
- sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
- else
- sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
-
pci_remove_resource_files(pdev);
if (pdev->rom_attr) {
@@ -1535,6 +1520,7 @@ static const struct attribute_group pci_dev_group = {
const struct attribute_group *pci_dev_groups[] = {
&pci_dev_group,
+ &pci_dev_config_attr_group,
NULL,
};
--
2.34.1
More information about the kernel-team
mailing list