| Message ID | 20211129143138.19190-2-tim.gardner@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [focal/linux-azure] PCI/sysfs: Convert "config" to static attribute | expand |
On Mon, Nov 29, 2021 at 07:31:38AM -0700, Tim Gardner wrote: > From: Krzysztof Wilczyński <kw@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@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@linux.com> > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> > (cherry picked from commit e1d3f3268b0e512ceb811dd4765e476626bde71c) > Signed-off-by: Tim Gardner <tim.gardner@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 Upstream, clean cherry-pick. Restricted to linux-azure and tested. Cascardo.
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, };