| Message ID | 20230904054329.865151-2-alistair.francis@wdc.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | [v7,1/3] PCI/DOE: Rename DOE protocol to feature | expand |
On Mon, 4 Sep 2023 15:43:28 +1000 Alistair Francis <alistair23@gmail.com> wrote: > The PCIe 6 specification added support for the Data Object Exchange (DOE). > When DOE is supported the Discovery Data Object Protocol must be > implemented. The protocol allows a requester to obtain information about > the other DOE features supported by the device. > > The kernel is already querying the DOE features supported and cacheing > the values. This patch exposes the values via sysfs. This will allow > userspace to determine which DOE features are supported by the PCIe > device. > > By exposing the information to userspace tools like lspci can relay the > information to users. By listing all of the supported features we can > allow userspace to parse and support the list, which might include > vendor specific features as well as yet to be supported features. > > Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Hi Alistair A few minor things inline. Thanks, Jonathan > --- > v7: > - Fixup the #ifdefs to keep the test robot happy > v6: > - Use "feature" instead of protocol > - Don't use any devm_* functions > - Add two more patches to the series > v5: > - Return the file name as the file contents > - Code cleanups and simplifications > v4: > - Fixup typos in the documentation > - Make it clear that the file names contain the information > - Small code cleanups > - Remove most #ifdefs > - Remove extra NULL assignment > v3: > - Expose each DOE feature as a separate file > v2: > - Add documentation > - Code cleanups > > This patch will create a doe_features directory for all > PCIe devies. This should be fixed by a pending sysfs fixup > patch. > > Documentation/ABI/testing/sysfs-bus-pci | 12 +++ > drivers/pci/doe.c | 111 ++++++++++++++++++++++++ > drivers/pci/pci-sysfs.c | 10 +++ > drivers/pci/pci.h | 3 + > include/linux/pci-doe.h | 1 + > 5 files changed, 137 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci > index ecf47559f495..e999e78cc2d5 100644 > --- a/Documentation/ABI/testing/sysfs-bus-pci > +++ b/Documentation/ABI/testing/sysfs-bus-pci > @@ -500,3 +500,15 @@ Description: > console drivers from the device. Raw users of pci-sysfs > resourceN attributes must be terminated prior to resizing. > Success of the resizing operation is not guaranteed. > + > +What: /sys/bus/pci/devices/.../doe_features > +Date: August 2023 > +Contact: Linux PCI developers <linux-pci@vger.kernel.org> > +Description: > + This directory contains a list of the supported > + Data Object Exchange (DOE) features. The feature values are in > + the file name. The contents of each file are the same as the > + name. > + The value comes from the device and specifies the vendor and > + data object type supported. The lower byte is the data object > + type and the next two bytes are the vendor ID. Given we already have a few defined, maybe an example would be useful here or a statement of the format > diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c > index 047be8c9d191..69cd391dd120 100644 > --- a/drivers/pci/doe.c > +++ b/drivers/pci/doe.c > @@ -47,6 +47,7 @@ > * @wq: Wait queue for work item > * @work_queue: Queue of pci_doe_work items > * @flags: Bit array of PCI_DOE_FLAG_* flags > + * @sysfs_attrs: Array of sysfs device attributes > */ > struct pci_doe_mb { > struct pci_dev *pdev; > @@ -56,6 +57,10 @@ struct pci_doe_mb { > wait_queue_head_t wq; > struct workqueue_struct *work_queue; > unsigned long flags; > + > +#ifdef CONFIG_SYSFS > + struct device_attribute *sysfs_attrs; > +#endif > }; > > struct pci_doe_feature { > @@ -92,6 +97,112 @@ struct pci_doe_task { > struct pci_doe_mb *doe_mb; > }; > > +#ifdef CONFIG_SYSFS > +static umode_t pci_doe_sysfs_attr_is_visible(struct kobject *kobj, > + struct attribute *a, int n) > +{ > + struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj)); > + struct pci_doe_mb *doe_mb; > + unsigned long index, j; > + void *entry; > + > + xa_for_each(&pdev->doe_mbs, index, doe_mb) { > + xa_for_each(&doe_mb->prots, j, entry) > + return a->mode; > + } > + > + return 0; > +} > + > +static struct attribute *pci_dev_doe_feature_attrs[] = { > + NULL, > +}; > + > +const struct attribute_group pci_dev_doe_feature_group = { > + .name = "doe_features", > + .attrs = pci_dev_doe_feature_attrs, > + .is_visible = pci_doe_sysfs_attr_is_visible, > +}; > + > +static ssize_t pci_doe_sysfs_feature_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return sysfs_emit(buf, "%s\n", attr->attr.name); > +} > + > +static int pci_doe_sysfs_feature_supports(struct pci_dev *pdev, > + struct pci_doe_mb *doe_mb) > +{ > + struct device *dev = &pdev->dev; > + struct device_attribute *attrs; > + unsigned long num_features = 0; > + unsigned long vid, type; > + unsigned long i; > + void *entry; > + int ret; > + > + xa_for_each(&doe_mb->prots, i, entry) > + num_features++; > + > + attrs = kcalloc(num_features, sizeof(*attrs), GFP_KERNEL); > + if (!attrs) > + return -ENOMEM; > + > + doe_mb->sysfs_attrs = attrs; > + xa_for_each(&doe_mb->prots, i, entry) { > + sysfs_attr_init(&attrs[i].attr); > + vid = xa_to_value(entry) >> 8; > + type = xa_to_value(entry) & 0xFF; > + attrs[i].attr.name = kasprintf(GFP_KERNEL, > + "0x%04lX:%02lX", vid, type); > + if (!attrs[i].attr.name) { > + ret = -ENOMEM; > + goto fail; > + } > + > + attrs[i].attr.mode = 0444; > + attrs[i].show = pci_doe_sysfs_feature_show; > + > + ret = sysfs_add_file_to_group(&dev->kobj, &attrs[i].attr, > + pci_dev_doe_feature_group.name); > + if (ret) If we get an error here... > + goto fail; > + } > + > + return 0; > + > +fail: > + doe_mb->sysfs_attrs = NULL; > + xa_for_each(&doe_mb->prots, i, entry) { > + if (attrs[i].show) .. show is set so I think we end up trying to remove a file that was never successfully added. > + sysfs_remove_file_from_group(&dev->kobj, &attrs[i].attr, > + pci_dev_doe_feature_group.name); > + kfree(attrs[i].attr.name); > + } > + > + kfree(attrs); > + > + return ret; > +} > + > +int doe_sysfs_init(struct pci_dev *pdev) > +{ > + struct pci_doe_mb *doe_mb; > + unsigned long index; > + int ret; > + > + xa_for_each(&pdev->doe_mbs, index, doe_mb) { > + ret = pci_doe_sysfs_feature_supports(pdev, doe_mb); > + Blank line seems pointless as good to group the error handling with statement that reported the error. > + if (ret) > + return ret; > + } > + > + return 0; > +} > +#endif > + > static int pci_doe_wait(struct pci_doe_mb *doe_mb, unsigned long timeout) > { > if (wait_event_timeout(doe_mb->wq, > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c > index d9eede2dbc0e..01bbd1f1cb9b 100644 > --- a/drivers/pci/pci-sysfs.c > +++ b/drivers/pci/pci-sysfs.c > @@ -16,6 +16,7 @@ > #include <linux/kernel.h> > #include <linux/sched.h> > #include <linux/pci.h> > +#include <linux/pci-doe.h> > #include <linux/stat.h> > #include <linux/export.h> > #include <linux/topology.h> > @@ -1230,6 +1231,12 @@ static int pci_create_resource_files(struct pci_dev *pdev) > int i; > int retval; > > + if (IS_ENABLED(CONFIG_PCI_DOE)) { > + retval = doe_sysfs_init(pdev); > + if (retval) > + return retval; > + } > + > /* Expose the PCI resources from this device as files */ > for (i = 0; i < PCI_STD_NUM_BARS; i++) { > > @@ -1655,6 +1662,9 @@ static const struct attribute_group *pci_dev_attr_groups[] = { > #endif > #ifdef CONFIG_PCIEASPM > &aspm_ctrl_attr_group, > +#endif > +#ifdef CONFIG_PCI_DOE > + &pci_dev_doe_feature_group, > #endif > NULL, > }; > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 39a8932dc340..b85dd83ddfcb 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -186,6 +186,9 @@ extern const struct attribute_group *pci_dev_groups[]; > extern const struct attribute_group *pcibus_groups[]; > extern const struct device_type pci_dev_type; > extern const struct attribute_group *pci_bus_groups[]; > +#ifdef CONFIG_SYSFS > +extern const struct attribute_group pci_dev_doe_feature_group; > +#endif > > extern unsigned long pci_hotplug_io_size; > extern unsigned long pci_hotplug_mmio_size; > diff --git a/include/linux/pci-doe.h b/include/linux/pci-doe.h > index 1f14aed4354b..4cc13d9ccb50 100644 > --- a/include/linux/pci-doe.h > +++ b/include/linux/pci-doe.h > @@ -22,4 +22,5 @@ int pci_doe(struct pci_doe_mb *doe_mb, u16 vendor, u8 type, > const void *request, size_t request_sz, > void *response, size_t response_sz); > > +int doe_sysfs_init(struct pci_dev *pci_dev); > #endif
diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index ecf47559f495..e999e78cc2d5 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -500,3 +500,15 @@ Description: console drivers from the device. Raw users of pci-sysfs resourceN attributes must be terminated prior to resizing. Success of the resizing operation is not guaranteed. + +What: /sys/bus/pci/devices/.../doe_features +Date: August 2023 +Contact: Linux PCI developers <linux-pci@vger.kernel.org> +Description: + This directory contains a list of the supported + Data Object Exchange (DOE) features. The feature values are in + the file name. The contents of each file are the same as the + name. + The value comes from the device and specifies the vendor and + data object type supported. The lower byte is the data object + type and the next two bytes are the vendor ID. diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c index 047be8c9d191..69cd391dd120 100644 --- a/drivers/pci/doe.c +++ b/drivers/pci/doe.c @@ -47,6 +47,7 @@ * @wq: Wait queue for work item * @work_queue: Queue of pci_doe_work items * @flags: Bit array of PCI_DOE_FLAG_* flags + * @sysfs_attrs: Array of sysfs device attributes */ struct pci_doe_mb { struct pci_dev *pdev; @@ -56,6 +57,10 @@ struct pci_doe_mb { wait_queue_head_t wq; struct workqueue_struct *work_queue; unsigned long flags; + +#ifdef CONFIG_SYSFS + struct device_attribute *sysfs_attrs; +#endif }; struct pci_doe_feature { @@ -92,6 +97,112 @@ struct pci_doe_task { struct pci_doe_mb *doe_mb; }; +#ifdef CONFIG_SYSFS +static umode_t pci_doe_sysfs_attr_is_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj)); + struct pci_doe_mb *doe_mb; + unsigned long index, j; + void *entry; + + xa_for_each(&pdev->doe_mbs, index, doe_mb) { + xa_for_each(&doe_mb->prots, j, entry) + return a->mode; + } + + return 0; +} + +static struct attribute *pci_dev_doe_feature_attrs[] = { + NULL, +}; + +const struct attribute_group pci_dev_doe_feature_group = { + .name = "doe_features", + .attrs = pci_dev_doe_feature_attrs, + .is_visible = pci_doe_sysfs_attr_is_visible, +}; + +static ssize_t pci_doe_sysfs_feature_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", attr->attr.name); +} + +static int pci_doe_sysfs_feature_supports(struct pci_dev *pdev, + struct pci_doe_mb *doe_mb) +{ + struct device *dev = &pdev->dev; + struct device_attribute *attrs; + unsigned long num_features = 0; + unsigned long vid, type; + unsigned long i; + void *entry; + int ret; + + xa_for_each(&doe_mb->prots, i, entry) + num_features++; + + attrs = kcalloc(num_features, sizeof(*attrs), GFP_KERNEL); + if (!attrs) + return -ENOMEM; + + doe_mb->sysfs_attrs = attrs; + xa_for_each(&doe_mb->prots, i, entry) { + sysfs_attr_init(&attrs[i].attr); + vid = xa_to_value(entry) >> 8; + type = xa_to_value(entry) & 0xFF; + attrs[i].attr.name = kasprintf(GFP_KERNEL, + "0x%04lX:%02lX", vid, type); + if (!attrs[i].attr.name) { + ret = -ENOMEM; + goto fail; + } + + attrs[i].attr.mode = 0444; + attrs[i].show = pci_doe_sysfs_feature_show; + + ret = sysfs_add_file_to_group(&dev->kobj, &attrs[i].attr, + pci_dev_doe_feature_group.name); + if (ret) + goto fail; + } + + return 0; + +fail: + doe_mb->sysfs_attrs = NULL; + xa_for_each(&doe_mb->prots, i, entry) { + if (attrs[i].show) + sysfs_remove_file_from_group(&dev->kobj, &attrs[i].attr, + pci_dev_doe_feature_group.name); + kfree(attrs[i].attr.name); + } + + kfree(attrs); + + return ret; +} + +int doe_sysfs_init(struct pci_dev *pdev) +{ + struct pci_doe_mb *doe_mb; + unsigned long index; + int ret; + + xa_for_each(&pdev->doe_mbs, index, doe_mb) { + ret = pci_doe_sysfs_feature_supports(pdev, doe_mb); + + if (ret) + return ret; + } + + return 0; +} +#endif + static int pci_doe_wait(struct pci_doe_mb *doe_mb, unsigned long timeout) { if (wait_event_timeout(doe_mb->wq, diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index d9eede2dbc0e..01bbd1f1cb9b 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -16,6 +16,7 @@ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/pci.h> +#include <linux/pci-doe.h> #include <linux/stat.h> #include <linux/export.h> #include <linux/topology.h> @@ -1230,6 +1231,12 @@ static int pci_create_resource_files(struct pci_dev *pdev) int i; int retval; + if (IS_ENABLED(CONFIG_PCI_DOE)) { + retval = doe_sysfs_init(pdev); + if (retval) + return retval; + } + /* Expose the PCI resources from this device as files */ for (i = 0; i < PCI_STD_NUM_BARS; i++) { @@ -1655,6 +1662,9 @@ static const struct attribute_group *pci_dev_attr_groups[] = { #endif #ifdef CONFIG_PCIEASPM &aspm_ctrl_attr_group, +#endif +#ifdef CONFIG_PCI_DOE + &pci_dev_doe_feature_group, #endif NULL, }; diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 39a8932dc340..b85dd83ddfcb 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -186,6 +186,9 @@ extern const struct attribute_group *pci_dev_groups[]; extern const struct attribute_group *pcibus_groups[]; extern const struct device_type pci_dev_type; extern const struct attribute_group *pci_bus_groups[]; +#ifdef CONFIG_SYSFS +extern const struct attribute_group pci_dev_doe_feature_group; +#endif extern unsigned long pci_hotplug_io_size; extern unsigned long pci_hotplug_mmio_size; diff --git a/include/linux/pci-doe.h b/include/linux/pci-doe.h index 1f14aed4354b..4cc13d9ccb50 100644 --- a/include/linux/pci-doe.h +++ b/include/linux/pci-doe.h @@ -22,4 +22,5 @@ int pci_doe(struct pci_doe_mb *doe_mb, u16 vendor, u8 type, const void *request, size_t request_sz, void *response, size_t response_sz); +int doe_sysfs_init(struct pci_dev *pci_dev); #endif
The PCIe 6 specification added support for the Data Object Exchange (DOE). When DOE is supported the Discovery Data Object Protocol must be implemented. The protocol allows a requester to obtain information about the other DOE features supported by the device. The kernel is already querying the DOE features supported and cacheing the values. This patch exposes the values via sysfs. This will allow userspace to determine which DOE features are supported by the PCIe device. By exposing the information to userspace tools like lspci can relay the information to users. By listing all of the supported features we can allow userspace to parse and support the list, which might include vendor specific features as well as yet to be supported features. Signed-off-by: Alistair Francis <alistair.francis@wdc.com> --- v7: - Fixup the #ifdefs to keep the test robot happy v6: - Use "feature" instead of protocol - Don't use any devm_* functions - Add two more patches to the series v5: - Return the file name as the file contents - Code cleanups and simplifications v4: - Fixup typos in the documentation - Make it clear that the file names contain the information - Small code cleanups - Remove most #ifdefs - Remove extra NULL assignment v3: - Expose each DOE feature as a separate file v2: - Add documentation - Code cleanups This patch will create a doe_features directory for all PCIe devies. This should be fixed by a pending sysfs fixup patch. Documentation/ABI/testing/sysfs-bus-pci | 12 +++ drivers/pci/doe.c | 111 ++++++++++++++++++++++++ drivers/pci/pci-sysfs.c | 10 +++ drivers/pci/pci.h | 3 + include/linux/pci-doe.h | 1 + 5 files changed, 137 insertions(+)