On 8/9/2023 4:28 PM, Alistair Francis 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 protocols supported by the device.
>
> The kernel is already querying the DOE protocols supported and cacheing
> the values. This patch exposes the values via sysfs. This will allow
> userspace to determine which DOE protocols 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 protocols we can
> allow userspace to parse and support the list, which might include
> vendor specific protocols as well as yet to be supported protocols.
>
> Signed-off-by: Alistair Francis <alistair.francis@xxxxxxx>
> ---
> v3:
> - Expose each DOE feature as a separate file
>
it will be nice to have entire version history ...
> Documentation/ABI/testing/sysfs-bus-pci | 10 +++
> drivers/pci/doe.c | 107 ++++++++++++++++++++++++
> drivers/pci/pci-sysfs.c | 7 ++
> include/linux/pci-doe.h | 1 +
> 4 files changed, 125 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> index ecf47559f495..e754b8efdb69 100644
> --- a/Documentation/ABI/testing/sysfs-bus-pci
> +++ b/Documentation/ABI/testing/sysfs-bus-pci
> @@ -500,3 +500,13 @@ 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_proto
> +Date: July 2023
> +Contact: Linux PCI developers <linux-pci@xxxxxxxxxxxxxxx>
> +Description:
> + This diectory contains a list of the supported Data Object Exchange (DOE)
> + features. Each feature is a single file.
> + 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.
can you run spell check above ?
> diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
> index 1b97a5ab71a9..d5cbcb6a457a 100644
> --- a/drivers/pci/doe.c
> +++ b/drivers/pci/doe.c
> @@ -56,6 +56,10 @@ 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_protocol {
> @@ -92,6 +96,109 @@ struct pci_doe_task {
> struct pci_doe_mb *doe_mb;
> };
>
> +#ifdef CONFIG_SYSFS
> +static struct attribute *pci_dev_doe_proto_attrs[] = {
> + NULL,
> +};
> +
> +static const struct attribute_group pci_dev_doe_proto_group = {
> + .name = "doe_protos",
> + .attrs = pci_dev_doe_proto_attrs,
> +};
> +
> +static void pci_doe_sysfs_remove_desc(struct pci_doe_mb *doe_mb)
> +{
> + struct device_attribute *attrs = doe_mb->sysfs_attrs;
> + unsigned long i;
> + void *entry;
> +
> + if (!attrs)
> + return;
> +
nit : following reads well and matches next NULL assignment, feel free
to ignore :-
if (!doe_mb->sysfs_attrs)
return;
> + doe_mb->sysfs_attrs = NULL;
> + xa_for_each(&doe_mb->prots, i, entry)
> + kfree(attrs[i].attr.name);
> +
> + kfree(attrs);
> +}
> +
> +static int pci_doe_sysfs_proto_supports(struct pci_dev *pdev, struct pci_doe_mb *doe_mb)
> +{
> + struct device_attribute *attrs;
> + struct device *dev = &pdev->dev;
> + unsigned long i;
> + int ret;
> + unsigned long num_protos = 0;
> + unsigned long vid, type;
> + void *entry;
> +
cosmetic: feel free to ignore but I'd use, feel free to ignore :-
struct device *dev = &pdev->dev;
struct device_attribute *attrs;
unsigned long num_protos = 0;
unsigned long vid, type;
unsigned long i;
void *entry;
int ret;
> + xa_for_each(&doe_mb->prots, i, entry)
> + num_protos++;
> +
> + attrs = kcalloc(num_protos, 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 = NULL;
> +
> + ret = sysfs_add_file_to_group(&dev->kobj, &attrs[i].attr,
> + pci_dev_doe_proto_group.name);
> + if (ret)
> + goto fail;
> + }
> +
> + return 0;
> +
> +fail:
> + pci_doe_sysfs_remove_desc(doe_mb);
> + return ret;
> +}
> +
> +int doe_sysfs_init(struct pci_dev *pdev)
> +{
> + unsigned long index, j;
> + int ret;
> + struct pci_doe_mb *doe_mb;
> + unsigned long total_protos = 0;
> + void *entry;
> +
cosmetic: same as above feel free to ignore this comment :-
unsigned long total_protos = 0;
struct pci_doe_mb *doe_mb;
unsigned long index, j;
void *entry;
int ret;
> + xa_for_each(&pdev->doe_mbs, index, doe_mb) {
> + xa_for_each(&doe_mb->prots, j, entry)
> + total_protos++;
> + }
> +
> + if (total_protos == 0)
> + return 0;
> +
> + ret = devm_device_add_group(&pdev->dev, &pci_dev_doe_proto_group);
> + if (ret) {
> + pci_err(pdev, "can't create DOE goup: %d\n", ret);
> + return ret;
> + }
> +
> + xa_for_each(&pdev->doe_mbs, index, doe_mb) {
> + ret = pci_doe_sysfs_proto_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 ab32a91f287b..cb25aba081bc 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>
> @@ -1226,6 +1227,12 @@ static int pci_create_resource_files(struct pci_dev *pdev)
> int i;
> int retval;
>
> +#ifdef CONFIG_PCI_DOE
> + retval = doe_sysfs_init(pdev);
> + if (retval)
> + return retval;
> +#endif
> +
how about following? unless there is a bug then ignore this comment ..
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++) {
>
> 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
-ck
