On Wed, Jan 18, 2023 at 08:35:51PM -0500, Tianfei Zhang wrote:
> To reprogram an PCIe-based FPGA card, a new image is
> burned into FLASH on the card and then the card BMC is
> triggered to reboot the card and load the new image.
>
> Two new operation callbacks are defined in hotplug_slot_ops
> to trigger the reprogramming of an FPGA-based PCIe card:
>
> - available_images: Optional: available FPGA images
> - image_load: Optional: trigger the FPGA to load a new image
>
> Signed-off-by: Tianfei Zhang <tianfei.zhang@xxxxxxxxx>
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> ---
> drivers/pci/hotplug/pci_hotplug_core.c | 88 ++++++++++++++++++++++++++
> include/linux/pci_hotplug.h | 5 ++
> 2 files changed, 93 insertions(+)
>
> diff --git a/drivers/pci/hotplug/pci_hotplug_core.c b/drivers/pci/hotplug/pci_hotplug_core.c
> index 058d5937d8a9..2b14b6513a03 100644
> --- a/drivers/pci/hotplug/pci_hotplug_core.c
> +++ b/drivers/pci/hotplug/pci_hotplug_core.c
> @@ -231,6 +231,52 @@ static struct pci_slot_attribute hotplug_slot_attr_test = {
> .store = test_write_file
> };
>
> +static ssize_t available_images_read_file(struct pci_slot *pci_slot, char *buf)
> +{
> + struct hotplug_slot *slot = pci_slot->hotplug;
> + ssize_t count = 0;
> +
> + if (!try_module_get(slot->owner))
> + return -ENODEV;
> +
> + if (slot->ops->available_images(slot, buf))
> + count = slot->ops->available_images(slot, buf);
> +
> + module_put(slot->owner);
> +
> + return count;
> +}
> +
> +static struct pci_slot_attribute hotplug_slot_attr_available_images = {
> + .attr = { .name = "available_images", .mode = 0444 },
> + .show = available_images_read_file,
If you name things properly, you can use the correct macros and not have
to open-code any of this :(
> +static ssize_t image_load_write_file(struct pci_slot *pci_slot,
> + const char *buf, size_t count)
> +{
> + struct hotplug_slot *slot = pci_slot->hotplug;
> + int retval = 0;
> +
> + if (!try_module_get(slot->owner))
> + return -ENODEV;
> +
> + if (slot->ops->image_load)
> + retval = slot->ops->image_load(slot, buf);
> +
> + module_put(slot->owner);
> +
> + if (retval)
> + return retval;
> +
> + return count;
> +}
> +
> +static struct pci_slot_attribute hotplug_slot_attr_image_load = {
> + .attr = { .name = "image_load", .mode = 0644 },
> + .store = image_load_write_file,
Same here, don't open-code this.
> +};
> +
> static bool has_power_file(struct pci_slot *pci_slot)
> {
> struct hotplug_slot *slot = pci_slot->hotplug;
> @@ -289,6 +335,20 @@ static bool has_test_file(struct pci_slot *pci_slot)
> return false;
> }
>
> +static bool has_available_images_file(struct pci_slot *pci_slot)
> +{
> + struct hotplug_slot *slot = pci_slot->hotplug;
> +
> + return slot && slot->ops && slot->ops->available_images;
> +}
> +
> +static bool has_image_load_file(struct pci_slot *pci_slot)
> +{
> + struct hotplug_slot *slot = pci_slot->hotplug;
> +
> + return slot && slot->ops && slot->ops->image_load;
> +}
> +
> static int fs_add_slot(struct pci_slot *pci_slot)
> {
> int retval = 0;
> @@ -331,8 +391,30 @@ static int fs_add_slot(struct pci_slot *pci_slot)
> goto exit_test;
> }
>
> + if (has_available_images_file(pci_slot)) {
> + retval = sysfs_create_file(&pci_slot->kobj,
> + &hotplug_slot_attr_available_images.attr);
> + if (retval)
> + goto exit_available_images;
> + }
> +
> + if (has_image_load_file(pci_slot)) {
> + retval = sysfs_create_file(&pci_slot->kobj,
> + &hotplug_slot_attr_image_load.attr);
> + if (retval)
> + goto exit_image_load;
> + }
> +
> goto exit;
>
> +exit_image_load:
> + if (has_adapter_file(pci_slot))
> + sysfs_remove_file(&pci_slot->kobj,
> + &hotplug_slot_attr_available_images.attr);
> +exit_available_images:
> + if (has_adapter_file(pci_slot))
> + sysfs_remove_file(&pci_slot->kobj,
> + &hotplug_slot_attr_test.attr);
> exit_test:
> if (has_adapter_file(pci_slot))
> sysfs_remove_file(&pci_slot->kobj,
> @@ -372,6 +454,12 @@ static void fs_remove_slot(struct pci_slot *pci_slot)
> if (has_test_file(pci_slot))
> sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_test.attr);
>
> + if (has_available_images_file(pci_slot))
> + sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_available_images.attr);
> +
> + if (has_image_load_file(pci_slot))
> + sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_image_load.attr);
> +
Ick no, please just make this an attribute group that properly shows or
does not show, the attribute when created. Do not manually add
individual sysfs files.
Yes, I know the existing code does this, so it's not really your fault,
but let's not persist in making this code even messier. Convert to a
group first and then your new files will be added automagically without
having to care about anything here at all.
thanks,
greg k-h
