2021-07-05 14:23:58

by Amey Narkhede

[permalink] [raw]
Subject: [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism

Add reset_method sysfs attribute to enable user to query and set user
preferred device reset methods and their ordering.

Co-developed-by: Alex Williamson <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>
Signed-off-by: Amey Narkhede <[email protected]>
---
Documentation/ABI/testing/sysfs-bus-pci | 19 +++++
drivers/pci/pci-sysfs.c | 103 ++++++++++++++++++++++++
2 files changed, 122 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index ef00fada2..43f4e33c7 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -121,6 +121,25 @@ Description:
child buses, and re-discover devices removed earlier
from this part of the device tree.

+What: /sys/bus/pci/devices/.../reset_method
+Date: March 2021
+Contact: Amey Narkhede <[email protected]>
+Description:
+ Some devices allow an individual function to be reset
+ without affecting other functions in the same slot.
+
+ For devices that have this support, a file named
+ reset_method will be present in sysfs. Initially reading
+ this file will give names of the device supported reset
+ methods and their ordering. After write, this file will
+ give names and ordering of currently enabled reset methods.
+ Writing the name or comma separated list of names of any of
+ the device supported reset methods to this file will set
+ the reset methods and their ordering to be used when
+ resetting the device. Writing empty string to this file
+ will disable ability to reset the device and writing
+ "default" will return to the original value.
+
What: /sys/bus/pci/devices/.../reset
Date: July 2009
Contact: Michael S. Tsirkin <[email protected]>
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 316f70c3e..8a740e211 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1334,6 +1334,108 @@ static const struct attribute_group pci_dev_rom_attr_group = {
.is_bin_visible = pci_dev_rom_attr_is_visible,
};

+static ssize_t reset_method_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ ssize_t len = 0;
+ int i, idx;
+
+ for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
+ idx = pdev->reset_methods[i];
+ if (!idx)
+ break;
+
+ len += sysfs_emit_at(buf, len, "%s%s", len ? "," : "",
+ pci_reset_fn_methods[idx].name);
+ }
+
+ if (len)
+ len += sysfs_emit_at(buf, len, "\n");
+
+ return len;
+}
+
+static ssize_t reset_method_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ int n = 0;
+ char *name, *options = NULL;
+ u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
+
+ if (count >= (PAGE_SIZE - 1))
+ return -EINVAL;
+
+ if (sysfs_streq(buf, "")) {
+ pci_warn(pdev, "All device reset methods disabled by user");
+ goto set_reset_methods;
+ }
+
+ if (sysfs_streq(buf, "default")) {
+ pci_init_reset_methods(pdev);
+ return count;
+ }
+
+ options = kstrndup(buf, count, GFP_KERNEL);
+ if (!options)
+ return -ENOMEM;
+
+ while ((name = strsep(&options, ",")) != NULL) {
+ int i;
+
+ if (sysfs_streq(name, ""))
+ continue;
+
+ name = strim(name);
+
+ for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
+ if (sysfs_streq(name, pci_reset_fn_methods[i].name) &&
+ !pci_reset_fn_methods[i].reset_fn(pdev, 1)) {
+ reset_methods[n++] = i;
+ break;
+ }
+ }
+
+ if (i == PCI_NUM_RESET_METHODS) {
+ kfree(options);
+ return -EINVAL;
+ }
+ }
+
+ if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && reset_methods[0] != 1)
+ pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
+
+set_reset_methods:
+ memcpy(pdev->reset_methods, reset_methods, sizeof(reset_methods));
+ kfree(options);
+ return count;
+}
+static DEVICE_ATTR_RW(reset_method);
+
+static struct attribute *pci_dev_reset_method_attrs[] = {
+ &dev_attr_reset_method.attr,
+ NULL,
+};
+
+static umode_t pci_dev_reset_method_attr_is_visible(struct kobject *kobj,
+ struct attribute *a, int n)
+{
+ struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+
+ if (!pci_reset_supported(pdev))
+ return 0;
+
+ return a->mode;
+}
+
+static const struct attribute_group pci_dev_reset_method_attr_group = {
+ .attrs = pci_dev_reset_method_attrs,
+ .is_visible = pci_dev_reset_method_attr_is_visible,
+};
+
static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
@@ -1491,6 +1593,7 @@ const struct attribute_group *pci_dev_groups[] = {
&pci_dev_config_attr_group,
&pci_dev_rom_attr_group,
&pci_dev_reset_attr_group,
+ &pci_dev_reset_method_attr_group,
&pci_dev_vpd_attr_group,
#ifdef CONFIG_DMI
&pci_dev_smbios_attr_group,
--
2.32.0


2021-07-06 05:18:23

by Leon Romanovsky

[permalink] [raw]
Subject: Re: [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism

On Mon, Jul 05, 2021 at 07:51:34PM +0530, Amey Narkhede wrote:
> Add reset_method sysfs attribute to enable user to query and set user
> preferred device reset methods and their ordering.
>
> Co-developed-by: Alex Williamson <[email protected]>
> Signed-off-by: Alex Williamson <[email protected]>
> Signed-off-by: Amey Narkhede <[email protected]>
> ---
> Documentation/ABI/testing/sysfs-bus-pci | 19 +++++
> drivers/pci/pci-sysfs.c | 103 ++++++++++++++++++++++++
> 2 files changed, 122 insertions(+)
>

Thanks,
Reviewed-by: Leon Romanovsky <[email protected]>

2021-07-11 16:52:31

by Raphael Norwitz

[permalink] [raw]
Subject: Re: [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism

On Mon, Jul 05, 2021 at 07:51:34PM +0530, Amey Narkhede wrote:
> Add reset_method sysfs attribute to enable user to query and set user
> preferred device reset methods and their ordering.
>
> Co-developed-by: Alex Williamson <[email protected]>
> Signed-off-by: Alex Williamson <[email protected]>
> Signed-off-by: Amey Narkhede <[email protected]>

Just some spacing NITs.

Reviewed-by: Raphael Norwitz <[email protected]>

> ---
> Documentation/ABI/testing/sysfs-bus-pci | 19 +++++
> drivers/pci/pci-sysfs.c | 103 ++++++++++++++++++++++++
> 2 files changed, 122 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> index ef00fada2..43f4e33c7 100644
> --- a/Documentation/ABI/testing/sysfs-bus-pci
> +++ b/Documentation/ABI/testing/sysfs-bus-pci
> @@ -121,6 +121,25 @@ Description:
> child buses, and re-discover devices removed earlier
> from this part of the device tree.
>
> +What: /sys/bus/pci/devices/.../reset_method
> +Date: March 2021
> +Contact: Amey Narkhede <[email protected]>
> +Description:
> + Some devices allow an individual function to be reset
> + without affecting other functions in the same slot.
> +
> + For devices that have this support, a file named
> + reset_method will be present in sysfs. Initially reading
> + this file will give names of the device supported reset
> + methods and their ordering. After write, this file will
> + give names and ordering of currently enabled reset methods.
> + Writing the name or comma separated list of names of any of
> + the device supported reset methods to this file will set
> + the reset methods and their ordering to be used when
> + resetting the device. Writing empty string to this file
> + will disable ability to reset the device and writing
> + "default" will return to the original value.
> +
> What: /sys/bus/pci/devices/.../reset
> Date: July 2009
> Contact: Michael S. Tsirkin <[email protected]>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index 316f70c3e..8a740e211 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -1334,6 +1334,108 @@ static const struct attribute_group pci_dev_rom_attr_group = {
> .is_bin_visible = pci_dev_rom_attr_is_visible,
> };
>
> +static ssize_t reset_method_show(struct device *dev,

Nit: spaces on the following two lines. "struct device_attribute *attr"
and "char *buf" should be in line with "struct device *dev"

> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct pci_dev *pdev = to_pci_dev(dev);
> + ssize_t len = 0;
> + int i, idx;
> +
> + for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
> + idx = pdev->reset_methods[i];
> + if (!idx)
> + break;
> +
> + len += sysfs_emit_at(buf, len, "%s%s", len ? "," : "",
> + pci_reset_fn_methods[idx].name);
> + }
> +
> + if (len)
> + len += sysfs_emit_at(buf, len, "\n");
> +
> + return len;
> +}
> +
> +static ssize_t reset_method_store(struct device *dev,

Nit: spaces on the following two lines

> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct pci_dev *pdev = to_pci_dev(dev);
> + int n = 0;
> + char *name, *options = NULL;
> + u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
> +
> + if (count >= (PAGE_SIZE - 1))
> + return -EINVAL;
> +
> + if (sysfs_streq(buf, "")) {
> + pci_warn(pdev, "All device reset methods disabled by user");
> + goto set_reset_methods;
> + }
> +
> + if (sysfs_streq(buf, "default")) {
> + pci_init_reset_methods(pdev);
> + return count;
> + }
> +
> + options = kstrndup(buf, count, GFP_KERNEL);
> + if (!options)
> + return -ENOMEM;
> +
> + while ((name = strsep(&options, ",")) != NULL) {
> + int i;
> +
> + if (sysfs_streq(name, ""))
> + continue;
> +
> + name = strim(name);
> +
> + for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
> + if (sysfs_streq(name, pci_reset_fn_methods[i].name) &&
> + !pci_reset_fn_methods[i].reset_fn(pdev, 1)) {
> + reset_methods[n++] = i;
> + break;
> + }
> + }
> +
> + if (i == PCI_NUM_RESET_METHODS) {
> + kfree(options);
> + return -EINVAL;
> + }
> + }
> +
> + if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && reset_methods[0] != 1)
> + pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
> +
> +set_reset_methods:
> + memcpy(pdev->reset_methods, reset_methods, sizeof(reset_methods));
> + kfree(options);
> + return count;
> +}
> +static DEVICE_ATTR_RW(reset_method);
> +
> +static struct attribute *pci_dev_reset_method_attrs[] = {
> + &dev_attr_reset_method.attr,
> + NULL,
> +};
> +
> +static umode_t pci_dev_reset_method_attr_is_visible(struct kobject *kobj,

Nit: ditto - spacing.

> + struct attribute *a, int n)
> +{
> + struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
> +
> + if (!pci_reset_supported(pdev))
> + return 0;
> +
> + return a->mode;
> +}
> +
> +static const struct attribute_group pci_dev_reset_method_attr_group = {
> + .attrs = pci_dev_reset_method_attrs,
> + .is_visible = pci_dev_reset_method_attr_is_visible,
> +};
> +
> static ssize_t reset_store(struct device *dev, struct device_attribute *attr,

Nit: spacing following line.

> const char *buf, size_t count)
> {
> @@ -1491,6 +1593,7 @@ const struct attribute_group *pci_dev_groups[] = {
> &pci_dev_config_attr_group,
> &pci_dev_rom_attr_group,
> &pci_dev_reset_attr_group,
> + &pci_dev_reset_method_attr_group,
> &pci_dev_vpd_attr_group,
> #ifdef CONFIG_DMI
> &pci_dev_smbios_attr_group,
> --
> 2.32.0
>
>

2021-07-14 12:01:15

by Amey Narkhede

[permalink] [raw]
Subject: Re: [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism

On 21/07/11 04:51PM, Raphael Norwitz wrote:
> On Mon, Jul 05, 2021 at 07:51:34PM +0530, Amey Narkhede wrote:
> > Add reset_method sysfs attribute to enable user to query and set user
> > preferred device reset methods and their ordering.
> >
> > Co-developed-by: Alex Williamson <[email protected]>
> > Signed-off-by: Alex Williamson <[email protected]>
> > Signed-off-by: Amey Narkhede <[email protected]>
>
> Just some spacing NITs.
>
> Reviewed-by: Raphael Norwitz <[email protected]>
>
> > ---
> > Documentation/ABI/testing/sysfs-bus-pci | 19 +++++
> > drivers/pci/pci-sysfs.c | 103 ++++++++++++++++++++++++
> > 2 files changed, 122 insertions(+)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> > index ef00fada2..43f4e33c7 100644
> > --- a/Documentation/ABI/testing/sysfs-bus-pci
> > +++ b/Documentation/ABI/testing/sysfs-bus-pci
> > @@ -121,6 +121,25 @@ Description:
> > child buses, and re-discover devices removed earlier
> > from this part of the device tree.
> >
> > +What: /sys/bus/pci/devices/.../reset_method
> > +Date: March 2021
> > +Contact: Amey Narkhede <[email protected]>
> > +Description:
> > + Some devices allow an individual function to be reset
> > + without affecting other functions in the same slot.
> > +
> > + For devices that have this support, a file named
> > + reset_method will be present in sysfs. Initially reading
> > + this file will give names of the device supported reset
> > + methods and their ordering. After write, this file will
> > + give names and ordering of currently enabled reset methods.
> > + Writing the name or comma separated list of names of any of
> > + the device supported reset methods to this file will set
> > + the reset methods and their ordering to be used when
> > + resetting the device. Writing empty string to this file
> > + will disable ability to reset the device and writing
> > + "default" will return to the original value.
> > +
> > What: /sys/bus/pci/devices/.../reset
> > Date: July 2009
> > Contact: Michael S. Tsirkin <[email protected]>
> > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> > index 316f70c3e..8a740e211 100644
> > --- a/drivers/pci/pci-sysfs.c
> > +++ b/drivers/pci/pci-sysfs.c
> > @@ -1334,6 +1334,108 @@ static const struct attribute_group pci_dev_rom_attr_group = {
> > .is_bin_visible = pci_dev_rom_attr_is_visible,
> > };
> >
> > +static ssize_t reset_method_show(struct device *dev,
>
> Nit: spaces on the following two lines. "struct device_attribute *attr"
> and "char *buf" should be in line with "struct device *dev"
>
Not sure what happened when creating the patches but on my editor spaces
seems to consistent as you suggested here. For some reason git
format-patch is acting weird.

Thanks,
Amey
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct pci_dev *pdev = to_pci_dev(dev);
> > + ssize_t len = 0;
> > + int i, idx;
> > +
> > + for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
> > + idx = pdev->reset_methods[i];
> > + if (!idx)
> > + break;
> > +
> > + len += sysfs_emit_at(buf, len, "%s%s", len ? "," : "",
> > + pci_reset_fn_methods[idx].name);
> > + }
> > +
> > + if (len)
> > + len += sysfs_emit_at(buf, len, "\n");
> > +
> > + return len;
> > +}
> > +
> > +static ssize_t reset_method_store(struct device *dev,
>
> Nit: spaces on the following two lines
>
> > + struct device_attribute *attr,
> > + const char *buf, size_t count)
> > +{
> > + struct pci_dev *pdev = to_pci_dev(dev);
> > + int n = 0;
> > + char *name, *options = NULL;
> > + u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
> > +
> > + if (count >= (PAGE_SIZE - 1))
> > + return -EINVAL;
> > +
> > + if (sysfs_streq(buf, "")) {
> > + pci_warn(pdev, "All device reset methods disabled by user");
> > + goto set_reset_methods;
> > + }
> > +
> > + if (sysfs_streq(buf, "default")) {
> > + pci_init_reset_methods(pdev);
> > + return count;
> > + }
> > +
> > + options = kstrndup(buf, count, GFP_KERNEL);
> > + if (!options)
> > + return -ENOMEM;
> > +
> > + while ((name = strsep(&options, ",")) != NULL) {
> > + int i;
> > +
> > + if (sysfs_streq(name, ""))
> > + continue;
> > +
> > + name = strim(name);
> > +
> > + for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
> > + if (sysfs_streq(name, pci_reset_fn_methods[i].name) &&
> > + !pci_reset_fn_methods[i].reset_fn(pdev, 1)) {
> > + reset_methods[n++] = i;
> > + break;
> > + }
> > + }
> > +
> > + if (i == PCI_NUM_RESET_METHODS) {
> > + kfree(options);
> > + return -EINVAL;
> > + }
> > + }
> > +
> > + if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && reset_methods[0] != 1)
> > + pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
> > +
> > +set_reset_methods:
> > + memcpy(pdev->reset_methods, reset_methods, sizeof(reset_methods));
> > + kfree(options);
> > + return count;
> > +}
> > +static DEVICE_ATTR_RW(reset_method);
> > +
> > +static struct attribute *pci_dev_reset_method_attrs[] = {
> > + &dev_attr_reset_method.attr,
> > + NULL,
> > +};
> > +
> > +static umode_t pci_dev_reset_method_attr_is_visible(struct kobject *kobj,
>
> Nit: ditto - spacing.
>
> > + struct attribute *a, int n)
> > +{
> > + struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
> > +
> > + if (!pci_reset_supported(pdev))
> > + return 0;
> > +
> > + return a->mode;
> > +}
> > +
> > +static const struct attribute_group pci_dev_reset_method_attr_group = {
> > + .attrs = pci_dev_reset_method_attrs,
> > + .is_visible = pci_dev_reset_method_attr_is_visible,
> > +};
> > +
> > static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
>
> Nit: spacing following line.
>
> > const char *buf, size_t count)
> > {
> > @@ -1491,6 +1593,7 @@ const struct attribute_group *pci_dev_groups[] = {
> > &pci_dev_config_attr_group,
> > &pci_dev_rom_attr_group,
> > &pci_dev_reset_attr_group,
> > + &pci_dev_reset_method_attr_group,
> > &pci_dev_vpd_attr_group,
> > #ifdef CONFIG_DMI
> > &pci_dev_smbios_attr_group,
> > --
> > 2.32.0
> >
> >