2021-07-26 04:53:23

by Viresh Kumar

[permalink] [raw]
Subject: [PATCH V3 0/5] virtio: Add virtio-device bindings

Hi,

Currently the DT only provides support for following node types for virtio-mmio
nodes:

virtio_mmio@a000000 {
dma-coherent;
interrupts = <0x00 0x10 0x01>;
reg = <0x00 0xa000000 0x00 0x200>;
compatible = "virtio,mmio";
};

Here, each virtio-mmio corresponds to a virtio-device. But there is no way for
other users in the DT to show their dependency on virtio devices.

This patchset provides that support.

The first patch adds virtio-device bindings to allow for device sub-nodes to be
present and the second patch updates the virtio core to update the of_node.

Other patches add bindings for i2c and gpio devices.

Tested on x86 with qemu for arm64.

Pending:
- Arnd suggested that "virtio,deviceXX" may be a better compatible string, while
I used "virtio,XX" to match what PCI and USB do currently. I didn't change it
yet to hear Rob's view on the same before making the change, in case he has
any preferences.

V2/2.1->V3:
- Added review-tags from Arnd and Wolfram.
- Only the 5th patch changed otherwise:
- Use of_device_is_compatible() instead of keeping a list of devices.
- Use snprintf (with BUG_ON on return value) to create the compatible string,
whose length is fixed using "virtio,XXXXXXXX".
- Use dev_of_node().

V1->V2:
- The changes (both binding and code) are made at virtio level, instead of
virtio-mmio. This allows the same to be used by all device types, irrespective
of the transport mechanism.

- Dropped the reg property and used compatible in the form "virtio,<DID>".

- Dropped dt-bindings/virtio/virtio_ids.h.

- Add a patch to sync virtio-ids from spec, required for the last patch.

--
Viresh

Viresh Kumar (5):
dt-bindings: virtio: Add binding for virtio devices
dt-bindings: i2c: Add bindings for i2c-virtio
dt-bindings: gpio: Add bindings for gpio-virtio
uapi: virtio_ids: Sync ids with specification
virtio: Bind virtio device to device-tree node

.../devicetree/bindings/gpio/gpio-virtio.yaml | 60 +++++++++++++++++++
.../devicetree/bindings/i2c/i2c-virtio.yaml | 51 ++++++++++++++++
.../devicetree/bindings/virtio/mmio.yaml | 2 +-
.../bindings/virtio/virtio-device.yaml | 47 +++++++++++++++
drivers/virtio/virtio.c | 57 +++++++++++++++++-
include/uapi/linux/virtio_ids.h | 12 ++++
6 files changed, 225 insertions(+), 4 deletions(-)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
create mode 100644 Documentation/devicetree/bindings/i2c/i2c-virtio.yaml
create mode 100644 Documentation/devicetree/bindings/virtio/virtio-device.yaml

--
2.31.1.272.g89b43f80a514


2021-07-26 04:53:53

by Viresh Kumar

[permalink] [raw]
Subject: [PATCH V3 4/5] uapi: virtio_ids: Sync ids with specification

This synchronizes the virtio ids with the latest list from virtio
specification.

Signed-off-by: Viresh Kumar <[email protected]>
---
include/uapi/linux/virtio_ids.h | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h
index 70a8057ad4bb..3c8e11820fdb 100644
--- a/include/uapi/linux/virtio_ids.h
+++ b/include/uapi/linux/virtio_ids.h
@@ -54,8 +54,20 @@
#define VIRTIO_ID_SOUND 25 /* virtio sound */
#define VIRTIO_ID_FS 26 /* virtio filesystem */
#define VIRTIO_ID_PMEM 27 /* virtio pmem */
+#define VIRTIO_ID_RPMB 28 /* virtio rpmb */
#define VIRTIO_ID_MAC80211_HWSIM 29 /* virtio mac80211-hwsim */
+#define VIRTIO_ID_VIDEO_ENCODER 30 /* virtio video encoder */
+#define VIRTIO_ID_VIDEO_DECODER 31 /* virtio video decoder */
+#define VIRTIO_ID_SCMI 32 /* virtio scmi */
+#define VIRTIO_ID_NITRO_SEC_MOD 33 /* virtio nitro secure module*/
+#define VIRTIO_ID_I2C_ADAPTER 34 /* virtio i2c adapter */
+#define VIRTIO_ID_WATCHDOG 35 /* virtio watchdog */
+#define VIRTIO_ID_CAN 36 /* virtio can */
+#define VIRTIO_ID_DMABUF 37 /* virtio dmabuf */
+#define VIRTIO_ID_PARAM_SERV 38 /* virtio parameter server */
+#define VIRTIO_ID_AUDIO_POLICY 39 /* virtio audio policy */
#define VIRTIO_ID_BT 40 /* virtio bluetooth */
+#define VIRTIO_ID_GPIO 41 /* virtio gpio */

/*
* Virtio Transitional IDs
--
2.31.1.272.g89b43f80a514

2021-07-26 04:53:57

by Viresh Kumar

[permalink] [raw]
Subject: [PATCH V3 5/5] virtio: Bind virtio device to device-tree node

Bind the virtio devices with their of_node. This will help users of the
virtio devices to mention their dependencies on the device in the DT
itself. Like GPIO pin users can use the phandle of the device node, or
the node may contain more subnodes to add i2c or spi eeproms and other
users.

Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>
---
drivers/virtio/virtio.c | 57 ++++++++++++++++++++++++++++++++++++++---
1 file changed, 54 insertions(+), 3 deletions(-)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 4b15c00c0a0a..d001e84a5b23 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -4,6 +4,7 @@
#include <linux/virtio_config.h>
#include <linux/module.h>
#include <linux/idr.h>
+#include <linux/of.h>
#include <uapi/linux/virtio_ids.h>

/* Unique numbering for virtio devices. */
@@ -292,6 +293,9 @@ static int virtio_dev_remove(struct device *_d)

/* Acknowledge the device's existence again. */
virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
+
+ of_node_put(dev->dev.of_node);
+
return 0;
}

@@ -319,6 +323,43 @@ void unregister_virtio_driver(struct virtio_driver *driver)
}
EXPORT_SYMBOL_GPL(unregister_virtio_driver);

+static int virtio_device_of_init(struct virtio_device *dev)
+{
+ struct device_node *np, *pnode = dev_of_node(dev->dev.parent);
+ char compat[] = "virtio,XXXXXXXX"; /* Reserve enough space 32-bit id */
+ int ret, count;
+
+ if (!pnode)
+ return 0;
+
+ count = of_get_available_child_count(pnode);
+ if (!count)
+ return 0;
+
+ /* There can be only 1 child node */
+ if (WARN_ON(count > 1))
+ return -EINVAL;
+
+ np = of_get_next_available_child(pnode, NULL);
+ if (WARN_ON(!np))
+ return -ENODEV;
+
+ BUG_ON(snprintf(compat, sizeof(compat), "virtio,%x", dev->id.device) >=
+ sizeof(compat));
+
+ if (!of_device_is_compatible(np, compat)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ dev->dev.of_node = np;
+ return 0;
+
+out:
+ of_node_put(np);
+ return ret;
+}
+
/**
* register_virtio_device - register virtio device
* @dev : virtio device to be registered
@@ -343,6 +384,10 @@ int register_virtio_device(struct virtio_device *dev)
dev->index = err;
dev_set_name(&dev->dev, "virtio%u", dev->index);

+ err = virtio_device_of_init(dev);
+ if (err)
+ goto out_ida_remove;
+
spin_lock_init(&dev->config_lock);
dev->config_enabled = false;
dev->config_change_pending = false;
@@ -362,10 +407,16 @@ int register_virtio_device(struct virtio_device *dev)
*/
err = device_add(&dev->dev);
if (err)
- ida_simple_remove(&virtio_index_ida, dev->index);
+ goto out_of_node_put;
+
+ return 0;
+
+out_of_node_put:
+ of_node_put(dev->dev.of_node);
+out_ida_remove:
+ ida_simple_remove(&virtio_index_ida, dev->index);
out:
- if (err)
- virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
+ virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
return err;
}
EXPORT_SYMBOL_GPL(register_virtio_device);
--
2.31.1.272.g89b43f80a514

2021-07-26 04:54:22

by Viresh Kumar

[permalink] [raw]
Subject: [PATCH V3 3/5] dt-bindings: gpio: Add bindings for gpio-virtio

This patch adds binding for virtio GPIO controller, it is based on
virtio-device bindings.

Signed-off-by: Viresh Kumar <[email protected]>
---
.../devicetree/bindings/gpio/gpio-virtio.yaml | 60 +++++++++++++++++++
1 file changed, 60 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio-virtio.yaml

diff --git a/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml b/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
new file mode 100644
index 000000000000..96108cfb7a08
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/gpio-virtio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Virtio GPIO controller
+
+maintainers:
+ - Viresh Kumar <[email protected]>
+
+allOf:
+ - $ref: /schemas/gpio/gpio.yaml#
+ - $ref: /schemas/virtio/virtio-device.yaml#
+
+description:
+ Virtio GPIO controller, see /schemas/virtio/virtio-device.yaml for more
+ details.
+
+properties:
+ $nodename:
+ pattern: '^gpio-virtio(-[a-z0-9]+)?$'
+
+ compatible:
+ const: virtio,29
+
+ gpio-controller: true
+
+ "#gpio-cells":
+ const: 2
+
+ interrupt-controller: true
+
+ "#interrupt-cells":
+ const: 2
+
+required:
+ - compatible
+ - gpio-controller
+ - "#gpio-cells"
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ virtio@3000 {
+ compatible = "virtio,mmio";
+ reg = <0x3000 0x100>;
+ interrupts = <41>;
+
+ gpio: gpio-virtio {
+ compatible = "virtio,29";
+ gpio-controller;
+ #gpio-cells = <2>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ };
+ };
+
+...
--
2.31.1.272.g89b43f80a514

2021-07-26 08:15:54

by Arnd Bergmann

[permalink] [raw]
Subject: Re: [PATCH V3 3/5] dt-bindings: gpio: Add bindings for gpio-virtio

On Mon, Jul 26, 2021 at 6:53 AM Viresh Kumar <[email protected]> wrote:
>
> This patch adds binding for virtio GPIO controller, it is based on
> virtio-device bindings.
>
> Signed-off-by: Viresh Kumar <[email protected]>

Reviewed-by: Arnd Bergmann <[email protected]>, except

> +
> +properties:
> + $nodename:
> + pattern: '^gpio-virtio(-[a-z0-9]+)?$'
> +
> + gpio: gpio-virtio {
> + compatible = "virtio,29";

The node name here does not appear to be mandated by the schema, but
most others name it "gpio", so I would do the same here instead of
"gpio-virtio".

Arnd

2021-07-26 15:12:12

by Rob Herring

[permalink] [raw]
Subject: Re: [PATCH V3 3/5] dt-bindings: gpio: Add bindings for gpio-virtio

On Sun, Jul 25, 2021 at 10:52 PM Viresh Kumar <[email protected]> wrote:
>
> This patch adds binding for virtio GPIO controller, it is based on
> virtio-device bindings.
>
> Signed-off-by: Viresh Kumar <[email protected]>
> ---
> .../devicetree/bindings/gpio/gpio-virtio.yaml | 60 +++++++++++++++++++
> 1 file changed, 60 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
>
> diff --git a/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml b/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
> new file mode 100644
> index 000000000000..96108cfb7a08
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
> @@ -0,0 +1,60 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/gpio/gpio-virtio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Virtio GPIO controller
> +
> +maintainers:
> + - Viresh Kumar <[email protected]>
> +
> +allOf:
> + - $ref: /schemas/gpio/gpio.yaml#

You don't need to include this.

> + - $ref: /schemas/virtio/virtio-device.yaml#
> +
> +description:
> + Virtio GPIO controller, see /schemas/virtio/virtio-device.yaml for more
> + details.
> +
> +properties:
> + $nodename:
> + pattern: '^gpio-virtio(-[a-z0-9]+)?$'
> +
> + compatible:
> + const: virtio,29
> +
> + gpio-controller: true
> +
> + "#gpio-cells":
> + const: 2
> +
> + interrupt-controller: true
> +
> + "#interrupt-cells":
> + const: 2
> +
> +required:
> + - compatible
> + - gpio-controller
> + - "#gpio-cells"
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + virtio@3000 {
> + compatible = "virtio,mmio";
> + reg = <0x3000 0x100>;
> + interrupts = <41>;
> +
> + gpio: gpio-virtio {
> + compatible = "virtio,29";
> + gpio-controller;
> + #gpio-cells = <2>;
> + interrupt-controller;
> + #interrupt-cells = <2>;
> + };
> + };
> +
> +...
> --
> 2.31.1.272.g89b43f80a514
>

2021-09-13 09:23:49

by Alexey Kardashevskiy

[permalink] [raw]
Subject: Re: [PATCH V3 5/5] virtio: Bind virtio device to device-tree node



On 26/07/2021 14:51, Viresh Kumar wrote:
> Bind the virtio devices with their of_node. This will help users of the
> virtio devices to mention their dependencies on the device in the DT
> itself. Like GPIO pin users can use the phandle of the device node, or
> the node may contain more subnodes to add i2c or spi eeproms and other
> users.
>
> Reviewed-by: Arnd Bergmann <[email protected]>
> Signed-off-by: Viresh Kumar <[email protected]>
> ---
> drivers/virtio/virtio.c | 57 ++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 54 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> index 4b15c00c0a0a..d001e84a5b23 100644
> --- a/drivers/virtio/virtio.c
> +++ b/drivers/virtio/virtio.c
> @@ -4,6 +4,7 @@
> #include <linux/virtio_config.h>
> #include <linux/module.h>
> #include <linux/idr.h>
> +#include <linux/of.h>
> #include <uapi/linux/virtio_ids.h>
>
> /* Unique numbering for virtio devices. */
> @@ -292,6 +293,9 @@ static int virtio_dev_remove(struct device *_d)
>
> /* Acknowledge the device's existence again. */
> virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
> +
> + of_node_put(dev->dev.of_node);
> +
> return 0;
> }
>
> @@ -319,6 +323,43 @@ void unregister_virtio_driver(struct virtio_driver *driver)
> }
> EXPORT_SYMBOL_GPL(unregister_virtio_driver);
>
> +static int virtio_device_of_init(struct virtio_device *dev)
> +{
> + struct device_node *np, *pnode = dev_of_node(dev->dev.parent);
> + char compat[] = "virtio,XXXXXXXX"; /* Reserve enough space 32-bit id */
> + int ret, count;
> +
> + if (!pnode)
> + return 0;
> +
> + count = of_get_available_child_count(pnode);
> + if (!count)
> + return 0;
> +
> + /* There can be only 1 child node */
> + if (WARN_ON(count > 1))
> + return -EINVAL;
> +
> + np = of_get_next_available_child(pnode, NULL);
> + if (WARN_ON(!np))
> + return -ENODEV;
> +
> + BUG_ON(snprintf(compat, sizeof(compat), "virtio,%x", dev->id.device) >=
> + sizeof(compat));
> +
> + if (!of_device_is_compatible(np, compat)) {


This broke powerpc/pseries as there these virtio devices are PCI so
there is no "compat" - PCI vendor id/device ids play role of "compat".
Thanks,




> + ret = -EINVAL;
> + goto out;
> + }
> +
> + dev->dev.of_node = np;
> + return 0;
> +
> +out:
> + of_node_put(np);
> + return ret;
> +}
> +
> /**
> * register_virtio_device - register virtio device
> * @dev : virtio device to be registered
> @@ -343,6 +384,10 @@ int register_virtio_device(struct virtio_device *dev)
> dev->index = err;
> dev_set_name(&dev->dev, "virtio%u", dev->index);
>
> + err = virtio_device_of_init(dev);
> + if (err)
> + goto out_ida_remove;
> +
> spin_lock_init(&dev->config_lock);
> dev->config_enabled = false;
> dev->config_change_pending = false;
> @@ -362,10 +407,16 @@ int register_virtio_device(struct virtio_device *dev)
> */
> err = device_add(&dev->dev);
> if (err)
> - ida_simple_remove(&virtio_index_ida, dev->index);
> + goto out_of_node_put;
> +
> + return 0;
> +
> +out_of_node_put:
> + of_node_put(dev->dev.of_node);
> +out_ida_remove:
> + ida_simple_remove(&virtio_index_ida, dev->index);
> out:
> - if (err)
> - virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
> + virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
> return err;
> }
> EXPORT_SYMBOL_GPL(register_virtio_device);
>

--
Alexey

2021-09-13 09:46:46

by Michael S. Tsirkin

[permalink] [raw]
Subject: Re: [PATCH V3 5/5] virtio: Bind virtio device to device-tree node

On Mon, Sep 13, 2021 at 07:19:17PM +1000, Alexey Kardashevskiy wrote:
>
>
> On 26/07/2021 14:51, Viresh Kumar wrote:
> > Bind the virtio devices with their of_node. This will help users of the
> > virtio devices to mention their dependencies on the device in the DT
> > itself. Like GPIO pin users can use the phandle of the device node, or
> > the node may contain more subnodes to add i2c or spi eeproms and other
> > users.
> >
> > Reviewed-by: Arnd Bergmann <[email protected]>
> > Signed-off-by: Viresh Kumar <[email protected]>
> > ---
> > drivers/virtio/virtio.c | 57 ++++++++++++++++++++++++++++++++++++++---
> > 1 file changed, 54 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> > index 4b15c00c0a0a..d001e84a5b23 100644
> > --- a/drivers/virtio/virtio.c
> > +++ b/drivers/virtio/virtio.c
> > @@ -4,6 +4,7 @@
> > #include <linux/virtio_config.h>
> > #include <linux/module.h>
> > #include <linux/idr.h>
> > +#include <linux/of.h>
> > #include <uapi/linux/virtio_ids.h>
> >
> > /* Unique numbering for virtio devices. */
> > @@ -292,6 +293,9 @@ static int virtio_dev_remove(struct device *_d)
> >
> > /* Acknowledge the device's existence again. */
> > virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
> > +
> > + of_node_put(dev->dev.of_node);
> > +
> > return 0;
> > }
> >
> > @@ -319,6 +323,43 @@ void unregister_virtio_driver(struct virtio_driver *driver)
> > }
> > EXPORT_SYMBOL_GPL(unregister_virtio_driver);
> >
> > +static int virtio_device_of_init(struct virtio_device *dev)
> > +{
> > + struct device_node *np, *pnode = dev_of_node(dev->dev.parent);
> > + char compat[] = "virtio,XXXXXXXX"; /* Reserve enough space 32-bit id */
> > + int ret, count;
> > +
> > + if (!pnode)
> > + return 0;
> > +
> > + count = of_get_available_child_count(pnode);
> > + if (!count)
> > + return 0;
> > +
> > + /* There can be only 1 child node */
> > + if (WARN_ON(count > 1))
> > + return -EINVAL;
> > +
> > + np = of_get_next_available_child(pnode, NULL);
> > + if (WARN_ON(!np))
> > + return -ENODEV;
> > +
> > + BUG_ON(snprintf(compat, sizeof(compat), "virtio,%x", dev->id.device) >=
> > + sizeof(compat));
> > +
> > + if (!of_device_is_compatible(np, compat)) {
>
>
> This broke powerpc/pseries as there these virtio devices are PCI so
> there is no "compat" - PCI vendor id/device ids play role of "compat".
> Thanks,

Hmm now that you say this I wonder why do we bother
with this check, too. When can this be invoked for something
that is not a virtio device? And is it enough to just
skip of_node initialization then?


>
>
>
> > + ret = -EINVAL;


So basically ret = 0 above?


> > + goto out;
> > + }
> > +
> > + dev->dev.of_node = np;
> > + return 0;
> > +
> > +out:
> > + of_node_put(np);
> > + return ret;
> > +}
> > +
> > /**
> > * register_virtio_device - register virtio device
> > * @dev : virtio device to be registered
> > @@ -343,6 +384,10 @@ int register_virtio_device(struct virtio_device *dev)
> > dev->index = err;
> > dev_set_name(&dev->dev, "virtio%u", dev->index);
> >
> > + err = virtio_device_of_init(dev);
> > + if (err)
> > + goto out_ida_remove;
> > +
> > spin_lock_init(&dev->config_lock);
> > dev->config_enabled = false;
> > dev->config_change_pending = false;
> > @@ -362,10 +407,16 @@ int register_virtio_device(struct virtio_device *dev)
> > */
> > err = device_add(&dev->dev);
> > if (err)
> > - ida_simple_remove(&virtio_index_ida, dev->index);
> > + goto out_of_node_put;
> > +
> > + return 0;
> > +
> > +out_of_node_put:
> > + of_node_put(dev->dev.of_node);
> > +out_ida_remove:
> > + ida_simple_remove(&virtio_index_ida, dev->index);
> > out:
> > - if (err)
> > - virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
> > + virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
> > return err;
> > }
> > EXPORT_SYMBOL_GPL(register_virtio_device);
> >
>
> --
> Alexey

2021-09-13 10:38:49

by Alexey Kardashevskiy

[permalink] [raw]
Subject: Re: [PATCH V3 5/5] virtio: Bind virtio device to device-tree node



On 13/09/2021 19:45, Michael S. Tsirkin wrote:
> On Mon, Sep 13, 2021 at 07:19:17PM +1000, Alexey Kardashevskiy wrote:
>>
>>
>> On 26/07/2021 14:51, Viresh Kumar wrote:
>>> Bind the virtio devices with their of_node. This will help users of the
>>> virtio devices to mention their dependencies on the device in the DT
>>> itself. Like GPIO pin users can use the phandle of the device node, or
>>> the node may contain more subnodes to add i2c or spi eeproms and other
>>> users.
>>>
>>> Reviewed-by: Arnd Bergmann <[email protected]>
>>> Signed-off-by: Viresh Kumar <[email protected]>
>>> ---
>>> drivers/virtio/virtio.c | 57 ++++++++++++++++++++++++++++++++++++++---
>>> 1 file changed, 54 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
>>> index 4b15c00c0a0a..d001e84a5b23 100644
>>> --- a/drivers/virtio/virtio.c
>>> +++ b/drivers/virtio/virtio.c
>>> @@ -4,6 +4,7 @@
>>> #include <linux/virtio_config.h>
>>> #include <linux/module.h>
>>> #include <linux/idr.h>
>>> +#include <linux/of.h>
>>> #include <uapi/linux/virtio_ids.h>
>>>
>>> /* Unique numbering for virtio devices. */
>>> @@ -292,6 +293,9 @@ static int virtio_dev_remove(struct device *_d)
>>>
>>> /* Acknowledge the device's existence again. */
>>> virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
>>> +
>>> + of_node_put(dev->dev.of_node);
>>> +
>>> return 0;
>>> }
>>>
>>> @@ -319,6 +323,43 @@ void unregister_virtio_driver(struct virtio_driver *driver)
>>> }
>>> EXPORT_SYMBOL_GPL(unregister_virtio_driver);
>>>
>>> +static int virtio_device_of_init(struct virtio_device *dev)
>>> +{
>>> + struct device_node *np, *pnode = dev_of_node(dev->dev.parent);
>>> + char compat[] = "virtio,XXXXXXXX"; /* Reserve enough space 32-bit id */
>>> + int ret, count;
>>> +
>>> + if (!pnode)
>>> + return 0;
>>> +
>>> + count = of_get_available_child_count(pnode);
>>> + if (!count)
>>> + return 0;
>>> +
>>> + /* There can be only 1 child node */
>>> + if (WARN_ON(count > 1))
>>> + return -EINVAL;
>>> +
>>> + np = of_get_next_available_child(pnode, NULL);
>>> + if (WARN_ON(!np))
>>> + return -ENODEV;
>>> +
>>> + BUG_ON(snprintf(compat, sizeof(compat), "virtio,%x", dev->id.device) >=
>>> + sizeof(compat));
>>> +
>>> + if (!of_device_is_compatible(np, compat)) {
>>
>>
>> This broke powerpc/pseries as there these virtio devices are PCI so
>> there is no "compat" - PCI vendor id/device ids play role of "compat".
>> Thanks,
>
> Hmm now that you say this I wonder why do we bother
> with this check, too. When can this be invoked for something
> that is not a virtio device? And is it enough to just
> skip of_node initialization then?


I am not following here, the problem device is virtio-scsi which is
virtio-derived, or you meant that virtio which hosts virtio-bus?

>
>>
>>
>>
>>> + ret = -EINVAL;
>
>
> So basically ret = 0 above?


Yup, this does fix it. Thanks,

>
>
>>> + goto out;
>>> + }
>>> +
>>> + dev->dev.of_node = np;
>>> + return 0;
>>> +
>>> +out:
>>> + of_node_put(np);
>>> + return ret;
>>> +}
>>> +
>>> /**
>>> * register_virtio_device - register virtio device
>>> * @dev : virtio device to be registered
>>> @@ -343,6 +384,10 @@ int register_virtio_device(struct virtio_device *dev)
>>> dev->index = err;
>>> dev_set_name(&dev->dev, "virtio%u", dev->index);
>>>
>>> + err = virtio_device_of_init(dev);
>>> + if (err)
>>> + goto out_ida_remove;
>>> +
>>> spin_lock_init(&dev->config_lock);
>>> dev->config_enabled = false;
>>> dev->config_change_pending = false;
>>> @@ -362,10 +407,16 @@ int register_virtio_device(struct virtio_device *dev)
>>> */
>>> err = device_add(&dev->dev);
>>> if (err)
>>> - ida_simple_remove(&virtio_index_ida, dev->index);
>>> + goto out_of_node_put;
>>> +
>>> + return 0;
>>> +
>>> +out_of_node_put:
>>> + of_node_put(dev->dev.of_node);
>>> +out_ida_remove:
>>> + ida_simple_remove(&virtio_index_ida, dev->index);
>>> out:
>>> - if (err)
>>> - virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
>>> + virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
>>> return err;
>>> }
>>> EXPORT_SYMBOL_GPL(register_virtio_device);
>>>
>>
>> --
>> Alexey
>

--
Alexey

2021-09-13 15:39:14

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH V3 5/5] virtio: Bind virtio device to device-tree node

On Mon, Jul 26, 2021 at 10:21:45AM +0530, Viresh Kumar wrote:
> Bind the virtio devices with their of_node. This will help users of the
> virtio devices to mention their dependencies on the device in the DT
> itself. Like GPIO pin users can use the phandle of the device node, or
> the node may contain more subnodes to add i2c or spi eeproms and other
> users.
>
> Reviewed-by: Arnd Bergmann <[email protected]>
> Signed-off-by: Viresh Kumar <[email protected]>

This patch causes a boot failure on sparc64: The virtio device no longer
instantiates. Reverting this patch fixes the problem. Bisect log attached.

Guenter

---
# bad: [6880fa6c56601bb8ed59df6c30fd390cc5f6dd8f] Linux 5.15-rc1
# good: [926de8c4326c14fcf35f1de142019043597a4fac] Merge tag 'acpi-5.15-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
git bisect start 'HEAD' '926de8c4326c'
# good: [8177a5c96229ff24da1e362789e359b68b4f34f5] Merge tag 'libata-5.15-2021-09-11' of git://git.kernel.dk/linux-block
git bisect good 8177a5c96229ff24da1e362789e359b68b4f34f5
# bad: [78e709522d2c012cb0daad2e668506637bffb7c2] Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
git bisect bad 78e709522d2c012cb0daad2e668506637bffb7c2
# bad: [7bc7f61897b66bef78bb5952e3d1e9f3aaf9ccca] Documentation: Add documentation for VDUSE
git bisect bad 7bc7f61897b66bef78bb5952e3d1e9f3aaf9ccca
# bad: [41116599a0731f4cd451e9d191d879ab45e31945] virtio/vsock: add 'VIRTIO_VSOCK_SEQ_EOR' bit.
git bisect bad 41116599a0731f4cd451e9d191d879ab45e31945
# good: [5262912ef3cfc5e518892c3d67fb36412cb813e2] vdpa/mlx5: Add support for control VQ and MAC setting
git bisect good 5262912ef3cfc5e518892c3d67fb36412cb813e2
# good: [7f815fce08d563006e43d1b7d2f9a0a4f3b832f3] dt-bindings: i2c: Add bindings for i2c-virtio
git bisect good 7f815fce08d563006e43d1b7d2f9a0a4f3b832f3
# good: [d5a8680dfab0547a4ecd708b1fe9de48598a6757] uapi: virtio_ids: Sync ids with specification
git bisect good d5a8680dfab0547a4ecd708b1fe9de48598a6757
# bad: [9af8f1061646e8e22b66413bedf7b3e2ab3d69e5] virtio/vsock: rename 'EOR' to 'EOM' bit.
git bisect bad 9af8f1061646e8e22b66413bedf7b3e2ab3d69e5
# bad: [694a1116b405d887c893525a6766b390989c8606] virtio: Bind virtio device to device-tree node
git bisect bad 694a1116b405d887c893525a6766b390989c8606
# first bad commit: [694a1116b405d887c893525a6766b390989c8606] virtio: Bind virtio device to device-tree node

2021-09-13 16:23:23

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH V3 5/5] virtio: Bind virtio device to device-tree node

On Mon, Sep 13, 2021 at 07:49:07AM -0700, Guenter Roeck wrote:
> On Mon, Jul 26, 2021 at 10:21:45AM +0530, Viresh Kumar wrote:
> > Bind the virtio devices with their of_node. This will help users of the
> > virtio devices to mention their dependencies on the device in the DT
> > itself. Like GPIO pin users can use the phandle of the device node, or
> > the node may contain more subnodes to add i2c or spi eeproms and other
> > users.
> >
> > Reviewed-by: Arnd Bergmann <[email protected]>
> > Signed-off-by: Viresh Kumar <[email protected]>
>
> This patch causes a boot failure on sparc64: The virtio device no longer
> instantiates. Reverting this patch fixes the problem. Bisect log attached.
>

In case it matters: The problem is here:

+ if (!of_device_is_compatible(np, compat)) {
+ ret = -EINVAL;
+ goto out;
+ }

Guenter

> Guenter
>
> ---
> # bad: [6880fa6c56601bb8ed59df6c30fd390cc5f6dd8f] Linux 5.15-rc1
> # good: [926de8c4326c14fcf35f1de142019043597a4fac] Merge tag 'acpi-5.15-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
> git bisect start 'HEAD' '926de8c4326c'
> # good: [8177a5c96229ff24da1e362789e359b68b4f34f5] Merge tag 'libata-5.15-2021-09-11' of git://git.kernel.dk/linux-block
> git bisect good 8177a5c96229ff24da1e362789e359b68b4f34f5
> # bad: [78e709522d2c012cb0daad2e668506637bffb7c2] Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
> git bisect bad 78e709522d2c012cb0daad2e668506637bffb7c2
> # bad: [7bc7f61897b66bef78bb5952e3d1e9f3aaf9ccca] Documentation: Add documentation for VDUSE
> git bisect bad 7bc7f61897b66bef78bb5952e3d1e9f3aaf9ccca
> # bad: [41116599a0731f4cd451e9d191d879ab45e31945] virtio/vsock: add 'VIRTIO_VSOCK_SEQ_EOR' bit.
> git bisect bad 41116599a0731f4cd451e9d191d879ab45e31945
> # good: [5262912ef3cfc5e518892c3d67fb36412cb813e2] vdpa/mlx5: Add support for control VQ and MAC setting
> git bisect good 5262912ef3cfc5e518892c3d67fb36412cb813e2
> # good: [7f815fce08d563006e43d1b7d2f9a0a4f3b832f3] dt-bindings: i2c: Add bindings for i2c-virtio
> git bisect good 7f815fce08d563006e43d1b7d2f9a0a4f3b832f3
> # good: [d5a8680dfab0547a4ecd708b1fe9de48598a6757] uapi: virtio_ids: Sync ids with specification
> git bisect good d5a8680dfab0547a4ecd708b1fe9de48598a6757
> # bad: [9af8f1061646e8e22b66413bedf7b3e2ab3d69e5] virtio/vsock: rename 'EOR' to 'EOM' bit.
> git bisect bad 9af8f1061646e8e22b66413bedf7b3e2ab3d69e5
> # bad: [694a1116b405d887c893525a6766b390989c8606] virtio: Bind virtio device to device-tree node
> git bisect bad 694a1116b405d887c893525a6766b390989c8606
> # first bad commit: [694a1116b405d887c893525a6766b390989c8606] virtio: Bind virtio device to device-tree node