[RFC 05/18] remoteproc: Create platform device for vdev

From: Arnaud Pouliquen
Date: Thu Apr 16 2020 - 12:14:52 EST

Manage the vdev as a platform device. The platform device is created
when a vdev resource is detected in the resource table.
The rvdev is now managed in rproc_virtio platform.
The rdev->refcount is now useless.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
---
drivers/remoteproc/remoteproc_core.c | 57 +++---
drivers/remoteproc/remoteproc_internal.h | 10 +-
drivers/remoteproc/remoteproc_virtio.c | 213 ++++++++++++++---------
include/linux/remoteproc.h | 9 +-
4 files changed, 175 insertions(+), 114 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 32056449bb72..5dcef62d8d1d 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -31,6 +31,7 @@
#include <linux/idr.h>
#include <linux/elf.h>
#include <linux/crc32.h>
+#include <linux/of_platform.h>
#include <linux/of_reserved_mem.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_ring.h>
@@ -440,7 +441,9 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
int offset, int avail)
{
struct device *dev = &rproc->dev;
- struct rproc_vdev *rvdev;
+ struct rproc_vdev_data vdev_data;
+ struct platform_device *pdev;
+ int ret;

/* make sure resource isn't truncated */
if (struct_size(rsc, vring, rsc->num_of_vrings) + rsc->config_len >
@@ -455,37 +458,43 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
return -EINVAL;
}

- dev_dbg(dev, "vdev rsc: id %d, dfeatures 0x%x, cfg len %d, %d vrings\n",
- rsc->id, rsc->dfeatures, rsc->config_len, rsc->num_of_vrings);
+ vdev_data.rsc_offset = offset;
+ vdev_data.rsc = rsc;
+ vdev_data.id = rsc->id;
+ vdev_data.index = rproc->nb_vdev;

- /* we currently support only two vrings per rvdev */
- if (rsc->num_of_vrings > ARRAY_SIZE(rvdev->vring)) {
- dev_err(dev, "too many vrings: %d\n", rsc->num_of_vrings);
- return -EINVAL;
+ dev_dbg(dev, "%s: rsc_offset = %d rsc = %p id = %d\n",
+ __func__, vdev_data.rsc_offset, vdev_data.rsc, vdev_data.id);
+
+ pdev = platform_device_register_data(dev, "rproc-virtio",
+ rproc->nb_vdev, &vdev_data,
+ sizeof(vdev_data));
+ ret = PTR_ERR_OR_ZERO(pdev);
+ if (ret) {
+ dev_err(rproc->dev.parent,
+ "failed to create rproc-virtio device\n");
+ return ret;
}
+ rproc->nb_vdev++;

- rvdev = kzalloc(sizeof(*rvdev), GFP_KERNEL);
- if (!rvdev)
- return -ENOMEM;
+ return 0;
+}

- kref_init(&rvdev->refcount);
+static void rproc_vdev_release(struct rproc_vdev *rvdev)
+{
+ struct device *dev = &rvdev->pdev->dev;

- rvdev->rsc = rsc;
- rvdev->rsc_offset = offset;
- rvdev->id = rsc->id;
- rvdev->rproc = rproc;
- rvdev->index = rproc->nb_vdev++;
+ if (!dev->of_node)
+ platform_device_unregister(rvdev->pdev);
+}

+void rproc_register_rvdev(struct rproc *rproc, struct rproc_vdev *rvdev)
+{
list_add_tail(&rvdev->node, &rproc->rvdevs);
-
- return rproc_virtio_device_add(rvdev);
}

-void rproc_vdev_release(struct kref *ref)
+void rproc_unregister_rvdev(struct rproc_vdev *rvdev)
{
- struct rproc_vdev *rvdev = container_of(ref, struct rproc_vdev, refcount);
-
- rproc_virtio_device_remove(rvdev);
list_del(&rvdev->node);
}

@@ -1192,9 +1201,9 @@ static void rproc_resource_cleanup(struct rproc *rproc)
kfree(entry);
}

- /* clean up remote vdev entries */
+ /* clean up virtio platform devices */
list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node)
- kref_put(&rvdev->refcount, rproc_vdev_release);
+ rproc_vdev_release(rvdev);

rproc_coredump_cleanup(rproc);
}
diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
index fad95f1a50c1..f5eaffac2fcd 100644
--- a/drivers/remoteproc/remoteproc_internal.h
+++ b/drivers/remoteproc/remoteproc_internal.h
@@ -24,10 +24,18 @@ struct rproc_debug_trace {
struct rproc_mem_entry trace_mem;
};

+struct rproc_vdev_data {
+ u32 rsc_offset;
+ struct fw_rsc_vdev *rsc;
+ unsigned int id;
+ unsigned int index;
+};
+
/* from remoteproc_core.c */
void rproc_release(struct kref *kref);
irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id);
-void rproc_vdev_release(struct kref *ref);
+void rproc_register_rvdev(struct rproc *rproc, struct rproc_vdev *rvdev);
+void rproc_unregister_rvdev(struct rproc_vdev *rvdev);

/* from remoteproc_virtio.c */
int rproc_virtio_device_add(struct rproc_vdev *rvdev);
diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index 0f7efac7d4f3..2a0f33ccd929 100644
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -2,6 +2,7 @@
/*
* Remote processor messaging transport (OMAP platform-specific bits)
*
+ * Copyright (C) 2020 ST STMicroelectronics.
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
*
@@ -11,14 +12,15 @@

#include <linux/dma-mapping.h>
#include <linux/export.h>
+#include <linux/module.h>
#include <linux/of_reserved_mem.h>
+#include <linux/platform_device.h>
#include <linux/remoteproc.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_ring.h>
#include <linux/err.h>
-#include <linux/kref.h>
#include <linux/slab.h>

#include "remoteproc_internal.h"
@@ -296,41 +298,23 @@ static const struct virtio_config_ops rproc_virtio_config_ops = {
.set = rproc_virtio_set,
};

-/**
- * rproc_rvdev_release() - release the existence of a rvdev
- *
- * @dev: the subdevice's dev
- */
-static void rproc_virtio_rvdev_release(struct device *dev)
-{
- struct rproc_vdev *rvdev = container_of(dev, struct rproc_vdev, dev);
-
- of_reserved_mem_device_release(dev);
-
- kfree(rvdev);
-}
-
-/*
- * This function is called whenever vdev is released, and is responsible
- * to decrement the remote processor's refcount which was taken when vdev was
- * added.
- *
- * Never call this function directly; it will be called by the driver
- * core when needed.
- */
static void rproc_virtio_dev_release(struct device *dev)
{
struct virtio_device *vdev = dev_to_virtio(dev);
- struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
struct rproc *rproc = vdev_to_rproc(vdev);

- kfree(vdev);
-
- kref_put(&rvdev->refcount, rproc_vdev_release);
-
put_device(&rproc->dev);
}

+static void rproc_virtio_dev_init(struct rproc_vdev *rvdev)
+{
+ memset(&rvdev->vdev, 0, sizeof(rvdev->vdev));
+ rvdev->vdev.dev.parent = &rvdev->pdev->dev;
+ rvdev->vdev.dev.release = rproc_virtio_dev_release;
+ rvdev->vdev.config = &rproc_virtio_config_ops;
+ rvdev->vdev.id.device = rvdev->id;
+}
+
/**
* rproc_vdev_start() - register an rproc-induced virtio device
* @subdev: the rproc virtio subdevice
@@ -345,8 +329,8 @@ static int rproc_vitio_start(struct rproc_subdev *subdev)
struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev,
subdev);
struct rproc *rproc = rvdev->rproc;
- struct device *dev = &rvdev->dev;
- struct virtio_device *vdev;
+ struct device *dev = &rvdev->pdev->dev;
+ struct virtio_device *vdev = &rvdev->vdev;
struct rproc_mem_entry *mem;
int ret;

@@ -387,29 +371,15 @@ static int rproc_vitio_start(struct rproc_subdev *subdev)
}

/* Allocate virtio device */
- vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
- if (!vdev) {
- ret = -ENOMEM;
- goto out;
- }
- vdev->id.device = rvdev->id,
- vdev->config = &rproc_virtio_config_ops,
- vdev->dev.parent = dev;
- vdev->dev.release = rproc_virtio_dev_release;
+ rproc_virtio_dev_init(rvdev);

/*
* We're indirectly making a non-temporary copy of the rproc pointer
* here, because drivers probed with this vdev will indirectly
* access the wrapping rproc.
- *
- * Therefore we must increment the rproc refcount here, and decrement
- * it _only_ when the vdev is released.
*/
get_device(&rproc->dev);

- /* Reference the vdev and vring allocations */
- kref_get(&rvdev->refcount);
-
ret = register_virtio_device(vdev);
if (ret) {
put_device(&vdev->dev);
@@ -427,17 +397,9 @@ static int rproc_vitio_start(struct rproc_subdev *subdev)
static int rproc_remove_virtio_dev(struct device *dev, void *data)
{
struct virtio_device *vdev = dev_to_virtio(dev);
- struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
- struct rproc_vring *rvring;
- int id;

unregister_virtio_device(vdev);

- for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
- rvring = &rvdev->vring[id];
- rproc_free_vring(rvring);
- }
-
return 0;
}
/**
@@ -451,12 +413,12 @@ static void rproc_vitio_stop(struct rproc_subdev *subdev, bool crashed)
{
struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev,
subdev);
+ struct device *dev = &rvdev->pdev->dev;
int ret;

- ret = device_for_each_child(&rvdev->dev, NULL, rproc_remove_virtio_dev);
+ ret = device_for_each_child(dev, NULL, rproc_remove_virtio_dev);
if (ret)
- dev_warn(&rvdev->dev, "can't remove vdev child device: %d\n",
- ret);
+ dev_warn(dev, "can't remove vdev child device: %d\n", ret);
}

static const struct rproc_subdev rproc_virtio_subdev = {
@@ -464,42 +426,35 @@ static const struct rproc_subdev rproc_virtio_subdev = {
.stop = rproc_vitio_stop
};

-int rproc_virtio_device_add(struct rproc_vdev *rvdev)
+static int rproc_virtio_bind(struct device *dev)
{
+ struct rproc_vdev *rvdev = dev_get_drvdata(dev);
struct rproc *rproc = rvdev->rproc;
struct fw_rsc_vdev *rsc = rvdev->rsc;
- char name[16];
int ret, i;

- /* Initialise vdev subdevice */
- snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
- rvdev->dev.parent = &rproc->dev;
- rvdev->dev.dma_pfn_offset = rproc->dev.parent->dma_pfn_offset;
- rvdev->dev.release = rproc_virtio_rvdev_release;
- dev_set_name(&rvdev->dev, "%s#%s", dev_name(rvdev->dev.parent), name);
- dev_set_drvdata(&rvdev->dev, rvdev);
+ /* test if a resource has been associated to the vdev */
+ if (!rvdev->rsc)
+ return 0;

- ret = device_register(&rvdev->dev);
- if (ret) {
- put_device(&rvdev->dev);
- return ret;
- }
- /* Make device dma capable by inheriting from parent's capabilities */
- set_dma_ops(&rvdev->dev, get_dma_ops(rproc->dev.parent));
+ dev_dbg(dev, "vdev rsc: id %d, dfeatures 0x%x, cfg len %d, %d vrings\n",
+ rsc->id, rsc->dfeatures, rsc->config_len, rsc->num_of_vrings);

- ret = dma_coerce_mask_and_coherent(&rvdev->dev,
- dma_get_mask(rproc->dev.parent));
- if (ret) {
- dev_warn(&rvdev->dev,
- "Failed to set DMA mask %llx. Trying to continue... %x\n",
- dma_get_mask(rproc->dev.parent), ret);
+ /* we currently support only two vrings per rvdev */
+ if (rsc->num_of_vrings > ARRAY_SIZE(rvdev->vring)) {
+ dev_err(dev, "too many vrings: %d\n", rsc->num_of_vrings);
+ return -EINVAL;
}

+ /* If no resource table or no vdev nothing to do */
+ if (!rsc || !rsc->num_of_vrings)
+ return 0;
+
/* parse the vrings */
for (i = 0; i < rsc->num_of_vrings; i++) {
ret = rproc_parse_vring(rvdev, rsc, i);
if (ret)
- goto free_rvdev;
+ return ret;
}

/* allocate the vring resources */
@@ -510,9 +465,12 @@ int rproc_virtio_device_add(struct rproc_vdev *rvdev)
}

rvdev->subdev = rproc_virtio_subdev;
+ rvdev->id = rsc->id;

rproc_add_subdev(rproc, &rvdev->subdev);

+ dev_dbg(dev, "virtio dev %d bound\n", rvdev->index);
+
return 0;

free_vg:
@@ -522,16 +480,103 @@ int rproc_virtio_device_add(struct rproc_vdev *rvdev)
rproc_free_vring(rvring);
}

-free_rvdev:
- device_unregister(&rvdev->dev);
-
return ret;
}

-void rproc_virtio_device_remove(struct rproc_vdev *rvdev)
+static void rproc_virtio_unbind(struct device *dev)
{
+ struct rproc_vdev *rvdev = dev_get_drvdata(dev);
struct rproc *rproc = rvdev->rproc;
+ struct rproc_vring *rvring;
+ int id;
+
+ /*test if a resource has been associated to the vdev */
+ if (!rvdev->rsc)
+ return;
+
+ for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
+ rvring = &rvdev->vring[id];
+ rproc_free_vring(rvring);
+ }

rproc_remove_subdev(rproc, &rvdev->subdev);
- device_unregister(&rvdev->dev);
+
+ dev_dbg(dev, "virtio dev %d unbound\n", rvdev->index);
}
+
+static int rproc_virtio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct rproc_vdev *rvdev;
+ struct rproc *rproc;
+ int ret;
+
+ rvdev = devm_kzalloc(&pdev->dev, sizeof(*rvdev), GFP_KERNEL);
+ if (!rvdev)
+ return -ENOMEM;
+
+ if (dev->of_node) {
+ /*
+ * The platform device is declared in the device tree
+ * retrieve rproc struct through the remoteproc platform
+ */
+ rproc = rproc_get_by_node(dev->parent->of_node);
+
+ /* the reg is used to specify the vdev index */
+ if (of_property_read_u32(np, "reg", &rvdev->index))
+ return -EINVAL;
+ } else {
+ struct rproc_vdev_data *vdev_data = pdev->dev.platform_data;
+
+ if (!vdev_data)
+ return -EINVAL;
+
+ rproc = container_of(dev->parent, struct rproc, dev);
+
+ rvdev->rsc_offset = vdev_data->rsc_offset;
+ rvdev->rsc = vdev_data->rsc;
+ rvdev->id = vdev_data->id;
+ rvdev->index = vdev_data->index;
+
+ ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
+ if (ret)
+ return ret;
+ }
+ rvdev->pdev = pdev;
+ rvdev->rproc = rproc;
+
+ platform_set_drvdata(pdev, rvdev);
+
+ rproc_register_rvdev(rproc, rvdev);
+
+ return rproc_virtio_bind(dev);
+}
+
+static int rproc_virtio_remove(struct platform_device *pdev)
+{
+ rproc_virtio_unbind(&pdev->dev);
+
+ return 0;
+}
+
+/* Platform driver */
+static const struct of_device_id rproc_virtio_match[] = {
+ { .compatible = "rproc-virtio", },
+ {},
+};
+
+static struct platform_driver rproc_virtio_driver = {
+ .probe = rproc_virtio_probe,
+ .remove = rproc_virtio_remove,
+ .driver = {
+ .name = "rproc-virtio",
+ .of_match_table = rproc_virtio_match,
+ },
+};
+
+module_platform_driver(rproc_virtio_driver);
+
+MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>");
+MODULE_DESCRIPTION("Platform bus driver for rproc based virtio devices");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index ab9762563ae0..eb5bd568f11e 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -560,8 +560,8 @@ struct rproc_vring {

/**
* struct rproc_vdev - remoteproc state for a supported virtio device
- * @refcount: reference counter for the vdev and vring allocations
* @subdev: handle for registering the vdev as a rproc subdevice
+ * @pdev: remoteproc virtio platform device
* @id: virtio device id (as in virtio_ids.h)
* @node: list node
* @rproc: the rproc handle
@@ -572,10 +572,9 @@ struct rproc_vring {
* @index: vdev position versus other vdev declared in resource table
*/
struct rproc_vdev {
- struct kref refcount;
-
struct rproc_subdev subdev;
- struct device dev;
+ struct platform_device *pdev;
+ struct virtio_device vdev;

unsigned int id;
struct list_head node;
@@ -628,7 +627,7 @@ int rproc_coredump_add_custom_segment(struct rproc *rproc,

static inline struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
{
- return container_of(vdev->dev.parent, struct rproc_vdev, dev);
+ return container_of(vdev, struct rproc_vdev, vdev);
}

static inline struct rproc *vdev_to_rproc(struct virtio_device *vdev)
--
2.17.1