[PATCH 9/9] firmware: arm_ffa: Setup in-kernel users of FFA partitions

Sudeep Holla
2020-08-29T17:11:52Z

In order to also enable in-kernel users of FFA interface along with
the access to user-space applications, let us add simple set of operations
for such devices.

The in-kernel users are registered without the character device interface.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
drivers/firmware/arm_ffa/driver.c | 119 ++++++++++++++++++++++++++----
include/linux/arm_ffa.h | 12 +++
2 files changed, 117 insertions(+), 14 deletions(-)

diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index 96113e594db6..811558ef2a1d 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -372,6 +372,97 @@ static void ffa_device_put(struct ffa_device *ffa_dev)
mutex_unlock(&ffa_dev->mutex);
}

+static int ffa_dev_open(struct ffa_device *ffa_dev)
+{
+ ffa_device_get(ffa_dev);
+
+ return 0;
+}
+
+static int ffa_dev_close(struct ffa_device *ffa_dev)
+{
+ ffa_device_put(ffa_dev);
+
+ return 0;
+}
+
+static long
+ffa_dev_ioctl(struct ffa_device *ffa_dev, unsigned int ioctl, void *arg)
+{
+ long r = -EINVAL;
+
+ switch (ioctl) {
+ case FFA_GET_API_VERSION:
+ r = drv_info->version;
+ break;
+ case FFA_GET_PARTITION_ID:
+ r = ffa_dev->vm_id;
+ break;
+ case FFA_GET_PARTITION_INFO: {
+ struct ffa_part_info *pinfo = arg;
+
+ if (ffa_partition_probe(pinfo->uuid_str, &pinfo->info) != 1)
+ r = -E2BIG;
+ break;
+ }
+ case FFA_SEND_RECEIVE_SYNC: {
+ struct ffa_send_recv_sync *kdata = arg;
+
+ r = ffa_msg_send_direct_req(ffa_dev->vm_id, kdata->endpoint_id,
+ &kdata->data);
+ break;
+ }
+ case FFA_SEND_RECEIVE_ASYNC: {
+ struct ffa_send_recv_async *kdata = arg;
+
+ if (kdata->length < 0 || kdata->length > RXTX_BUFFER_SIZE) {
+ r = -EINVAL;
+ break;
+ }
+
+ r = ffa_msg_send(ffa_dev->vm_id, kdata->endpoint_id,
+ kdata->buffer, kdata->length);
+ break;
+ }
+ default:
+ r = -EINVAL;
+ }
+
+ return r;
+}
+
+struct ffa_dev_ops ffa_ops = {
+ .open = ffa_dev_open,
+ .close = ffa_dev_close,
+ .ioctl = ffa_dev_ioctl,
+};
+
+struct ffa_dev_ops *ffa_dev_ops_get(struct ffa_device *dev)
+{
+ struct list_head *p;
+ struct ffa_dev_ops *ops = NULL;
+
+ if (uuid_is_null(&dev->uuid))
+ return NULL;
+
+ mutex_lock(&ffa_devs_list_mutex);
+
+ list_for_each(p, &ffa_devs_list) {
+ struct ffa_device *tmp_dev;
+
+ tmp_dev = list_to_ffa_dev(p);
+
+ if (uuid_equal(&tmp_dev->uuid, &dev->uuid)) {
+ ops = &ffa_ops;
+ break;
+ }
+ }
+
+ mutex_unlock(&ffa_devs_list_mutex);
+
+ return ops;
+}
+
static int ffa_open(struct inode *inode, struct file *filp)
{
struct ffa_device *ffa_dev;
@@ -380,7 +471,7 @@ static int ffa_open(struct inode *inode, struct file *filp)
if (!ffa_dev)
return -EINVAL;

- ffa_device_get(ffa_dev);
+ ffa_dev_open(ffa_dev);

filp->private_data = ffa_dev;

@@ -391,7 +482,7 @@ static int ffa_release(struct inode *inode, struct file *filp)
{
struct ffa_device *ffa_dev = filp->private_data;

- ffa_device_put(ffa_dev);
+ ffa_dev_close(ffa_dev);

filp->private_data = NULL;

@@ -406,14 +497,10 @@ static long ffa_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)

switch (ioctl) {
case FFA_GET_API_VERSION:
- if (arg)
- goto out;
- r = drv_info->version;
- break;
case FFA_GET_PARTITION_ID:
if (arg)
goto out;
- r = ffa_dev->vm_id;
+ r = ffa_dev_ioctl(ffa_dev, FFA_GET_PARTITION_ID, NULL);
break;
case FFA_GET_PARTITION_INFO: {
struct ffa_partition_info pbuf;
@@ -499,7 +586,8 @@ static const struct file_operations ffa_fops = {
.llseek = noop_llseek,
};

-static int ffa_device_alloc_register(const char *name, u16 vm_id, uuid_t *uuid)
+static int ffa_device_alloc_register(const char *name, u16 vm_id,
+ uuid_t *uuid, bool cdev_if)
{
int ret;
struct ffa_device *ffa_dev;
@@ -514,7 +602,7 @@ static int ffa_device_alloc_register(const char *name, u16 vm_id, uuid_t *uuid)

dev_set_name(&ffa_dev->dev, name);
dev_set_drvdata(&ffa_dev->dev, drv_info);
- cdev_init(&ffa_dev->cdev, &ffa_fops);
+ cdev_init(&ffa_dev->cdev, cdev_if ? &ffa_fops : NULL);

ret = ffa_device_register(ffa_dev);
if (ret)
@@ -527,13 +615,13 @@ static int ffa_device_alloc_register(const char *name, u16 vm_id, uuid_t *uuid)
return 0;
}

-static int ffa_setup_partitions(void)
+static int ffa_setup_partitions(bool hyp)
{
int ret;
struct ffa_partition_info pbuf;
struct device_node *child, *parent;
const char *p_uuid, *pfx = "Ignoring FFA partition";
- const char *compatible = "arm,ffa-1.0-hypervisor";
+ const char *compatible = hyp ? "arm,ffa-1.0-hypervisor" : "arm,ffa-1.0";
uuid_t uuid = UUID_INIT(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);

parent = of_find_compatible_node(NULL, NULL, compatible);
@@ -567,7 +655,7 @@ static int ffa_setup_partitions(void)
return -EINVAL;
}

- ret = ffa_device_alloc_register(p_uuid, pbuf.id, &uuid);
+ ret = ffa_device_alloc_register(p_uuid, pbuf.id, &uuid, hyp);
if (ret) {
pr_err("%s: failed to register %s\n", pfx, p_uuid);
continue;
@@ -624,12 +712,15 @@ static int __init ffa_init(void)
mutex_init(&drv_info->tx_lock);

/* This will be default device both in theguests and host */
- ret = ffa_device_alloc_register("self", drv_info->vm_id, NULL);
+ ret = ffa_device_alloc_register("self", drv_info->vm_id, NULL, true);
if (ret)
return ret;

/* Set up all the partitions that KVM hypervisor maintains */
- ffa_setup_partitions();
+ ffa_setup_partitions(true);
+
+ /* Set up all the partitions which have in-kernel drivers */
+ ffa_setup_partitions(false);

return 0;
free_pages:
diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h
index 6824e0633c77..1df7399d207d 100644
--- a/include/linux/arm_ffa.h
+++ b/include/linux/arm_ffa.h
@@ -11,6 +11,7 @@
#include <linux/module.h>
#include <linux/types.h>
#include <linux/uuid.h>
+#include <uapi/linux/arm_ffa.h>

struct ffa_device {
u32 vm_id;
@@ -39,12 +40,19 @@ struct ffa_driver {

#define to_ffa_driver(d) container_of(d, struct ffa_driver, driver)

+struct ffa_dev_ops {
+ int (*open)(struct ffa_device *dev);
+ int (*close)(struct ffa_device *dev);
+ long (*ioctl)(struct ffa_device *dev, unsigned int ioctl, void *arg);
+};
+
#if IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT)
int ffa_device_register(struct ffa_device *ffa_dev);
void ffa_device_unregister(struct ffa_device *ffa_dev);
int ffa_driver_register(struct ffa_driver *driver, struct module *owner,
const char *mod_name);
void ffa_driver_unregister(struct ffa_driver *driver);
+struct ffa_dev_ops *ffa_dev_ops_get(struct ffa_device *dev);

#else
static inline int ffa_device_register(struct ffa_device *ffa_dev)
@@ -63,6 +71,10 @@ ffa_driver_register(struct ffa_driver *driver, struct module *owner,

static inline void ffa_driver_unregister(struct ffa_driver *driver) {}

+struct ffa_dev_ops *ffa_dev_ops_get(struct ffa_device *dev)
+{
+ return NULL;
+}
#endif /* CONFIG_ARM_FFA_TRANSPORT */

#define ffa_register(driver) \
--
2.17.1