Thread (24 messages) 24 messages, 6 authors, 2020-11-03

Re: [PATCH 8/9] firmware: arm_ffa: Setup and register all the KVM managed partitions

From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Date: 2020-09-01 16:36:33
Also in: linux-arm-kernel

On Sat, 29 Aug 2020 18:09:22 +0100
Sudeep Holla [off-list ref] wrote:
Parse the FFA nodes from the device-tree and register all the partitions
managed by the KVM hypervisor.

All the partitions including the host(self) are registered as the
character device with a set of file operations. Most of the interface
will concentrated in the ioctl.

For now, we have a tiny set of initial ioctls implemented.

Signed-off-by: Sudeep Holla <redacted>
A few trivial comments inline.
---
 drivers/firmware/arm_ffa/bus.c    |   2 +
 drivers/firmware/arm_ffa/driver.c | 378 +++++++++++++++++++++++++++++-
 include/linux/arm_ffa.h           |   3 +
 include/uapi/linux/arm_ffa.h      |  56 +++++
 4 files changed, 438 insertions(+), 1 deletion(-)
 create mode 100644 include/uapi/linux/arm_ffa.h
...
quoted hunk ↗ jump to hunk
diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index 3670ba400f89..96113e594db6 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -22,11 +22,17 @@
 #define DRIVER_NAME "ARM FF-A"
 #define pr_fmt(fmt) DRIVER_NAME ": " fmt
 
+#include <linux/arm_ffa.h>
 #include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/fs.h>
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/slab.h>
-#include <linux/arm_ffa.h>
Ah. Fix that in the earlier patch rather than adding then moving it.
+#include <linux/uaccess.h>
+#include <linux/uuid.h>
+#include <uapi/linux/arm_ffa.h>
 
 #include "common.h"
 
...
+
+static long ffa_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
+{
+	long r = -EINVAL;
+	void __user *argp = (void __user *)arg;
+	struct ffa_device *ffa_dev = filp->private_data;
+
+	switch (ioctl) {
+	case FFA_GET_API_VERSION:
+		if (arg)
+			goto out;
Perhaps more readable (and a little shorter) with early returns?
+		r = drv_info->version;
+		break;
+	case FFA_GET_PARTITION_ID:
+		if (arg)
+			goto out;
+		r = ffa_dev->vm_id;
+		break;
+	case FFA_GET_PARTITION_INFO: {
+		struct ffa_partition_info pbuf;
+		struct ffa_part_info __user *pinfo = argp;
+		struct ffa_part_info info;
+		unsigned int count;
+
+		r = -EFAULT;
+		if (copy_from_user(&info, pinfo, sizeof(info)))
+			break;
+		count = ffa_partition_probe(info.uuid_str, &pbuf);
+		if (count > 1) {
+			r = -E2BIG;
+			break;
+		}
+		r = -EFAULT;
+		if (copy_to_user(pinfo, &info, sizeof(info)))
+			break;
+		r = 0;
+		break;
+	}
+	case FFA_SEND_RECEIVE_SYNC: {
+		struct ffa_send_recv_sync __user *udata = argp;
+		struct ffa_send_recv_sync kdata;
+
+		r = -EFAULT;
+		if (copy_from_user(&kdata, udata, sizeof(kdata)))
+			break;
+		r = ffa_msg_send_direct_req(ffa_dev->vm_id, kdata.endpoint_id,
+					    &kdata.data);
+		if (r)
+			break;
+		if (copy_to_user(udata, &kdata, sizeof(kdata)))
+			break;
+		break;
+	}
+	case FFA_SEND_RECEIVE_ASYNC: {
+		struct ffa_send_recv_async __user *udata = argp;
+		struct ffa_send_recv_async kdata;
+		void *buf;
+
+		r = -EFAULT;
+		if (copy_from_user(&kdata, udata, sizeof(kdata)))
+			break;
+
+		if (kdata.length < 0 || kdata.length > RXTX_BUFFER_SIZE) {
+			r = -EINVAL;
+			break;
+		}
+
+		buf = kzalloc(kdata.length, GFP_KERNEL);
+		if (!buf) {
+			r = -ENOMEM;
+			break;
+		}
+
+		if (copy_from_user(buf, udata->buffer, kdata.length)) {
+			kfree(buf);
+			break;
+		}
+
+		r = ffa_msg_send(ffa_dev->vm_id, kdata.endpoint_id, buf,
+				 kdata.length);
+		if (r) {
+			kfree(buf);
+			break;
+		}
+
+		break;
+	}
+	default:
+		r = -EINVAL;
+	}
+out:
+	return r;
+}
+
...
quoted hunk ↗ jump to hunk
 static int __init ffa_init(void)
 {
 	int ret;
@@ -262,6 +623,14 @@ static int __init ffa_init(void)
 	mutex_init(&drv_info->rx_lock);
 	mutex_init(&drv_info->tx_lock);
 
+	/* This will be default device both in theguests and host */
the guests
quoted hunk ↗ jump to hunk
+	ret = ffa_device_alloc_register("self", drv_info->vm_id, NULL);
+	if (ret)
+		return ret;
+
+	/* Set up all the partitions that KVM hypervisor maintains */
+	ffa_setup_partitions();
+
 	return 0;
 free_pages:
 	if (drv_info->tx_buffer)
@@ -275,6 +644,13 @@ module_init(ffa_init);
 
 static void __exit ffa_exit(void)
 {
+	struct list_head *p;
+
+	mutex_lock(&ffa_devs_list_mutex);
+	list_for_each(p, &ffa_devs_list)
+		ffa_device_unregister(list_to_ffa_dev(p));
+	mutex_unlock(&ffa_devs_list_mutex);
+
 	ffa_rxtx_unmap(drv_info->vm_id);
 	free_pages_exact(drv_info->tx_buffer, RXTX_BUFFER_SIZE);
 	free_pages_exact(drv_info->rx_buffer, RXTX_BUFFER_SIZE);
...

Jonathan
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