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

Sudeep Holla
2020-08-29T17:11:43Z

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 <sudeep.holla@arm.com>
---
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

diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c
index b5789bd4dfcd..4af354e16750 100644
--- a/drivers/firmware/arm_ffa/bus.c
+++ b/drivers/firmware/arm_ffa/bus.c
@@ -78,6 +78,7 @@ static void ffa_release_device(struct device *dev)
{
struct ffa_device *ffa_dev = to_ffa_dev(dev);

+ mutex_destroy(&ffa_dev->mutex);
kfree(ffa_dev);
}

@@ -115,6 +116,7 @@ int ffa_device_register(struct ffa_device *ffa_dev)

dev = &ffa_dev->dev;
cdev = &ffa_dev->cdev;
+ mutex_init(&ffa_dev->mutex);

dev->bus = &ffa_bus_type;
dev->type = &ffa_dev_type;
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>
+#include <linux/uaccess.h>
+#include <linux/uuid.h>
+#include <uapi/linux/arm_ffa.h>

#include "common.h"

@@ -122,6 +128,13 @@
/* Keeping RX TX buffer size as 64K for now */
#define RXTX_BUFFER_SIZE SZ_64K

+#define list_to_ffa_dev(n) container_of(n, struct ffa_device, node)
+
+/* List of all FFA devices active in system */
+static LIST_HEAD(ffa_devs_list);
+/* Protection for the entire list */
+static DEFINE_MUTEX(ffa_devs_list_mutex);
+
static ffa_fn *invoke_ffa_fn;

static const int ffa_linux_errmap[] = {
@@ -178,6 +191,20 @@ static int ffa_version_check(u32 *version)
return 0;
}

+static int ffa_rx_release(void)
+{
+ ffa_res_t ret;
+
+ ret = invoke_ffa_fn(FFA_RX_RELEASE, 0, 0, 0, 0, 0, 0, 0);
+
+ if (ret.a0 == FFA_ERROR)
+ return ffa_to_linux_errno((int)ret.a2);
+
+ /* check for ret.a0 == FFA_RX_RELEASE ? */
+
+ return 0;
+}
+
static int ffa_rxtx_map(phys_addr_t tx_buf, phys_addr_t rx_buf, u32 pg_cnt)
{
ffa_res_t ret;
@@ -202,6 +229,50 @@ static int ffa_rxtx_unmap(u16 vm_id)
return 0;
}

+static int ffa_partition_info_get(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3,
+ struct ffa_partition_info **buffer)
+{
+ int count;
+ ffa_res_t partition_info;
+
+ mutex_lock(&drv_info->rx_lock);
+ partition_info = invoke_ffa_fn(FFA_PARTITION_INFO_GET, uuid0, uuid1,
+ uuid2, uuid3, 0, 0, 0);
+
+ if (partition_info.a0 == FFA_ERROR)
+ return ffa_to_linux_errno((int)partition_info.a2);
+
+ count = partition_info.a2;
+
+ if (buffer)
+ memcpy(*buffer, drv_info->rx_buffer, sizeof(*buffer) * count);
+
+ ffa_rx_release();
+
+ mutex_unlock(&drv_info->rx_lock);
+
+ return count;
+}
+
+static int ffa_partition_probe(const char *uuid_str,
+ struct ffa_partition_info *buffer)
+{
+ int count;
+ uuid_t uuid;
+ u32 uuid0_4[4] = { 0 };
+
+ if (uuid_parse(uuid_str, &uuid)) {
+ pr_err("invalid uuid (%s)\n", uuid_str);
+ return -ENODEV;
+ }
+
+ export_uuid((u8 *)uuid0_4, &uuid);
+ count = ffa_partition_info_get(uuid0_4[0], uuid0_4[1], uuid0_4[2],
+ uuid0_4[3], &buffer);
+
+ return count;
+}
+
#define VM_ID_MASK GENMASK(15, 0)
static int ffa_id_get(u16 *vm_id)
{
@@ -217,6 +288,296 @@ static int ffa_id_get(u16 *vm_id)
return 0;
}

+static int ffa_msg_send(u16 src_id, u16 dst_id, void *buf, u32 len)
+{
+ ffa_res_t ret;
+ u32 src_dst_ids = PACK_TARGET_INFO(src_id, dst_id);
+
+ mutex_lock(&drv_info->tx_lock);
+
+ memcpy(drv_info->tx_buffer, buf, len);
+
+ ret = invoke_ffa_fn(FFA_MSG_SEND, src_dst_ids, 0, len, 0, 0, 0, 0);
+
+ mutex_unlock(&drv_info->tx_lock);
+
+ if (ret.a0 == FFA_ERROR)
+ return ffa_to_linux_errno((int)ret.a2);
+
+ return 0;
+}
+
+static int ffa_msg_send_direct_req(u16 src_id, u16 dst_id,
+ struct ffa_send_direct_data *data)
+{
+ u32 src_dst_ids = PACK_TARGET_INFO(src_id, dst_id);
+ ffa_res_t ret;
+
+ ret = invoke_ffa_fn(FFA_FN_NATIVE(MSG_SEND_DIRECT_REQ), src_dst_ids, 0,
+ data->data0, data->data1, data->data2,
+ data->data3, data->data4);
+
+ while (ret.a0 == FFA_INTERRUPT)
+ ret = invoke_ffa_fn(FFA_RUN, ret.a1, 0, 0, 0, 0, 0, 0);
+ if (ret.a0 == FFA_ERROR)
+ return ffa_to_linux_errno((int)ret.a2);
+
+ if (ret.a0 == FFA_FN_NATIVE(MSG_SEND_DIRECT_RESP)) {
+ data->data0 = ret.a3;
+ data->data1 = ret.a4;
+ data->data2 = ret.a5;
+ data->data3 = ret.a6;
+ data->data4 = ret.a7;
+ }
+
+ return 0;
+}
+
+static struct ffa_device *ffa_device_get_from_minor(int minor)
+{
+ struct list_head *p;
+ struct ffa_device *ffa_dev = NULL;
+
+ mutex_lock(&ffa_devs_list_mutex);
+
+ list_for_each(p, &ffa_devs_list) {
+ struct device *dev;
+ struct ffa_device *tmp_dev;
+
+ tmp_dev = list_to_ffa_dev(p);
+ dev = &tmp_dev->dev;
+
+ if (minor == MINOR(dev->devt)) {
+ ffa_dev = tmp_dev;
+ break;
+ }
+ }
+
+ mutex_unlock(&ffa_devs_list_mutex);
+
+ return ffa_dev;
+}
+
+static void ffa_device_get(struct ffa_device *ffa_dev)
+{
+ mutex_lock(&ffa_dev->mutex);
+ ffa_dev->num_users++;
+ mutex_unlock(&ffa_dev->mutex);
+}
+
+static void ffa_device_put(struct ffa_device *ffa_dev)
+{
+ mutex_lock(&ffa_dev->mutex);
+ ffa_dev->num_users--;
+ mutex_unlock(&ffa_dev->mutex);
+}
+
+static int ffa_open(struct inode *inode, struct file *filp)
+{
+ struct ffa_device *ffa_dev;
+
+ ffa_dev = ffa_device_get_from_minor(iminor(inode));
+ if (!ffa_dev)
+ return -EINVAL;
+
+ ffa_device_get(ffa_dev);
+
+ filp->private_data = ffa_dev;
+
+ return 0;
+}
+
+static int ffa_release(struct inode *inode, struct file *filp)
+{
+ struct ffa_device *ffa_dev = filp->private_data;
+
+ ffa_device_put(ffa_dev);
+
+ filp->private_data = NULL;
+
+ return 0;
+}
+
+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;
+ 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;
+}
+
+static const struct file_operations ffa_fops = {
+ .owner = THIS_MODULE,
+ .open = ffa_open,
+ .release = ffa_release,
+ .unlocked_ioctl = ffa_ioctl,
+ .llseek = noop_llseek,
+};
+
+static int ffa_device_alloc_register(const char *name, u16 vm_id, uuid_t *uuid)
+{
+ int ret;
+ struct ffa_device *ffa_dev;
+
+ ffa_dev = kzalloc(sizeof(*ffa_dev), GFP_KERNEL);
+ if (!ffa_dev)
+ return -ENOMEM;
+
+ ffa_dev->vm_id = vm_id;
+ if (uuid)
+ memcpy(uuid, &ffa_dev->uuid, sizeof(*uuid));
+
+ dev_set_name(&ffa_dev->dev, name);
+ dev_set_drvdata(&ffa_dev->dev, drv_info);
+ cdev_init(&ffa_dev->cdev, &ffa_fops);
+
+ ret = ffa_device_register(ffa_dev);
+ if (ret)
+ return ret;
+
+ mutex_lock(&ffa_devs_list_mutex);
+ list_add_tail(&ffa_dev->node, &ffa_devs_list);
+ mutex_unlock(&ffa_devs_list_mutex);
+
+ return 0;
+}
+
+static int ffa_setup_partitions(void)
+{
+ 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";
+ uuid_t uuid = UUID_INIT(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
+
+ parent = of_find_compatible_node(NULL, NULL, compatible);
+ if (!parent)
+ return 0;
+
+ for_each_child_of_node(parent, child) {
+ if (!of_device_is_compatible(child, "arm,ffa-1.0-partition")) {
+ of_node_put(child);
+ continue;
+ }
+
+ if (of_property_read_string(child, "uuid", &p_uuid)) {
+ pr_err("%s: failed to parse \"uuid\" property\n", pfx);
+ of_node_put(child);
+ continue;
+ }
+
+ of_node_put(child);
+
+ if (uuid_parse(p_uuid, &uuid)) {
+ pr_err("%s: invalid \"uuid\" property (%s)\n",
+ pfx, p_uuid);
+ continue;
+ }
+
+ ret = ffa_partition_probe(p_uuid, &pbuf);
+ if (ret != 1) {
+ pr_err("%s: %s partition info probe failed\n",
+ pfx, p_uuid);
+ return -EINVAL;
+ }
+
+ ret = ffa_device_alloc_register(p_uuid, pbuf.id, &uuid);
+ if (ret) {
+ pr_err("%s: failed to register %s\n", pfx, p_uuid);
+ continue;
+ }
+ }
+
+ of_node_put(parent);
+ return 0;
+}
+
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 */
+ 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);
diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h
index 2fe16176149f..6824e0633c77 100644
--- a/include/linux/arm_ffa.h
+++ b/include/linux/arm_ffa.h
@@ -17,6 +17,9 @@ struct ffa_device {
uuid_t uuid;
struct device dev;
struct cdev cdev;
+ size_t num_users;
+ struct mutex mutex; /* protects num_users */
+ struct list_head node;
};

#define to_ffa_dev(d) container_of(d, struct ffa_device, dev)
diff --git a/include/uapi/linux/arm_ffa.h b/include/uapi/linux/arm_ffa.h
new file mode 100644
index 000000000000..88ddddb4742f
--- /dev/null
+++ b/include/uapi/linux/arm_ffa.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2020 Arm Ltd.
+ */
+
+#ifndef _UAPI_LINUX_ARM_FFA_H
+#define _UAPI_LINUX_ARM_FFA_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+#define FFA_BASE 0xFF
+
+struct ffa_partition_info {
+ __u16 id;
+ __u16 exec_ctxt;
+/* partition supports receipt of direct requests */
+#define FFA_PARTITION_DIRECT_RECV BIT(0)
+/* partition can send direct requests. */
+#define FFA_PARTITION_DIRECT_SEND BIT(1)
+/* partition can send and receive indirect messages. */
+#define FFA_PARTITION_INDIRECT_MSG BIT(2)
+ __u32 properties;
+};
+
+struct ffa_part_info {
+ char uuid_str[36];
+ struct ffa_partition_info info;
+};
+
+struct ffa_send_direct_data {
+ unsigned long data0;
+ unsigned long data1;
+ unsigned long data2;
+ unsigned long data3;
+ unsigned long data4;
+};
+
+struct ffa_send_recv_sync {
+ __u16 endpoint_id;
+ struct ffa_send_direct_data data;
+};
+
+struct ffa_send_recv_async {
+ __u16 endpoint_id;
+ int length;
+ char buffer[];
+};
+
+#define FFA_GET_API_VERSION _IO(FFA_BASE, 0x00)
+#define FFA_GET_PARTITION_ID _IO(FFA_BASE, 0x01)
+#define FFA_GET_PARTITION_INFO _IOWR(FFA_BASE, 0x02, struct ffa_part_info)
+#define FFA_SEND_RECEIVE_SYNC _IOWR(FFA_BASE, 0x03, struct ffa_send_recv_sync)
+#define FFA_SEND_RECEIVE_ASYNC _IOW(FFA_BASE, 0x04, struct ffa_send_recv_async)
+
+#endif /*_UAPI_LINUX_ARM_FFA_H*/
--
2.17.1