[PATCH v2 7/9] firmware: arm_ffa: Setup in-kernel users of FFA partitions
Jens Wiklander
jens.wiklander at linaro.org
Sat Nov 28 08:36:55 EST 2020
Hi Sudeep,
On Tue, Nov 03, 2020 at 05:43:48PM +0000, Sudeep Holla wrote:
> Parse the FFA nodes from the device-tree and register all the partitions
> whose services will be used in the kernel.
>
> In order to also enable in-kernel users of FFA interface, 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 at arm.com>
> ---
> drivers/firmware/arm_ffa/bus.c | 2 +
> drivers/firmware/arm_ffa/driver.c | 281 ++++++++++++++++++++++++++++++
> include/linux/arm_ffa.h | 15 ++
> include/uapi/linux/arm_ffa.h | 56 ++++++
> 4 files changed, 354 insertions(+)
> 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 2dbcf356bd8b..de4f8b54271a 100644
> --- a/drivers/firmware/arm_ffa/bus.c
> +++ b/drivers/firmware/arm_ffa/bus.c
> @@ -90,6 +90,7 @@ 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);
> }
>
> @@ -127,6 +128,7 @@ 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 1c4a5e5095b5..2e5fa56fffb7 100644
> --- a/drivers/firmware/arm_ffa/driver.c
> +++ b/drivers/firmware/arm_ffa/driver.c
> @@ -24,9 +24,16 @@
>
> #include <linux/arm_ffa.h>
> #include <linux/bitfield.h>
> +#include <linux/device.h>
> +#include <linux/fs.h>
> #include <linux/io.h>
> +#include <linux/kernel.h>
> #include <linux/module.h>
> +#include <linux/of.h>
> #include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <linux/uuid.h>
> +#include <uapi/linux/arm_ffa.h>
>
> #include "common.h"
>
> @@ -48,6 +55,13 @@
> /* 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[] = {
> @@ -104,6 +118,20 @@ 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;
> @@ -128,6 +156,50 @@ 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)
> {
> @@ -143,6 +215,205 @@ static int ffa_id_get(u16 *vm_id)
> 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 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 const struct ffa_dev_ops ffa_ops;
> +
> +const struct ffa_dev_ops *ffa_dev_ops_get(struct ffa_device *dev)
> +{
> + struct list_head *p;
> + const 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_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:
> + return drv_info->version;
> + case FFA_GET_PARTITION_ID:
> + return ffa_dev->vm_id;
> + 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;
> + }
> + default:
> + r = -EINVAL;
> + }
> +
> + return r;
> +}
> +
> +static const struct ffa_dev_ops ffa_ops = {
> + .open = ffa_dev_open,
> + .close = ffa_dev_close,
> + .ioctl = ffa_dev_ioctl,
> +};
> +
> +static int ffa_device_alloc_register(const char *name, u16 vm_id, uuid_t *uuid,
> + const struct file_operations *fops)
> +{
> + 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)
> + uuid_copy(&ffa_dev->uuid, uuid);
> +
> + dev_set_name(&ffa_dev->dev, name);
> + dev_set_drvdata(&ffa_dev->dev, drv_info);
> + cdev_init(&ffa_dev->cdev, 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;
> +}
> +
> +int ffa_setup_partitions(const char *compatible,
> + const struct file_operations *fops)
> +{
> + int ret;
> + struct ffa_partition_info pbuf;
> + struct device_node *child, *parent;
> + const char *p_uuid, *pfx = "Ignoring FFA partition";
> + 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, fops);
> + 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;
> @@ -192,6 +463,9 @@ static int __init ffa_init(void)
> mutex_init(&drv_info->rx_lock);
> mutex_init(&drv_info->tx_lock);
>
> + /* Set up all the partitions which have in-kernel drivers */
> + ffa_setup_partitions("arm,ffa-1.0", NULL);
> +
> return 0;
> free_pages:
> if (drv_info->tx_buffer)
> @@ -205,6 +479,13 @@ 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 6185d0d12f15..719ef02fe42d 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>
>
> #define FFA_SMC(calling_convention, func_num) \
> ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, (calling_convention), \
> @@ -94,6 +95,9 @@ 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)
> @@ -113,12 +117,19 @@ 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);
> +};
I assume that all interaction with a SP is done via ffa_ops->ioctl().
For example the ffa_msg_send_direct_req() function is then called via:
struct ffa_send_recv_sync arg = { .endpoint_id = xxx, .data = yyy };
rc = ffa_ops->ioctl(ffa_dev, FFA_SEND_RECEIVE_SYNC, &arg);
That isn't too hard to use, but is a bit inconvenient and less safe
compared to a plain:
rc = ffa_ops->send_recieve_sync(ffa_dev, xxx, yyy);
I don't see any big win in then next patch with ffa_ioctl() either. That
function must still do some actions specific for each ioctl id. So I'm a
bit curious about the design choice.
Cheers,
Jens
> +
> #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);
> +const struct ffa_dev_ops *ffa_dev_ops_get(struct ffa_device *dev);
>
> #else
> static inline int ffa_device_register(struct ffa_device *ffa_dev)
> @@ -137,6 +148,10 @@ ffa_driver_register(struct ffa_driver *driver, struct module *owner,
>
> static inline void ffa_driver_unregister(struct ffa_driver *driver) {}
>
> +const struct ffa_dev_ops *ffa_dev_ops_get(struct ffa_device *dev)
> +{
> + return NULL;
> +}
> #endif /* CONFIG_ARM_FFA_TRANSPORT */
>
> #define ffa_register(driver) \
> 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*/
> --
> 2.25.1
>
More information about the linux-arm-kernel
mailing list