[PATCH] firmware: arm_scmi: support optee shared memory in optee transport
Etienne Carriere
etienne.carriere at linaro.org
Wed Apr 20 23:36:04 PDT 2022
Dear all,
On Wed, 20 Apr 2022 at 16:23, Etienne Carriere
<etienne.carriere at linaro.org> wrote:
>
> Adds support for tee shared memory in optee scmi transport. When using
> tee shared memory, scmi optee transport manages SCMI messages using
> msg protocol (from msg.c) in shared memory, whereas smt (from shmem.c)
> protocol is used with static IOMEM shared buffers.
>
> Signed-off-by: Etienne Carriere <etienne.carriere at linaro.org>
> ---
> drivers/firmware/arm_scmi/optee.c | 133 ++++++++++++++++++++++++------
> 1 file changed, 109 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
> index 8302a2b4aeeb..6ff51b750b7b 100644
> --- a/drivers/firmware/arm_scmi/optee.c
> +++ b/drivers/firmware/arm_scmi/optee.c
> @@ -64,6 +64,22 @@ enum scmi_optee_pta_cmd {
> * [in] value[0].b: Requested capabilities mask (enum pta_scmi_caps)
> */
> PTA_SCMI_CMD_GET_CHANNEL = 3,
> +
> + /*
> + * PTA_SCMI_CMD_PROCESS_MSG_CHANNEL - Process SCMI message in a MSG
> + * buffer pointed by memref parameters
> + *
> + * [in] value[0].a: Channel handle
> + * [in] memref[1]: Message buffer (MSG and SCMI payload)
> + * [out] memref[2]: Response buffer (MSG and SCMI payload)
> + *
> + * Shared memories used for SCMI message/response are MSG buffers
> + * referenced by param[1] and param[2]. MSG transport protocol
> + * uses a 32bit header to carry SCMI meta-data (protocol ID and
> + * protocol message ID) followed by the effective SCMI message
> + * payload.
> + */
> + PTA_SCMI_CMD_PROCESS_MSG_CHANNEL = 4,
> };
>
> /*
> @@ -72,9 +88,17 @@ enum scmi_optee_pta_cmd {
> * PTA_SCMI_CAPS_SMT_HEADER
> * When set, OP-TEE supports command using SMT header protocol (SCMI shmem) in
> * shared memory buffers to carry SCMI protocol synchronisation information.
> + *
> + * PTA_SCMI_CAPS_MSG_HEADER
> + * When set, OP-TEE supports command using MSG header protocol in an OP-TEE
> + * shared memory to carry SCMI protocol synchronisation information and SCMI
> + * message payload.
> */
> #define PTA_SCMI_CAPS_NONE 0
> #define PTA_SCMI_CAPS_SMT_HEADER BIT(0)
> +#define PTA_SCMI_CAPS_MSG_HEADER BIT(1)
> +#define PTA_SCMI_CAPS_MASK (PTA_SCMI_CAPS_SMT_HEADER | \
> + PTA_SCMI_CAPS_MSG_HEADER)
>
> /**
> * struct scmi_optee_channel - Description of an OP-TEE SCMI channel
> @@ -85,7 +109,8 @@ enum scmi_optee_pta_cmd {
> * @mu: Mutex protection on channel access
> * @cinfo: SCMI channel information
> * @shmem: Virtual base address of the shared memory
> - * @tee_shm: Reference to TEE shared memory or NULL if using static shmem
> + * @req: Shared memory protocol handle for SCMI request and synchronous response
> + * @tee_shm: TEE shared memory handle @req or NULL if using IOMEM shmem
> * @link: Reference in agent's channel list
> */
> struct scmi_optee_channel {
> @@ -94,7 +119,10 @@ struct scmi_optee_channel {
> u32 caps;
> struct mutex mu;
> struct scmi_chan_info *cinfo;
> - struct scmi_shared_mem __iomem *shmem;
> + union {
> + struct scmi_shared_mem __iomem *shmem;
> + struct scmi_msg_payld *msg;
> + } req;
> struct tee_shm *tee_shm;
> struct list_head link;
> };
> @@ -178,8 +206,8 @@ static int get_capabilities(struct scmi_optee_agent *agent)
>
> caps = param[0].u.value.a;
>
> - if (!(caps & PTA_SCMI_CAPS_SMT_HEADER)) {
> - dev_err(agent->dev, "OP-TEE SCMI PTA doesn't support SMT\n");
> + if (!(caps & (PTA_SCMI_CAPS_SMT_HEADER | PTA_SCMI_CAPS_MSG_HEADER))) {
> + dev_err(agent->dev, "OP-TEE SCMI PTA doesn't support SMT and MSG\n");
> return -EOPNOTSUPP;
> }
>
> @@ -193,9 +221,14 @@ static int get_channel(struct scmi_optee_channel *channel)
> struct device *dev = scmi_optee_private->dev;
> struct tee_ioctl_invoke_arg arg = { };
> struct tee_param param[1] = { };
> - unsigned int caps = PTA_SCMI_CAPS_SMT_HEADER;
> + unsigned int caps = 0;
> int ret;
>
> + if (channel->tee_shm)
> + caps = PTA_SCMI_CAPS_MSG_HEADER;
> + else
> + caps = PTA_SCMI_CAPS_SMT_HEADER;
> +
> arg.func = PTA_SCMI_CMD_GET_CHANNEL;
> arg.session = channel->tee_session;
> arg.num_params = 1;
> @@ -249,6 +282,37 @@ static int invoke_process_smt_channel(struct scmi_optee_channel *channel)
> return 0;
> }
>
> +static int invoke_process_msg_channel(struct scmi_optee_channel *channel, size_t msg_size)
> +{
> + struct tee_ioctl_invoke_arg arg = {
> + .func = PTA_SCMI_CMD_PROCESS_MSG_CHANNEL,
> + .session = channel->tee_session,
> + .num_params = 3,
> + };
> + struct tee_param param[3] = { };
> + int ret;
> +
> + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
> + param[0].u.value.a = channel->channel_id;
> +
> + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
> + param[1].u.memref.shm = channel->tee_shm;
> + param[1].u.memref.size = msg_size;
> +
> + param[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
> + param[2].u.memref.shm = channel->tee_shm;
> + param[2].u.memref.size = SCMI_OPTEE_MAX_MSG_SIZE;
> +
> + ret = tee_client_invoke_func(scmi_optee_private->tee_ctx, &arg, param);
> + if (ret < 0 || arg.ret) {
> + dev_err(scmi_optee_private->dev, "Can't invoke channel %u: %d / %#x\n",
> + channel->channel_id, ret, arg.ret);
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> static int scmi_optee_link_supplier(struct device *dev)
> {
> if (!scmi_optee_private) {
> @@ -279,7 +343,26 @@ static void scmi_optee_clear_channel(struct scmi_chan_info *cinfo)
> {
> struct scmi_optee_channel *channel = cinfo->transport_info;
>
> - shmem_clear_channel(channel->shmem);
> + if (!channel->tee_shm)
> + shmem_clear_channel(channel->req.shmem);
> +}
> +
> +static int setup_dynamic_shmem(struct device *dev, struct scmi_optee_channel *channel)
> +{
> + const size_t msg_size = SCMI_OPTEE_MAX_MSG_SIZE;
> + void *shbuf;
> +
> + channel->tee_shm = tee_shm_alloc_kernel_buf(scmi_optee_private->tee_ctx, msg_size);
> + if (IS_ERR(channel->tee_shm)) {
> + dev_err(channel->cinfo->dev, "shmem allocation failed\n");
> + return -ENOMEM;
> + }
> +
> + shbuf = tee_shm_get_va(channel->tee_shm, 0);
> + memset(shbuf, 0, msg_size);
> + channel->req.msg = shbuf;
> +
> + return 0;
> }
>
> static int setup_static_shmem(struct device *dev, struct scmi_chan_info *cinfo,
> @@ -304,8 +387,8 @@ static int setup_static_shmem(struct device *dev, struct scmi_chan_info *cinfo,
>
> size = resource_size(&res);
>
> - channel->shmem = devm_ioremap(dev, res.start, size);
> - if (!channel->shmem) {
> + channel->req.shmem = devm_ioremap(dev, res.start, size);
> + if (!channel->req.shmem) {
> dev_err(dev, "Failed to ioremap SCMI Tx shared memory\n");
> ret = -EADDRNOTAVAIL;
> goto out;
> @@ -325,7 +408,7 @@ static int setup_shmem(struct device *dev, struct scmi_chan_info *cinfo,
> if (of_find_property(cinfo->dev->of_node, "shmem", NULL))
> return setup_static_shmem(dev, cinfo, channel);
> else
> - return -ENOMEM;
> + return setup_dynamic_shmem(dev, channel);
> }
>
> static int scmi_optee_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, bool tx)
> @@ -405,27 +488,27 @@ static int scmi_optee_chan_free(int id, void *p, void *data)
> return 0;
> }
>
> -static struct scmi_shared_mem __iomem *
> -get_channel_shm(struct scmi_optee_channel *chan, struct scmi_xfer *xfer)
> -{
> - if (!chan)
> - return NULL;
> -
> - return chan->shmem;
> -}
> -
> -
> static int scmi_optee_send_message(struct scmi_chan_info *cinfo,
> struct scmi_xfer *xfer)
> {
> struct scmi_optee_channel *channel = cinfo->transport_info;
> - struct scmi_shared_mem __iomem *shmem = get_channel_shm(channel, xfer);
> + u32 scmi_msg_hdr;
> int ret;
>
> mutex_lock(&channel->mu);
> - shmem_tx_prepare(shmem, xfer);
>
> - ret = invoke_process_smt_channel(channel);
> + if (channel->tee_shm) {
> + msg_tx_prepare(channel->req.msg, xfer);
> + ret = invoke_process_msg_channel(channel, msg_command_size(xfer));
> + scmi_msg_hdr = msg_read_header(channel->req.msg);
> + } else {
> + shmem_tx_prepare(channel->req.shmem, xfer);
> + ret = invoke_process_smt_channel(channel);
> + scmi_msg_hdr = shmem_read_header(channel->req.shmem);
> + }
> +
> + scmi_rx_callback(cinfo, scmi_msg_hdr, NULL);
My mistake. Calling scmi_rx_callback() is not needed since
.sync_cmds_completed_on_ret flag is set.
I'll send a v2 removing this call.
Regards,
Etienne
> +
> if (ret)
> mutex_unlock(&channel->mu);
>
> @@ -436,9 +519,11 @@ static void scmi_optee_fetch_response(struct scmi_chan_info *cinfo,
> struct scmi_xfer *xfer)
> {
> struct scmi_optee_channel *channel = cinfo->transport_info;
> - struct scmi_shared_mem __iomem *shmem = get_channel_shm(channel, xfer);
>
> - shmem_fetch_response(shmem, xfer);
> + if (channel->tee_shm)
> + msg_fetch_response(channel->req.msg, SCMI_OPTEE_MAX_MSG_SIZE, xfer);
> + else
> + shmem_fetch_response(channel->req.shmem, xfer);
> }
>
> static void scmi_optee_mark_txdone(struct scmi_chan_info *cinfo, int ret,
> --
> 2.17.1
>
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