On Fri, Sep 21, 2018 at 12:44:22PM +0300, Avri Altman wrote:
> The UFS host software uses a combination of a host register set,
> and Transfer Request Descriptors in system memory to communicate
> with host controller hardware. In its mmio space, a separate places
> are assigned to UTP Transfer Request Descriptor ("utrd") list, and
> to UTP Task Management Request Descriptor ("utmrd") list.
>
> The provided API supports utrd-typed requests: nop out
> and device management commands. It also supports utmrd-type
> requests: task management requests.
> Other UPIU types are not supported for now.
>
> We utilize the already existing code for tag and task work queues.
> That is, all utrd-typed UPIUs are "disguised" as device management
> commands. Similarly, the utmrd-typed UPUIs uses the task management
> infrastructure.
>
> It is up to the caller to fill the upiu request properly,
> as it will be copied without any further input validations.
>
> Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
> ---
> drivers/scsi/ufs/ufs.h | 1 +
> drivers/scsi/ufs/ufshcd.c | 175 ++++++++++++++++++++++++++++++++++++++++++++++
> drivers/scsi/ufs/ufshcd.h | 6 ++
> 3 files changed, 182 insertions(+)
>
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index f5800c32..58087d3 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -414,6 +414,7 @@ enum {
> MASK_RSP_UPIU_DATA_SEG_LEN = 0xFFFF,
> MASK_RSP_EXCEPTION_EVENT = 0x10000,
> MASK_TM_SERVICE_RESP = 0xFF,
> + MASK_TM_FUNC = 0xFF,
> };
>
> /* Task management service response */
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 241710e..f73edf9 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -257,6 +257,7 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
> static irqreturn_t ufshcd_intr(int irq, void *__hba);
> static int ufshcd_change_power_mode(struct ufs_hba *hba,
> struct ufs_pa_layer_attr *pwr_mode);
> +
> static inline bool ufshcd_valid_tag(struct ufs_hba *hba, int tag)
> {
> return tag >= 0 && tag < hba->nutrs;
> @@ -5676,6 +5677,180 @@ static int ufshcd_issue_tm_cmd(struct ufs_hba *hba, int lun_id, int task_id,
> }
>
> /**
> + * ufshcd_issue_devman_upiu_cmd - API for sending "utrd" type requests
> + * @hba: per-adapter instance
> + * @req_upiu: upiu request
> + * @rsp_upiu: upiu reply
> + * @msgcode: message code, one of UPIU Transaction Codes Initiator to Target
> + * @desc_buff: pointer to descriptor buffer, NULL if NA
> + * @buff_len: descriptor size, 0 if NA
> + * @rw: either READ or WRITE
> + *
> + * Those type of requests uses UTP Transfer Request Descriptor - utrd.
> + * Therefore, it "rides" the device management infrastructure: uses its tag and
> + * tasks work queues.
> + *
> + * Since there is only one available tag for device management commands,
> + * the caller is expected to hold the hba->dev_cmd.lock mutex.
> + */
> +static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,
> + struct utp_upiu_req *req_upiu,
> + struct utp_upiu_req *rsp_upiu,
> + u8 *desc_buff, int *buff_len,
> + int cmd_type, int rw)
> +{
> + struct ufshcd_lrb *lrbp;
> + int err = 0;
> + int tag;
> + struct completion wait;
> + unsigned long flags;
> + u32 upiu_flags;
> +
> + down_read(&hba->clk_scaling_lock);
> +
> + wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag));
> +
> + init_completion(&wait);
> + lrbp = &hba->lrb[tag];
> + WARN_ON(lrbp->cmd);
> +
> + lrbp->cmd = NULL;
> + lrbp->sense_bufflen = 0;
> + lrbp->sense_buffer = NULL;
> + lrbp->task_tag = tag;
> + lrbp->lun = 0;
> + lrbp->intr_cmd = true;
> + hba->dev_cmd.type = cmd_type;
> +
> + switch (hba->ufs_version) {
> + case UFSHCI_VERSION_10:
> + case UFSHCI_VERSION_11:
> + lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
> + break;
> + default:
> + lrbp->command_type = UTP_CMD_TYPE_UFS_STORAGE;
> + break;
> + }
> +
> + /* update the task tag in the request upiu */
> + req_upiu->header.dword_0 |= cpu_to_be32(tag);
> +
> + ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
> +
> + /* just copy the upiu request as it is */
> + memcpy(lrbp->ucd_req_ptr, req_upiu, sizeof(*lrbp->ucd_req_ptr));
> + if (desc_buff && rw == WRITE) {
> + /* The Data Segment Area is optional depending upon the query
> + * function value. for WRITE DESCRIPTOR, the data segment
> + * follows right after the tsf.
> + */
> + memcpy(lrbp->ucd_req_ptr + 1, desc_buff, *buff_len);
> + *buff_len = 0;
> + }
> +
> + memset(lrbp->ucd_rsp_ptr, 0, sizeof(struct utp_upiu_rsp));
> +
> + hba->dev_cmd.complete = &wait;
> +
> + /* Make sure descriptors are ready before ringing the doorbell */
> + wmb();
> + spin_lock_irqsave(hba->host->host_lock, flags);
> + ufshcd_send_command(hba, tag);
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> +
> + /*
> + * ignore the returning value here - ufshcd_check_query_response is
> + * bound to fail since dev_cmd.query and dev_cmd.type were left empty.
> + * read the response directly ignoring all errors.
> + */
> + ufshcd_wait_for_dev_cmd(hba, lrbp, QUERY_REQ_TIMEOUT);
> +
> + /* just copy the upiu response as it is */
> + memcpy(rsp_upiu, lrbp->ucd_rsp_ptr, sizeof(*rsp_upiu));
> +
> + ufshcd_put_dev_cmd_tag(hba, tag);
> + wake_up(&hba->dev_cmd.tag_wq);
> + up_read(&hba->clk_scaling_lock);
> + return err;
> +}
> +
> +/**
> + * ufshcd_exec_raw_upiu_cmd - API function for sending raw upiu commands
> + * @hba: per-adapter instance
> + * @req_upiu: upiu request
> + * @rsp_upiu: upiu reply - only 8 DW as we do not support scsi commands
> + * @msgcode: message code, one of UPIU Transaction Codes Initiator to Target
> + * @desc_buff: pointer to descriptor buffer, NULL if NA
> + * @buff_len: descriptor size, 0 if NA
> + * @rw: either READ or WRITE
Actually, this isn't a normal READ vs WRITE, but it is read/write or
none. Either we should move this to a enum dma_data_direction,
or still apply an arbitrary read vs write and check for a 0 buff_len
instead of passing the magic UFS_BSG_NOP later in this series.
