root/drivers/ufs/core/ufs_bsg.c
// SPDX-License-Identifier: GPL-2.0
/*
 * bsg endpoint that supports UPIUs
 *
 * Copyright (C) 2018 Western Digital Corporation
 */

#include <linux/bsg-lib.h>
#include <linux/dma-mapping.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include "ufs_bsg.h"
#include <ufs/ufshcd.h>
#include "ufshcd-priv.h"

static int ufs_bsg_get_query_desc_size(struct ufs_hba *hba, int *desc_len,
                                       struct utp_upiu_query *qr)
{
        int desc_size = be16_to_cpu(qr->length);

        if (desc_size <= 0)
                return -EINVAL;

        *desc_len = min_t(int, QUERY_DESC_MAX_SIZE, desc_size);

        return 0;
}

static int ufs_bsg_alloc_desc_buffer(struct ufs_hba *hba, struct bsg_job *job,
                                     uint8_t **desc_buff, int *desc_len,
                                     enum query_opcode desc_op)
{
        struct ufs_bsg_request *bsg_request = job->request;
        struct utp_upiu_query *qr;
        u8 *descp;

        if (desc_op != UPIU_QUERY_OPCODE_WRITE_DESC &&
            desc_op != UPIU_QUERY_OPCODE_READ_DESC)
                goto out;

        qr = &bsg_request->upiu_req.qr;
        if (ufs_bsg_get_query_desc_size(hba, desc_len, qr)) {
                dev_err(hba->dev, "Illegal desc size\n");
                return -EINVAL;
        }

        if (*desc_len > job->request_payload.payload_len) {
                dev_err(hba->dev, "Illegal desc size\n");
                return -EINVAL;
        }

        descp = kzalloc(*desc_len, GFP_KERNEL);
        if (!descp)
                return -ENOMEM;

        if (desc_op == UPIU_QUERY_OPCODE_WRITE_DESC)
                sg_copy_to_buffer(job->request_payload.sg_list,
                                  job->request_payload.sg_cnt, descp,
                                  *desc_len);

        *desc_buff = descp;

out:
        return 0;
}

static int ufs_bsg_exec_advanced_rpmb_req(struct ufs_hba *hba, struct bsg_job *job)
{
        struct ufs_rpmb_request *rpmb_request = job->request;
        struct ufs_rpmb_reply *rpmb_reply = job->reply;
        struct bsg_buffer *payload = NULL;
        enum dma_data_direction dir;
        struct scatterlist *sg_list = NULL;
        int rpmb_req_type;
        int sg_cnt = 0;
        int ret;
        int data_len;

        if (hba->ufs_version < ufshci_version(4, 0) || !hba->dev_info.b_advanced_rpmb_en)
                return -EINVAL;

        if (rpmb_request->ehs_req.length != 2 || rpmb_request->ehs_req.ehs_type != 1)
                return -EINVAL;

        rpmb_req_type = be16_to_cpu(rpmb_request->ehs_req.meta.req_resp_type);

        switch (rpmb_req_type) {
        case UFS_RPMB_WRITE_KEY:
        case UFS_RPMB_READ_CNT:
        case UFS_RPMB_PURGE_ENABLE:
                dir = DMA_NONE;
                break;
        case UFS_RPMB_WRITE:
        case UFS_RPMB_SEC_CONF_WRITE:
                dir = DMA_TO_DEVICE;
                break;
        case UFS_RPMB_READ:
        case UFS_RPMB_SEC_CONF_READ:
        case UFS_RPMB_PURGE_STATUS_READ:
                dir = DMA_FROM_DEVICE;
                break;
        default:
                return -EINVAL;
        }

        if (dir != DMA_NONE) {
                payload = &job->request_payload;
                if (!payload->payload_len || !payload->sg_cnt)
                        return -EINVAL;

                sg_cnt = dma_map_sg(hba->host->dma_dev, payload->sg_list, payload->sg_cnt, dir);
                if (unlikely(!sg_cnt))
                        return -ENOMEM;
                sg_list = payload->sg_list;
                data_len = payload->payload_len;
        }

        ret = ufshcd_advanced_rpmb_req_handler(hba, &rpmb_request->bsg_request.upiu_req,
                                   &rpmb_reply->bsg_reply.upiu_rsp, &rpmb_request->ehs_req,
                                   &rpmb_reply->ehs_rsp, sg_cnt, sg_list, dir);

        if (dir != DMA_NONE) {
                dma_unmap_sg(hba->host->dma_dev, payload->sg_list, payload->sg_cnt, dir);

                if (!ret)
                        rpmb_reply->bsg_reply.reply_payload_rcv_len = data_len;
        }

        return ret;
}

static int ufs_bsg_request(struct bsg_job *job)
{
        struct ufs_bsg_request *bsg_request = job->request;
        struct ufs_bsg_reply *bsg_reply = job->reply;
        struct ufs_hba *hba = shost_priv(dev_to_shost(job->dev->parent));
        struct uic_command uc = {};
        int msgcode;
        uint8_t *buff = NULL;
        int desc_len = 0;
        enum query_opcode desc_op = UPIU_QUERY_OPCODE_NOP;
        int ret;
        bool rpmb = false;

        bsg_reply->reply_payload_rcv_len = 0;

        ufshcd_rpm_get_sync(hba);

        msgcode = bsg_request->msgcode;
        switch (msgcode) {
        case UPIU_TRANSACTION_QUERY_REQ:
                desc_op = bsg_request->upiu_req.qr.opcode;
                ret = ufs_bsg_alloc_desc_buffer(hba, job, &buff, &desc_len, desc_op);
                if (ret)
                        goto out;
                fallthrough;
        case UPIU_TRANSACTION_NOP_OUT:
        case UPIU_TRANSACTION_TASK_REQ:
                ret = ufshcd_exec_raw_upiu_cmd(hba, &bsg_request->upiu_req,
                                               &bsg_reply->upiu_rsp, msgcode,
                                               buff, &desc_len, desc_op);
                if (ret)
                        dev_err(hba->dev, "exe raw upiu: error code %d\n", ret);
                else if (desc_op == UPIU_QUERY_OPCODE_READ_DESC && desc_len) {
                        bsg_reply->reply_payload_rcv_len =
                                sg_copy_from_buffer(job->request_payload.sg_list,
                                                    job->request_payload.sg_cnt,
                                                    buff, desc_len);
                }
                break;
        case UPIU_TRANSACTION_UIC_CMD:
                memcpy(&uc, &bsg_request->upiu_req.uc, UIC_CMD_SIZE);
                ret = ufshcd_send_bsg_uic_cmd(hba, &uc);
                if (ret)
                        dev_err(hba->dev, "send uic cmd: error code %d\n", ret);

                memcpy(&bsg_reply->upiu_rsp.uc, &uc, UIC_CMD_SIZE);

                break;
        case UPIU_TRANSACTION_ARPMB_CMD:
                rpmb = true;
                ret = ufs_bsg_exec_advanced_rpmb_req(hba, job);
                if (ret)
                        dev_err(hba->dev, "ARPMB OP failed: error code  %d\n", ret);
                break;
        default:
                ret = -ENOTSUPP;
                dev_err(hba->dev, "unsupported msgcode 0x%x\n", msgcode);

                break;
        }

out:
        ufshcd_rpm_put_sync(hba);
        kfree(buff);
        bsg_reply->result = ret;
        /* complete the job here only if no error */
        if (ret == 0) {
                job->reply_len = rpmb ? sizeof(struct ufs_rpmb_reply) :
                                        sizeof(struct ufs_bsg_reply);
                bsg_job_done(job, ret, bsg_reply->reply_payload_rcv_len);
        }

        return ret;
}

/**
 * ufs_bsg_remove - detach and remove the added ufs-bsg node
 * @hba: per adapter object
 *
 * Should be called when unloading the driver.
 */
void ufs_bsg_remove(struct ufs_hba *hba)
{
        struct device *bsg_dev = &hba->bsg_dev;

        if (!hba->bsg_queue)
                return;

        bsg_remove_queue(hba->bsg_queue);
        hba->bsg_queue = NULL;

        device_del(bsg_dev);
        put_device(bsg_dev);
}

static inline void ufs_bsg_node_release(struct device *dev)
{
        put_device(dev->parent);
}

/**
 * ufs_bsg_probe - Add ufs bsg device node
 * @hba: per adapter object
 *
 * Called during initial loading of the driver, and before scsi_scan_host.
 *
 * Returns: 0 (success).
 */
int ufs_bsg_probe(struct ufs_hba *hba)
{
        struct device *bsg_dev = &hba->bsg_dev;
        struct Scsi_Host *shost = hba->host;
        struct device *parent = &shost->shost_gendev;
        struct request_queue *q;
        int ret;

        device_initialize(bsg_dev);

        bsg_dev->parent = get_device(parent);
        bsg_dev->release = ufs_bsg_node_release;

        dev_set_name(bsg_dev, "ufs-bsg%u", shost->host_no);

        ret = device_add(bsg_dev);
        if (ret)
                goto out;

        q = bsg_setup_queue(bsg_dev, dev_name(bsg_dev), NULL, ufs_bsg_request,
                        NULL, 0);
        if (IS_ERR(q)) {
                ret = PTR_ERR(q);
                device_del(bsg_dev);
                goto out;
        }

        hba->bsg_queue = q;

        return 0;

out:
        dev_err(bsg_dev, "fail to initialize a bsg dev %d\n", shost->host_no);
        put_device(bsg_dev);
        return ret;
}