drivers/scsi/ufs/ufs_bsg.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * bsg endpoint that supports UPIUs
   4  *
   5  * Copyright (C) 2018 Western Digital Corporation
   6  */
   7 #include "ufs_bsg.h"
   8
   9 static int ufs_bsg_get_query_desc_size(struct ufs_hba *hba, int *desc_len,
  10                                        struct utp_upiu_query *qr)
  11 {
  12         int desc_size = be16_to_cpu(qr->length);
  13         int desc_id = qr->idn;
  14         int ret;
  15
  16         if (desc_size <= 0)
  17                 return -EINVAL;
  18
  19         ret = ufshcd_map_desc_id_to_length(hba, desc_id, desc_len);
  20         if (ret || !*desc_len)
  21                 return -EINVAL;
  22
  23         *desc_len = min_t(int, *desc_len, desc_size);
  24
  25         return 0;
  26 }
  27
  28 static int ufs_bsg_verify_query_size(struct ufs_hba *hba,
  29                                      unsigned int request_len,
  30                                      unsigned int reply_len)
  31 {
  32         int min_req_len = sizeof(struct ufs_bsg_request);
  33         int min_rsp_len = sizeof(struct ufs_bsg_reply);
  34
  35         if (min_req_len > request_len || min_rsp_len > reply_len) {
  36                 dev_err(hba->dev, "not enough space assigned\n");
  37                 return -EINVAL;
  38         }
  39
  40         return 0;
  41 }
  42
  43 static int ufs_bsg_alloc_desc_buffer(struct ufs_hba *hba, struct bsg_job *job,
  44                                      uint8_t **desc_buff, int *desc_len,
  45                                      enum query_opcode desc_op)
  46 {
  47         struct ufs_bsg_request *bsg_request = job->request;
  48         struct utp_upiu_query *qr;
  49         u8 *descp;
  50
  51         if (desc_op != UPIU_QUERY_OPCODE_WRITE_DESC &&
  52             desc_op != UPIU_QUERY_OPCODE_READ_DESC)
  53                 goto out;
  54
  55         qr = &bsg_request->upiu_req.qr;
  56         if (ufs_bsg_get_query_desc_size(hba, desc_len, qr)) {
  57                 dev_err(hba->dev, "Illegal desc size\n");
  58                 return -EINVAL;
  59         }
  60
  61         if (*desc_len > job->request_payload.payload_len) {
  62                 dev_err(hba->dev, "Illegal desc size\n");
  63                 return -EINVAL;
  64         }
  65
  66         descp = kzalloc(*desc_len, GFP_KERNEL);
  67         if (!descp)
  68                 return -ENOMEM;
  69
  70         if (desc_op == UPIU_QUERY_OPCODE_WRITE_DESC)
  71                 sg_copy_to_buffer(job->request_payload.sg_list,
  72                                   job->request_payload.sg_cnt, descp,
  73                                   *desc_len);
  74
  75         *desc_buff = descp;
  76
  77 out:
  78         return 0;
  79 }
  80
  81 static int ufs_bsg_request(struct bsg_job *job)
  82 {
  83         struct ufs_bsg_request *bsg_request = job->request;
  84         struct ufs_bsg_reply *bsg_reply = job->reply;
  85         struct ufs_hba *hba = shost_priv(dev_to_shost(job->dev->parent));
  86         unsigned int req_len = job->request_len;
  87         unsigned int reply_len = job->reply_len;
  88         struct uic_command uc = {};
  89         int msgcode;
  90         uint8_t *desc_buff = NULL;
  91         int desc_len = 0;
  92         enum query_opcode desc_op = UPIU_QUERY_OPCODE_NOP;
  93         int ret;
  94
  95         ret = ufs_bsg_verify_query_size(hba, req_len, reply_len);
  96         if (ret)
  97                 goto out;
  98
  99         bsg_reply->reply_payload_rcv_len = 0;
 100
 101         msgcode = bsg_request->msgcode;
 102         switch (msgcode) {
 103         case UPIU_TRANSACTION_QUERY_REQ:
 104                 desc_op = bsg_request->upiu_req.qr.opcode;
 105                 ret = ufs_bsg_alloc_desc_buffer(hba, job, &desc_buff,
 106                                                 &desc_len, desc_op);
 107                 if (ret)
 108                         goto out;
 109
 110                 /* fall through */
 111         case UPIU_TRANSACTION_NOP_OUT:
 112         case UPIU_TRANSACTION_TASK_REQ:
 113                 ret = ufshcd_exec_raw_upiu_cmd(hba, &bsg_request->upiu_req,
 114                                                &bsg_reply->upiu_rsp, msgcode,
 115                                                desc_buff, &desc_len, desc_op);
 116                 if (ret)
 117                         dev_err(hba->dev,
 118                                 "exe raw upiu: error code %d\n", ret);
 119
 120                 break;
 121         case UPIU_TRANSACTION_UIC_CMD:
 122                 memcpy(&uc, &bsg_request->upiu_req.uc, UIC_CMD_SIZE);
 123                 ret = ufshcd_send_uic_cmd(hba, &uc);
 124                 if (ret)
 125                         dev_dbg(hba->dev,
 126                                 "send uic cmd: error code %d\n", ret);
 127
 128                 memcpy(&bsg_reply->upiu_rsp.uc, &uc, UIC_CMD_SIZE);
 129
 130                 break;
 131         default:
 132                 ret = -ENOTSUPP;
 133                 dev_err(hba->dev, "unsupported msgcode 0x%x\n", msgcode);
 134
 135                 break;
 136         }
 137
 138         if (!desc_buff)
 139                 goto out;
 140
 141         if (desc_op == UPIU_QUERY_OPCODE_READ_DESC && desc_len)
 142                 bsg_reply->reply_payload_rcv_len =
 143                         sg_copy_from_buffer(job->request_payload.sg_list,
 144                                             job->request_payload.sg_cnt,
 145                                             desc_buff, desc_len);
 146
 147         kfree(desc_buff);
 148
 149 out:
 150         bsg_reply->result = ret;
 151         job->reply_len = sizeof(struct ufs_bsg_reply);
 152         bsg_job_done(job, ret, bsg_reply->reply_payload_rcv_len);
 153
 154         return ret;
 155 }
 156
 157 /**
 158  * ufs_bsg_remove - detach and remove the added ufs-bsg node
 159  *
 160  * Should be called when unloading the driver.
 161  */
 162 void ufs_bsg_remove(struct ufs_hba *hba)
 163 {
 164         struct device *bsg_dev = &hba->bsg_dev;
 165
 166         if (!hba->bsg_queue)
 167                 return;
 168
 169         bsg_remove_queue(hba->bsg_queue);
 170
 171         device_del(bsg_dev);
 172         put_device(bsg_dev);
 173 }
 174
 175 static inline void ufs_bsg_node_release(struct device *dev)
 176 {
 177         put_device(dev->parent);
 178 }
 179
 180 /**
 181  * ufs_bsg_probe - Add ufs bsg device node
 182  * @hba: per adapter object
 183  *
 184  * Called during initial loading of the driver, and before scsi_scan_host.
 185  */
 186 int ufs_bsg_probe(struct ufs_hba *hba)
 187 {
 188         struct device *bsg_dev = &hba->bsg_dev;
 189         struct Scsi_Host *shost = hba->host;
 190         struct device *parent = &shost->shost_gendev;
 191         struct request_queue *q;
 192         int ret;
 193
 194         device_initialize(bsg_dev);
 195
 196         bsg_dev->parent = get_device(parent);
 197         bsg_dev->release = ufs_bsg_node_release;
 198
 199         dev_set_name(bsg_dev, "ufs-bsg");
 200
 201         ret = device_add(bsg_dev);
 202         if (ret)
 203                 goto out;
 204
 205         q = bsg_setup_queue(bsg_dev, dev_name(bsg_dev), ufs_bsg_request, NULL, 0);
 206         if (IS_ERR(q)) {
 207                 ret = PTR_ERR(q);
 208                 goto out;
 209         }
 210
 211         hba->bsg_queue = q;
 212
 213         return 0;
 214
 215 out:
 216         dev_err(bsg_dev, "fail to initialize a bsg dev %d\n", shost->host_no);
 217         put_device(bsg_dev);
 218         return ret;
 219 }