xref: /openbmc/linux/drivers/ufs/core/ufs_bsg.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * bsg endpoint that supports UPIUs
4  *
5  * Copyright (C) 2018 Western Digital Corporation
6  */
7 
8 #include <linux/bsg-lib.h>
9 #include <scsi/scsi.h>
10 #include <scsi/scsi_host.h>
11 #include "ufs_bsg.h"
12 #include <ufs/ufshcd.h>
13 #include "ufshcd-priv.h"
14 
15 static int ufs_bsg_get_query_desc_size(struct ufs_hba *hba, int *desc_len,
16 				       struct utp_upiu_query *qr)
17 {
18 	int desc_size = be16_to_cpu(qr->length);
19 	int desc_id = qr->idn;
20 
21 	if (desc_size <= 0)
22 		return -EINVAL;
23 
24 	ufshcd_map_desc_id_to_length(hba, desc_id, desc_len);
25 	if (!*desc_len)
26 		return -EINVAL;
27 
28 	*desc_len = min_t(int, *desc_len, desc_size);
29 
30 	return 0;
31 }
32 
33 static int ufs_bsg_verify_query_size(struct ufs_hba *hba,
34 				     unsigned int request_len,
35 				     unsigned int reply_len)
36 {
37 	int min_req_len = sizeof(struct ufs_bsg_request);
38 	int min_rsp_len = sizeof(struct ufs_bsg_reply);
39 
40 	if (min_req_len > request_len || min_rsp_len > reply_len) {
41 		dev_err(hba->dev, "not enough space assigned\n");
42 		return -EINVAL;
43 	}
44 
45 	return 0;
46 }
47 
48 static int ufs_bsg_alloc_desc_buffer(struct ufs_hba *hba, struct bsg_job *job,
49 				     uint8_t **desc_buff, int *desc_len,
50 				     enum query_opcode desc_op)
51 {
52 	struct ufs_bsg_request *bsg_request = job->request;
53 	struct utp_upiu_query *qr;
54 	u8 *descp;
55 
56 	if (desc_op != UPIU_QUERY_OPCODE_WRITE_DESC &&
57 	    desc_op != UPIU_QUERY_OPCODE_READ_DESC)
58 		goto out;
59 
60 	qr = &bsg_request->upiu_req.qr;
61 	if (ufs_bsg_get_query_desc_size(hba, desc_len, qr)) {
62 		dev_err(hba->dev, "Illegal desc size\n");
63 		return -EINVAL;
64 	}
65 
66 	if (*desc_len > job->request_payload.payload_len) {
67 		dev_err(hba->dev, "Illegal desc size\n");
68 		return -EINVAL;
69 	}
70 
71 	descp = kzalloc(*desc_len, GFP_KERNEL);
72 	if (!descp)
73 		return -ENOMEM;
74 
75 	if (desc_op == UPIU_QUERY_OPCODE_WRITE_DESC)
76 		sg_copy_to_buffer(job->request_payload.sg_list,
77 				  job->request_payload.sg_cnt, descp,
78 				  *desc_len);
79 
80 	*desc_buff = descp;
81 
82 out:
83 	return 0;
84 }
85 
86 static int ufs_bsg_request(struct bsg_job *job)
87 {
88 	struct ufs_bsg_request *bsg_request = job->request;
89 	struct ufs_bsg_reply *bsg_reply = job->reply;
90 	struct ufs_hba *hba = shost_priv(dev_to_shost(job->dev->parent));
91 	unsigned int req_len = job->request_len;
92 	unsigned int reply_len = job->reply_len;
93 	struct uic_command uc = {};
94 	int msgcode;
95 	uint8_t *desc_buff = NULL;
96 	int desc_len = 0;
97 	enum query_opcode desc_op = UPIU_QUERY_OPCODE_NOP;
98 	int ret;
99 
100 	ret = ufs_bsg_verify_query_size(hba, req_len, reply_len);
101 	if (ret)
102 		goto out;
103 
104 	bsg_reply->reply_payload_rcv_len = 0;
105 
106 	ufshcd_rpm_get_sync(hba);
107 
108 	msgcode = bsg_request->msgcode;
109 	switch (msgcode) {
110 	case UPIU_TRANSACTION_QUERY_REQ:
111 		desc_op = bsg_request->upiu_req.qr.opcode;
112 		ret = ufs_bsg_alloc_desc_buffer(hba, job, &desc_buff,
113 						&desc_len, desc_op);
114 		if (ret) {
115 			ufshcd_rpm_put_sync(hba);
116 			goto out;
117 		}
118 
119 		fallthrough;
120 	case UPIU_TRANSACTION_NOP_OUT:
121 	case UPIU_TRANSACTION_TASK_REQ:
122 		ret = ufshcd_exec_raw_upiu_cmd(hba, &bsg_request->upiu_req,
123 					       &bsg_reply->upiu_rsp, msgcode,
124 					       desc_buff, &desc_len, desc_op);
125 		if (ret)
126 			dev_err(hba->dev,
127 				"exe raw upiu: error code %d\n", ret);
128 
129 		break;
130 	case UPIU_TRANSACTION_UIC_CMD:
131 		memcpy(&uc, &bsg_request->upiu_req.uc, UIC_CMD_SIZE);
132 		ret = ufshcd_send_uic_cmd(hba, &uc);
133 		if (ret)
134 			dev_err(hba->dev,
135 				"send uic cmd: error code %d\n", ret);
136 
137 		memcpy(&bsg_reply->upiu_rsp.uc, &uc, UIC_CMD_SIZE);
138 
139 		break;
140 	default:
141 		ret = -ENOTSUPP;
142 		dev_err(hba->dev, "unsupported msgcode 0x%x\n", msgcode);
143 
144 		break;
145 	}
146 
147 	ufshcd_rpm_put_sync(hba);
148 
149 	if (!desc_buff)
150 		goto out;
151 
152 	if (desc_op == UPIU_QUERY_OPCODE_READ_DESC && desc_len)
153 		bsg_reply->reply_payload_rcv_len =
154 			sg_copy_from_buffer(job->request_payload.sg_list,
155 					    job->request_payload.sg_cnt,
156 					    desc_buff, desc_len);
157 
158 	kfree(desc_buff);
159 
160 out:
161 	bsg_reply->result = ret;
162 	job->reply_len = sizeof(struct ufs_bsg_reply);
163 	/* complete the job here only if no error */
164 	if (ret == 0)
165 		bsg_job_done(job, ret, bsg_reply->reply_payload_rcv_len);
166 
167 	return ret;
168 }
169 
170 /**
171  * ufs_bsg_remove - detach and remove the added ufs-bsg node
172  * @hba: per adapter object
173  *
174  * Should be called when unloading the driver.
175  */
176 void ufs_bsg_remove(struct ufs_hba *hba)
177 {
178 	struct device *bsg_dev = &hba->bsg_dev;
179 
180 	if (!hba->bsg_queue)
181 		return;
182 
183 	bsg_remove_queue(hba->bsg_queue);
184 
185 	device_del(bsg_dev);
186 	put_device(bsg_dev);
187 }
188 
189 static inline void ufs_bsg_node_release(struct device *dev)
190 {
191 	put_device(dev->parent);
192 }
193 
194 /**
195  * ufs_bsg_probe - Add ufs bsg device node
196  * @hba: per adapter object
197  *
198  * Called during initial loading of the driver, and before scsi_scan_host.
199  */
200 int ufs_bsg_probe(struct ufs_hba *hba)
201 {
202 	struct device *bsg_dev = &hba->bsg_dev;
203 	struct Scsi_Host *shost = hba->host;
204 	struct device *parent = &shost->shost_gendev;
205 	struct request_queue *q;
206 	int ret;
207 
208 	device_initialize(bsg_dev);
209 
210 	bsg_dev->parent = get_device(parent);
211 	bsg_dev->release = ufs_bsg_node_release;
212 
213 	dev_set_name(bsg_dev, "ufs-bsg%u", shost->host_no);
214 
215 	ret = device_add(bsg_dev);
216 	if (ret)
217 		goto out;
218 
219 	q = bsg_setup_queue(bsg_dev, dev_name(bsg_dev), ufs_bsg_request, NULL, 0);
220 	if (IS_ERR(q)) {
221 		ret = PTR_ERR(q);
222 		goto out;
223 	}
224 
225 	hba->bsg_queue = q;
226 
227 	return 0;
228 
229 out:
230 	dev_err(bsg_dev, "fail to initialize a bsg dev %d\n", shost->host_no);
231 	put_device(bsg_dev);
232 	return ret;
233 }
234