1 /*******************************************************************************
2 * SCSI RDMA Protocol lib functions
4 * Copyright (C) 2006 FUJITA Tomonori <tomof@acm.org>
5 * Copyright (C) 2016 Bryant G. Ly <bryantly@linux.vnet.ibm.com> IBM Corp.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 ***********************************************************************/
19 #define pr_fmt(fmt) "libsrp: " fmt
21 #include <linux/printk.h>
22 #include <linux/err.h>
23 #include <linux/slab.h>
24 #include <linux/kfifo.h>
25 #include <linux/scatterlist.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/module.h>
29 #include <target/target_core_base.h>
31 #include "ibmvscsi_tgt.h"
33 static int srp_iu_pool_alloc(struct srp_queue *q, size_t max,
34 struct srp_buf **ring)
39 q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL);
42 q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL);
46 spin_lock_init(&q->lock);
47 kfifo_init(&q->queue, (void *)q->pool, max * sizeof(void *));
49 for (i = 0, iue = q->items; i < max; i++) {
50 kfifo_in(&q->queue, (void *)&iue, sizeof(void *));
61 static void srp_iu_pool_free(struct srp_queue *q)
67 static struct srp_buf **srp_ring_alloc(struct device *dev,
68 size_t max, size_t size)
70 struct srp_buf **ring;
73 ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
77 for (i = 0; i < max; i++) {
78 ring[i] = kzalloc(sizeof(*ring[i]), GFP_KERNEL);
81 ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
89 for (i = 0; i < max && ring[i]; i++) {
91 dma_free_coherent(dev, size, ring[i]->buf,
101 static void srp_ring_free(struct device *dev, struct srp_buf **ring,
102 size_t max, size_t size)
106 for (i = 0; i < max; i++) {
107 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
113 int srp_target_alloc(struct srp_target *target, struct device *dev,
114 size_t nr, size_t iu_size)
118 spin_lock_init(&target->lock);
122 target->srp_iu_size = iu_size;
123 target->rx_ring_size = nr;
124 target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
125 if (!target->rx_ring)
127 err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
131 dev_set_drvdata(target->dev, target);
135 srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
139 void srp_target_free(struct srp_target *target)
141 dev_set_drvdata(target->dev, NULL);
142 srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
143 target->srp_iu_size);
144 srp_iu_pool_free(&target->iu_queue);
147 struct iu_entry *srp_iu_get(struct srp_target *target)
149 struct iu_entry *iue = NULL;
151 if (kfifo_out_locked(&target->iu_queue.queue, (void *)&iue,
153 &target->iu_queue.lock) != sizeof(void *)) {
154 WARN_ONCE(1, "unexpected fifo state");
159 iue->target = target;
164 void srp_iu_put(struct iu_entry *iue)
166 kfifo_in_locked(&iue->target->iu_queue.queue, (void *)&iue,
167 sizeof(void *), &iue->target->iu_queue.lock);
170 static int srp_direct_data(struct ibmvscsis_cmd *cmd, struct srp_direct_buf *md,
171 enum dma_data_direction dir, srp_rdma_t rdma_io,
172 int dma_map, int ext_desc)
174 struct iu_entry *iue = NULL;
175 struct scatterlist *sg = NULL;
176 int err, nsg = 0, len;
180 sg = cmd->se_cmd.t_data_sg;
181 nsg = dma_map_sg(iue->target->dev, sg, cmd->se_cmd.t_data_nents,
184 pr_err("fail to map %p %d\n", iue,
185 cmd->se_cmd.t_data_nents);
188 len = min(cmd->se_cmd.data_length, be32_to_cpu(md->len));
190 len = be32_to_cpu(md->len);
193 err = rdma_io(cmd, sg, nsg, md, 1, dir, len);
196 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
201 static int srp_indirect_data(struct ibmvscsis_cmd *cmd, struct srp_cmd *srp_cmd,
202 struct srp_indirect_buf *id,
203 enum dma_data_direction dir, srp_rdma_t rdma_io,
204 int dma_map, int ext_desc)
206 struct iu_entry *iue = NULL;
207 struct srp_direct_buf *md = NULL;
208 struct scatterlist dummy, *sg = NULL;
209 dma_addr_t token = 0;
211 int nmd, nsg = 0, len;
213 if (dma_map || ext_desc) {
215 sg = cmd->se_cmd.t_data_sg;
218 nmd = be32_to_cpu(id->table_desc.len) / sizeof(struct srp_direct_buf);
220 if ((dir == DMA_FROM_DEVICE && nmd == srp_cmd->data_in_desc_cnt) ||
221 (dir == DMA_TO_DEVICE && nmd == srp_cmd->data_out_desc_cnt)) {
222 md = &id->desc_list[0];
226 if (ext_desc && dma_map) {
227 md = dma_alloc_coherent(iue->target->dev,
228 be32_to_cpu(id->table_desc.len),
231 pr_err("Can't get dma memory %u\n",
232 be32_to_cpu(id->table_desc.len));
236 sg_init_one(&dummy, md, be32_to_cpu(id->table_desc.len));
237 sg_dma_address(&dummy) = token;
238 sg_dma_len(&dummy) = be32_to_cpu(id->table_desc.len);
239 err = rdma_io(cmd, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
240 be32_to_cpu(id->table_desc.len));
242 pr_err("Error copying indirect table %d\n", err);
246 pr_err("This command uses external indirect buffer\n");
252 nsg = dma_map_sg(iue->target->dev, sg, cmd->se_cmd.t_data_nents,
255 pr_err("fail to map %p %d\n", iue,
256 cmd->se_cmd.t_data_nents);
260 len = min(cmd->se_cmd.data_length, be32_to_cpu(id->len));
262 len = be32_to_cpu(id->len);
265 err = rdma_io(cmd, sg, nsg, md, nmd, dir, len);
268 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
271 if (token && dma_map) {
272 dma_free_coherent(iue->target->dev,
273 be32_to_cpu(id->table_desc.len), md, token);
278 static int data_out_desc_size(struct srp_cmd *cmd)
281 u8 fmt = cmd->buf_fmt >> 4;
284 case SRP_NO_DATA_DESC:
286 case SRP_DATA_DESC_DIRECT:
287 size = sizeof(struct srp_direct_buf);
289 case SRP_DATA_DESC_INDIRECT:
290 size = sizeof(struct srp_indirect_buf) +
291 sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
294 pr_err("client error. Invalid data_out_format %x\n", fmt);
301 * TODO: this can be called multiple times for a single command if it
302 * has very long data.
304 int srp_transfer_data(struct ibmvscsis_cmd *cmd, struct srp_cmd *srp_cmd,
305 srp_rdma_t rdma_io, int dma_map, int ext_desc)
307 struct srp_direct_buf *md;
308 struct srp_indirect_buf *id;
309 enum dma_data_direction dir;
313 if (!cmd->se_cmd.t_data_nents)
316 offset = srp_cmd->add_cdb_len & ~3;
318 dir = srp_cmd_direction(srp_cmd);
319 if (dir == DMA_FROM_DEVICE)
320 offset += data_out_desc_size(srp_cmd);
322 if (dir == DMA_TO_DEVICE)
323 format = srp_cmd->buf_fmt >> 4;
325 format = srp_cmd->buf_fmt & ((1U << 4) - 1);
328 case SRP_NO_DATA_DESC:
330 case SRP_DATA_DESC_DIRECT:
331 md = (struct srp_direct_buf *)(srp_cmd->add_data + offset);
332 err = srp_direct_data(cmd, md, dir, rdma_io, dma_map, ext_desc);
334 case SRP_DATA_DESC_INDIRECT:
335 id = (struct srp_indirect_buf *)(srp_cmd->add_data + offset);
336 err = srp_indirect_data(cmd, srp_cmd, id, dir, rdma_io, dma_map,
340 pr_err("Unknown format %d %x\n", dir, format);
347 u64 srp_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
349 struct srp_direct_buf *md;
350 struct srp_indirect_buf *id;
352 uint offset = cmd->add_cdb_len & ~3;
355 if (dir == DMA_TO_DEVICE) {
356 fmt = cmd->buf_fmt >> 4;
358 fmt = cmd->buf_fmt & ((1U << 4) - 1);
359 offset += data_out_desc_size(cmd);
363 case SRP_NO_DATA_DESC:
365 case SRP_DATA_DESC_DIRECT:
366 md = (struct srp_direct_buf *)(cmd->add_data + offset);
367 len = be32_to_cpu(md->len);
369 case SRP_DATA_DESC_INDIRECT:
370 id = (struct srp_indirect_buf *)(cmd->add_data + offset);
371 len = be32_to_cpu(id->len);
374 pr_err("invalid data format %x\n", fmt);
380 int srp_get_desc_table(struct srp_cmd *srp_cmd, enum dma_data_direction *dir,
383 struct srp_indirect_buf *idb;
384 struct srp_direct_buf *db;
389 * The pointer computations below will only be compiled correctly
390 * if srp_cmd::add_data is declared as s8*, u8*, s8[] or u8[], so check
391 * whether srp_cmd::add_data has been declared as a byte pointer.
393 BUILD_BUG_ON(!__same_type(srp_cmd->add_data[0], (s8)0)
394 && !__same_type(srp_cmd->add_data[0], (u8)0));
404 if (srp_cmd->buf_fmt & 0xf)
405 *dir = DMA_FROM_DEVICE;
406 else if (srp_cmd->buf_fmt >> 4)
407 *dir = DMA_TO_DEVICE;
409 add_cdb_offset = srp_cmd->add_cdb_len & ~3;
410 if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) ||
411 ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) {
412 db = (struct srp_direct_buf *)(srp_cmd->add_data
414 *data_len = be32_to_cpu(db->len);
415 } else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) ||
416 ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) {
417 idb = (struct srp_indirect_buf *)(srp_cmd->add_data
420 *data_len = be32_to_cpu(idb->len);
425 MODULE_DESCRIPTION("SCSI RDMA Protocol lib functions");
426 MODULE_AUTHOR("FUJITA Tomonori");
427 MODULE_LICENSE("GPL");