libsrp provides helper functions for SRP target drivers.
The next step would be to add initiator support to merge the two SRP
initiator drivers (ibmvscsi and ib_srp) in mainline.
Some SRP target drivers would be out of drivers/scsi/ so I added an
entry for libsrp in drivers/scsi/Kconfig, though I'm not sure about
it.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
---
drivers/scsi/Kconfig | 9 +
drivers/scsi/Makefile | 1
drivers/scsi/libsrp.c | 448 +++++++++++++++++++++++++++++++++++++++++++++++++
include/scsi/libsrp.h | 75 ++++++++
4 files changed, 533 insertions(+), 0 deletions(-)
create mode 100644 drivers/scsi/libsrp.c
create mode 100644 include/scsi/libsrp.h
04bec8adfeeee4a0b0a04627d5f8b7d6261f0c4a
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 5b5eeb4..cf3558b 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -1834,6 +1834,15 @@ config ZFCP
called zfcp. If you want to compile it as a module, say M here
and read <file:Documentation/modules.txt>.
+config SCSI_SRP
+ tristate "SCSI RDMA Protocol helper library"
+ depends on SCSI
+ help
+ If you wish to use SRP target drivers, say Y.
+
+ To compile this driver as a module, choose M here: the
+ module will be called libsrp.
+
endmenu
source "drivers/scsi/pcmcia/Kconfig"
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 3d81b8d..0779523 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -123,6 +123,7 @@ obj-$(CONFIG_SCSI_FCAL) += fcal.o
obj-$(CONFIG_SCSI_LASI700) += 53c700.o lasi700.o
obj-$(CONFIG_SCSI_NSP32) += nsp32.o
obj-$(CONFIG_SCSI_IPR) += ipr.o
+obj-$(CONFIG_SCSI_SRP) += libsrp.o
obj-$(CONFIG_SCSI_IBMVSCSI) += ibmvscsi/
obj-$(CONFIG_SCSI_SATA_AHCI) += libata.o ahci.o
obj-$(CONFIG_SCSI_SATA_SVW) += libata.o sata_svw.o
diff --git a/drivers/scsi/libsrp.c b/drivers/scsi/libsrp.c
new file mode 100644
index 0000000..2a2cfd6
--- /dev/null
+++ b/drivers/scsi/libsrp.c
@@ -0,0 +1,448 @@
+/*
+ * SCSI RDAM Protocol lib functions
+ *
+ * Copyright (C) 2006 FUJITA Tomonori <tomof@xxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+#include <linux/err.h>
+#include <linux/kfifo.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_tgt.h>
+#include <scsi/srp.h>
+#include <scsi/libsrp.h>
+
+enum srp_task_attributes {
+ SRP_SIMPLE_TASK = 0,
+ SRP_HEAD_TASK = 1,
+ SRP_ORDERED_TASK = 2,
+ SRP_ACA_TASK = 4
+};
+
+/* tmp - will replace with SCSI logging stuff */
+#define eprintk(fmt, args...) \
+do { \
+ printk("%s(%d) " fmt, __FUNCTION__, __LINE__, ##args); \
+} while (0)
+/* #define dprintk eprintk */
+#define dprintk(fmt, args...)
+
+static int srp_iu_pool_alloc(struct srp_queue *q, size_t max,
+ struct srp_buf **ring)
+{
+ int i;
+ struct iu_entry *iue;
+
+ q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL);
+ if (!q->pool)
+ return -ENOMEM;
+ q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL);
+ if (!q->items)
+ goto free_pool;
+
+ spin_lock_init(&q->lock);
+ q->queue = kfifo_init((void *) q->pool, max * sizeof(void *),
+ GFP_KERNEL, &q->lock);
+ if (IS_ERR(q->queue))
+ goto free_item;
+
+ for (i = 0, iue = q->items; i < max; i++) {
+ __kfifo_put(q->queue, (void *) &iue, sizeof(void *));
+ iue->sbuf = ring[i];
+ iue++;
+ }
+ return 0;
+
+free_item:
+ kfree(q->items);
+free_pool:
+ kfree(q->pool);
+ return -ENOMEM;
+}
+
+static void srp_iu_pool_free(struct srp_queue *q)
+{
+ kfree(q->items);
+ kfree(q->pool);
+}
+
+static struct srp_buf ** srp_ring_alloc(struct device *dev,
+ size_t max, size_t size)
+{
+ int i;
+ struct srp_buf **ring;
+
+ ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
+ if (!ring)
+ return NULL;
+
+ for (i = 0; i < max; i++) {
+ ring[i] = kzalloc(sizeof(struct srp_buf), GFP_KERNEL);
+ if (!ring[i])
+ goto out;
+ ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
+ GFP_KERNEL);
+ if (!ring[i]->buf)
+ goto out;
+ }
+ return ring;
+
+out:
+ for (i = 0; i < max && ring[i]; i++) {
+ if (ring[i]->buf)
+ dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
+ kfree(ring[i]);
+ }
+ kfree(ring);
+
+ return NULL;
+}
+
+static void srp_ring_free(struct device *dev, struct srp_buf **ring, size_t max,
+ size_t size)
+{
+ int i;
+
+ for (i = 0; i < max; i++) {
+ dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
+ kfree(ring[i]);
+ }
+}
+
+int srp_target_alloc(struct srp_target *target, struct device *dev,
+ size_t nr, size_t iu_size)
+{
+ int err;
+
+ spin_lock_init(&target->lock);
+ INIT_LIST_HEAD(&target->cmd_queue);
+
+ target->dev = dev;
+ target->dev->driver_data = target;
+
+ target->srp_iu_size = iu_size;
+ target->rx_ring_size = nr;
+ target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
+ if (!target->rx_ring)
+ return -ENOMEM;
+ err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
+ if (err)
+ goto free_ring;
+
+ return 0;
+
+free_ring:
+ srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(srp_target_alloc);
+
+void srp_target_free(struct srp_target *target)
+{
+ srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
+ target->srp_iu_size);
+ srp_iu_pool_free(&target->iu_queue);
+}
+EXPORT_SYMBOL_GPL(srp_target_free);
+
+struct iu_entry *srp_iu_get(struct srp_target *target)
+{
+ struct iu_entry *iue = NULL;
+
+ kfifo_get(target->iu_queue.queue, (void *) &iue, sizeof(void *));
+ BUG_ON(!iue);
+
+ iue->target = target;
+ iue->scmd = NULL;
+ INIT_LIST_HEAD(&iue->ilist);
+ iue->flags = 0;
+ return iue;
+}
+EXPORT_SYMBOL_GPL(srp_iu_get);
+
+void srp_iu_put(struct iu_entry *iue)
+{
+ kfifo_put(iue->target->iu_queue.queue, (void *) &iue, sizeof(void *));
+}
+EXPORT_SYMBOL_GPL(srp_iu_put);
+
+static int direct_data(struct scsi_cmnd *scmd, struct srp_direct_buf *md,
+ enum dma_data_direction dir, rdma_io_t rdma_io)
+{
+ struct iu_entry *iue = (struct iu_entry *) scmd->SCp.ptr;
+ struct srp_target *target = iue->target;
+ struct scatterlist *sg = scmd->request_buffer;
+ int nsg, err;
+
+ dprintk("%p %u %u %u %d\n", iue, scmd->request_bufflen, scmd->bufflen,
+ md->len, scmd->use_sg);
+
+ nsg = dma_map_sg(target->dev, sg, scmd->use_sg, DMA_BIDIRECTIONAL);
+ if (!nsg) {
+ printk("fail to map %p %d\n", iue, scmd->use_sg);
+ return 0;
+ }
+ err = rdma_io(iue, sg, nsg, md, 1, dir,
+ min(scmd->request_bufflen, md->len));
+
+ dma_unmap_sg(target->dev, sg, nsg, DMA_BIDIRECTIONAL);
+
+ return err;
+}
+
+static int indirect_data(struct scsi_cmnd *scmd, struct srp_cmd *cmd,
+ struct srp_indirect_buf *id,
+ enum dma_data_direction dir, rdma_io_t rdma_io)
+{
+ struct iu_entry *iue = (struct iu_entry *) scmd->SCp.ptr;
+ struct srp_target *target = iue->target;
+ struct srp_direct_buf *md;
+ struct scatterlist dummy, *sg = scmd->request_buffer;
+ dma_addr_t token = 0;
+ long err;
+ unsigned int done = 0;
+ int nmd, nsg;
+
+ nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
+
+ dprintk("%p %u %u %u %u %d %d %d\n",
+ iue, scmd->request_bufflen, scmd->bufflen,
+ id->len, scmd->offset, nmd,
+ cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
+
+ if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
+ (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
+ md = &id->desc_list[0];
+ goto rdma;
+ }
+
+ md = dma_alloc_coherent(target->dev, id->table_desc.len,
+ &token, GFP_KERNEL);
+ if (!md) {
+ eprintk("Can't get dma memory %u\n", id->table_desc.len);
+ return 0;
+ }
+
+ sg_init_one(&dummy, md, id->table_desc.len);
+ sg_dma_address(&dummy) = token;
+ err = rdma_io(iue, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
+ id->table_desc.len);
+ if (err < 0) {
+ eprintk("Error copying indirect table %ld\n", err);
+ goto free_mem;
+ }
+
+rdma:
+ nsg = dma_map_sg(target->dev, sg, scmd->use_sg, DMA_BIDIRECTIONAL);
+ if (!nsg) {
+ eprintk("fail to map %p %d\n", iue, scmd->use_sg);
+ goto free_mem;
+ }
+
+ err = rdma_io(iue, sg, nsg, md, nmd, dir,
+ min(scmd->request_bufflen, id->len));
+ dma_unmap_sg(target->dev, sg, nsg, DMA_BIDIRECTIONAL);
+
+free_mem:
+ if (token)
+ dma_free_coherent(target->dev, id->table_desc.len, md, token);
+
+ return done;
+}
+
+static int data_out_desc_size(struct srp_cmd *cmd)
+{
+ int size = 0;
+ u8 fmt = cmd->buf_fmt >> 4;
+
+ switch (fmt) {
+ case SRP_NO_DATA_DESC:
+ break;
+ case SRP_DATA_DESC_DIRECT:
+ size = sizeof(struct srp_direct_buf);
+ break;
+ case SRP_DATA_DESC_INDIRECT:
+ size = sizeof(struct srp_indirect_buf) +
+ sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
+ break;
+ default:
+ eprintk("client error. Invalid data_out_format %x\n", fmt);
+ break;
+ }
+ return size;
+}
+
+static int __srp_transfer_data(struct scsi_cmnd *scmd, struct srp_cmd *cmd,
+ enum dma_data_direction dir, rdma_io_t rdma_io)
+{
+ struct srp_direct_buf *md;
+ struct srp_indirect_buf *id;
+ int offset, err = 0;
+ u8 format;
+
+ offset = cmd->add_cdb_len * 4;
+ if (dir == DMA_FROM_DEVICE)
+ offset += data_out_desc_size(cmd);
+
+ if (dir == DMA_TO_DEVICE)
+ format = cmd->buf_fmt >> 4;
+ else
+ format = cmd->buf_fmt & ((1U << 4) - 1);
+
+ switch (format) {
+ case SRP_NO_DATA_DESC:
+ break;
+ case SRP_DATA_DESC_DIRECT:
+ md = (struct srp_direct_buf *)
+ (cmd->add_data + offset);
+ err = direct_data(scmd, md, dir, rdma_io);
+ break;
+ case SRP_DATA_DESC_INDIRECT:
+ id = (struct srp_indirect_buf *)
+ (cmd->add_data + offset);
+ err = indirect_data(scmd, cmd, id, dir, rdma_io);
+ break;
+ default:
+ eprintk("Unknown format %d %x\n", dir, format);
+ break;
+ }
+
+ return err;
+}
+
+/* TODO: this can be called multiple times for a single command. */
+int srp_transfer_data(struct scsi_cmnd *scmd, struct srp_cmd *cmd,
+ rdma_io_t rdma_io)
+{
+ struct iu_entry *iue = (struct iu_entry *) scmd->SCp.ptr;
+ enum dma_data_direction dir;
+
+ if (test_bit(V_WRITE, &iue->flags))
+ dir = DMA_TO_DEVICE;
+ else
+ dir = DMA_FROM_DEVICE;
+ __srp_transfer_data(scmd, cmd, dir, rdma_io);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(srp_transfer_data);
+
+static int vscsis_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
+{
+ struct srp_direct_buf *md;
+ struct srp_indirect_buf *id;
+ int len = 0, offset = cmd->add_cdb_len * 4;
+ u8 fmt;
+
+ if (dir == DMA_TO_DEVICE)
+ fmt = cmd->buf_fmt >> 4;
+ else {
+ fmt = cmd->buf_fmt & ((1U << 4) - 1);
+ offset += data_out_desc_size(cmd);
+ }
+
+ switch (fmt) {
+ case SRP_NO_DATA_DESC:
+ break;
+ case SRP_DATA_DESC_DIRECT:
+ md = (struct srp_direct_buf *) (cmd->add_data + offset);
+ len = md->len;
+ break;
+ case SRP_DATA_DESC_INDIRECT:
+ id = (struct srp_indirect_buf *) (cmd->add_data + offset);
+ len = id->len;
+ break;
+ default:
+ eprintk("invalid data format %x\n", fmt);
+ break;
+ }
+ return len;
+}
+
+static uint8_t getcontrolbyte(u8 *cdb)
+{
+ return cdb[COMMAND_SIZE(cdb[0]) - 1];
+}
+
+static inline uint8_t getlink(struct srp_cmd *cmd)
+{
+ return (getcontrolbyte(cmd->cdb) & 0x01);
+}
+
+int srp_cmd_perform(struct iu_entry *iue, struct srp_cmd *cmd)
+{
+ struct Scsi_host *shost = iue->target->shost;
+ enum dma_data_direction data_dir;
+ struct scsi_cmnd *scmd;
+ int tag, len;
+
+ if (getlink(cmd))
+ __set_bit(V_LINKED, &iue->flags);
+
+ tag = MSG_SIMPLE_TAG;
+
+ switch (cmd->task_attr) {
+ case SRP_SIMPLE_TASK:
+ tag = MSG_SIMPLE_TAG;
+ break;
+ case SRP_ORDERED_TASK:
+ tag = MSG_ORDERED_TAG;
+ break;
+ case SRP_HEAD_TASK:
+ tag = MSG_HEAD_TAG;
+ break;
+ default:
+ eprintk("Task attribute %d not supported\n", cmd->task_attr);
+ tag = MSG_ORDERED_TAG;
+ }
+
+ switch (cmd->cdb[0]) {
+ case WRITE_6:
+ case WRITE_10:
+ case WRITE_VERIFY:
+ case WRITE_12:
+ case WRITE_VERIFY_12:
+ __set_bit(V_WRITE, &iue->flags);
+ }
+
+ if (cmd->buf_fmt >> 4)
+ data_dir = DMA_TO_DEVICE;
+ else
+ data_dir = DMA_FROM_DEVICE;
+ len = vscsis_data_length(cmd, data_dir);
+
+ dprintk("%p %x %lx %d %d %d %llx\n", iue, cmd->cdb[0],
+ cmd->lun, data_dir, len, tag, (unsigned long long) cmd->tag);
+
+ scmd = scsi_host_get_command(shost, data_dir, GFP_KERNEL);
+ BUG_ON(!scmd);
+ scmd->SCp.ptr = (char *) iue;
+ memcpy(scmd->data_cmnd, cmd->cdb, MAX_COMMAND_SIZE);
+ scmd->request_bufflen = len;
+ scmd->tag = tag;
+ iue->scmd = scmd;
+ scsi_tgt_queue_command(scmd, (struct scsi_lun *) &cmd->lun, cmd->tag);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(srp_cmd_perform);
+
+MODULE_DESCRIPTION("SCSI RDAM Protocol lib functions");
+MODULE_AUTHOR("FUJITA Tomonori");
+MODULE_LICENSE("GPL");
diff --git a/include/scsi/libsrp.h b/include/scsi/libsrp.h
new file mode 100644
index 0000000..9dd10ff
--- /dev/null
+++ b/include/scsi/libsrp.h
@@ -0,0 +1,75 @@
+#ifndef __LIBSRP_H__
+#define __LIBSRP_H__
+
+#include <linux/list.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <scsi/srp.h>
+
+enum iue_flags {
+ V_DIOVER,
+ V_WRITE,
+ V_LINKED,
+ V_FLYING,
+};
+
+struct srp_buf {
+ dma_addr_t dma;
+ void *buf;
+};
+
+struct srp_queue {
+ void *pool;
+ void *items;
+ struct kfifo *queue;
+ spinlock_t lock;
+};
+
+struct srp_target {
+ struct Scsi_Host *shost;
+ struct device *dev;
+
+ spinlock_t lock;
+ struct list_head cmd_queue;
+
+ size_t srp_iu_size;
+ struct srp_queue iu_queue;
+ size_t rx_ring_size;
+ struct srp_buf **rx_ring;
+
+ /* IB needs tx_ring too */
+
+ void *ldata;
+};
+
+struct iu_entry {
+ struct srp_target *target;
+ struct scsi_cmnd *scmd;
+
+ struct list_head ilist;
+ dma_addr_t remote_token;
+ unsigned long flags;
+
+ struct srp_buf *sbuf;
+};
+
+typedef int (rdma_io_t) (struct iu_entry *, struct scatterlist *, int,
+ struct srp_direct_buf *, int,
+ enum dma_data_direction, unsigned int);
+
+static inline struct srp_target *host_to_target(struct Scsi_Host *host)
+{
+ return (struct srp_target *) host->hostdata;
+}
+
+extern int srp_target_alloc(struct srp_target *, struct device *, size_t, size_t);
+extern void srp_target_free(struct srp_target *);
+
+extern struct iu_entry *srp_iu_get(struct srp_target *);
+extern void srp_iu_put(struct iu_entry *);
+
+extern int srp_cmd_perform(struct iu_entry *iue, struct srp_cmd *cmd);
+extern int srp_transfer_data(struct scsi_cmnd *scmd, struct srp_cmd *cmd,
+ rdma_io_t rdma_io);
+
+#endif
--
1.1.3
-
: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
