[SCSI] scsi tgt: SCSI RDMA Protocol library functions
authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Thu, 30 Nov 2006 18:00:50 +0000 (03:00 +0900)
committerJames Bottomley <jejb@mulgrave.il.steeleye.com>
Sun, 3 Dec 2006 15:27:33 +0000 (09:27 -0600)
libsrp provides helper functions for SRP target drivers.

Some SRP target drivers would be out of drivers/scsi/ so we added an
entry for libsrp in drivers/scsi/Kconfig.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Santiago Leon <santil@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
drivers/scsi/Kconfig
drivers/scsi/Makefile
drivers/scsi/libsrp.c [new file with mode: 0644]
include/scsi/libsrp.h [new file with mode: 0644]

index 1301d5222c07704db2e9be4f0100560c8cdefecd..5570cdbf8f111d889de5173a44124f0fed5c4df1 100644 (file)
@@ -1760,6 +1760,16 @@ 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 && PCI
+       select SCSI_TGT
+       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"
index 8f86c1b96ff7777a6fda9dfda5ee4eab043cc8b8..00691c4c3a6f4fa3efa5fb58257f23d31c449878 100644 (file)
@@ -126,6 +126,7 @@ 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-$(CONFIG_SCSI_HPTIOP)      += hptiop.o
 obj-$(CONFIG_SCSI_STEX)                += stex.o
diff --git a/drivers/scsi/libsrp.c b/drivers/scsi/libsrp.c
new file mode 100644 (file)
index 0000000..89403b0
--- /dev/null
@@ -0,0 +1,441 @@
+/*
+ * SCSI RDAM Protocol lib functions
+ *
+ * Copyright (C) 2006 FUJITA Tomonori <tomof@acm.org>
+ *
+ * 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 <linux/pci.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 *));
+       if (!iue)
+               return iue;
+       iue->target = target;
+       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 srp_direct_data(struct scsi_cmnd *sc, struct srp_direct_buf *md,
+                          enum dma_data_direction dir, srp_rdma_t rdma_io,
+                          int dma_map, int ext_desc)
+{
+       struct iu_entry *iue = NULL;
+       struct scatterlist *sg = NULL;
+       int err, nsg = 0, len;
+
+       if (dma_map) {
+               iue = (struct iu_entry *) sc->SCp.ptr;
+               sg = sc->request_buffer;
+
+               dprintk("%p %u %u %d\n", iue, sc->request_bufflen,
+                       md->len, sc->use_sg);
+
+               nsg = dma_map_sg(iue->target->dev, sg, sc->use_sg,
+                                DMA_BIDIRECTIONAL);
+               if (!nsg) {
+                       printk("fail to map %p %d\n", iue, sc->use_sg);
+                       return 0;
+               }
+               len = min(sc->request_bufflen, md->len);
+       } else
+               len = md->len;
+
+       err = rdma_io(sc, sg, nsg, md, 1, dir, len);
+
+       if (dma_map)
+               dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
+
+       return err;
+}
+
+static int srp_indirect_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
+                            struct srp_indirect_buf *id,
+                            enum dma_data_direction dir, srp_rdma_t rdma_io,
+                            int dma_map, int ext_desc)
+{
+       struct iu_entry *iue = NULL;
+       struct srp_direct_buf *md = NULL;
+       struct scatterlist dummy, *sg = NULL;
+       dma_addr_t token = 0;
+       long err;
+       unsigned int done = 0;
+       int nmd, nsg = 0, len;
+
+       if (dma_map || ext_desc) {
+               iue = (struct iu_entry *) sc->SCp.ptr;
+               sg = sc->request_buffer;
+
+               dprintk("%p %u %u %d %d\n",
+                       iue, sc->request_bufflen, id->len,
+                       cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
+       }
+
+       nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
+
+       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;
+       }
+
+       if (ext_desc && dma_map) {
+               md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
+                               &token, GFP_KERNEL);
+               if (!md) {
+                       eprintk("Can't get dma memory %u\n", id->table_desc.len);
+                       return -ENOMEM;
+               }
+
+               sg_init_one(&dummy, md, id->table_desc.len);
+               sg_dma_address(&dummy) = token;
+               err = rdma_io(sc, &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;
+               }
+       } else {
+               eprintk("This command uses external indirect buffer\n");
+               return -EINVAL;
+       }
+
+rdma:
+       if (dma_map) {
+               nsg = dma_map_sg(iue->target->dev, sg, sc->use_sg, DMA_BIDIRECTIONAL);
+               if (!nsg) {
+                       eprintk("fail to map %p %d\n", iue, sc->use_sg);
+                       goto free_mem;
+               }
+               len = min(sc->request_bufflen, id->len);
+       } else
+               len = id->len;
+
+       err = rdma_io(sc, sg, nsg, md, nmd, dir, len);
+
+       if (dma_map)
+               dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
+
+free_mem:
+       if (token && dma_map)
+               dma_free_coherent(iue->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;
+}
+
+/*
+ * TODO: this can be called multiple times for a single command if it
+ * has very long data.
+ */
+int srp_transfer_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
+                     srp_rdma_t rdma_io, int dma_map, int ext_desc)
+{
+       struct srp_direct_buf *md;
+       struct srp_indirect_buf *id;
+       enum dma_data_direction dir;
+       int offset, err = 0;
+       u8 format;
+
+       offset = cmd->add_cdb_len * 4;
+
+       dir = srp_cmd_direction(cmd);
+       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 = srp_direct_data(sc, md, dir, rdma_io, dma_map, ext_desc);
+               break;
+       case SRP_DATA_DESC_INDIRECT:
+               id = (struct srp_indirect_buf *)
+                       (cmd->add_data + offset);
+               err = srp_indirect_data(sc, cmd, id, dir, rdma_io, dma_map,
+                                       ext_desc);
+               break;
+       default:
+               eprintk("Unknown format %d %x\n", dir, format);
+               break;
+       }
+
+       return err;
+}
+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;
+}
+
+int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
+                 u64 addr)
+{
+       enum dma_data_direction dir;
+       struct scsi_cmnd *sc;
+       int tag, len, err;
+
+       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;
+       }
+
+       dir = srp_cmd_direction(cmd);
+       len = vscsis_data_length(cmd, dir);
+
+       dprintk("%p %x %lx %d %d %d %llx\n", info, cmd->cdb[0],
+               cmd->lun, dir, len, tag, (unsigned long long) cmd->tag);
+
+       sc = scsi_host_get_command(shost, dir, GFP_KERNEL);
+       if (!sc)
+               return -ENOMEM;
+
+       sc->SCp.ptr = info;
+       memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
+       sc->request_bufflen = len;
+       sc->request_buffer = (void *) (unsigned long) addr;
+       sc->tag = tag;
+       err = scsi_tgt_queue_command(sc, (struct scsi_lun *) &cmd->lun, cmd->tag);
+       if (err)
+               scsi_host_put_command(shost, sc);
+
+       return err;
+}
+EXPORT_SYMBOL_GPL(srp_cmd_queue);
+
+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 (file)
index 0000000..d143171
--- /dev/null
@@ -0,0 +1,77 @@
+#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;
+
+       void *ldata;
+};
+
+struct iu_entry {
+       struct srp_target *target;
+
+       struct list_head ilist;
+       dma_addr_t remote_token;
+       unsigned long flags;
+
+       struct srp_buf *sbuf;
+};
+
+typedef int (srp_rdma_t)(struct scsi_cmnd *, struct scatterlist *, int,
+                        struct srp_direct_buf *, int,
+                        enum dma_data_direction, unsigned int);
+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_queue(struct Scsi_Host *, struct srp_cmd *, void *, u64);
+extern int srp_transfer_data(struct scsi_cmnd *, struct srp_cmd *,
+                            srp_rdma_t, int, int);
+
+
+static inline struct srp_target *host_to_srp_target(struct Scsi_Host *host)
+{
+       return (struct srp_target *) host->hostdata;
+}
+
+static inline int srp_cmd_direction(struct srp_cmd *cmd)
+{
+       return (cmd->buf_fmt >> 4) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+}
+
+#endif