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[SCSI] scsi tgt: SCSI RDMA Protocol library functions

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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>
This commit is contained in:
FUJITA Tomonori 2006-12-01 03:00:50 +09:00 committed by James Bottomley
parent c603d04ef6
commit 26b1482344
4 changed files with 529 additions and 0 deletions
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10
drivers/scsi/Kconfig
View 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"

1
drivers/scsi/Makefile
View 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

441
drivers/scsi/libsrp.c Normal file
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@ -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");

77
include/scsi/libsrp.h Normal file
View file

@ -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