[SCSI] scsi tgt: SCSI RDMA Protocol library functions (26b14823) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/scsi/Kconfig

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Original line number	Diff line number	Diff line
		@@ -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"

drivers/scsi/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/scsi/libsrp.c

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+441 −0

Original line number	Diff line number	Diff line
		/*
		* 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");

include/scsi/libsrp.h

0 → 100644

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Original line number	Diff line number	Diff line
		#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