[deliverable/linux.git] / drivers / target / target_core_rd.c

/*******************************************************************************
 * Filename:  target_core_rd.c
 *
 * This file contains the Storage Engine <-> Ramdisk transport
 * specific functions.
 *
 * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
 * Copyright (c) 2005, 2006, 2007 SBE, Inc.
 * Copyright (c) 2007-2010 Rising Tide Systems
 * Copyright (c) 2008-2010 Linux-iSCSI.org
 *
 * Nicholas A. Bellinger <nab@kernel.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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 ******************************************************************************/

#include <linux/string.h>
#include <linux/parser.h>
#include <linux/timer.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>

#include <target/target_core_base.h>
#include <target/target_core_backend.h>

#include "target_core_rd.h"

static struct se_subsystem_api rd_mcp_template;

/*	rd_attach_hba(): (Part of se_subsystem_api_t template)
 *
 *
 */
static int rd_attach_hba(struct se_hba *hba, u32 host_id)
{
	struct rd_host *rd_host;

	rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
	if (!rd_host) {
		pr_err("Unable to allocate memory for struct rd_host\n");
		return -ENOMEM;
	}

	rd_host->rd_host_id = host_id;

	hba->hba_ptr = rd_host;

	pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
		" Generic Target Core Stack %s\n", hba->hba_id,
		RD_HBA_VERSION, TARGET_CORE_MOD_VERSION);

	return 0;
}

static void rd_detach_hba(struct se_hba *hba)
{
	struct rd_host *rd_host = hba->hba_ptr;

	pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
		" Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);

	kfree(rd_host);
	hba->hba_ptr = NULL;
}

/*	rd_release_device_space():
 *
 *
 */
static void rd_release_device_space(struct rd_dev *rd_dev)
{
	u32 i, j, page_count = 0, sg_per_table;
	struct rd_dev_sg_table *sg_table;
	struct page *pg;
	struct scatterlist *sg;

	if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
		return;

	sg_table = rd_dev->sg_table_array;

	for (i = 0; i < rd_dev->sg_table_count; i++) {
		sg = sg_table[i].sg_table;
		sg_per_table = sg_table[i].rd_sg_count;

		for (j = 0; j < sg_per_table; j++) {
			pg = sg_page(&sg[j]);
			if (pg) {
				__free_page(pg);
				page_count++;
			}
		}

		kfree(sg);
	}

	pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
		" Device ID: %u, pages %u in %u tables total bytes %lu\n",
		rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
		rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);

	kfree(sg_table);
	rd_dev->sg_table_array = NULL;
	rd_dev->sg_table_count = 0;
}


/*	rd_build_device_space():
 *
 *
 */
static int rd_build_device_space(struct rd_dev *rd_dev)
{
	u32 i = 0, j, page_offset = 0, sg_per_table, sg_tables, total_sg_needed;
	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
				sizeof(struct scatterlist));
	struct rd_dev_sg_table *sg_table;
	struct page *pg;
	struct scatterlist *sg;

	if (rd_dev->rd_page_count <= 0) {
		pr_err("Illegal page count: %u for Ramdisk device\n",
			rd_dev->rd_page_count);
		return -EINVAL;
	}
	total_sg_needed = rd_dev->rd_page_count;

	sg_tables = (total_sg_needed / max_sg_per_table) + 1;

	sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
	if (!sg_table) {
		pr_err("Unable to allocate memory for Ramdisk"
			" scatterlist tables\n");
		return -ENOMEM;
	}

	rd_dev->sg_table_array = sg_table;
	rd_dev->sg_table_count = sg_tables;

	while (total_sg_needed) {
		sg_per_table = (total_sg_needed > max_sg_per_table) ?
			max_sg_per_table : total_sg_needed;

		sg = kzalloc(sg_per_table * sizeof(struct scatterlist),
				GFP_KERNEL);
		if (!sg) {
			pr_err("Unable to allocate scatterlist array"
				" for struct rd_dev\n");
			return -ENOMEM;
		}

		sg_init_table(sg, sg_per_table);

		sg_table[i].sg_table = sg;
		sg_table[i].rd_sg_count = sg_per_table;
		sg_table[i].page_start_offset = page_offset;
		sg_table[i++].page_end_offset = (page_offset + sg_per_table)
						- 1;

		for (j = 0; j < sg_per_table; j++) {
			pg = alloc_pages(GFP_KERNEL, 0);
			if (!pg) {
				pr_err("Unable to allocate scatterlist"
					" pages for struct rd_dev_sg_table\n");
				return -ENOMEM;
			}
			sg_assign_page(&sg[j], pg);
			sg[j].length = PAGE_SIZE;
		}

		page_offset += sg_per_table;
		total_sg_needed -= sg_per_table;
	}

	pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
		" %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
		rd_dev->rd_dev_id, rd_dev->rd_page_count,
		rd_dev->sg_table_count);

	return 0;
}

static void *rd_allocate_virtdevice(struct se_hba *hba, const char *name)
{
	struct rd_dev *rd_dev;
	struct rd_host *rd_host = hba->hba_ptr;

	rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
	if (!rd_dev) {
		pr_err("Unable to allocate memory for struct rd_dev\n");
		return NULL;
	}

	rd_dev->rd_host = rd_host;

	return rd_dev;
}

static struct se_device *rd_create_virtdevice(struct se_hba *hba,
		struct se_subsystem_dev *se_dev, void *p)
{
	struct se_device *dev;
	struct se_dev_limits dev_limits;
	struct rd_dev *rd_dev = p;
	struct rd_host *rd_host = hba->hba_ptr;
	int dev_flags = 0, ret;
	char prod[16], rev[4];

	memset(&dev_limits, 0, sizeof(struct se_dev_limits));

	ret = rd_build_device_space(rd_dev);
	if (ret < 0)
		goto fail;

	snprintf(prod, 16, "RAMDISK-MCP");
	snprintf(rev, 4, "%s", RD_MCP_VERSION);

	dev_limits.limits.logical_block_size = RD_BLOCKSIZE;
	dev_limits.limits.max_hw_sectors = UINT_MAX;
	dev_limits.limits.max_sectors = UINT_MAX;
	dev_limits.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
	dev_limits.queue_depth = RD_DEVICE_QUEUE_DEPTH;

	dev = transport_add_device_to_core_hba(hba,
			&rd_mcp_template, se_dev, dev_flags, rd_dev,
			&dev_limits, prod, rev);
	if (!dev)
		goto fail;

	rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;

	pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
		" %u pages in %u tables, %lu total bytes\n",
		rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
		rd_dev->sg_table_count,
		(unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));

	return dev;

fail:
	rd_release_device_space(rd_dev);
	return ERR_PTR(ret);
}

static void rd_free_device(void *p)
{
	struct rd_dev *rd_dev = p;

	rd_release_device_space(rd_dev);
	kfree(rd_dev);
}

static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
{
	u32 i;
	struct rd_dev_sg_table *sg_table;

	for (i = 0; i < rd_dev->sg_table_count; i++) {
		sg_table = &rd_dev->sg_table_array[i];
		if ((sg_table->page_start_offset <= page) &&
		    (sg_table->page_end_offset >= page))
			return sg_table;
	}

	pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
			page);

	return NULL;
}

static int rd_execute_rw(struct se_cmd *cmd)
{
	struct scatterlist *sgl = cmd->t_data_sg;
	u32 sgl_nents = cmd->t_data_nents;
	enum dma_data_direction data_direction = cmd->data_direction;
	struct se_device *se_dev = cmd->se_dev;
	struct rd_dev *dev = se_dev->dev_ptr;
	struct rd_dev_sg_table *table;
	struct scatterlist *rd_sg;
	struct sg_mapping_iter m;
	u32 rd_offset;
	u32 rd_size;
	u32 rd_page;
	u32 src_len;
	u64 tmp;

	tmp = cmd->t_task_lba * se_dev->se_sub_dev->se_dev_attrib.block_size;
	rd_offset = do_div(tmp, PAGE_SIZE);
	rd_page = tmp;
	rd_size = cmd->data_length;

	table = rd_get_sg_table(dev, rd_page);
	if (!table)
		return -EINVAL;

	rd_sg = &table->sg_table[rd_page - table->page_start_offset];

	pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
			dev->rd_dev_id,
			data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
			cmd->t_task_lba, rd_size, rd_page, rd_offset);

	src_len = PAGE_SIZE - rd_offset;
	sg_miter_start(&m, sgl, sgl_nents,
			data_direction == DMA_FROM_DEVICE ?
				SG_MITER_TO_SG : SG_MITER_FROM_SG);
	while (rd_size) {
		u32 len;
		void *rd_addr;

		sg_miter_next(&m);
		len = min((u32)m.length, src_len);
		m.consumed = len;

		rd_addr = sg_virt(rd_sg) + rd_offset;

		if (data_direction == DMA_FROM_DEVICE)
			memcpy(m.addr, rd_addr, len);
		else
			memcpy(rd_addr, m.addr, len);

		rd_size -= len;
		if (!rd_size)
			continue;

		src_len -= len;
		if (src_len) {
			rd_offset += len;
			continue;
		}

		/* rd page completed, next one please */
		rd_page++;
		rd_offset = 0;
		src_len = PAGE_SIZE;
		if (rd_page <= table->page_end_offset) {
			rd_sg++;
			continue;
		}

		table = rd_get_sg_table(dev, rd_page);
		if (!table) {
			sg_miter_stop(&m);
			return -EINVAL;
		}

		/* since we increment, the first sg entry is correct */
		rd_sg = table->sg_table;
	}
	sg_miter_stop(&m);

	target_complete_cmd(cmd, SAM_STAT_GOOD);
	return 0;
}

enum {
	Opt_rd_pages, Opt_err
};

static match_table_t tokens = {
	{Opt_rd_pages, "rd_pages=%d"},
	{Opt_err, NULL}
};

static ssize_t rd_set_configfs_dev_params(
	struct se_hba *hba,
	struct se_subsystem_dev *se_dev,
	const char *page,
	ssize_t count)
{
	struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
	char *orig, *ptr, *opts;
	substring_t args[MAX_OPT_ARGS];
	int ret = 0, arg, token;

	opts = kstrdup(page, GFP_KERNEL);
	if (!opts)
		return -ENOMEM;

	orig = opts;

	while ((ptr = strsep(&opts, ",\n")) != NULL) {
		if (!*ptr)
			continue;

		token = match_token(ptr, tokens, args);
		switch (token) {
		case Opt_rd_pages:
			match_int(args, &arg);
			rd_dev->rd_page_count = arg;
			pr_debug("RAMDISK: Referencing Page"
				" Count: %u\n", rd_dev->rd_page_count);
			rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
			break;
		default:
			break;
		}
	}

	kfree(orig);
	return (!ret) ? count : ret;
}

static ssize_t rd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
{
	struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;

	if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
		pr_debug("Missing rd_pages= parameter\n");
		return -EINVAL;
	}

	return 0;
}

static ssize_t rd_show_configfs_dev_params(
	struct se_hba *hba,
	struct se_subsystem_dev *se_dev,
	char *b)
{
	struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
	ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: rd_mcp\n",
			rd_dev->rd_dev_id);
	bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
			"  SG_table_count: %u\n", rd_dev->rd_page_count,
			PAGE_SIZE, rd_dev->sg_table_count);
	return bl;
}

static u32 rd_get_device_rev(struct se_device *dev)
{
	return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
}

static u32 rd_get_device_type(struct se_device *dev)
{
	return TYPE_DISK;
}

static sector_t rd_get_blocks(struct se_device *dev)
{
	struct rd_dev *rd_dev = dev->dev_ptr;
	unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
			dev->se_sub_dev->se_dev_attrib.block_size) - 1;

	return blocks_long;
}

static struct spc_ops rd_spc_ops = {
	.execute_rw		= rd_execute_rw,
};

static int rd_parse_cdb(struct se_cmd *cmd)
{
	return sbc_parse_cdb(cmd, &rd_spc_ops);
}

static struct se_subsystem_api rd_mcp_template = {
	.name			= "rd_mcp",
	.transport_type		= TRANSPORT_PLUGIN_VHBA_VDEV,
	.attach_hba		= rd_attach_hba,
	.detach_hba		= rd_detach_hba,
	.allocate_virtdevice	= rd_allocate_virtdevice,
	.create_virtdevice	= rd_create_virtdevice,
	.free_device		= rd_free_device,
	.parse_cdb		= rd_parse_cdb,
	.check_configfs_dev_params = rd_check_configfs_dev_params,
	.set_configfs_dev_params = rd_set_configfs_dev_params,
	.show_configfs_dev_params = rd_show_configfs_dev_params,
	.get_device_rev		= rd_get_device_rev,
	.get_device_type	= rd_get_device_type,
	.get_blocks		= rd_get_blocks,
};

int __init rd_module_init(void)
{
	int ret;

	ret = transport_subsystem_register(&rd_mcp_template);
	if (ret < 0) {
		return ret;
	}

	return 0;
}

void rd_module_exit(void)
{
	transport_subsystem_release(&rd_mcp_template);
}
Commit	Line	Data
c66ac9db NB	1	/*******************************************************************************
	2	* Filename: target_core_rd.c
	3	*
	4	* This file contains the Storage Engine <-> Ramdisk transport
	5	* specific functions.
	6	*
	7	* Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
	8	* Copyright (c) 2005, 2006, 2007 SBE, Inc.
	9	* Copyright (c) 2007-2010 Rising Tide Systems
	10	* Copyright (c) 2008-2010 Linux-iSCSI.org
	11	*
	12	* Nicholas A. Bellinger <nab@kernel.org>
	13	*
	14	* This program is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU General Public License as published by
	16	* the Free Software Foundation; either version 2 of the License, or
	17	* (at your option) any later version.
	18	*
	19	* This program is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU General Public License
	25	* along with this program; if not, write to the Free Software
	26	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	27	*
	28	******************************************************************************/
	29
c66ac9db NB	30	#include <linux/string.h>
	31	#include <linux/parser.h>
	32	#include <linux/timer.h>
	33	#include <linux/blkdev.h>
	34	#include <linux/slab.h>
	35	#include <linux/spinlock.h>
c66ac9db NB	36	#include <scsi/scsi.h>
	37	#include <scsi/scsi_host.h>
	38
	39	#include <target/target_core_base.h>
c4795fb2	40	#include <target/target_core_backend.h>
c66ac9db NB	41
	42	#include "target_core_rd.h"
	43
c66ac9db NB	44	static struct se_subsystem_api rd_mcp_template;
c66ac9db NB	45
c66ac9db NB	46	/* rd_attach_hba(): (Part of se_subsystem_api_t template)
	47	*
	48	*
	49	*/
	50	static int rd_attach_hba(struct se_hba *hba, u32 host_id)
	51	{
	52	struct rd_host *rd_host;
	53
	54	rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
6708bb27 AG	55	if (!rd_host) {
6708bb27 AG	56	pr_err("Unable to allocate memory for struct rd_host\n");
c66ac9db NB	57	return -ENOMEM;
	58	}
	59
	60	rd_host->rd_host_id = host_id;
	61
5951146d	62	hba->hba_ptr = rd_host;
c66ac9db	63
6708bb27	64	pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
c66ac9db NB	65	" Generic Target Core Stack %s\n", hba->hba_id,
c66ac9db NB	66	RD_HBA_VERSION, TARGET_CORE_MOD_VERSION);
c66ac9db NB	67
	68	return 0;
	69	}
	70
	71	static void rd_detach_hba(struct se_hba *hba)
	72	{
	73	struct rd_host *rd_host = hba->hba_ptr;
	74
6708bb27	75	pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
c66ac9db NB	76	" Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
	77
	78	kfree(rd_host);
	79	hba->hba_ptr = NULL;
	80	}
	81
	82	/* rd_release_device_space():
	83	*
	84	*
	85	*/
	86	static void rd_release_device_space(struct rd_dev *rd_dev)
	87	{
	88	u32 i, j, page_count = 0, sg_per_table;
	89	struct rd_dev_sg_table *sg_table;
	90	struct page *pg;
	91	struct scatterlist *sg;
	92
	93	if (!rd_dev->sg_table_array \|\| !rd_dev->sg_table_count)
	94	return;
	95
	96	sg_table = rd_dev->sg_table_array;
	97
	98	for (i = 0; i < rd_dev->sg_table_count; i++) {
	99	sg = sg_table[i].sg_table;
	100	sg_per_table = sg_table[i].rd_sg_count;
	101
	102	for (j = 0; j < sg_per_table; j++) {
	103	pg = sg_page(&sg[j]);
6708bb27	104	if (pg) {
c66ac9db NB	105	__free_page(pg);
	106	page_count++;
	107	}
	108	}
	109
	110	kfree(sg);
	111	}
	112
6708bb27	113	pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
c66ac9db NB	114	" Device ID: %u, pages %u in %u tables total bytes %lu\n",
	115	rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
	116	rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
	117
	118	kfree(sg_table);
	119	rd_dev->sg_table_array = NULL;
	120	rd_dev->sg_table_count = 0;
	121	}
	122
	123
	124	/* rd_build_device_space():
	125	*
	126	*
	127	*/
	128	static int rd_build_device_space(struct rd_dev *rd_dev)
	129	{
	130	u32 i = 0, j, page_offset = 0, sg_per_table, sg_tables, total_sg_needed;
	131	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
	132	sizeof(struct scatterlist));
	133	struct rd_dev_sg_table *sg_table;
	134	struct page *pg;
	135	struct scatterlist *sg;
	136
	137	if (rd_dev->rd_page_count <= 0) {
6708bb27	138	pr_err("Illegal page count: %u for Ramdisk device\n",
c66ac9db	139	rd_dev->rd_page_count);
065f9716	140	return -EINVAL;
c66ac9db NB	141	}
	142	total_sg_needed = rd_dev->rd_page_count;
	143
	144	sg_tables = (total_sg_needed / max_sg_per_table) + 1;
	145
	146	sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
6708bb27 AG	147	if (!sg_table) {
6708bb27 AG	148	pr_err("Unable to allocate memory for Ramdisk"
c66ac9db	149	" scatterlist tables\n");
065f9716	150	return -ENOMEM;
c66ac9db NB	151	}
	152
	153	rd_dev->sg_table_array = sg_table;
	154	rd_dev->sg_table_count = sg_tables;
	155
	156	while (total_sg_needed) {
	157	sg_per_table = (total_sg_needed > max_sg_per_table) ?
	158	max_sg_per_table : total_sg_needed;
	159
	160	sg = kzalloc(sg_per_table * sizeof(struct scatterlist),
	161	GFP_KERNEL);
6708bb27 AG	162	if (!sg) {
6708bb27 AG	163	pr_err("Unable to allocate scatterlist array"
c66ac9db	164	" for struct rd_dev\n");
065f9716	165	return -ENOMEM;
c66ac9db NB	166	}
c66ac9db NB	167
6708bb27	168	sg_init_table(sg, sg_per_table);
c66ac9db NB	169
	170	sg_table[i].sg_table = sg;
	171	sg_table[i].rd_sg_count = sg_per_table;
	172	sg_table[i].page_start_offset = page_offset;
	173	sg_table[i++].page_end_offset = (page_offset + sg_per_table)
	174	- 1;
	175
	176	for (j = 0; j < sg_per_table; j++) {
	177	pg = alloc_pages(GFP_KERNEL, 0);
6708bb27 AG	178	if (!pg) {
6708bb27 AG	179	pr_err("Unable to allocate scatterlist"
c66ac9db	180	" pages for struct rd_dev_sg_table\n");
065f9716	181	return -ENOMEM;
c66ac9db NB	182	}
	183	sg_assign_page(&sg[j], pg);
	184	sg[j].length = PAGE_SIZE;
	185	}
	186
	187	page_offset += sg_per_table;
	188	total_sg_needed -= sg_per_table;
	189	}
	190
6708bb27	191	pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
c66ac9db NB	192	" %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
	193	rd_dev->rd_dev_id, rd_dev->rd_page_count,
	194	rd_dev->sg_table_count);
	195
	196	return 0;
	197	}
	198
8feb58d0	199	static void rd_allocate_virtdevice(struct se_hba hba, const char *name)
c66ac9db NB	200	{
	201	struct rd_dev *rd_dev;
	202	struct rd_host *rd_host = hba->hba_ptr;
	203
	204	rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
6708bb27 AG	205	if (!rd_dev) {
6708bb27 AG	206	pr_err("Unable to allocate memory for struct rd_dev\n");
c66ac9db NB	207	return NULL;
	208	}
	209
	210	rd_dev->rd_host = rd_host;
c66ac9db NB	211
	212	return rd_dev;
	213	}
	214
8feb58d0 CH	215	static struct se_device rd_create_virtdevice(struct se_hba hba,
8feb58d0 CH	216	struct se_subsystem_dev se_dev, void p)
c66ac9db NB	217	{
	218	struct se_device *dev;
	219	struct se_dev_limits dev_limits;
	220	struct rd_dev *rd_dev = p;
	221	struct rd_host *rd_host = hba->hba_ptr;
065f9716	222	int dev_flags = 0, ret;
c66ac9db NB	223	char prod[16], rev[4];
	224
	225	memset(&dev_limits, 0, sizeof(struct se_dev_limits));
	226
065f9716 DC	227	ret = rd_build_device_space(rd_dev);
065f9716 DC	228	if (ret < 0)
c66ac9db NB	229	goto fail;
c66ac9db NB	230
8feb58d0 CH	231	snprintf(prod, 16, "RAMDISK-MCP");
8feb58d0 CH	232	snprintf(rev, 4, "%s", RD_MCP_VERSION);
c66ac9db NB	233
c66ac9db NB	234	dev_limits.limits.logical_block_size = RD_BLOCKSIZE;
83799efb CH	235	dev_limits.limits.max_hw_sectors = UINT_MAX;
83799efb CH	236	dev_limits.limits.max_sectors = UINT_MAX;
c66ac9db NB	237	dev_limits.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
	238	dev_limits.queue_depth = RD_DEVICE_QUEUE_DEPTH;
	239
	240	dev = transport_add_device_to_core_hba(hba,
5951146d	241	&rd_mcp_template, se_dev, dev_flags, rd_dev,
c66ac9db	242	&dev_limits, prod, rev);
6708bb27	243	if (!dev)
c66ac9db NB	244	goto fail;
	245
	246	rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
c66ac9db	247
8feb58d0	248	pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
c66ac9db	249	" %u pages in %u tables, %lu total bytes\n",
8feb58d0	250	rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
c66ac9db NB	251	rd_dev->sg_table_count,
	252	(unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
	253
	254	return dev;
	255
	256	fail:
	257	rd_release_device_space(rd_dev);
613640e4	258	return ERR_PTR(ret);
c66ac9db NB	259	}
c66ac9db NB	260
c66ac9db NB	261	static void rd_free_device(void *p)
	262	{
	263	struct rd_dev *rd_dev = p;
	264
	265	rd_release_device_space(rd_dev);
	266	kfree(rd_dev);
	267	}
	268
c66ac9db NB	269	static struct rd_dev_sg_table rd_get_sg_table(struct rd_dev rd_dev, u32 page)
	270	{
	271	u32 i;
	272	struct rd_dev_sg_table *sg_table;
	273
	274	for (i = 0; i < rd_dev->sg_table_count; i++) {
	275	sg_table = &rd_dev->sg_table_array[i];
	276	if ((sg_table->page_start_offset <= page) &&
	277	(sg_table->page_end_offset >= page))
	278	return sg_table;
	279	}
	280
6708bb27	281	pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
c66ac9db NB	282	page);
	283
	284	return NULL;
	285	}
	286
0c2ad7d1	287	static int rd_execute_rw(struct se_cmd *cmd)
c66ac9db	288	{
0c2ad7d1 CH	289	struct scatterlist *sgl = cmd->t_data_sg;
	290	u32 sgl_nents = cmd->t_data_nents;
	291	enum dma_data_direction data_direction = cmd->data_direction;
5787cacd	292	struct se_device *se_dev = cmd->se_dev;
8feb58d0	293	struct rd_dev *dev = se_dev->dev_ptr;
c66ac9db	294	struct rd_dev_sg_table *table;
65b0c78d SAS	295	struct scatterlist *rd_sg;
65b0c78d SAS	296	struct sg_mapping_iter m;
8feb58d0 CH	297	u32 rd_offset;
	298	u32 rd_size;
	299	u32 rd_page;
65b0c78d	300	u32 src_len;
8feb58d0	301	u64 tmp;
c66ac9db	302
5787cacd	303	tmp = cmd->t_task_lba * se_dev->se_sub_dev->se_dev_attrib.block_size;
8feb58d0 CH	304	rd_offset = do_div(tmp, PAGE_SIZE);
8feb58d0 CH	305	rd_page = tmp;
5787cacd	306	rd_size = cmd->data_length;
8feb58d0 CH	307
8feb58d0 CH	308	table = rd_get_sg_table(dev, rd_page);
6708bb27	309	if (!table)
e3d6f909	310	return -EINVAL;
c66ac9db	311
8feb58d0	312	rd_sg = &table->sg_table[rd_page - table->page_start_offset];
6708bb27	313
65b0c78d	314	pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
8feb58d0	315	dev->rd_dev_id,
5787cacd CH	316	data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
5787cacd CH	317	cmd->t_task_lba, rd_size, rd_page, rd_offset);
c66ac9db	318
65b0c78d	319	src_len = PAGE_SIZE - rd_offset;
5787cacd CH	320	sg_miter_start(&m, sgl, sgl_nents,
5787cacd CH	321	data_direction == DMA_FROM_DEVICE ?
8feb58d0 CH	322	SG_MITER_TO_SG : SG_MITER_FROM_SG);
8feb58d0 CH	323	while (rd_size) {
65b0c78d SAS	324	u32 len;
65b0c78d SAS	325	void *rd_addr;
c66ac9db	326
65b0c78d SAS	327	sg_miter_next(&m);
	328	len = min((u32)m.length, src_len);
	329	m.consumed = len;
c66ac9db	330
65b0c78d	331	rd_addr = sg_virt(rd_sg) + rd_offset;
6708bb27	332
5787cacd	333	if (data_direction == DMA_FROM_DEVICE)
65b0c78d SAS	334	memcpy(m.addr, rd_addr, len);
	335	else
	336	memcpy(rd_addr, m.addr, len);
c66ac9db	337
8feb58d0 CH	338	rd_size -= len;
8feb58d0 CH	339	if (!rd_size)
c66ac9db NB	340	continue;
c66ac9db NB	341
65b0c78d SAS	342	src_len -= len;
	343	if (src_len) {
	344	rd_offset += len;
c66ac9db NB	345	continue;
c66ac9db NB	346	}
6708bb27	347
65b0c78d	348	/* rd page completed, next one please */
8feb58d0	349	rd_page++;
65b0c78d SAS	350	rd_offset = 0;
65b0c78d SAS	351	src_len = PAGE_SIZE;
8feb58d0	352	if (rd_page <= table->page_end_offset) {
65b0c78d	353	rd_sg++;
c66ac9db NB	354	continue;
c66ac9db NB	355	}
6708bb27	356
8feb58d0	357	table = rd_get_sg_table(dev, rd_page);
65b0c78d SAS	358	if (!table) {
65b0c78d SAS	359	sg_miter_stop(&m);
e3d6f909	360	return -EINVAL;
65b0c78d	361	}
c66ac9db	362
65b0c78d SAS	363	/* since we increment, the first sg entry is correct */
65b0c78d SAS	364	rd_sg = table->sg_table;
c66ac9db	365	}
65b0c78d	366	sg_miter_stop(&m);
c66ac9db	367
5787cacd	368	target_complete_cmd(cmd, SAM_STAT_GOOD);
03e98c9e	369	return 0;
c66ac9db NB	370	}
c66ac9db NB	371
c66ac9db NB	372	enum {
	373	Opt_rd_pages, Opt_err
	374	};
	375
	376	static match_table_t tokens = {
	377	{Opt_rd_pages, "rd_pages=%d"},
	378	{Opt_err, NULL}
	379	};
	380
	381	static ssize_t rd_set_configfs_dev_params(
	382	struct se_hba *hba,
	383	struct se_subsystem_dev *se_dev,
	384	const char *page,
	385	ssize_t count)
	386	{
	387	struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
	388	char orig, ptr, *opts;
	389	substring_t args[MAX_OPT_ARGS];
	390	int ret = 0, arg, token;
	391
	392	opts = kstrdup(page, GFP_KERNEL);
	393	if (!opts)
	394	return -ENOMEM;
	395
	396	orig = opts;
	397
90c161b6	398	while ((ptr = strsep(&opts, ",\n")) != NULL) {
c66ac9db NB	399	if (!*ptr)
	400	continue;
	401
	402	token = match_token(ptr, tokens, args);
	403	switch (token) {
	404	case Opt_rd_pages:
	405	match_int(args, &arg);
	406	rd_dev->rd_page_count = arg;
6708bb27	407	pr_debug("RAMDISK: Referencing Page"
c66ac9db NB	408	" Count: %u\n", rd_dev->rd_page_count);
	409	rd_dev->rd_flags \|= RDF_HAS_PAGE_COUNT;
	410	break;
	411	default:
	412	break;
	413	}
	414	}
	415
	416	kfree(orig);
	417	return (!ret) ? count : ret;
	418	}
	419
	420	static ssize_t rd_check_configfs_dev_params(struct se_hba hba, struct se_subsystem_dev se_dev)
	421	{
	422	struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
	423
	424	if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
6708bb27	425	pr_debug("Missing rd_pages= parameter\n");
e3d6f909	426	return -EINVAL;
c66ac9db NB	427	}
	428
	429	return 0;
	430	}
	431
	432	static ssize_t rd_show_configfs_dev_params(
	433	struct se_hba *hba,
	434	struct se_subsystem_dev *se_dev,
	435	char *b)
	436	{
	437	struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
8feb58d0 CH	438	ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
8feb58d0 CH	439	rd_dev->rd_dev_id);
c66ac9db NB	440	bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu"
	441	" SG_table_count: %u\n", rd_dev->rd_page_count,
	442	PAGE_SIZE, rd_dev->sg_table_count);
	443	return bl;
	444	}
	445
c66ac9db NB	446	static u32 rd_get_device_rev(struct se_device *dev)
	447	{
	448	return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
	449	}
	450
	451	static u32 rd_get_device_type(struct se_device *dev)
	452	{
	453	return TYPE_DISK;
	454	}
	455
	456	static sector_t rd_get_blocks(struct se_device *dev)
	457	{
	458	struct rd_dev *rd_dev = dev->dev_ptr;
	459	unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
e3d6f909	460	dev->se_sub_dev->se_dev_attrib.block_size) - 1;
c66ac9db NB	461
	462	return blocks_long;
	463	}
	464
0c2ad7d1 CH	465	static struct spc_ops rd_spc_ops = {
	466	.execute_rw = rd_execute_rw,
	467	};
	468
	469	static int rd_parse_cdb(struct se_cmd *cmd)
	470	{
	471	return sbc_parse_cdb(cmd, &rd_spc_ops);
	472	}
	473
c66ac9db NB	474	static struct se_subsystem_api rd_mcp_template = {
	475	.name = "rd_mcp",
	476	.transport_type = TRANSPORT_PLUGIN_VHBA_VDEV,
	477	.attach_hba = rd_attach_hba,
	478	.detach_hba = rd_detach_hba,
8feb58d0 CH	479	.allocate_virtdevice = rd_allocate_virtdevice,
8feb58d0 CH	480	.create_virtdevice = rd_create_virtdevice,
c66ac9db	481	.free_device = rd_free_device,
0c2ad7d1	482	.parse_cdb = rd_parse_cdb,
c66ac9db NB	483	.check_configfs_dev_params = rd_check_configfs_dev_params,
	484	.set_configfs_dev_params = rd_set_configfs_dev_params,
	485	.show_configfs_dev_params = rd_show_configfs_dev_params,
c66ac9db NB	486	.get_device_rev = rd_get_device_rev,
	487	.get_device_type = rd_get_device_type,
	488	.get_blocks = rd_get_blocks,
	489	};
	490
	491	int __init rd_module_init(void)
	492	{
	493	int ret;
	494
c66ac9db NB	495	ret = transport_subsystem_register(&rd_mcp_template);
c66ac9db NB	496	if (ret < 0) {
c66ac9db NB	497	return ret;
	498	}
	499
	500	return 0;
	501	}
	502
	503	void rd_module_exit(void)
	504	{
c66ac9db NB	505	transport_subsystem_release(&rd_mcp_template);
c66ac9db NB	506	}