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

// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
 * Filename:  target_core_rd.c
 *
 * This file contains the Storage Engine <-> Ramdisk transport
 * specific functions.
 *
 * (c) Copyright 2003-2013 Datera, Inc.
 *
 * Nicholas A. Bellinger <nab@kernel.org>
 *
 ******************************************************************************/

#include <linux/string.h>
#include <linux/parser.h>
#include <linux/highmem.h>
#include <linux/timer.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <scsi/scsi_proto.h>

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

#include "target_core_rd.h"

static inline struct rd_dev *RD_DEV(struct se_device *dev)
{
	return container_of(dev, struct rd_dev, dev);
}

static int rd_attach_hba(struct se_hba *hba, u32 host_id)
{
	struct rd_host *rd_host;

	rd_host = kzalloc(sizeof(*rd_host), GFP_KERNEL);
	if (!rd_host)
		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_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;
}

static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
				 u32 sg_table_count)
{
	struct page *pg;
	struct scatterlist *sg;
	u32 i, j, page_count = 0, sg_per_table;

	for (i = 0; i < 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);
	}

	kfree(sg_table);
	return page_count;
}

static void rd_release_device_space(struct rd_dev *rd_dev)
{
	u32 page_count;

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

	page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
					  rd_dev->sg_table_count);

	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);

	rd_dev->sg_table_array = NULL;
	rd_dev->sg_table_count = 0;
}


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

	while (total_sg_needed) {
		unsigned int chain_entry = 0;

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

		/*
		 * Reserve extra element for chain entry
		 */
		if (sg_per_table < total_sg_needed)
			chain_entry = 1;

		sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
				GFP_KERNEL);
		if (!sg)
			return -ENOMEM;

		sg_init_table(sg, sg_per_table + chain_entry);

		if (i > 0) {
			sg_chain(sg_table[i - 1].sg_table,
				 max_sg_per_table + 1, sg);
		}

		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;

			p = kmap(pg);
			memset(p, init_payload, PAGE_SIZE);
			kunmap(pg);
		}

		page_offset += sg_per_table;
		total_sg_needed -= sg_per_table;
	}

	return 0;
}

static int rd_build_device_space(struct rd_dev *rd_dev)
{
	struct rd_dev_sg_table *sg_table;
	u32 sg_tables, total_sg_needed;
	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
				sizeof(struct scatterlist));
	int rc;

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

	/* Don't need backing pages for NULLIO */
	if (rd_dev->rd_flags & RDF_NULLIO)
		return 0;

	total_sg_needed = rd_dev->rd_page_count;

	sg_tables = (total_sg_needed / max_sg_per_table) + 1;
	sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
	if (!sg_table)
		return -ENOMEM;

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

	rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
	if (rc)
		return rc;

	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_release_prot_space(struct rd_dev *rd_dev)
{
	u32 page_count;

	if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
		return;

	page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
					  rd_dev->sg_prot_count);

	pr_debug("CORE_RD[%u] - Released protection 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);

	rd_dev->sg_prot_array = NULL;
	rd_dev->sg_prot_count = 0;
}

static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
{
	struct rd_dev_sg_table *sg_table;
	u32 total_sg_needed, sg_tables;
	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
				sizeof(struct scatterlist));
	int rc;

	if (rd_dev->rd_flags & RDF_NULLIO)
		return 0;
	/*
	 * prot_length=8byte dif data
	 * tot sg needed = rd_page_count * (PGSZ/block_size) *
	 * 		   (prot_length/block_size) + pad
	 * PGSZ canceled each other.
	 */
	total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;

	sg_tables = (total_sg_needed / max_sg_per_table) + 1;
	sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
	if (!sg_table)
		return -ENOMEM;

	rd_dev->sg_prot_array = sg_table;
	rd_dev->sg_prot_count = sg_tables;

	rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
	if (rc)
		return rc;

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

	return 0;
}

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

	rd_dev = kzalloc(sizeof(*rd_dev), GFP_KERNEL);
	if (!rd_dev)
		return NULL;

	rd_dev->rd_host = rd_host;

	return &rd_dev->dev;
}

static int rd_configure_device(struct se_device *dev)
{
	struct rd_dev *rd_dev = RD_DEV(dev);
	struct rd_host *rd_host = dev->se_hba->hba_ptr;
	int ret;

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

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

	dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
	dev->dev_attrib.hw_max_sectors = UINT_MAX;
	dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
	dev->dev_attrib.is_nonrot = 1;

	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 0;

fail:
	rd_release_device_space(rd_dev);
	return ret;
}

static void rd_dev_call_rcu(struct rcu_head *p)
{
	struct se_device *dev = container_of(p, struct se_device, rcu_head);
	struct rd_dev *rd_dev = RD_DEV(dev);

	kfree(rd_dev);
}

static void rd_free_device(struct se_device *dev)
{
	call_rcu(&dev->rcu_head, rd_dev_call_rcu);
}

static void rd_destroy_device(struct se_device *dev)
{
	struct rd_dev *rd_dev = RD_DEV(dev);

	rd_release_device_space(rd_dev);
}

static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
{
	struct rd_dev_sg_table *sg_table;
	u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
				sizeof(struct scatterlist));

	i = page / sg_per_table;
	if (i < rd_dev->sg_table_count) {
		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 struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
{
	struct rd_dev_sg_table *sg_table;
	u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
				sizeof(struct scatterlist));

	i = page / sg_per_table;
	if (i < rd_dev->sg_prot_count) {
		sg_table = &rd_dev->sg_prot_array[i];
		if ((sg_table->page_start_offset <= page) &&
		     (sg_table->page_end_offset >= page))
			return sg_table;
	}

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

	return NULL;
}

static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_read)
{
	struct se_device *se_dev = cmd->se_dev;
	struct rd_dev *dev = RD_DEV(se_dev);
	struct rd_dev_sg_table *prot_table;
	struct scatterlist *prot_sg;
	u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
	u32 prot_offset, prot_page;
	u32 prot_npages __maybe_unused;
	u64 tmp;
	sense_reason_t rc = 0;

	tmp = cmd->t_task_lba * se_dev->prot_length;
	prot_offset = do_div(tmp, PAGE_SIZE);
	prot_page = tmp;

	prot_table = rd_get_prot_table(dev, prot_page);
	if (!prot_table)
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	prot_sg = &prot_table->sg_table[prot_page -
					prot_table->page_start_offset];

	if (se_dev->dev_attrib.pi_prot_verify) {
		if (is_read)
			rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
					    prot_sg, prot_offset);
		else
			rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
					    cmd->t_prot_sg, 0);
	}
	if (!rc)
		sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);

	return rc;
}

static sense_reason_t
rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
	      enum dma_data_direction data_direction)
{
	struct se_device *se_dev = cmd->se_dev;
	struct rd_dev *dev = RD_DEV(se_dev);
	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;
	sense_reason_t rc;

	if (dev->rd_flags & RDF_NULLIO) {
		target_complete_cmd(cmd, SAM_STAT_GOOD);
		return 0;
	}

	tmp = cmd->t_task_lba * se_dev->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 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	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);

	if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
	    data_direction == DMA_TO_DEVICE) {
		rc = rd_do_prot_rw(cmd, false);
		if (rc)
			return rc;
	}

	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);
		if (!(u32)m.length) {
			pr_debug("RD[%u]: invalid sgl %p len %zu\n",
				 dev->rd_dev_id, m.addr, m.length);
			sg_miter_stop(&m);
			return TCM_INCORRECT_AMOUNT_OF_DATA;
		}
		len = min((u32)m.length, src_len);
		if (len > rd_size) {
			pr_debug("RD[%u]: size underrun page %d offset %d "
				 "size %d\n", dev->rd_dev_id,
				 rd_page, rd_offset, rd_size);
			len = rd_size;
		}
		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 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
		}

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

	if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
	    data_direction == DMA_FROM_DEVICE) {
		rc = rd_do_prot_rw(cmd, true);
		if (rc)
			return rc;
	}

	target_complete_cmd(cmd, SAM_STAT_GOOD);
	return 0;
}

enum {
	Opt_rd_pages, Opt_rd_nullio, Opt_err
};

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

static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
		const char *page, ssize_t count)
{
	struct rd_dev *rd_dev = RD_DEV(dev);
	char *orig, *ptr, *opts;
	substring_t args[MAX_OPT_ARGS];
	int 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;
		case Opt_rd_nullio:
			match_int(args, &arg);
			if (arg != 1)
				break;

			pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
			rd_dev->rd_flags |= RDF_NULLIO;
			break;
		default:
			break;
		}
	}

	kfree(orig);
	return count;
}

static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
{
	struct rd_dev *rd_dev = RD_DEV(dev);

	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  nullio: %d\n", rd_dev->rd_page_count,
			PAGE_SIZE, rd_dev->sg_table_count,
			!!(rd_dev->rd_flags & RDF_NULLIO));
	return bl;
}

static sector_t rd_get_blocks(struct se_device *dev)
{
	struct rd_dev *rd_dev = RD_DEV(dev);

	unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
			dev->dev_attrib.block_size) - 1;

	return blocks_long;
}

static int rd_init_prot(struct se_device *dev)
{
	struct rd_dev *rd_dev = RD_DEV(dev);

        if (!dev->dev_attrib.pi_prot_type)
		return 0;

	return rd_build_prot_space(rd_dev, dev->prot_length,
				   dev->dev_attrib.block_size);
}

static void rd_free_prot(struct se_device *dev)
{
	struct rd_dev *rd_dev = RD_DEV(dev);

	rd_release_prot_space(rd_dev);
}

static struct sbc_ops rd_sbc_ops = {
	.execute_rw		= rd_execute_rw,
};

static sense_reason_t
rd_parse_cdb(struct se_cmd *cmd)
{
	return sbc_parse_cdb(cmd, &rd_sbc_ops);
}

static const struct target_backend_ops rd_mcp_ops = {
	.name			= "rd_mcp",
	.inquiry_prod		= "RAMDISK-MCP",
	.inquiry_rev		= RD_MCP_VERSION,
	.attach_hba		= rd_attach_hba,
	.detach_hba		= rd_detach_hba,
	.alloc_device		= rd_alloc_device,
	.configure_device	= rd_configure_device,
	.destroy_device		= rd_destroy_device,
	.free_device		= rd_free_device,
	.parse_cdb		= rd_parse_cdb,
	.set_configfs_dev_params = rd_set_configfs_dev_params,
	.show_configfs_dev_params = rd_show_configfs_dev_params,
	.get_device_type	= sbc_get_device_type,
	.get_blocks		= rd_get_blocks,
	.init_prot		= rd_init_prot,
	.free_prot		= rd_free_prot,
	.tb_dev_attrib_attrs	= sbc_attrib_attrs,
};

int __init rd_module_init(void)
{
	return transport_backend_register(&rd_mcp_ops);
}

void rd_module_exit(void)
{
	target_backend_unregister(&rd_mcp_ops);
}
Commit	Line	Data
1a59d1b8	1	// SPDX-License-Identifier: GPL-2.0-or-later
c66ac9db NB	2	/*******************************************************************************
	3	* Filename: target_core_rd.c
	4	*
	5	* This file contains the Storage Engine <-> Ramdisk transport
	6	* specific functions.
	7	*
4c76251e	8	* (c) Copyright 2003-2013 Datera, Inc.
c66ac9db NB	9	*
	10	* Nicholas A. Bellinger <nab@kernel.org>
	11	*
c66ac9db NB	12	******************************************************************************/
c66ac9db NB	13
c66ac9db NB	14	#include <linux/string.h>
c66ac9db NB	15	#include <linux/parser.h>
8dcf07be	16	#include <linux/highmem.h>
c66ac9db	17	#include <linux/timer.h>
8dcf07be	18	#include <linux/scatterlist.h>
c66ac9db NB	19	#include <linux/slab.h>
c66ac9db NB	20	#include <linux/spinlock.h>
ba929992	21	#include <scsi/scsi_proto.h>
c66ac9db NB	22
c66ac9db NB	23	#include <target/target_core_base.h>
c4795fb2	24	#include <target/target_core_backend.h>
c66ac9db NB	25
	26	#include "target_core_rd.h"
	27
0fd97ccf CH	28	static inline struct rd_dev RD_DEV(struct se_device dev)
	29	{
	30	return container_of(dev, struct rd_dev, dev);
	31	}
c66ac9db	32
c66ac9db NB	33	static int rd_attach_hba(struct se_hba *hba, u32 host_id)
	34	{
	35	struct rd_host *rd_host;
	36
5d68fb72	37	rd_host = kzalloc(sizeof(*rd_host), GFP_KERNEL);
fbc4040b	38	if (!rd_host)
c66ac9db	39	return -ENOMEM;
c66ac9db NB	40
	41	rd_host->rd_host_id = host_id;
	42
5951146d	43	hba->hba_ptr = rd_host;
c66ac9db	44
6708bb27	45	pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
c66ac9db	46	" Generic Target Core Stack %s\n", hba->hba_id,
ce8dd25d	47	RD_HBA_VERSION, TARGET_CORE_VERSION);
c66ac9db NB	48
	49	return 0;
	50	}
	51
	52	static void rd_detach_hba(struct se_hba *hba)
	53	{
	54	struct rd_host *rd_host = hba->hba_ptr;
	55
6708bb27	56	pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
c66ac9db NB	57	" Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
	58
	59	kfree(rd_host);
	60	hba->hba_ptr = NULL;
	61	}
	62
4442dc8a NB	63	static u32 rd_release_sgl_table(struct rd_dev rd_dev, struct rd_dev_sg_table sg_table,
4442dc8a NB	64	u32 sg_table_count)
c66ac9db	65	{
c66ac9db NB	66	struct page *pg;
c66ac9db NB	67	struct scatterlist *sg;
4442dc8a	68	u32 i, j, page_count = 0, sg_per_table;
c66ac9db	69
4442dc8a	70	for (i = 0; i < sg_table_count; i++) {
c66ac9db NB	71	sg = sg_table[i].sg_table;
	72	sg_per_table = sg_table[i].rd_sg_count;
	73
	74	for (j = 0; j < sg_per_table; j++) {
	75	pg = sg_page(&sg[j]);
6708bb27	76	if (pg) {
c66ac9db NB	77	__free_page(pg);
	78	page_count++;
	79	}
	80	}
c66ac9db NB	81	kfree(sg);
	82	}
	83
4442dc8a NB	84	kfree(sg_table);
	85	return page_count;
	86	}
	87
	88	static void rd_release_device_space(struct rd_dev *rd_dev)
	89	{
	90	u32 page_count;
	91
	92	if (!rd_dev->sg_table_array \|\| !rd_dev->sg_table_count)
	93	return;
	94
	95	page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
	96	rd_dev->sg_table_count);
	97
6708bb27	98	pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
c66ac9db NB	99	" Device ID: %u, pages %u in %u tables total bytes %lu\n",
	100	rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
	101	rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
	102
c66ac9db NB	103	rd_dev->sg_table_array = NULL;
	104	rd_dev->sg_table_count = 0;
	105	}
	106
	107
	108	/* rd_build_device_space():
	109	*
	110	*
	111	*/
4442dc8a NB	112	static int rd_allocate_sgl_table(struct rd_dev rd_dev, struct rd_dev_sg_table sg_table,
4442dc8a NB	113	u32 total_sg_needed, unsigned char init_payload)
c66ac9db	114	{
4442dc8a	115	u32 i = 0, j, page_offset = 0, sg_per_table;
c66ac9db NB	116	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
c66ac9db NB	117	sizeof(struct scatterlist));
c66ac9db NB	118	struct page *pg;
c66ac9db NB	119	struct scatterlist *sg;
4442dc8a	120	unsigned char *p;
c66ac9db NB	121
c66ac9db NB	122	while (total_sg_needed) {
bfd9a53e AM	123	unsigned int chain_entry = 0;
bfd9a53e AM	124
c66ac9db NB	125	sg_per_table = (total_sg_needed > max_sg_per_table) ?
	126	max_sg_per_table : total_sg_needed;
	127
bfd9a53e AM	128	/*
	129	* Reserve extra element for chain entry
	130	*/
	131	if (sg_per_table < total_sg_needed)
	132	chain_entry = 1;
	133
bfd9a53e	134	sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
c66ac9db	135	GFP_KERNEL);
fbc4040b	136	if (!sg)
065f9716	137	return -ENOMEM;
c66ac9db	138
bfd9a53e AM	139	sg_init_table(sg, sg_per_table + chain_entry);
bfd9a53e AM	140
bfd9a53e AM	141	if (i > 0) {
	142	sg_chain(sg_table[i - 1].sg_table,
	143	max_sg_per_table + 1, sg);
	144	}
	145
c66ac9db NB	146	sg_table[i].sg_table = sg;
	147	sg_table[i].rd_sg_count = sg_per_table;
	148	sg_table[i].page_start_offset = page_offset;
	149	sg_table[i++].page_end_offset = (page_offset + sg_per_table)
	150	- 1;
	151
	152	for (j = 0; j < sg_per_table; j++) {
	153	pg = alloc_pages(GFP_KERNEL, 0);
6708bb27 AG	154	if (!pg) {
6708bb27 AG	155	pr_err("Unable to allocate scatterlist"
c66ac9db	156	" pages for struct rd_dev_sg_table\n");
065f9716	157	return -ENOMEM;
c66ac9db NB	158	}
	159	sg_assign_page(&sg[j], pg);
	160	sg[j].length = PAGE_SIZE;
4442dc8a NB	161
	162	p = kmap(pg);
	163	memset(p, init_payload, PAGE_SIZE);
	164	kunmap(pg);
c66ac9db NB	165	}
	166
	167	page_offset += sg_per_table;
	168	total_sg_needed -= sg_per_table;
	169	}
	170
4442dc8a NB	171	return 0;
	172	}
	173
	174	static int rd_build_device_space(struct rd_dev *rd_dev)
	175	{
	176	struct rd_dev_sg_table *sg_table;
	177	u32 sg_tables, total_sg_needed;
	178	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
	179	sizeof(struct scatterlist));
	180	int rc;
	181
	182	if (rd_dev->rd_page_count <= 0) {
	183	pr_err("Illegal page count: %u for Ramdisk device\n",
	184	rd_dev->rd_page_count);
	185	return -EINVAL;
	186	}
	187
	188	/* Don't need backing pages for NULLIO */
	189	if (rd_dev->rd_flags & RDF_NULLIO)
	190	return 0;
	191
	192	total_sg_needed = rd_dev->rd_page_count;
	193
	194	sg_tables = (total_sg_needed / max_sg_per_table) + 1;
55ec4092	195	sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
fbc4040b	196	if (!sg_table)
4442dc8a	197	return -ENOMEM;
4442dc8a NB	198
	199	rd_dev->sg_table_array = sg_table;
	200	rd_dev->sg_table_count = sg_tables;
	201
	202	rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
	203	if (rc)
	204	return rc;
	205
6708bb27	206	pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
4442dc8a NB	207	" %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
	208	rd_dev->rd_dev_id, rd_dev->rd_page_count,
	209	rd_dev->sg_table_count);
c66ac9db NB	210
	211	return 0;
	212	}
	213
d7e8eb5d NB	214	static void rd_release_prot_space(struct rd_dev *rd_dev)
	215	{
	216	u32 page_count;
	217
	218	if (!rd_dev->sg_prot_array \|\| !rd_dev->sg_prot_count)
	219	return;
	220
	221	page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
	222	rd_dev->sg_prot_count);
	223
	224	pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
	225	" Device ID: %u, pages %u in %u tables total bytes %lu\n",
	226	rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
	227	rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
	228
	229	rd_dev->sg_prot_array = NULL;
	230	rd_dev->sg_prot_count = 0;
	231	}
	232
9d2e59f2	233	static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
d7e8eb5d NB	234	{
	235	struct rd_dev_sg_table *sg_table;
	236	u32 total_sg_needed, sg_tables;
	237	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
	238	sizeof(struct scatterlist));
	239	int rc;
	240
	241	if (rd_dev->rd_flags & RDF_NULLIO)
	242	return 0;
9d2e59f2 QT	243	/*
	244	* prot_length=8byte dif data
	245	* tot sg needed = rd_page_count * (PGSZ/block_size) *
	246	* (prot_length/block_size) + pad
	247	* PGSZ canceled each other.
	248	*/
	249	total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
d7e8eb5d NB	250
d7e8eb5d NB	251	sg_tables = (total_sg_needed / max_sg_per_table) + 1;
55ec4092	252	sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
fbc4040b	253	if (!sg_table)
d7e8eb5d	254	return -ENOMEM;
d7e8eb5d NB	255
	256	rd_dev->sg_prot_array = sg_table;
	257	rd_dev->sg_prot_count = sg_tables;
	258
	259	rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
	260	if (rc)
	261	return rc;
	262
	263	pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
	264	" %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
	265	rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
	266
	267	return 0;
	268	}
	269
0fd97ccf	270	static struct se_device rd_alloc_device(struct se_hba hba, const char *name)
c66ac9db NB	271	{
	272	struct rd_dev *rd_dev;
	273	struct rd_host *rd_host = hba->hba_ptr;
	274
5d68fb72	275	rd_dev = kzalloc(sizeof(*rd_dev), GFP_KERNEL);
fbc4040b	276	if (!rd_dev)
c66ac9db	277	return NULL;
c66ac9db NB	278
c66ac9db NB	279	rd_dev->rd_host = rd_host;
c66ac9db	280
0fd97ccf	281	return &rd_dev->dev;
c66ac9db NB	282	}
c66ac9db NB	283
0fd97ccf	284	static int rd_configure_device(struct se_device *dev)
c66ac9db	285	{
0fd97ccf CH	286	struct rd_dev *rd_dev = RD_DEV(dev);
	287	struct rd_host *rd_host = dev->se_hba->hba_ptr;
	288	int ret;
c66ac9db	289
0fd97ccf CH	290	if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
	291	pr_debug("Missing rd_pages= parameter\n");
	292	return -EINVAL;
	293	}
c66ac9db	294
065f9716 DC	295	ret = rd_build_device_space(rd_dev);
065f9716 DC	296	if (ret < 0)
c66ac9db NB	297	goto fail;
c66ac9db NB	298
0fd97ccf CH	299	dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
	300	dev->dev_attrib.hw_max_sectors = UINT_MAX;
	301	dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
5dacbfc9	302	dev->dev_attrib.is_nonrot = 1;
c66ac9db NB	303
c66ac9db NB	304	rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
c66ac9db	305
8feb58d0	306	pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
c66ac9db	307	" %u pages in %u tables, %lu total bytes\n",
8feb58d0	308	rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
c66ac9db NB	309	rd_dev->sg_table_count,
	310	(unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
	311
0fd97ccf	312	return 0;
c66ac9db NB	313
	314	fail:
	315	rd_release_device_space(rd_dev);
0fd97ccf	316	return ret;
c66ac9db NB	317	}
c66ac9db NB	318
4cc987ea NB	319	static void rd_dev_call_rcu(struct rcu_head *p)
	320	{
	321	struct se_device *dev = container_of(p, struct se_device, rcu_head);
	322	struct rd_dev *rd_dev = RD_DEV(dev);
	323
	324	kfree(rd_dev);
	325	}
	326
0fd97ccf	327	static void rd_free_device(struct se_device *dev)
92634706 MC	328	{
	329	call_rcu(&dev->rcu_head, rd_dev_call_rcu);
	330	}
	331
	332	static void rd_destroy_device(struct se_device *dev)
c66ac9db	333	{
0fd97ccf	334	struct rd_dev *rd_dev = RD_DEV(dev);
c66ac9db NB	335
c66ac9db NB	336	rd_release_device_space(rd_dev);
c66ac9db NB	337	}
c66ac9db NB	338
c66ac9db NB	339	static struct rd_dev_sg_table rd_get_sg_table(struct rd_dev rd_dev, u32 page)
c66ac9db NB	340	{
c66ac9db	341	struct rd_dev_sg_table *sg_table;
8f67835f MS	342	u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
8f67835f MS	343	sizeof(struct scatterlist));
c66ac9db	344
8f67835f MS	345	i = page / sg_per_table;
8f67835f MS	346	if (i < rd_dev->sg_table_count) {
c66ac9db NB	347	sg_table = &rd_dev->sg_table_array[i];
	348	if ((sg_table->page_start_offset <= page) &&
	349	(sg_table->page_end_offset >= page))
	350	return sg_table;
	351	}
	352
6708bb27	353	pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
c66ac9db NB	354	page);
	355
	356	return NULL;
	357	}
	358
6e611119 NB	359	static struct rd_dev_sg_table rd_get_prot_table(struct rd_dev rd_dev, u32 page)
	360	{
	361	struct rd_dev_sg_table *sg_table;
	362	u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
	363	sizeof(struct scatterlist));
	364
	365	i = page / sg_per_table;
	366	if (i < rd_dev->sg_prot_count) {
	367	sg_table = &rd_dev->sg_prot_array[i];
	368	if ((sg_table->page_start_offset <= page) &&
	369	(sg_table->page_end_offset >= page))
	370	return sg_table;
	371	}
	372
	373	pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
	374	page);
	375
	376	return NULL;
	377	}
	378
f75b6fae	379	static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_read)
6766cc81 AM	380	{
	381	struct se_device *se_dev = cmd->se_dev;
	382	struct rd_dev *dev = RD_DEV(se_dev);
	383	struct rd_dev_sg_table *prot_table;
	384	struct scatterlist *prot_sg;
	385	u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
	386	u32 prot_offset, prot_page;
bfd9a53e	387	u32 prot_npages __maybe_unused;
6766cc81	388	u64 tmp;
056e8924	389	sense_reason_t rc = 0;
6766cc81 AM	390
	391	tmp = cmd->t_task_lba * se_dev->prot_length;
	392	prot_offset = do_div(tmp, PAGE_SIZE);
	393	prot_page = tmp;
	394
	395	prot_table = rd_get_prot_table(dev, prot_page);
	396	if (!prot_table)
	397	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	398
	399	prot_sg = &prot_table->sg_table[prot_page -
	400	prot_table->page_start_offset];
	401
056e8924 DM	402	if (se_dev->dev_attrib.pi_prot_verify) {
	403	if (is_read)
	404	rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
	405	prot_sg, prot_offset);
	406	else
	407	rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
	408	cmd->t_prot_sg, 0);
	409	}
f75b6fae SG	410	if (!rc)
	411	sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);
	412
6766cc81 AM	413	return rc;
	414	}
	415
de103c93	416	static sense_reason_t
a82a9538 NB	417	rd_execute_rw(struct se_cmd cmd, struct scatterlist sgl, u32 sgl_nents,
a82a9538 NB	418	enum dma_data_direction data_direction)
c66ac9db	419	{
5787cacd	420	struct se_device *se_dev = cmd->se_dev;
0fd97ccf	421	struct rd_dev *dev = RD_DEV(se_dev);
c66ac9db	422	struct rd_dev_sg_table *table;
65b0c78d SAS	423	struct scatterlist *rd_sg;
65b0c78d SAS	424	struct sg_mapping_iter m;
8feb58d0 CH	425	u32 rd_offset;
	426	u32 rd_size;
	427	u32 rd_page;
65b0c78d	428	u32 src_len;
8feb58d0	429	u64 tmp;
6e611119	430	sense_reason_t rc;
c66ac9db	431
52c07423 NB	432	if (dev->rd_flags & RDF_NULLIO) {
	433	target_complete_cmd(cmd, SAM_STAT_GOOD);
	434	return 0;
	435	}
	436
0fd97ccf	437	tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
8feb58d0 CH	438	rd_offset = do_div(tmp, PAGE_SIZE);
8feb58d0 CH	439	rd_page = tmp;
5787cacd	440	rd_size = cmd->data_length;
8feb58d0 CH	441
8feb58d0 CH	442	table = rd_get_sg_table(dev, rd_page);
6708bb27	443	if (!table)
de103c93	444	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
c66ac9db	445
8feb58d0	446	rd_sg = &table->sg_table[rd_page - table->page_start_offset];
6708bb27	447
65b0c78d	448	pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
8feb58d0	449	dev->rd_dev_id,
5787cacd CH	450	data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
5787cacd CH	451	cmd->t_task_lba, rd_size, rd_page, rd_offset);
c66ac9db	452
1762742f NB	453	if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
1762742f NB	454	data_direction == DMA_TO_DEVICE) {
f75b6fae	455	rc = rd_do_prot_rw(cmd, false);
6e611119 NB	456	if (rc)
	457	return rc;
	458	}
	459
65b0c78d	460	src_len = PAGE_SIZE - rd_offset;
5787cacd CH	461	sg_miter_start(&m, sgl, sgl_nents,
5787cacd CH	462	data_direction == DMA_FROM_DEVICE ?
8feb58d0 CH	463	SG_MITER_TO_SG : SG_MITER_FROM_SG);
8feb58d0 CH	464	while (rd_size) {
65b0c78d SAS	465	u32 len;
65b0c78d SAS	466	void *rd_addr;
c66ac9db	467
65b0c78d	468	sg_miter_next(&m);
bbf344e5 HR	469	if (!(u32)m.length) {
	470	pr_debug("RD[%u]: invalid sgl %p len %zu\n",
	471	dev->rd_dev_id, m.addr, m.length);
	472	sg_miter_stop(&m);
	473	return TCM_INCORRECT_AMOUNT_OF_DATA;
	474	}
65b0c78d	475	len = min((u32)m.length, src_len);
bbf344e5 HR	476	if (len > rd_size) {
	477	pr_debug("RD[%u]: size underrun page %d offset %d "
	478	"size %d\n", dev->rd_dev_id,
	479	rd_page, rd_offset, rd_size);
	480	len = rd_size;
	481	}
65b0c78d	482	m.consumed = len;
c66ac9db	483
65b0c78d	484	rd_addr = sg_virt(rd_sg) + rd_offset;
6708bb27	485
5787cacd	486	if (data_direction == DMA_FROM_DEVICE)
65b0c78d SAS	487	memcpy(m.addr, rd_addr, len);
	488	else
	489	memcpy(rd_addr, m.addr, len);
c66ac9db	490
8feb58d0 CH	491	rd_size -= len;
8feb58d0 CH	492	if (!rd_size)
c66ac9db NB	493	continue;
c66ac9db NB	494
65b0c78d SAS	495	src_len -= len;
	496	if (src_len) {
	497	rd_offset += len;
c66ac9db NB	498	continue;
c66ac9db NB	499	}
6708bb27	500
65b0c78d	501	/* rd page completed, next one please */
8feb58d0	502	rd_page++;
65b0c78d SAS	503	rd_offset = 0;
65b0c78d SAS	504	src_len = PAGE_SIZE;
8feb58d0	505	if (rd_page <= table->page_end_offset) {
65b0c78d	506	rd_sg++;
c66ac9db NB	507	continue;
c66ac9db NB	508	}
6708bb27	509
8feb58d0	510	table = rd_get_sg_table(dev, rd_page);
65b0c78d SAS	511	if (!table) {
65b0c78d SAS	512	sg_miter_stop(&m);
de103c93	513	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
65b0c78d	514	}
c66ac9db	515
65b0c78d SAS	516	/* since we increment, the first sg entry is correct */
65b0c78d SAS	517	rd_sg = table->sg_table;
c66ac9db	518	}
65b0c78d	519	sg_miter_stop(&m);
c66ac9db	520
1762742f NB	521	if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
1762742f NB	522	data_direction == DMA_FROM_DEVICE) {
f75b6fae	523	rc = rd_do_prot_rw(cmd, true);
6e611119 NB	524	if (rc)
	525	return rc;
	526	}
	527
5787cacd	528	target_complete_cmd(cmd, SAM_STAT_GOOD);
03e98c9e	529	return 0;
c66ac9db NB	530	}
c66ac9db NB	531
c66ac9db	532	enum {
52c07423	533	Opt_rd_pages, Opt_rd_nullio, Opt_err
c66ac9db NB	534	};
	535
	536	static match_table_t tokens = {
	537	{Opt_rd_pages, "rd_pages=%d"},
52c07423	538	{Opt_rd_nullio, "rd_nullio=%d"},
c66ac9db NB	539	{Opt_err, NULL}
	540	};
	541
0fd97ccf CH	542	static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
0fd97ccf CH	543	const char *page, ssize_t count)
c66ac9db	544	{
0fd97ccf	545	struct rd_dev *rd_dev = RD_DEV(dev);
c66ac9db NB	546	char orig, ptr, *opts;
c66ac9db NB	547	substring_t args[MAX_OPT_ARGS];
fb418240	548	int arg, token;
c66ac9db NB	549
	550	opts = kstrdup(page, GFP_KERNEL);
	551	if (!opts)
	552	return -ENOMEM;
	553
	554	orig = opts;
	555
90c161b6	556	while ((ptr = strsep(&opts, ",\n")) != NULL) {
c66ac9db NB	557	if (!*ptr)
	558	continue;
	559
	560	token = match_token(ptr, tokens, args);
	561	switch (token) {
	562	case Opt_rd_pages:
	563	match_int(args, &arg);
	564	rd_dev->rd_page_count = arg;
6708bb27	565	pr_debug("RAMDISK: Referencing Page"
c66ac9db NB	566	" Count: %u\n", rd_dev->rd_page_count);
	567	rd_dev->rd_flags \|= RDF_HAS_PAGE_COUNT;
	568	break;
52c07423 NB	569	case Opt_rd_nullio:
	570	match_int(args, &arg);
	571	if (arg != 1)
	572	break;
	573
	574	pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
	575	rd_dev->rd_flags \|= RDF_NULLIO;
	576	break;
c66ac9db NB	577	default:
	578	break;
	579	}
	580	}
	581
	582	kfree(orig);
fb418240	583	return count;
c66ac9db NB	584	}
c66ac9db NB	585
0fd97ccf	586	static ssize_t rd_show_configfs_dev_params(struct se_device dev, char b)
c66ac9db	587	{
0fd97ccf	588	struct rd_dev *rd_dev = RD_DEV(dev);
c66ac9db	589
8feb58d0 CH	590	ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
8feb58d0 CH	591	rd_dev->rd_dev_id);
c66ac9db	592	bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu"
52c07423 NB	593	" SG_table_count: %u nullio: %d\n", rd_dev->rd_page_count,
	594	PAGE_SIZE, rd_dev->sg_table_count,
	595	!!(rd_dev->rd_flags & RDF_NULLIO));
c66ac9db NB	596	return bl;
	597	}
	598
c66ac9db NB	599	static sector_t rd_get_blocks(struct se_device *dev)
c66ac9db NB	600	{
0fd97ccf CH	601	struct rd_dev *rd_dev = RD_DEV(dev);
0fd97ccf CH	602
c66ac9db	603	unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
0fd97ccf	604	dev->dev_attrib.block_size) - 1;
c66ac9db NB	605
	606	return blocks_long;
	607	}
	608
d7e8eb5d NB	609	static int rd_init_prot(struct se_device *dev)
	610	{
	611	struct rd_dev *rd_dev = RD_DEV(dev);
	612
	613	if (!dev->dev_attrib.pi_prot_type)
	614	return 0;
	615
9d2e59f2 QT	616	return rd_build_prot_space(rd_dev, dev->prot_length,
9d2e59f2 QT	617	dev->dev_attrib.block_size);
d7e8eb5d NB	618	}
	619
	620	static void rd_free_prot(struct se_device *dev)
	621	{
	622	struct rd_dev *rd_dev = RD_DEV(dev);
	623
	624	rd_release_prot_space(rd_dev);
	625	}
	626
9e999a6c	627	static struct sbc_ops rd_sbc_ops = {
0c2ad7d1 CH	628	.execute_rw = rd_execute_rw,
	629	};
	630
de103c93 CH	631	static sense_reason_t
de103c93 CH	632	rd_parse_cdb(struct se_cmd *cmd)
0c2ad7d1	633	{
9e999a6c	634	return sbc_parse_cdb(cmd, &rd_sbc_ops);
0c2ad7d1 CH	635	}
0c2ad7d1 CH	636
0a06d430	637	static const struct target_backend_ops rd_mcp_ops = {
c66ac9db	638	.name = "rd_mcp",
0fd97ccf CH	639	.inquiry_prod = "RAMDISK-MCP",
0fd97ccf CH	640	.inquiry_rev = RD_MCP_VERSION,
c66ac9db NB	641	.attach_hba = rd_attach_hba,
c66ac9db NB	642	.detach_hba = rd_detach_hba,
0fd97ccf CH	643	.alloc_device = rd_alloc_device,
0fd97ccf CH	644	.configure_device = rd_configure_device,
92634706	645	.destroy_device = rd_destroy_device,
c66ac9db	646	.free_device = rd_free_device,
0c2ad7d1	647	.parse_cdb = rd_parse_cdb,
c66ac9db NB	648	.set_configfs_dev_params = rd_set_configfs_dev_params,
c66ac9db NB	649	.show_configfs_dev_params = rd_show_configfs_dev_params,
6f23ac8a	650	.get_device_type = sbc_get_device_type,
c66ac9db	651	.get_blocks = rd_get_blocks,
d7e8eb5d NB	652	.init_prot = rd_init_prot,
d7e8eb5d NB	653	.free_prot = rd_free_prot,
5873c4d1	654	.tb_dev_attrib_attrs = sbc_attrib_attrs,
c66ac9db NB	655	};
	656
	657	int __init rd_module_init(void)
	658	{
0a06d430	659	return transport_backend_register(&rd_mcp_ops);
c66ac9db NB	660	}
	661
	662	void rd_module_exit(void)
	663	{
0a06d430	664	target_backend_unregister(&rd_mcp_ops);
c66ac9db	665	}