1 files changed, 678 insertions, 0 deletions

diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
new file mode 100644
index 000000000..a6e8106ab
--- /dev/null
+++ b/drivers/target/target_core_rd.c
@@ -0,0 +1,678 @@
+/*******************************************************************************
+ * 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>
+ *
+ * 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/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);
+}