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-rw-r--r--drivers/target/target_core_rd.c665
1 files changed, 665 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..bf936bbec
--- /dev/null
+++ b/drivers/target/target_core_rd.c
@@ -0,0 +1,665 @@
+// 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 = kmalloc_array(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);
+}
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