/******************************************************************************* * Filename: target_core_rd.c * * This file contains the Storage Engine <-> Ramdisk transport * specific functions. * * (c) Copyright 2003-2013 Datera, Inc. * * Nicholas A. Bellinger * * 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 #include #include #include #include #include #include #include #include #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(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; } 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; #ifdef CONFIG_ARCH_HAS_SG_CHAIN /* * Reserve extra element for chain entry */ if (sg_per_table < total_sg_needed) chain_entry = 1; #endif /* CONFIG_ARCH_HAS_SG_CHAIN */ sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg), 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 + chain_entry); #ifdef CONFIG_ARCH_HAS_SG_CHAIN if (i > 0) { sg_chain(sg_table[i - 1].sg_table, max_sg_per_table + 1, sg); } #endif /* CONFIG_ARCH_HAS_SG_CHAIN */ 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 = 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; 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 = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL); if (!sg_table) { pr_err("Unable to allocate memory for Ramdisk protection" " scatterlist tables\n"); 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(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->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; 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_free_device(struct se_device *dev) { struct rd_dev *rd_dev = RD_DEV(dev); 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) { 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; bool need_to_release = false; 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 = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 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]; #ifndef CONFIG_ARCH_HAS_SG_CHAIN prot_npages = DIV_ROUND_UP(prot_offset + sectors * se_dev->prot_length, PAGE_SIZE); /* * Allocate temporaly contiguous scatterlist entries if prot pages * straddles multiple scatterlist tables. */ if (prot_table->page_end_offset < prot_page + prot_npages - 1) { int i; prot_sg = kcalloc(prot_npages, sizeof(*prot_sg), GFP_KERNEL); if (!prot_sg) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; need_to_release = true; sg_init_table(prot_sg, prot_npages); for (i = 0; i < prot_npages; i++) { if (prot_page + i > prot_table->page_end_offset) { prot_table = rd_get_prot_table(dev, prot_page + i); if (!prot_table) { kfree(prot_sg); return rc; } sg_unmark_end(&prot_sg[i - 1]); } prot_sg[i] = prot_table->sg_table[prot_page + i - prot_table->page_start_offset]; } } #endif /* !CONFIG_ARCH_HAS_SG_CHAIN */ 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); if (need_to_release) kfree(prot_sg); 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 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; 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 (!ret) ? count : ret; } 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, .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); }