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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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#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_obj(*rd_host); 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_objs(*sg, sg_per_table + chain_entry); 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 = kzalloc_objs(*sg_table, sg_tables); 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 = kzalloc_objs(*sg_table, sg_tables); 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_obj(*rd_dev); 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_trd_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_rd_dummy, Opt_err};
static match_table_t tokens = { {Opt_rd_pages, "rd_pages=%d"}, {Opt_rd_nullio, "rd_nullio=%d"}, {Opt_rd_dummy, "rd_dummy=%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; case Opt_rd_dummy: match_int(args, &arg); if (arg != 1) break;
pr_debug("RAMDISK: Setting DUMMY flag: %d\n", arg); rd_dev->rd_flags |= RDF_DUMMY; 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 dummy: %d\n", rd_dev->rd_page_count, PAGE_SIZE, rd_dev->sg_table_count, !!(rd_dev->rd_flags & RDF_NULLIO), !!(rd_dev->rd_flags & RDF_DUMMY)); return bl;}
static u32 rd_get_device_type(struct se_device *dev){ if (RD_DEV(dev)->rd_flags & RDF_DUMMY) return 0x3f; /* Unknown device type, not connected */ else return sbc_get_device_type(dev);}
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 exec_cmd_ops rd_exec_cmd_ops = { .execute_rw = rd_execute_rw,};
static sense_reason_trd_parse_cdb(struct se_cmd *cmd){ return sbc_parse_cdb(cmd, &rd_exec_cmd_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 = rd_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);}