diff options
Diffstat (limited to 'drivers/target/target_core_sbc.c')
| -rw-r--r-- | drivers/target/target_core_sbc.c | 450 |
1 files changed, 450 insertions, 0 deletions
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c new file mode 100644 index 000000000000..9d1ca3814876 --- /dev/null +++ b/drivers/target/target_core_sbc.c @@ -0,0 +1,450 @@ +/* + * SCSI Block Commands (SBC) parsing and emulation. + * + * Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc. + * Copyright (c) 2005, 2006, 2007 SBE, Inc. + * Copyright (c) 2007-2010 Rising Tide Systems + * Copyright (c) 2008-2010 Linux-iSCSI.org + * + * 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/kernel.h> +#include <linux/module.h> +#include <linux/ratelimit.h> +#include <asm/unaligned.h> +#include <scsi/scsi.h> + +#include <target/target_core_base.h> +#include <target/target_core_backend.h> +#include <target/target_core_fabric.h> + +#include "target_core_internal.h" +#include "target_core_ua.h" + + +static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors) +{ + return cmd->se_dev->se_sub_dev->se_dev_attrib.block_size * sectors; +} + +static int sbc_check_valid_sectors(struct se_cmd *cmd) +{ + struct se_device *dev = cmd->se_dev; + unsigned long long end_lba; + u32 sectors; + + sectors = cmd->data_length / dev->se_sub_dev->se_dev_attrib.block_size; + end_lba = dev->transport->get_blocks(dev) + 1; + + if (cmd->t_task_lba + sectors > end_lba) { + pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n", + cmd->t_task_lba, sectors, end_lba); + return -EINVAL; + } + + return 0; +} + +static inline u32 transport_get_sectors_6(unsigned char *cdb) +{ + /* + * Use 8-bit sector value. SBC-3 says: + * + * A TRANSFER LENGTH field set to zero specifies that 256 + * logical blocks shall be written. Any other value + * specifies the number of logical blocks that shall be + * written. + */ + return cdb[4] ? : 256; +} + +static inline u32 transport_get_sectors_10(unsigned char *cdb) +{ + return (u32)(cdb[7] << 8) + cdb[8]; +} + +static inline u32 transport_get_sectors_12(unsigned char *cdb) +{ + return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9]; +} + +static inline u32 transport_get_sectors_16(unsigned char *cdb) +{ + return (u32)(cdb[10] << 24) + (cdb[11] << 16) + + (cdb[12] << 8) + cdb[13]; +} + +/* + * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants + */ +static inline u32 transport_get_sectors_32(unsigned char *cdb) +{ + return (u32)(cdb[28] << 24) + (cdb[29] << 16) + + (cdb[30] << 8) + cdb[31]; + +} + +static inline u32 transport_lba_21(unsigned char *cdb) +{ + return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3]; +} + +static inline u32 transport_lba_32(unsigned char *cdb) +{ + return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5]; +} + +static inline unsigned long long transport_lba_64(unsigned char *cdb) +{ + unsigned int __v1, __v2; + + __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5]; + __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9]; + + return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32; +} + +/* + * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs + */ +static inline unsigned long long transport_lba_64_ext(unsigned char *cdb) +{ + unsigned int __v1, __v2; + + __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15]; + __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19]; + + return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32; +} + +static int sbc_write_same_supported(struct se_device *dev, + unsigned char *flags) +{ + if ((flags[0] & 0x04) || (flags[0] & 0x02)) { + pr_err("WRITE_SAME PBDATA and LBDATA" + " bits not supported for Block Discard" + " Emulation\n"); + return -ENOSYS; + } + + /* + * Currently for the emulated case we only accept + * tpws with the UNMAP=1 bit set. + */ + if (!(flags[0] & 0x08)) { + pr_err("WRITE_SAME w/o UNMAP bit not" + " supported for Block Discard Emulation\n"); + return -ENOSYS; + } + + return 0; +} + +static void xdreadwrite_callback(struct se_cmd *cmd) +{ + unsigned char *buf, *addr; + struct scatterlist *sg; + unsigned int offset; + int i; + int count; + /* + * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command + * + * 1) read the specified logical block(s); + * 2) transfer logical blocks from the data-out buffer; + * 3) XOR the logical blocks transferred from the data-out buffer with + * the logical blocks read, storing the resulting XOR data in a buffer; + * 4) if the DISABLE WRITE bit is set to zero, then write the logical + * blocks transferred from the data-out buffer; and + * 5) transfer the resulting XOR data to the data-in buffer. + */ + buf = kmalloc(cmd->data_length, GFP_KERNEL); + if (!buf) { + pr_err("Unable to allocate xor_callback buf\n"); + return; + } + /* + * Copy the scatterlist WRITE buffer located at cmd->t_data_sg + * into the locally allocated *buf + */ + sg_copy_to_buffer(cmd->t_data_sg, + cmd->t_data_nents, + buf, + cmd->data_length); + + /* + * Now perform the XOR against the BIDI read memory located at + * cmd->t_mem_bidi_list + */ + + offset = 0; + for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) { + addr = kmap_atomic(sg_page(sg)); + if (!addr) + goto out; + + for (i = 0; i < sg->length; i++) + *(addr + sg->offset + i) ^= *(buf + offset + i); + + offset += sg->length; + kunmap_atomic(addr); + } + +out: + kfree(buf); +} + +int sbc_parse_cdb(struct se_cmd *cmd, unsigned int *size) +{ + struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev; + struct se_device *dev = cmd->se_dev; + unsigned char *cdb = cmd->t_task_cdb; + u32 sectors = 0; + int ret; + + switch (cdb[0]) { + case READ_6: + sectors = transport_get_sectors_6(cdb); + cmd->t_task_lba = transport_lba_21(cdb); + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + break; + case READ_10: + sectors = transport_get_sectors_10(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + break; + case READ_12: + sectors = transport_get_sectors_12(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + break; + case READ_16: + sectors = transport_get_sectors_16(cdb); + cmd->t_task_lba = transport_lba_64(cdb); + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + break; + case WRITE_6: + sectors = transport_get_sectors_6(cdb); + cmd->t_task_lba = transport_lba_21(cdb); + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + break; + case WRITE_10: + case WRITE_VERIFY: + sectors = transport_get_sectors_10(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + if (cdb[1] & 0x8) + cmd->se_cmd_flags |= SCF_FUA; + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + break; + case WRITE_12: + sectors = transport_get_sectors_12(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + if (cdb[1] & 0x8) + cmd->se_cmd_flags |= SCF_FUA; + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + break; + case WRITE_16: + sectors = transport_get_sectors_16(cdb); + cmd->t_task_lba = transport_lba_64(cdb); + if (cdb[1] & 0x8) + cmd->se_cmd_flags |= SCF_FUA; + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + break; + case XDWRITEREAD_10: + if ((cmd->data_direction != DMA_TO_DEVICE) || + !(cmd->se_cmd_flags & SCF_BIDI)) + goto out_invalid_cdb_field; + sectors = transport_get_sectors_10(cdb); + + cmd->t_task_lba = transport_lba_32(cdb); + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + + /* + * Setup BIDI XOR callback to be run after I/O completion. + */ + cmd->transport_complete_callback = &xdreadwrite_callback; + if (cdb[1] & 0x8) + cmd->se_cmd_flags |= SCF_FUA; + break; + case VARIABLE_LENGTH_CMD: + { + u16 service_action = get_unaligned_be16(&cdb[8]); + switch (service_action) { + case XDWRITEREAD_32: + sectors = transport_get_sectors_32(cdb); + + /* + * Use WRITE_32 and READ_32 opcodes for the emulated + * XDWRITE_READ_32 logic. + */ + cmd->t_task_lba = transport_lba_64_ext(cdb); + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + + /* + * Setup BIDI XOR callback to be run during after I/O + * completion. + */ + cmd->transport_complete_callback = &xdreadwrite_callback; + if (cdb[1] & 0x8) + cmd->se_cmd_flags |= SCF_FUA; + break; + case WRITE_SAME_32: + sectors = transport_get_sectors_32(cdb); + if (!sectors) { + pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not" + " supported\n"); + goto out_invalid_cdb_field; + } + + *size = sbc_get_size(cmd, 1); + cmd->t_task_lba = get_unaligned_be64(&cdb[12]); + + if (sbc_write_same_supported(dev, &cdb[10]) < 0) + goto out_unsupported_cdb; + cmd->execute_cmd = target_emulate_write_same; + break; + default: + pr_err("VARIABLE_LENGTH_CMD service action" + " 0x%04x not supported\n", service_action); + goto out_unsupported_cdb; + } + break; + } + case READ_CAPACITY: + *size = READ_CAP_LEN; + cmd->execute_cmd = target_emulate_readcapacity; + break; + case SERVICE_ACTION_IN: + switch (cmd->t_task_cdb[1] & 0x1f) { + case SAI_READ_CAPACITY_16: + cmd->execute_cmd = target_emulate_readcapacity_16; + break; + default: + pr_err("Unsupported SA: 0x%02x\n", + cmd->t_task_cdb[1] & 0x1f); + goto out_invalid_cdb_field; + } + *size = (cdb[10] << 24) | (cdb[11] << 16) | + (cdb[12] << 8) | cdb[13]; + break; + case SYNCHRONIZE_CACHE: + case SYNCHRONIZE_CACHE_16: + /* + * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE + */ + if (cdb[0] == SYNCHRONIZE_CACHE) { + sectors = transport_get_sectors_10(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + } else { + sectors = transport_get_sectors_16(cdb); + cmd->t_task_lba = transport_lba_64(cdb); + } + + *size = sbc_get_size(cmd, sectors); + + /* + * Check to ensure that LBA + Range does not exceed past end of + * device for IBLOCK and FILEIO ->do_sync_cache() backend calls + */ + if (cmd->t_task_lba || sectors) { + if (sbc_check_valid_sectors(cmd) < 0) + goto out_invalid_cdb_field; + } + cmd->execute_cmd = target_emulate_synchronize_cache; + break; + case UNMAP: + *size = get_unaligned_be16(&cdb[7]); + cmd->execute_cmd = target_emulate_unmap; + break; + case WRITE_SAME_16: + sectors = transport_get_sectors_16(cdb); + if (!sectors) { + pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n"); + goto out_invalid_cdb_field; + } + + *size = sbc_get_size(cmd, 1); + cmd->t_task_lba = get_unaligned_be64(&cdb[2]); + + if (sbc_write_same_supported(dev, &cdb[1]) < 0) + goto out_unsupported_cdb; + cmd->execute_cmd = target_emulate_write_same; + break; + case WRITE_SAME: + sectors = transport_get_sectors_10(cdb); + if (!sectors) { + pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n"); + goto out_invalid_cdb_field; + } + + *size = sbc_get_size(cmd, 1); + cmd->t_task_lba = get_unaligned_be32(&cdb[2]); + + /* + * Follow sbcr26 with WRITE_SAME (10) and check for the existence + * of byte 1 bit 3 UNMAP instead of original reserved field + */ + if (sbc_write_same_supported(dev, &cdb[1]) < 0) + goto out_unsupported_cdb; + cmd->execute_cmd = target_emulate_write_same; + break; + case VERIFY: + *size = 0; + cmd->execute_cmd = target_emulate_noop; + break; + default: + ret = spc_parse_cdb(cmd, size, false); + if (ret) + return ret; + } + + /* reject any command that we don't have a handler for */ + if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd) + goto out_unsupported_cdb; + + if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) { + if (sectors > su_dev->se_dev_attrib.fabric_max_sectors) { + printk_ratelimited(KERN_ERR "SCSI OP %02xh with too" + " big sectors %u exceeds fabric_max_sectors:" + " %u\n", cdb[0], sectors, + su_dev->se_dev_attrib.fabric_max_sectors); + goto out_invalid_cdb_field; + } + if (sectors > su_dev->se_dev_attrib.hw_max_sectors) { + printk_ratelimited(KERN_ERR "SCSI OP %02xh with too" + " big sectors %u exceeds backend hw_max_sectors:" + " %u\n", cdb[0], sectors, + su_dev->se_dev_attrib.hw_max_sectors); + goto out_invalid_cdb_field; + } + + *size = sbc_get_size(cmd, sectors); + } + + return 0; + +out_unsupported_cdb: + cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; + cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE; + return -EINVAL; +out_invalid_cdb_field: + cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; + cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD; + return -EINVAL; +} +EXPORT_SYMBOL(sbc_parse_cdb); |