From 957525a2424aad367d6e0efb64e440b2b37fa5cd Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Fri, 30 Mar 2012 11:29:15 -0700 Subject: [PATCH] target: Remove transport_do_task_sg_chain() and associated detritus Now that all fabrics are converted over to using se_cmd->t_data_sg directly, we can drop the task sg chaining support. With the modern memory allocation in target core, task sg chaining is needless overhead -- we would split up the main cmd sglist into pieces, and then splice those pieces back together instead of just using the original list directly. Signed-off-by: Roland Dreier Reviewed-by: Christoph Hellwig Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 70 -------------------------- include/target/target_core_base.h | 2 - include/target/target_core_fabric.h | 7 --- 3 files changed, 79 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index db05c75864e0..9fdc708d5040 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -3699,76 +3699,6 @@ static inline sector_t transport_limit_task_sectors( return sectors; } - -/* - * This function can be used by HW target mode drivers to create a linked - * scatterlist from all contiguously allocated struct se_task->task_sg[]. - * This is intended to be called during the completion path by TCM Core - * when struct target_core_fabric_ops->check_task_sg_chaining is enabled. - */ -void transport_do_task_sg_chain(struct se_cmd *cmd) -{ - struct scatterlist *sg_first = NULL; - struct scatterlist *sg_prev = NULL; - int sg_prev_nents = 0; - struct scatterlist *sg; - struct se_task *task; - u32 chained_nents = 0; - int i; - - BUG_ON(!cmd->se_tfo->task_sg_chaining); - - /* - * Walk the struct se_task list and setup scatterlist chains - * for each contiguously allocated struct se_task->task_sg[]. - */ - list_for_each_entry(task, &cmd->t_task_list, t_list) { - if (!task->task_sg) - continue; - - if (!sg_first) { - sg_first = task->task_sg; - chained_nents = task->task_sg_nents; - } else { - sg_chain(sg_prev, sg_prev_nents, task->task_sg); - chained_nents += task->task_sg_nents; - } - /* - * For the padded tasks, use the extra SGL vector allocated - * in transport_allocate_data_tasks() for the sg_prev_nents - * offset into sg_chain() above. - * - * We do not need the padding for the last task (or a single - * task), but in that case we will never use the sg_prev_nents - * value below which would be incorrect. - */ - sg_prev_nents = (task->task_sg_nents + 1); - sg_prev = task->task_sg; - } - /* - * Setup the starting pointer and total t_tasks_sg_linked_no including - * padding SGs for linking and to mark the end. - */ - cmd->t_tasks_sg_chained = sg_first; - cmd->t_tasks_sg_chained_no = chained_nents; - - pr_debug("Setup cmd: %p cmd->t_tasks_sg_chained: %p and" - " t_tasks_sg_chained_no: %u\n", cmd, cmd->t_tasks_sg_chained, - cmd->t_tasks_sg_chained_no); - - for_each_sg(cmd->t_tasks_sg_chained, sg, - cmd->t_tasks_sg_chained_no, i) { - - pr_debug("SG[%d]: %p page: %p length: %d offset: %d\n", - i, sg, sg_page(sg), sg->length, sg->offset); - if (sg_is_chain(sg)) - pr_debug("SG: %p sg_is_chain=1\n", sg); - if (sg_is_last(sg)) - pr_debug("SG: %p sg_is_last=1\n", sg); - } -} -EXPORT_SYMBOL(transport_do_task_sg_chain); - /* * Break up cmd into chunks transport can handle */ diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 6a02c99d54a5..8ec4e8232be4 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -572,7 +572,6 @@ struct se_cmd { unsigned char *t_task_cdb; unsigned char __t_task_cdb[TCM_MAX_COMMAND_SIZE]; unsigned long long t_task_lba; - u32 t_tasks_sg_chained_no; atomic_t t_fe_count; atomic_t t_se_count; atomic_t t_task_cdbs_left; @@ -593,7 +592,6 @@ struct se_cmd { struct completion t_transport_stop_comp; struct completion transport_lun_fe_stop_comp; struct completion transport_lun_stop_comp; - struct scatterlist *t_tasks_sg_chained; struct work_struct work; diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h index 10c690809601..83734ccc982c 100644 --- a/include/target/target_core_fabric.h +++ b/include/target/target_core_fabric.h @@ -3,12 +3,6 @@ struct target_core_fabric_ops { struct configfs_subsystem *tf_subsys; - /* - * Optional to signal struct se_task->task_sg[] padding entries - * for scatterlist chaining using transport_do_task_sg_link(), - * disabled by default - */ - bool task_sg_chaining; char *(*get_fabric_name)(void); u8 (*get_fabric_proto_ident)(struct se_portal_group *); char *(*tpg_get_wwn)(struct se_portal_group *); @@ -124,7 +118,6 @@ int transport_generic_handle_cdb_map(struct se_cmd *); int transport_generic_handle_data(struct se_cmd *); int transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *, u32, struct scatterlist *, u32); -void transport_do_task_sg_chain(struct se_cmd *); int transport_generic_new_cmd(struct se_cmd *); void transport_generic_process_write(struct se_cmd *); -- 2.30.2