From dd0107a08996c0ab8cac2b98ddbed5313e118e81 Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Tue, 13 Oct 2015 19:12:58 +0300 Subject: [PATCH] IB/iser: set block queue_virt_boundary The block layer can reliably guarantee that SG lists won't contain gaps (page unaligned) if a driver set the queue virt_boundary. With this setting the block layer will: - refuse merges if bios are not aligned to the virtual boundary - split bios/requests that are not aligned to the virtual boundary - or, bounce buffer SG_IOs that are not aligned to the virtual boundary Since iser is working in 4K page size, set the virt_boundary to 4K pages. With this setting, we can now safely remove the bounce buffering logic in iser. Signed-off-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Signed-off-by: Doug Ledford --- drivers/infiniband/ulp/iser/iscsi_iser.c | 12 +- drivers/infiniband/ulp/iser/iscsi_iser.h | 7 +- drivers/infiniband/ulp/iser/iser_initiator.c | 51 +--- drivers/infiniband/ulp/iser/iser_memory.c | 274 ------------------- 4 files changed, 18 insertions(+), 326 deletions(-) diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c index 3d0bdb87a653..2ea0a14125e8 100644 --- a/drivers/infiniband/ulp/iser/iscsi_iser.c +++ b/drivers/infiniband/ulp/iser/iscsi_iser.c @@ -762,9 +762,7 @@ iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *s stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */ stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt; stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt; - stats->custom_length = 1; - strcpy(stats->custom[0].desc, "fmr_unalign_cnt"); - stats->custom[0].value = conn->fmr_unalign_cnt; + stats->custom_length = 0; } static int iscsi_iser_get_ep_param(struct iscsi_endpoint *ep, @@ -969,6 +967,13 @@ static umode_t iser_attr_is_visible(int param_type, int param) return 0; } +static int iscsi_iser_slave_alloc(struct scsi_device *sdev) +{ + blk_queue_virt_boundary(sdev->request_queue, ~MASK_4K); + + return 0; +} + static struct scsi_host_template iscsi_iser_sht = { .module = THIS_MODULE, .name = "iSCSI Initiator over iSER", @@ -982,6 +987,7 @@ static struct scsi_host_template iscsi_iser_sht = { .eh_target_reset_handler = iscsi_eh_recover_target, .target_alloc = iscsi_target_alloc, .use_clustering = DISABLE_CLUSTERING, + .slave_alloc = iscsi_iser_slave_alloc, .proc_name = "iscsi_iser", .this_id = -1, .track_queue_depth = 1, diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h index a5edd6ede692..d8bbad9eb59b 100644 --- a/drivers/infiniband/ulp/iser/iscsi_iser.h +++ b/drivers/infiniband/ulp/iser/iscsi_iser.h @@ -227,18 +227,13 @@ enum iser_data_dir { * @size: num entries of this sg * @data_len: total beffer byte len * @dma_nents: returned by dma_map_sg - * @orig_sg: pointer to the original sg list (in case - * we used a copy) - * @orig_size: num entris of orig sg list */ struct iser_data_buf { struct scatterlist *sg; unsigned int size; unsigned long data_len; unsigned int dma_nents; - struct scatterlist *orig_sg; - unsigned int orig_size; - }; +}; /* fwd declarations */ struct iser_device; diff --git a/drivers/infiniband/ulp/iser/iser_initiator.c b/drivers/infiniband/ulp/iser/iser_initiator.c index d511879d8cdf..ffd00c420729 100644 --- a/drivers/infiniband/ulp/iser/iser_initiator.c +++ b/drivers/infiniband/ulp/iser/iser_initiator.c @@ -661,48 +661,14 @@ void iser_task_rdma_init(struct iscsi_iser_task *iser_task) void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task) { - int is_rdma_data_aligned = 1; - int is_rdma_prot_aligned = 1; int prot_count = scsi_prot_sg_count(iser_task->sc); - /* if we were reading, copy back to unaligned sglist, - * anyway dma_unmap and free the copy - */ - if (iser_task->data[ISER_DIR_IN].orig_sg) { - is_rdma_data_aligned = 0; - iser_finalize_rdma_unaligned_sg(iser_task, - &iser_task->data[ISER_DIR_IN], - ISER_DIR_IN); - } - - if (iser_task->data[ISER_DIR_OUT].orig_sg) { - is_rdma_data_aligned = 0; - iser_finalize_rdma_unaligned_sg(iser_task, - &iser_task->data[ISER_DIR_OUT], - ISER_DIR_OUT); - } - - if (iser_task->prot[ISER_DIR_IN].orig_sg) { - is_rdma_prot_aligned = 0; - iser_finalize_rdma_unaligned_sg(iser_task, - &iser_task->prot[ISER_DIR_IN], - ISER_DIR_IN); - } - - if (iser_task->prot[ISER_DIR_OUT].orig_sg) { - is_rdma_prot_aligned = 0; - iser_finalize_rdma_unaligned_sg(iser_task, - &iser_task->prot[ISER_DIR_OUT], - ISER_DIR_OUT); - } - if (iser_task->dir[ISER_DIR_IN]) { iser_unreg_rdma_mem(iser_task, ISER_DIR_IN); - if (is_rdma_data_aligned) - iser_dma_unmap_task_data(iser_task, - &iser_task->data[ISER_DIR_IN], - DMA_FROM_DEVICE); - if (prot_count && is_rdma_prot_aligned) + iser_dma_unmap_task_data(iser_task, + &iser_task->data[ISER_DIR_IN], + DMA_FROM_DEVICE); + if (prot_count) iser_dma_unmap_task_data(iser_task, &iser_task->prot[ISER_DIR_IN], DMA_FROM_DEVICE); @@ -710,11 +676,10 @@ void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task) if (iser_task->dir[ISER_DIR_OUT]) { iser_unreg_rdma_mem(iser_task, ISER_DIR_OUT); - if (is_rdma_data_aligned) - iser_dma_unmap_task_data(iser_task, - &iser_task->data[ISER_DIR_OUT], - DMA_TO_DEVICE); - if (prot_count && is_rdma_prot_aligned) + iser_dma_unmap_task_data(iser_task, + &iser_task->data[ISER_DIR_OUT], + DMA_TO_DEVICE); + if (prot_count) iser_dma_unmap_task_data(iser_task, &iser_task->prot[ISER_DIR_OUT], DMA_TO_DEVICE); diff --git a/drivers/infiniband/ulp/iser/iser_memory.c b/drivers/infiniband/ulp/iser/iser_memory.c index 4c46d67d37a1..3e0452c4248f 100644 --- a/drivers/infiniband/ulp/iser/iser_memory.c +++ b/drivers/infiniband/ulp/iser/iser_memory.c @@ -88,113 +88,6 @@ int iser_assign_reg_ops(struct iser_device *device) return 0; } -static void -iser_free_bounce_sg(struct iser_data_buf *data) -{ - struct scatterlist *sg; - int count; - - for_each_sg(data->sg, sg, data->size, count) - __free_page(sg_page(sg)); - - kfree(data->sg); - - data->sg = data->orig_sg; - data->size = data->orig_size; - data->orig_sg = NULL; - data->orig_size = 0; -} - -static int -iser_alloc_bounce_sg(struct iser_data_buf *data) -{ - struct scatterlist *sg; - struct page *page; - unsigned long length = data->data_len; - int i = 0, nents = DIV_ROUND_UP(length, PAGE_SIZE); - - sg = kcalloc(nents, sizeof(*sg), GFP_ATOMIC); - if (!sg) - goto err; - - sg_init_table(sg, nents); - while (length) { - u32 page_len = min_t(u32, length, PAGE_SIZE); - - page = alloc_page(GFP_ATOMIC); - if (!page) - goto err; - - sg_set_page(&sg[i], page, page_len, 0); - length -= page_len; - i++; - } - - data->orig_sg = data->sg; - data->orig_size = data->size; - data->sg = sg; - data->size = nents; - - return 0; - -err: - for (; i > 0; i--) - __free_page(sg_page(&sg[i - 1])); - kfree(sg); - - return -ENOMEM; -} - -static void -iser_copy_bounce(struct iser_data_buf *data, bool to_buffer) -{ - struct scatterlist *osg, *bsg = data->sg; - void *oaddr, *baddr; - unsigned int left = data->data_len; - unsigned int bsg_off = 0; - int i; - - for_each_sg(data->orig_sg, osg, data->orig_size, i) { - unsigned int copy_len, osg_off = 0; - - oaddr = kmap_atomic(sg_page(osg)) + osg->offset; - copy_len = min(left, osg->length); - while (copy_len) { - unsigned int len = min(copy_len, bsg->length - bsg_off); - - baddr = kmap_atomic(sg_page(bsg)) + bsg->offset; - if (to_buffer) - memcpy(baddr + bsg_off, oaddr + osg_off, len); - else - memcpy(oaddr + osg_off, baddr + bsg_off, len); - - kunmap_atomic(baddr - bsg->offset); - osg_off += len; - bsg_off += len; - copy_len -= len; - - if (bsg_off >= bsg->length) { - bsg = sg_next(bsg); - bsg_off = 0; - } - } - kunmap_atomic(oaddr - osg->offset); - left -= osg_off; - } -} - -static inline void -iser_copy_from_bounce(struct iser_data_buf *data) -{ - iser_copy_bounce(data, false); -} - -static inline void -iser_copy_to_bounce(struct iser_data_buf *data) -{ - iser_copy_bounce(data, true); -} - struct iser_fr_desc * iser_reg_desc_get_fr(struct ib_conn *ib_conn) { @@ -238,62 +131,6 @@ iser_reg_desc_put_fmr(struct ib_conn *ib_conn, { } -/** - * iser_start_rdma_unaligned_sg - */ -static int iser_start_rdma_unaligned_sg(struct iscsi_iser_task *iser_task, - struct iser_data_buf *data, - enum iser_data_dir cmd_dir) -{ - struct ib_device *dev = iser_task->iser_conn->ib_conn.device->ib_device; - int rc; - - rc = iser_alloc_bounce_sg(data); - if (rc) { - iser_err("Failed to allocate bounce for data len %lu\n", - data->data_len); - return rc; - } - - if (cmd_dir == ISER_DIR_OUT) - iser_copy_to_bounce(data); - - data->dma_nents = ib_dma_map_sg(dev, data->sg, data->size, - (cmd_dir == ISER_DIR_OUT) ? - DMA_TO_DEVICE : DMA_FROM_DEVICE); - if (!data->dma_nents) { - iser_err("Got dma_nents %d, something went wrong...\n", - data->dma_nents); - rc = -ENOMEM; - goto err; - } - - return 0; -err: - iser_free_bounce_sg(data); - return rc; -} - -/** - * iser_finalize_rdma_unaligned_sg - */ - -void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *iser_task, - struct iser_data_buf *data, - enum iser_data_dir cmd_dir) -{ - struct ib_device *dev = iser_task->iser_conn->ib_conn.device->ib_device; - - ib_dma_unmap_sg(dev, data->sg, data->size, - (cmd_dir == ISER_DIR_OUT) ? - DMA_TO_DEVICE : DMA_FROM_DEVICE); - - if (cmd_dir == ISER_DIR_IN) - iser_copy_from_bounce(data); - - iser_free_bounce_sg(data); -} - #define IS_4K_ALIGNED(addr) ((((unsigned long)addr) & ~MASK_4K) == 0) /** @@ -355,64 +192,6 @@ static int iser_sg_to_page_vec(struct iser_data_buf *data, return cur_page; } - -/** - * iser_data_buf_aligned_len - Tries to determine the maximal correctly aligned - * for RDMA sub-list of a scatter-gather list of memory buffers, and returns - * the number of entries which are aligned correctly. Supports the case where - * consecutive SG elements are actually fragments of the same physcial page. - */ -static int iser_data_buf_aligned_len(struct iser_data_buf *data, - struct ib_device *ibdev, - unsigned sg_tablesize) -{ - struct scatterlist *sg, *sgl, *next_sg = NULL; - u64 start_addr, end_addr; - int i, ret_len, start_check = 0; - - if (data->dma_nents == 1) - return 1; - - sgl = data->sg; - start_addr = ib_sg_dma_address(ibdev, sgl); - - if (unlikely(sgl[0].offset && - data->data_len >= sg_tablesize * PAGE_SIZE)) { - iser_dbg("can't register length %lx with offset %x " - "fall to bounce buffer\n", data->data_len, - sgl[0].offset); - return 0; - } - - for_each_sg(sgl, sg, data->dma_nents, i) { - if (start_check && !IS_4K_ALIGNED(start_addr)) - break; - - next_sg = sg_next(sg); - if (!next_sg) - break; - - end_addr = start_addr + ib_sg_dma_len(ibdev, sg); - start_addr = ib_sg_dma_address(ibdev, next_sg); - - if (end_addr == start_addr) { - start_check = 0; - continue; - } else - start_check = 1; - - if (!IS_4K_ALIGNED(end_addr)) - break; - } - ret_len = (next_sg) ? i : i+1; - - if (unlikely(ret_len != data->dma_nents)) - iser_warn("rdma alignment violation (%d/%d aligned)\n", - ret_len, data->dma_nents); - - return ret_len; -} - static void iser_data_buf_dump(struct iser_data_buf *data, struct ib_device *ibdev) { @@ -483,31 +262,6 @@ iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem, return 0; } -static int fall_to_bounce_buf(struct iscsi_iser_task *iser_task, - struct iser_data_buf *mem, - enum iser_data_dir cmd_dir) -{ - struct iscsi_conn *iscsi_conn = iser_task->iser_conn->iscsi_conn; - struct iser_device *device = iser_task->iser_conn->ib_conn.device; - - iscsi_conn->fmr_unalign_cnt++; - - if (iser_debug_level > 0) - iser_data_buf_dump(mem, device->ib_device); - - /* unmap the command data before accessing it */ - iser_dma_unmap_task_data(iser_task, mem, - (cmd_dir == ISER_DIR_OUT) ? - DMA_TO_DEVICE : DMA_FROM_DEVICE); - - /* allocate copy buf, if we are writing, copy the */ - /* unaligned scatterlist, dma map the copy */ - if (iser_start_rdma_unaligned_sg(iser_task, mem, cmd_dir) != 0) - return -ENOMEM; - - return 0; -} - /** * iser_reg_page_vec - Register physical memory * @@ -779,26 +533,6 @@ static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task, return 0; } -static int -iser_handle_unaligned_buf(struct iscsi_iser_task *task, - struct iser_data_buf *mem, - enum iser_data_dir dir) -{ - struct iser_conn *iser_conn = task->iser_conn; - struct iser_device *device = iser_conn->ib_conn.device; - int err, aligned_len; - - aligned_len = iser_data_buf_aligned_len(mem, device->ib_device, - iser_conn->scsi_sg_tablesize); - if (aligned_len != mem->dma_nents) { - err = fall_to_bounce_buf(task, mem, dir); - if (err) - return err; - } - - return 0; -} - static int iser_reg_prot_sg(struct iscsi_iser_task *task, struct iser_data_buf *mem, @@ -841,10 +575,6 @@ int iser_reg_rdma_mem(struct iscsi_iser_task *task, bool use_dma_key; int err; - err = iser_handle_unaligned_buf(task, mem, dir); - if (unlikely(err)) - return err; - use_dma_key = (mem->dma_nents == 1 && !iser_always_reg && scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL); @@ -867,10 +597,6 @@ int iser_reg_rdma_mem(struct iscsi_iser_task *task, if (scsi_prot_sg_count(task->sc)) { mem = &task->prot[dir]; - err = iser_handle_unaligned_buf(task, mem, dir); - if (unlikely(err)) - goto err_reg; - err = iser_reg_prot_sg(task, mem, desc, use_dma_key, prot_reg); if (unlikely(err)) -- 2.20.1