| /* |
| * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved. |
| * |
| * This software is available to you under a choice of one of two |
| * licenses. You may choose to be licensed under the terms of the GNU |
| * General Public License (GPL) Version 2, available from the file |
| * COPYING in the main directory of this source tree, or the |
| * OpenIB.org BSD license below: |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials |
| * provided with the distribution. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
| * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
| * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
| * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| * SOFTWARE. |
| */ |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/mm.h> |
| #include <linux/highmem.h> |
| #include <linux/scatterlist.h> |
| |
| #include "iscsi_iser.h" |
| |
| #define ISER_KMALLOC_THRESHOLD 0x20000 /* 128K - kmalloc limit */ |
| |
| /** |
| * iser_start_rdma_unaligned_sg |
| */ |
| static int iser_start_rdma_unaligned_sg(struct iscsi_iser_task *iser_task, |
| enum iser_data_dir cmd_dir) |
| { |
| int dma_nents; |
| struct ib_device *dev; |
| char *mem = NULL; |
| struct iser_data_buf *data = &iser_task->data[cmd_dir]; |
| unsigned long cmd_data_len = data->data_len; |
| |
| if (cmd_data_len > ISER_KMALLOC_THRESHOLD) |
| mem = (void *)__get_free_pages(GFP_ATOMIC, |
| ilog2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT); |
| else |
| mem = kmalloc(cmd_data_len, GFP_ATOMIC); |
| |
| if (mem == NULL) { |
| iser_err("Failed to allocate mem size %d %d for copying sglist\n", |
| data->size,(int)cmd_data_len); |
| return -ENOMEM; |
| } |
| |
| if (cmd_dir == ISER_DIR_OUT) { |
| /* copy the unaligned sg the buffer which is used for RDMA */ |
| struct scatterlist *sgl = (struct scatterlist *)data->buf; |
| struct scatterlist *sg; |
| int i; |
| char *p, *from; |
| |
| p = mem; |
| for_each_sg(sgl, sg, data->size, i) { |
| from = kmap_atomic(sg_page(sg)); |
| memcpy(p, |
| from + sg->offset, |
| sg->length); |
| kunmap_atomic(from); |
| p += sg->length; |
| } |
| } |
| |
| sg_init_one(&iser_task->data_copy[cmd_dir].sg_single, mem, cmd_data_len); |
| iser_task->data_copy[cmd_dir].buf = |
| &iser_task->data_copy[cmd_dir].sg_single; |
| iser_task->data_copy[cmd_dir].size = 1; |
| |
| iser_task->data_copy[cmd_dir].copy_buf = mem; |
| |
| dev = iser_task->iser_conn->ib_conn->device->ib_device; |
| dma_nents = ib_dma_map_sg(dev, |
| &iser_task->data_copy[cmd_dir].sg_single, |
| 1, |
| (cmd_dir == ISER_DIR_OUT) ? |
| DMA_TO_DEVICE : DMA_FROM_DEVICE); |
| BUG_ON(dma_nents == 0); |
| |
| iser_task->data_copy[cmd_dir].dma_nents = dma_nents; |
| return 0; |
| } |
| |
| /** |
| * iser_finalize_rdma_unaligned_sg |
| */ |
| void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *iser_task, |
| enum iser_data_dir cmd_dir) |
| { |
| struct ib_device *dev; |
| struct iser_data_buf *mem_copy; |
| unsigned long cmd_data_len; |
| |
| dev = iser_task->iser_conn->ib_conn->device->ib_device; |
| mem_copy = &iser_task->data_copy[cmd_dir]; |
| |
| ib_dma_unmap_sg(dev, &mem_copy->sg_single, 1, |
| (cmd_dir == ISER_DIR_OUT) ? |
| DMA_TO_DEVICE : DMA_FROM_DEVICE); |
| |
| if (cmd_dir == ISER_DIR_IN) { |
| char *mem; |
| struct scatterlist *sgl, *sg; |
| unsigned char *p, *to; |
| unsigned int sg_size; |
| int i; |
| |
| /* copy back read RDMA to unaligned sg */ |
| mem = mem_copy->copy_buf; |
| |
| sgl = (struct scatterlist *)iser_task->data[ISER_DIR_IN].buf; |
| sg_size = iser_task->data[ISER_DIR_IN].size; |
| |
| p = mem; |
| for_each_sg(sgl, sg, sg_size, i) { |
| to = kmap_atomic(sg_page(sg)); |
| memcpy(to + sg->offset, |
| p, |
| sg->length); |
| kunmap_atomic(to); |
| p += sg->length; |
| } |
| } |
| |
| cmd_data_len = iser_task->data[cmd_dir].data_len; |
| |
| if (cmd_data_len > ISER_KMALLOC_THRESHOLD) |
| free_pages((unsigned long)mem_copy->copy_buf, |
| ilog2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT); |
| else |
| kfree(mem_copy->copy_buf); |
| |
| mem_copy->copy_buf = NULL; |
| } |
| |
| #define IS_4K_ALIGNED(addr) ((((unsigned long)addr) & ~MASK_4K) == 0) |
| |
| /** |
| * iser_sg_to_page_vec - Translates scatterlist entries to physical addresses |
| * and returns the length of resulting physical address array (may be less than |
| * the original due to possible compaction). |
| * |
| * we build a "page vec" under the assumption that the SG meets the RDMA |
| * alignment requirements. Other then the first and last SG elements, all |
| * the "internal" elements can be compacted into a list whose elements are |
| * dma addresses of physical pages. The code supports also the weird case |
| * where --few fragments of the same page-- are present in the SG as |
| * consecutive elements. Also, it handles one entry SG. |
| */ |
| |
| static int iser_sg_to_page_vec(struct iser_data_buf *data, |
| struct iser_page_vec *page_vec, |
| struct ib_device *ibdev) |
| { |
| struct scatterlist *sg, *sgl = (struct scatterlist *)data->buf; |
| u64 start_addr, end_addr, page, chunk_start = 0; |
| unsigned long total_sz = 0; |
| unsigned int dma_len; |
| int i, new_chunk, cur_page, last_ent = data->dma_nents - 1; |
| |
| /* compute the offset of first element */ |
| page_vec->offset = (u64) sgl[0].offset & ~MASK_4K; |
| |
| new_chunk = 1; |
| cur_page = 0; |
| for_each_sg(sgl, sg, data->dma_nents, i) { |
| start_addr = ib_sg_dma_address(ibdev, sg); |
| if (new_chunk) |
| chunk_start = start_addr; |
| dma_len = ib_sg_dma_len(ibdev, sg); |
| end_addr = start_addr + dma_len; |
| total_sz += dma_len; |
| |
| /* collect page fragments until aligned or end of SG list */ |
| if (!IS_4K_ALIGNED(end_addr) && i < last_ent) { |
| new_chunk = 0; |
| continue; |
| } |
| new_chunk = 1; |
| |
| /* address of the first page in the contiguous chunk; |
| masking relevant for the very first SG entry, |
| which might be unaligned */ |
| page = chunk_start & MASK_4K; |
| do { |
| page_vec->pages[cur_page++] = page; |
| page += SIZE_4K; |
| } while (page < end_addr); |
| } |
| |
| page_vec->data_size = total_sz; |
| iser_dbg("page_vec->data_size:%d cur_page %d\n", page_vec->data_size,cur_page); |
| 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) |
| { |
| struct scatterlist *sgl, *sg, *next_sg = NULL; |
| u64 start_addr, end_addr; |
| int i, ret_len, start_check = 0; |
| |
| if (data->dma_nents == 1) |
| return 1; |
| |
| sgl = (struct scatterlist *)data->buf; |
| start_addr = ib_sg_dma_address(ibdev, sgl); |
| |
| 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; |
| iser_dbg("Found %d aligned entries out of %d in sg:0x%p\n", |
| ret_len, data->dma_nents, data); |
| return ret_len; |
| } |
| |
| static void iser_data_buf_dump(struct iser_data_buf *data, |
| struct ib_device *ibdev) |
| { |
| struct scatterlist *sgl = (struct scatterlist *)data->buf; |
| struct scatterlist *sg; |
| int i; |
| |
| if (iser_debug_level == 0) |
| return; |
| |
| for_each_sg(sgl, sg, data->dma_nents, i) |
| iser_warn("sg[%d] dma_addr:0x%lX page:0x%p " |
| "off:0x%x sz:0x%x dma_len:0x%x\n", |
| i, (unsigned long)ib_sg_dma_address(ibdev, sg), |
| sg_page(sg), sg->offset, |
| sg->length, ib_sg_dma_len(ibdev, sg)); |
| } |
| |
| static void iser_dump_page_vec(struct iser_page_vec *page_vec) |
| { |
| int i; |
| |
| iser_err("page vec length %d data size %d\n", |
| page_vec->length, page_vec->data_size); |
| for (i = 0; i < page_vec->length; i++) |
| iser_err("%d %lx\n",i,(unsigned long)page_vec->pages[i]); |
| } |
| |
| static void iser_page_vec_build(struct iser_data_buf *data, |
| struct iser_page_vec *page_vec, |
| struct ib_device *ibdev) |
| { |
| int page_vec_len = 0; |
| |
| page_vec->length = 0; |
| page_vec->offset = 0; |
| |
| iser_dbg("Translating sg sz: %d\n", data->dma_nents); |
| page_vec_len = iser_sg_to_page_vec(data, page_vec, ibdev); |
| iser_dbg("sg len %d page_vec_len %d\n", data->dma_nents,page_vec_len); |
| |
| page_vec->length = page_vec_len; |
| |
| if (page_vec_len * SIZE_4K < page_vec->data_size) { |
| iser_err("page_vec too short to hold this SG\n"); |
| iser_data_buf_dump(data, ibdev); |
| iser_dump_page_vec(page_vec); |
| BUG(); |
| } |
| } |
| |
| int iser_dma_map_task_data(struct iscsi_iser_task *iser_task, |
| struct iser_data_buf *data, |
| enum iser_data_dir iser_dir, |
| enum dma_data_direction dma_dir) |
| { |
| struct ib_device *dev; |
| |
| iser_task->dir[iser_dir] = 1; |
| dev = iser_task->iser_conn->ib_conn->device->ib_device; |
| |
| data->dma_nents = ib_dma_map_sg(dev, data->buf, data->size, dma_dir); |
| if (data->dma_nents == 0) { |
| iser_err("dma_map_sg failed!!!\n"); |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task) |
| { |
| struct ib_device *dev; |
| struct iser_data_buf *data; |
| |
| dev = iser_task->iser_conn->ib_conn->device->ib_device; |
| |
| if (iser_task->dir[ISER_DIR_IN]) { |
| data = &iser_task->data[ISER_DIR_IN]; |
| ib_dma_unmap_sg(dev, data->buf, data->size, DMA_FROM_DEVICE); |
| } |
| |
| if (iser_task->dir[ISER_DIR_OUT]) { |
| data = &iser_task->data[ISER_DIR_OUT]; |
| ib_dma_unmap_sg(dev, data->buf, data->size, DMA_TO_DEVICE); |
| } |
| } |
| |
| /** |
| * iser_reg_rdma_mem - Registers memory intended for RDMA, |
| * obtaining rkey and va |
| * |
| * returns 0 on success, errno code on failure |
| */ |
| int iser_reg_rdma_mem(struct iscsi_iser_task *iser_task, |
| enum iser_data_dir cmd_dir) |
| { |
| struct iscsi_conn *iscsi_conn = iser_task->iser_conn->iscsi_conn; |
| struct iser_conn *ib_conn = iser_task->iser_conn->ib_conn; |
| struct iser_device *device = ib_conn->device; |
| struct ib_device *ibdev = device->ib_device; |
| struct iser_data_buf *mem = &iser_task->data[cmd_dir]; |
| struct iser_regd_buf *regd_buf; |
| int aligned_len; |
| int err; |
| int i; |
| struct scatterlist *sg; |
| |
| regd_buf = &iser_task->rdma_regd[cmd_dir]; |
| |
| aligned_len = iser_data_buf_aligned_len(mem, ibdev); |
| if (aligned_len != mem->dma_nents) { |
| iscsi_conn->fmr_unalign_cnt++; |
| iser_warn("rdma alignment violation %d/%d aligned\n", |
| aligned_len, mem->size); |
| iser_data_buf_dump(mem, ibdev); |
| |
| /* unmap the command data before accessing it */ |
| iser_dma_unmap_task_data(iser_task); |
| |
| /* allocate copy buf, if we are writing, copy the */ |
| /* unaligned scatterlist, dma map the copy */ |
| if (iser_start_rdma_unaligned_sg(iser_task, cmd_dir) != 0) |
| return -ENOMEM; |
| mem = &iser_task->data_copy[cmd_dir]; |
| } |
| |
| /* if there a single dma entry, FMR is not needed */ |
| if (mem->dma_nents == 1) { |
| sg = (struct scatterlist *)mem->buf; |
| |
| regd_buf->reg.lkey = device->mr->lkey; |
| regd_buf->reg.rkey = device->mr->rkey; |
| regd_buf->reg.len = ib_sg_dma_len(ibdev, &sg[0]); |
| regd_buf->reg.va = ib_sg_dma_address(ibdev, &sg[0]); |
| regd_buf->reg.is_fmr = 0; |
| |
| iser_dbg("PHYSICAL Mem.register: lkey: 0x%08X rkey: 0x%08X " |
| "va: 0x%08lX sz: %ld]\n", |
| (unsigned int)regd_buf->reg.lkey, |
| (unsigned int)regd_buf->reg.rkey, |
| (unsigned long)regd_buf->reg.va, |
| (unsigned long)regd_buf->reg.len); |
| } else { /* use FMR for multiple dma entries */ |
| iser_page_vec_build(mem, ib_conn->page_vec, ibdev); |
| err = iser_reg_page_vec(ib_conn, ib_conn->page_vec, ®d_buf->reg); |
| if (err && err != -EAGAIN) { |
| iser_data_buf_dump(mem, ibdev); |
| iser_err("mem->dma_nents = %d (dlength = 0x%x)\n", |
| mem->dma_nents, |
| ntoh24(iser_task->desc.iscsi_header.dlength)); |
| iser_err("page_vec: data_size = 0x%x, length = %d, offset = 0x%x\n", |
| ib_conn->page_vec->data_size, ib_conn->page_vec->length, |
| ib_conn->page_vec->offset); |
| for (i=0 ; i<ib_conn->page_vec->length ; i++) |
| iser_err("page_vec[%d] = 0x%llx\n", i, |
| (unsigned long long) ib_conn->page_vec->pages[i]); |
| return err; |
| } |
| } |
| return 0; |
| } |