diff options
author | Or Gerlitz <ogerlitz@voltaire.com> | 2006-05-11 07:03:08 (GMT) |
---|---|---|
committer | Roland Dreier <rolandd@cisco.com> | 2006-06-22 14:51:12 (GMT) |
commit | 6461f64ab51e6929680df064b2682004a1548290 (patch) | |
tree | 52922f1830a6f6ed7fe546db9230a507f91974a7 /drivers/infiniband | |
parent | 1cfa0a75dbef1d5bf687aacafabb023288f6b36a (diff) | |
download | linux-fsl-qoriq-6461f64ab51e6929680df064b2682004a1548290.tar.xz |
IB/iser: iSER handling of memory for RDMA
This file contains the processing carried over an SG list associated with
a SCSI command such that it can be registered with the IB verbs. The
registration produces a network virtual address (VA) and a remote access
key (RKEY or STAG in iSER spec notation) which are used by the target for
its RDMA operation.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r-- | drivers/infiniband/ulp/iser/iser_memory.c | 401 |
1 files changed, 401 insertions, 0 deletions
diff --git a/drivers/infiniband/ulp/iser/iser_memory.c b/drivers/infiniband/ulp/iser/iser_memory.c new file mode 100644 index 0000000..31950a5 --- /dev/null +++ b/drivers/infiniband/ulp/iser/iser_memory.c @@ -0,0 +1,401 @@ +/* + * 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. + * + * $Id: iser_memory.c 6964 2006-05-07 11:11:43Z ogerlitz $ + */ +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/mm.h> +#include <asm/io.h> +#include <asm/scatterlist.h> +#include <linux/scatterlist.h> + +#include "iscsi_iser.h" + +#define ISER_KMALLOC_THRESHOLD 0x20000 /* 128K - kmalloc limit */ +/** + * Decrements the reference count for the + * registered buffer & releases it + * + * returns 0 if released, 1 if deferred + */ +int iser_regd_buff_release(struct iser_regd_buf *regd_buf) +{ + struct device *dma_device; + + if ((atomic_read(®d_buf->ref_count) == 0) || + atomic_dec_and_test(®d_buf->ref_count)) { + /* if we used the dma mr, unreg is just NOP */ + if (regd_buf->reg.rkey != 0) + iser_unreg_mem(®d_buf->reg); + + if (regd_buf->dma_addr) { + dma_device = regd_buf->device->ib_device->dma_device; + dma_unmap_single(dma_device, + regd_buf->dma_addr, + regd_buf->data_size, + regd_buf->direction); + } + /* else this regd buf is associated with task which we */ + /* dma_unmap_single/sg later */ + return 0; + } else { + iser_dbg("Release deferred, regd.buff: 0x%p\n", regd_buf); + return 1; + } +} + +/** + * iser_reg_single - fills registered buffer descriptor with + * registration information + */ +void iser_reg_single(struct iser_device *device, + struct iser_regd_buf *regd_buf, + enum dma_data_direction direction) +{ + dma_addr_t dma_addr; + + dma_addr = dma_map_single(device->ib_device->dma_device, + regd_buf->virt_addr, + regd_buf->data_size, direction); + BUG_ON(dma_mapping_error(dma_addr)); + + regd_buf->reg.lkey = device->mr->lkey; + regd_buf->reg.rkey = 0; /* indicate there's no need to unreg */ + regd_buf->reg.len = regd_buf->data_size; + regd_buf->reg.va = dma_addr; + + regd_buf->dma_addr = dma_addr; + regd_buf->direction = direction; +} + +/** + * iser_start_rdma_unaligned_sg + */ +int iser_start_rdma_unaligned_sg(struct iscsi_iser_cmd_task *iser_ctask, + enum iser_data_dir cmd_dir) +{ + int dma_nents; + struct device *dma_device; + char *mem = NULL; + struct iser_data_buf *data = &iser_ctask->data[cmd_dir]; + unsigned long cmd_data_len = data->data_len; + + if (cmd_data_len > ISER_KMALLOC_THRESHOLD) + mem = (void *)__get_free_pages(GFP_NOIO, + long_log2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT); + else + mem = kmalloc(cmd_data_len, GFP_NOIO); + + 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 *sg = (struct scatterlist *)data->buf; + int i; + char *p, *from; + + for (p = mem, i = 0; i < data->size; i++) { + from = kmap_atomic(sg[i].page, KM_USER0); + memcpy(p, + from + sg[i].offset, + sg[i].length); + kunmap_atomic(from, KM_USER0); + p += sg[i].length; + } + } + + sg_init_one(&iser_ctask->data_copy[cmd_dir].sg_single, mem, cmd_data_len); + iser_ctask->data_copy[cmd_dir].buf = + &iser_ctask->data_copy[cmd_dir].sg_single; + iser_ctask->data_copy[cmd_dir].size = 1; + + iser_ctask->data_copy[cmd_dir].copy_buf = mem; + + dma_device = iser_ctask->iser_conn->ib_conn->device->ib_device->dma_device; + + if (cmd_dir == ISER_DIR_OUT) + dma_nents = dma_map_sg(dma_device, + &iser_ctask->data_copy[cmd_dir].sg_single, + 1, DMA_TO_DEVICE); + else + dma_nents = dma_map_sg(dma_device, + &iser_ctask->data_copy[cmd_dir].sg_single, + 1, DMA_FROM_DEVICE); + + BUG_ON(dma_nents == 0); + + iser_ctask->data_copy[cmd_dir].dma_nents = dma_nents; + return 0; +} + +/** + * iser_finalize_rdma_unaligned_sg + */ +void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_cmd_task *iser_ctask, + enum iser_data_dir cmd_dir) +{ + struct device *dma_device; + struct iser_data_buf *mem_copy; + unsigned long cmd_data_len; + + dma_device = iser_ctask->iser_conn->ib_conn->device->ib_device->dma_device; + mem_copy = &iser_ctask->data_copy[cmd_dir]; + + if (cmd_dir == ISER_DIR_OUT) + dma_unmap_sg(dma_device, &mem_copy->sg_single, 1, + DMA_TO_DEVICE); + else + dma_unmap_sg(dma_device, &mem_copy->sg_single, 1, + DMA_FROM_DEVICE); + + if (cmd_dir == ISER_DIR_IN) { + char *mem; + struct scatterlist *sg; + unsigned char *p, *to; + unsigned int sg_size; + int i; + + /* copy back read RDMA to unaligned sg */ + mem = mem_copy->copy_buf; + + sg = (struct scatterlist *)iser_ctask->data[ISER_DIR_IN].buf; + sg_size = iser_ctask->data[ISER_DIR_IN].size; + + for (p = mem, i = 0; i < sg_size; i++){ + to = kmap_atomic(sg[i].page, KM_SOFTIRQ0); + memcpy(to + sg[i].offset, + p, + sg[i].length); + kunmap_atomic(to, KM_SOFTIRQ0); + p += sg[i].length; + } + } + + cmd_data_len = iser_ctask->data[cmd_dir].data_len; + + if (cmd_data_len > ISER_KMALLOC_THRESHOLD) + free_pages((unsigned long)mem_copy->copy_buf, + long_log2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT); + else + kfree(mem_copy->copy_buf); + + mem_copy->copy_buf = NULL; +} + +/** + * 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 scatterlist *sg = (struct scatterlist *)data->buf; + dma_addr_t first_addr, last_addr, page; + int start_aligned, end_aligned; + unsigned int cur_page = 0; + unsigned long total_sz = 0; + int i; + + /* compute the offset of first element */ + page_vec->offset = (u64) sg[0].offset; + + for (i = 0; i < data->dma_nents; i++) { + total_sz += sg_dma_len(&sg[i]); + + first_addr = sg_dma_address(&sg[i]); + last_addr = first_addr + sg_dma_len(&sg[i]); + + start_aligned = !(first_addr & ~PAGE_MASK); + end_aligned = !(last_addr & ~PAGE_MASK); + + /* continue to collect page fragments till aligned or SG ends */ + while (!end_aligned && (i + 1 < data->dma_nents)) { + i++; + total_sz += sg_dma_len(&sg[i]); + last_addr = sg_dma_address(&sg[i]) + sg_dma_len(&sg[i]); + end_aligned = !(last_addr & ~PAGE_MASK); + } + + first_addr = first_addr & PAGE_MASK; + + for (page = first_addr; page < last_addr; page += PAGE_SIZE) + page_vec->pages[cur_page++] = page; + + } + 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; +} + +#define MASK_4K ((1UL << 12) - 1) /* 0xFFF */ +#define IS_4K_ALIGNED(addr) ((((unsigned long)addr) & MASK_4K) == 0) + +/** + * 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 unsigned int iser_data_buf_aligned_len(struct iser_data_buf *data) +{ + struct scatterlist *sg; + dma_addr_t end_addr, next_addr; + int i, cnt; + unsigned int ret_len = 0; + + sg = (struct scatterlist *)data->buf; + + for (cnt = 0, i = 0; i < data->dma_nents; i++, cnt++) { + /* iser_dbg("Checking sg iobuf [%d]: phys=0x%08lX " + "offset: %ld sz: %ld\n", i, + (unsigned long)page_to_phys(sg[i].page), + (unsigned long)sg[i].offset, + (unsigned long)sg[i].length); */ + end_addr = sg_dma_address(&sg[i]) + + sg_dma_len(&sg[i]); + /* iser_dbg("Checking sg iobuf end address " + "0x%08lX\n", end_addr); */ + if (i + 1 < data->dma_nents) { + next_addr = sg_dma_address(&sg[i+1]); + /* are i, i+1 fragments of the same page? */ + if (end_addr == next_addr) + continue; + else if (!IS_4K_ALIGNED(end_addr)) { + ret_len = cnt + 1; + break; + } + } + } + if (i == data->dma_nents) + ret_len = cnt; /* loop ended */ + 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 scatterlist *sg = (struct scatterlist *)data->buf; + int i; + + for (i = 0; i < data->size; i++) + iser_err("sg[%d] dma_addr:0x%lX page:0x%p " + "off:%d sz:%d dma_len:%d\n", + i, (unsigned long)sg_dma_address(&sg[i]), + sg[i].page, sg[i].offset, + sg[i].length,sg_dma_len(&sg[i])); +} + +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) +{ + 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); + 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 * PAGE_SIZE < page_vec->data_size) { + iser_err("page_vec too short to hold this SG\n"); + iser_data_buf_dump(data); + iser_dump_page_vec(page_vec); + BUG(); + } +} + +/** + * 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_cmd_task *iser_ctask, + enum iser_data_dir cmd_dir) +{ + struct iser_conn *ib_conn = iser_ctask->iser_conn->ib_conn; + struct iser_data_buf *mem = &iser_ctask->data[cmd_dir]; + struct iser_regd_buf *regd_buf; + int aligned_len; + int err; + + regd_buf = &iser_ctask->rdma_regd[cmd_dir]; + + aligned_len = iser_data_buf_aligned_len(mem); + if (aligned_len != mem->size) { + iser_err("rdma alignment violation %d/%d aligned\n", + aligned_len, mem->size); + iser_data_buf_dump(mem); + /* allocate copy buf, if we are writing, copy the */ + /* unaligned scatterlist, dma map the copy */ + if (iser_start_rdma_unaligned_sg(iser_ctask, cmd_dir) != 0) + return -ENOMEM; + mem = &iser_ctask->data_copy[cmd_dir]; + } + + iser_page_vec_build(mem, ib_conn->page_vec); + err = iser_reg_page_vec(ib_conn, ib_conn->page_vec, ®d_buf->reg); + if (err) + return err; + + /* take a reference on this regd buf such that it will not be released * + * (eg in send dto completion) before we get the scsi response */ + atomic_inc(®d_buf->ref_count); + return 0; +} |