IB/iser: Reuse ib_sg_to_pages

We have in iser iser_sg_to_page_vec which has exactly
the same role as ib_sg_to_pages. Customize the page_vec
to hold a fake MR so we can reuse ib_sg_to_pages.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Sagi Grimberg 2015-12-09 14:12:00 +02:00 committed by Doug Ledford
parent 08ff089b12
commit bfe066e256
2 changed files with 25 additions and 85 deletions

View file

@ -585,9 +585,8 @@ struct iscsi_iser_task {
struct iser_page_vec {
u64 *pages;
int length;
int offset;
int data_size;
int npages;
struct ib_mr fake_mr;
};
/**

View file

@ -135,67 +135,6 @@ iser_reg_desc_put_fmr(struct ib_conn *ib_conn,
{
}
#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 ib_device *ibdev, u64 *pages,
int *offset, int *data_size)
{
struct scatterlist *sg, *sgl = data->sg;
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 */
*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 {
pages[cur_page++] = page;
page += SIZE_4K;
} while (page < end_addr);
}
*data_size = total_sz;
iser_dbg("page_vec->data_size:%d cur_page %d\n",
*data_size, cur_page);
return cur_page;
}
static void iser_data_buf_dump(struct iser_data_buf *data,
struct ib_device *ibdev)
{
@ -214,10 +153,10 @@ 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]);
iser_err("page vec npages %d data length %d\n",
page_vec->npages, page_vec->fake_mr.length);
for (i = 0; i < page_vec->npages; i++)
iser_err("vec[%d]: %llx\n", i, page_vec->pages[i]);
}
int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
@ -266,11 +205,16 @@ iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem,
return 0;
}
/**
* iser_reg_page_vec - Register physical memory
*
* returns: 0 on success, errno code on failure
*/
static int iser_set_page(struct ib_mr *mr, u64 addr)
{
struct iser_page_vec *page_vec =
container_of(mr, struct iser_page_vec, fake_mr);
page_vec->pages[page_vec->npages++] = addr;
return 0;
}
static
int iser_fast_reg_fmr(struct iscsi_iser_task *iser_task,
struct iser_data_buf *mem,
@ -284,22 +228,19 @@ int iser_fast_reg_fmr(struct iscsi_iser_task *iser_task,
struct ib_pool_fmr *fmr;
int ret, plen;
plen = iser_sg_to_page_vec(mem, device->ib_device,
page_vec->pages,
&page_vec->offset,
&page_vec->data_size);
page_vec->length = plen;
if (plen * SIZE_4K < page_vec->data_size) {
page_vec->npages = 0;
page_vec->fake_mr.page_size = SIZE_4K;
plen = ib_sg_to_pages(&page_vec->fake_mr, mem->sg,
mem->size, iser_set_page);
if (unlikely(plen < mem->size)) {
iser_err("page vec too short to hold this SG\n");
iser_data_buf_dump(mem, device->ib_device);
iser_dump_page_vec(page_vec);
return -EINVAL;
}
fmr = ib_fmr_pool_map_phys(fmr_pool,
page_vec->pages,
page_vec->length,
page_vec->pages[0]);
fmr = ib_fmr_pool_map_phys(fmr_pool, page_vec->pages,
page_vec->npages, page_vec->pages[0]);
if (IS_ERR(fmr)) {
ret = PTR_ERR(fmr);
iser_err("ib_fmr_pool_map_phys failed: %d\n", ret);
@ -308,8 +249,8 @@ int iser_fast_reg_fmr(struct iscsi_iser_task *iser_task,
reg->sge.lkey = fmr->fmr->lkey;
reg->rkey = fmr->fmr->rkey;
reg->sge.addr = page_vec->pages[0] + page_vec->offset;
reg->sge.length = page_vec->data_size;
reg->sge.addr = page_vec->fake_mr.iova;
reg->sge.length = page_vec->fake_mr.length;
reg->mem_h = fmr;
iser_dbg("fmr reg: lkey=0x%x, rkey=0x%x, addr=0x%llx,"