int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev, struct rds_ib_mr *ibmr,
struct scatterlist *sg, unsigned int nents)
{
struct ib_device *dev = rds_ibdev->dev;
struct rds_ib_fmr *fmr = &ibmr->u.fmr;
struct scatterlist *scat = sg;
u64 io_addr = 0;
u64 *dma_pages;
u32 len;
int page_cnt, sg_dma_len;
int i, j;
int ret;
sg_dma_len = ib_dma_map_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
if (unlikely(!sg_dma_len)) {
pr_warn("RDS/IB: %s failed!\n", __func__);
return -EBUSY;
}
len = 0;
page_cnt = 0;
for (i = 0; i < sg_dma_len; ++i) {
unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
if (dma_addr & ~PAGE_MASK) {
if (i > 0)
return -EINVAL;
else
++page_cnt;
}
if ((dma_addr + dma_len) & ~PAGE_MASK) {
if (i < sg_dma_len - 1)
return -EINVAL;
else
++page_cnt;
}
len += dma_len;
}
page_cnt += len >> PAGE_SHIFT;
if (page_cnt > ibmr->pool->fmr_attr.max_pages)
return -EINVAL;
dma_pages = kmalloc_node(sizeof(u64) * page_cnt, GFP_ATOMIC,
rdsibdev_to_node(rds_ibdev));
if (!dma_pages)
return -ENOMEM;
page_cnt = 0;
for (i = 0; i < sg_dma_len; ++i) {
unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
for (j = 0; j < dma_len; j += PAGE_SIZE)
dma_pages[page_cnt++] =
(dma_addr & PAGE_MASK) + j;
}
ret = ib_map_phys_fmr(fmr->fmr, dma_pages, page_cnt, io_addr);
if (ret)
goto out;
/* Success - we successfully remapped the MR, so we can
* safely tear down the old mapping.
*/
rds_ib_teardown_mr(ibmr);
ibmr->sg = scat;
ibmr->sg_len = nents;
ibmr->sg_dma_len = sg_dma_len;
ibmr->remap_count++;
if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
else
rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
ret = 0;
out:
kfree(dma_pages);
return ret;
}
/* Use the ib_map_phys_fmr() verb to register a memory region
* for remote access via RDMA READ or RDMA WRITE.
*/
static int
fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
int nsegs, bool writing)
{
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
struct ib_device *device = ia->ri_device;
enum dma_data_direction direction = rpcrdma_data_dir(writing);
struct rpcrdma_mr_seg *seg1 = seg;
int len, pageoff, i, rc;
struct rpcrdma_mw *mw;
mw = seg1->rl_mw;
seg1->rl_mw = NULL;
if (!mw) {
mw = rpcrdma_get_mw(r_xprt);
if (!mw)
return -ENOMEM;
} else {
/* this is a retransmit; generate a fresh rkey */
rc = __fmr_unmap(mw);
if (rc)
return rc;
}
pageoff = offset_in_page(seg1->mr_offset);
seg1->mr_offset -= pageoff; /* start of page */
seg1->mr_len += pageoff;
len = -pageoff;
if (nsegs > RPCRDMA_MAX_FMR_SGES)
nsegs = RPCRDMA_MAX_FMR_SGES;
for (i = 0; i < nsegs;) {
rpcrdma_map_one(device, seg, direction);
mw->r.fmr.physaddrs[i] = seg->mr_dma;
len += seg->mr_len;
++seg;
++i;
/* Check for holes */
if ((i < nsegs && offset_in_page(seg->mr_offset)) ||
offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len))
break;
}
rc = ib_map_phys_fmr(mw->r.fmr.fmr, mw->r.fmr.physaddrs,
i, seg1->mr_dma);
if (rc)
goto out_maperr;
seg1->rl_mw = mw;
seg1->mr_rkey = mw->r.fmr.fmr->rkey;
seg1->mr_base = seg1->mr_dma + pageoff;
seg1->mr_nsegs = i;
seg1->mr_len = len;
return i;
out_maperr:
dprintk("RPC: %s: ib_map_phys_fmr %u@0x%llx+%i (%d) status %i\n",
__func__, len, (unsigned long long)seg1->mr_dma,
pageoff, i, rc);
while (i--)
rpcrdma_unmap_one(device, --seg);
return rc;
}