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RDMA/srp: Remove support for FMR memory registration
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FMR is not supported on most recent RDMA devices (that use fast memory
registration mechanism). Also, FMR was recently removed from NFS/RDMA
ULP.

Link: https://lore.kernel.org/r/2-v3-f58e6669d5d3+2cf-fmr_removal_jgg@mellanox.com
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
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Max Gurtovoy authored and Jason Gunthorpe committed Jun 2, 2020
1 parent 1fc4313 commit f273ad4
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Showing 2 changed files with 22 additions and 227 deletions.
222 changes: 16 additions & 206 deletions drivers/infiniband/ulp/srp/ib_srp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -71,7 +71,6 @@ static unsigned int srp_sg_tablesize;
static unsigned int cmd_sg_entries;
static unsigned int indirect_sg_entries;
static bool allow_ext_sg;
static bool prefer_fr = true;
static bool register_always = true;
static bool never_register;
static int topspin_workarounds = 1;
Expand All @@ -95,10 +94,6 @@ module_param(topspin_workarounds, int, 0444);
MODULE_PARM_DESC(topspin_workarounds,
"Enable workarounds for Topspin/Cisco SRP target bugs if != 0");

module_param(prefer_fr, bool, 0444);
MODULE_PARM_DESC(prefer_fr,
"Whether to use fast registration if both FMR and fast registration are supported");

module_param(register_always, bool, 0444);
MODULE_PARM_DESC(register_always,
"Use memory registration even for contiguous memory regions");
Expand Down Expand Up @@ -388,24 +383,6 @@ static int srp_new_cm_id(struct srp_rdma_ch *ch)
srp_new_ib_cm_id(ch);
}

static struct ib_fmr_pool *srp_alloc_fmr_pool(struct srp_target_port *target)
{
struct srp_device *dev = target->srp_host->srp_dev;
struct ib_fmr_pool_param fmr_param;

memset(&fmr_param, 0, sizeof(fmr_param));
fmr_param.pool_size = target->mr_pool_size;
fmr_param.dirty_watermark = fmr_param.pool_size / 4;
fmr_param.cache = 1;
fmr_param.max_pages_per_fmr = dev->max_pages_per_mr;
fmr_param.page_shift = ilog2(dev->mr_page_size);
fmr_param.access = (IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_WRITE |
IB_ACCESS_REMOTE_READ);

return ib_create_fmr_pool(dev->pd, &fmr_param);
}

/**
* srp_destroy_fr_pool() - free the resources owned by a pool
* @pool: Fast registration pool to be destroyed.
Expand Down Expand Up @@ -556,7 +533,6 @@ static int srp_create_ch_ib(struct srp_rdma_ch *ch)
struct ib_qp_init_attr *init_attr;
struct ib_cq *recv_cq, *send_cq;
struct ib_qp *qp;
struct ib_fmr_pool *fmr_pool = NULL;
struct srp_fr_pool *fr_pool = NULL;
const int m = 1 + dev->use_fast_reg * target->mr_per_cmd * 2;
int ret;
Expand Down Expand Up @@ -619,14 +595,6 @@ static int srp_create_ch_ib(struct srp_rdma_ch *ch)
"FR pool allocation failed (%d)\n", ret);
goto err_qp;
}
} else if (dev->use_fmr) {
fmr_pool = srp_alloc_fmr_pool(target);
if (IS_ERR(fmr_pool)) {
ret = PTR_ERR(fmr_pool);
shost_printk(KERN_WARNING, target->scsi_host, PFX
"FMR pool allocation failed (%d)\n", ret);
goto err_qp;
}
}

if (ch->qp)
Expand All @@ -644,10 +612,6 @@ static int srp_create_ch_ib(struct srp_rdma_ch *ch)
if (ch->fr_pool)
srp_destroy_fr_pool(ch->fr_pool);
ch->fr_pool = fr_pool;
} else if (dev->use_fmr) {
if (ch->fmr_pool)
ib_destroy_fmr_pool(ch->fmr_pool);
ch->fmr_pool = fmr_pool;
}

kfree(init_attr);
Expand Down Expand Up @@ -702,9 +666,6 @@ static void srp_free_ch_ib(struct srp_target_port *target,
if (dev->use_fast_reg) {
if (ch->fr_pool)
srp_destroy_fr_pool(ch->fr_pool);
} else if (dev->use_fmr) {
if (ch->fmr_pool)
ib_destroy_fmr_pool(ch->fmr_pool);
}

srp_destroy_qp(ch);
Expand Down Expand Up @@ -1017,12 +978,8 @@ static void srp_free_req_data(struct srp_target_port *target,

for (i = 0; i < target->req_ring_size; ++i) {
req = &ch->req_ring[i];
if (dev->use_fast_reg) {
if (dev->use_fast_reg)
kfree(req->fr_list);
} else {
kfree(req->fmr_list);
kfree(req->map_page);
}
if (req->indirect_dma_addr) {
ib_dma_unmap_single(ibdev, req->indirect_dma_addr,
target->indirect_size,
Expand Down Expand Up @@ -1056,16 +1013,8 @@ static int srp_alloc_req_data(struct srp_rdma_ch *ch)
GFP_KERNEL);
if (!mr_list)
goto out;
if (srp_dev->use_fast_reg) {
if (srp_dev->use_fast_reg)
req->fr_list = mr_list;
} else {
req->fmr_list = mr_list;
req->map_page = kmalloc_array(srp_dev->max_pages_per_mr,
sizeof(void *),
GFP_KERNEL);
if (!req->map_page)
goto out;
}
req->indirect_desc = kmalloc(target->indirect_size, GFP_KERNEL);
if (!req->indirect_desc)
goto out;
Expand Down Expand Up @@ -1272,11 +1221,6 @@ static void srp_unmap_data(struct scsi_cmnd *scmnd,
if (req->nmdesc)
srp_fr_pool_put(ch->fr_pool, req->fr_list,
req->nmdesc);
} else if (dev->use_fmr) {
struct ib_pool_fmr **pfmr;

for (i = req->nmdesc, pfmr = req->fmr_list; i > 0; i--, pfmr++)
ib_fmr_pool_unmap(*pfmr);
}

ib_dma_unmap_sg(ibdev, scsi_sglist(scmnd), scsi_sg_count(scmnd),
Expand Down Expand Up @@ -1472,50 +1416,6 @@ static void srp_map_desc(struct srp_map_state *state, dma_addr_t dma_addr,
state->ndesc++;
}

static int srp_map_finish_fmr(struct srp_map_state *state,
struct srp_rdma_ch *ch)
{
struct srp_target_port *target = ch->target;
struct srp_device *dev = target->srp_host->srp_dev;
struct ib_pool_fmr *fmr;
u64 io_addr = 0;

if (state->fmr.next >= state->fmr.end) {
shost_printk(KERN_ERR, ch->target->scsi_host,
PFX "Out of MRs (mr_per_cmd = %d)\n",
ch->target->mr_per_cmd);
return -ENOMEM;
}

WARN_ON_ONCE(!dev->use_fmr);

if (state->npages == 0)
return 0;

if (state->npages == 1 && target->global_rkey) {
srp_map_desc(state, state->base_dma_addr, state->dma_len,
target->global_rkey);
goto reset_state;
}

fmr = ib_fmr_pool_map_phys(ch->fmr_pool, state->pages,
state->npages, io_addr);
if (IS_ERR(fmr))
return PTR_ERR(fmr);

*state->fmr.next++ = fmr;
state->nmdesc++;

srp_map_desc(state, state->base_dma_addr & ~dev->mr_page_mask,
state->dma_len, fmr->fmr->rkey);

reset_state:
state->npages = 0;
state->dma_len = 0;

return 0;
}

static void srp_reg_mr_err_done(struct ib_cq *cq, struct ib_wc *wc)
{
srp_handle_qp_err(cq, wc, "FAST REG");
Expand Down Expand Up @@ -1606,74 +1506,6 @@ static int srp_map_finish_fr(struct srp_map_state *state,
return n;
}

static int srp_map_sg_entry(struct srp_map_state *state,
struct srp_rdma_ch *ch,
struct scatterlist *sg)
{
struct srp_target_port *target = ch->target;
struct srp_device *dev = target->srp_host->srp_dev;
dma_addr_t dma_addr = sg_dma_address(sg);
unsigned int dma_len = sg_dma_len(sg);
unsigned int len = 0;
int ret;

WARN_ON_ONCE(!dma_len);

while (dma_len) {
unsigned offset = dma_addr & ~dev->mr_page_mask;

if (state->npages == dev->max_pages_per_mr ||
(state->npages > 0 && offset != 0)) {
ret = srp_map_finish_fmr(state, ch);
if (ret)
return ret;
}

len = min_t(unsigned int, dma_len, dev->mr_page_size - offset);

if (!state->npages)
state->base_dma_addr = dma_addr;
state->pages[state->npages++] = dma_addr & dev->mr_page_mask;
state->dma_len += len;
dma_addr += len;
dma_len -= len;
}

/*
* If the end of the MR is not on a page boundary then we need to
* close it out and start a new one -- we can only merge at page
* boundaries.
*/
ret = 0;
if ((dma_addr & ~dev->mr_page_mask) != 0)
ret = srp_map_finish_fmr(state, ch);
return ret;
}

static int srp_map_sg_fmr(struct srp_map_state *state, struct srp_rdma_ch *ch,
struct srp_request *req, struct scatterlist *scat,
int count)
{
struct scatterlist *sg;
int i, ret;

state->pages = req->map_page;
state->fmr.next = req->fmr_list;
state->fmr.end = req->fmr_list + ch->target->mr_per_cmd;

for_each_sg(scat, sg, count, i) {
ret = srp_map_sg_entry(state, ch, sg);
if (ret)
return ret;
}

ret = srp_map_finish_fmr(state, ch);
if (ret)
return ret;

return 0;
}

static int srp_map_sg_fr(struct srp_map_state *state, struct srp_rdma_ch *ch,
struct srp_request *req, struct scatterlist *scat,
int count)
Expand Down Expand Up @@ -1733,7 +1565,6 @@ static int srp_map_idb(struct srp_rdma_ch *ch, struct srp_request *req,
struct srp_device *dev = target->srp_host->srp_dev;
struct srp_map_state state;
struct srp_direct_buf idb_desc;
u64 idb_pages[1];
struct scatterlist idb_sg[1];
int ret;

Expand All @@ -1756,14 +1587,6 @@ static int srp_map_idb(struct srp_rdma_ch *ch, struct srp_request *req,
if (ret < 0)
return ret;
WARN_ON_ONCE(ret < 1);
} else if (dev->use_fmr) {
state.pages = idb_pages;
state.pages[0] = (req->indirect_dma_addr &
dev->mr_page_mask);
state.npages = 1;
ret = srp_map_finish_fmr(&state, ch);
if (ret < 0)
return ret;
} else {
return -EINVAL;
}
Expand All @@ -1787,9 +1610,6 @@ static void srp_check_mapping(struct srp_map_state *state,
if (dev->use_fast_reg)
for (i = 0, pfr = req->fr_list; i < state->nmdesc; i++, pfr++)
mr_len += (*pfr)->mr->length;
else if (dev->use_fmr)
for (i = 0; i < state->nmdesc; i++)
mr_len += be32_to_cpu(req->indirect_desc[i].len);
if (desc_len != scsi_bufflen(req->scmnd) ||
mr_len > scsi_bufflen(req->scmnd))
pr_err("Inconsistent: scsi len %d <> desc len %lld <> mr len %lld; ndesc %d; nmdesc = %d\n",
Expand Down Expand Up @@ -1904,8 +1724,6 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch,
state.desc = req->indirect_desc;
if (dev->use_fast_reg)
ret = srp_map_sg_fr(&state, ch, req, scat, count);
else if (dev->use_fmr)
ret = srp_map_sg_fmr(&state, ch, req, scat, count);
else
ret = srp_map_sg_dma(&state, ch, req, scat, count);
req->nmdesc = state.nmdesc;
Expand Down Expand Up @@ -3874,26 +3692,26 @@ static ssize_t srp_create_target(struct device *dev,
goto out;
}

if (!srp_dev->has_fmr && !srp_dev->has_fr && !target->allow_ext_sg &&
if (!srp_dev->has_fr && !target->allow_ext_sg &&
target->cmd_sg_cnt < target->sg_tablesize) {
pr_warn("No MR pool and no external indirect descriptors, limiting sg_tablesize to cmd_sg_cnt\n");
target->sg_tablesize = target->cmd_sg_cnt;
}

if (srp_dev->use_fast_reg || srp_dev->use_fmr) {
if (srp_dev->use_fast_reg) {
bool gaps_reg = (ibdev->attrs.device_cap_flags &
IB_DEVICE_SG_GAPS_REG);

max_sectors_per_mr = srp_dev->max_pages_per_mr <<
(ilog2(srp_dev->mr_page_size) - 9);
if (!gaps_reg) {
/*
* FR and FMR can only map one HCA page per entry. If
* the start address is not aligned on a HCA page
* boundary two entries will be used for the head and
* the tail although these two entries combined
* contain at most one HCA page of data. Hence the "+
* 1" in the calculation below.
* FR can only map one HCA page per entry. If the start
* address is not aligned on a HCA page boundary two
* entries will be used for the head and the tail
* although these two entries combined contain at most
* one HCA page of data. Hence the "+ 1" in the
* calculation below.
*
* The indirect data buffer descriptor is contiguous
* so the memory for that buffer will only be
Expand Down Expand Up @@ -4174,23 +3992,15 @@ static int srp_add_one(struct ib_device *device)
srp_dev->max_pages_per_mr = min_t(u64, SRP_MAX_PAGES_PER_MR,
max_pages_per_mr);

srp_dev->has_fmr = (device->ops.alloc_fmr &&
device->ops.dealloc_fmr &&
device->ops.map_phys_fmr &&
device->ops.unmap_fmr);
srp_dev->has_fr = (attr->device_cap_flags &
IB_DEVICE_MEM_MGT_EXTENSIONS);
if (!never_register && !srp_dev->has_fmr && !srp_dev->has_fr) {
dev_warn(&device->dev, "neither FMR nor FR is supported\n");
} else if (!never_register &&
attr->max_mr_size >= 2 * srp_dev->mr_page_size) {
srp_dev->use_fast_reg = (srp_dev->has_fr &&
(!srp_dev->has_fmr || prefer_fr));
srp_dev->use_fmr = !srp_dev->use_fast_reg && srp_dev->has_fmr;
}
if (!never_register && !srp_dev->has_fr)
dev_warn(&device->dev, "FR is not supported\n");
else if (!never_register &&
attr->max_mr_size >= 2 * srp_dev->mr_page_size)
srp_dev->use_fast_reg = srp_dev->has_fr;

if (never_register || !register_always ||
(!srp_dev->has_fmr && !srp_dev->has_fr))
if (never_register || !register_always || !srp_dev->has_fr)
flags |= IB_PD_UNSAFE_GLOBAL_RKEY;

if (srp_dev->use_fast_reg) {
Expand Down
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