RDMA/siw: Fix SGL mapping issues

All user level and most in-kernel applications submit WQEs
where the SG list entries are all of a single type.
iSER in particular, however, will send us WQEs with mixed SG
types: sge[0] = kernel buffer, sge[1] = PBL region.
Check and set is_kva on each SG entry individually instead of
assuming the first SGE type carries through to the last.
This fixes iSER over siw.

Fixes: b9be6f18cf9e ("rdma/siw: transmit path")
Reported-by: Krishnamraju Eraparaju <krishna2@chelsio.com>
Tested-by: Krishnamraju Eraparaju <krishna2@chelsio.com>
Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
Link: https://lore.kernel.org/r/20190822150741.21871-1-bmt@zurich.ibm.com
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c b/drivers/infiniband/sw/siw/siw_qp_tx.c
index 43020d2..42c6362 100644 (file)
--- a/drivers/infiniband/sw/siw/siw_qp_tx.c
+++ b/drivers/infiniband/sw/siw/siw_qp_tx.c
@@ -398,15 +398,13 @@ static int siw_0copy_tx(struct socket *s, struct page **page,
 
 #define MAX_TRAILER (MPA_CRC_SIZE + 4)
 
-static void siw_unmap_pages(struct page **pages, int hdr_len, int num_maps)
+static void siw_unmap_pages(struct page **pp, unsigned long kmap_mask)
 {
-       if (hdr_len) {
-               ++pages;
-               --num_maps;
-       }
-       while (num_maps-- > 0) {
-               kunmap(*pages);
-               pages++;
+       while (kmap_mask) {
+               if (kmap_mask & BIT(0))
+                       kunmap(*pp);
+               pp++;
+               kmap_mask >>= 1;
        }
 }
 
@@ -437,6 +435,7 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
        unsigned int data_len = c_tx->bytes_unsent, hdr_len = 0, trl_len = 0,
                     sge_off = c_tx->sge_off, sge_idx = c_tx->sge_idx,
                     pbl_idx = c_tx->pbl_idx;
+       unsigned long kmap_mask = 0L;
 
        if (c_tx->state == SIW_SEND_HDR) {
                if (c_tx->use_sendpage) {
@@ -463,8 +462,7 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
 
                if (!(tx_flags(wqe) & SIW_WQE_INLINE)) {
                        mem = wqe->mem[sge_idx];
-                       if (!mem->mem_obj)
-                               is_kva = 1;
+                       is_kva = mem->mem_obj == NULL ? 1 : 0;
                } else {
                        is_kva = 1;
                }
@@ -500,12 +498,7 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
                                        p = siw_get_upage(mem->umem,
                                                          sge->laddr + sge_off);
                                if (unlikely(!p)) {
-                                       if (hdr_len)
-                                               seg--;
-                                       if (!c_tx->use_sendpage && seg) {
-                                               siw_unmap_pages(page_array,
-                                                               hdr_len, seg);
-                                       }
+                                       siw_unmap_pages(page_array, kmap_mask);
                                        wqe->processed -= c_tx->bytes_unsent;
                                        rv = -EFAULT;
                                        goto done_crc;
@@ -515,6 +508,10 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
                                if (!c_tx->use_sendpage) {
                                        iov[seg].iov_base = kmap(p) + fp_off;
                                        iov[seg].iov_len = plen;
+
+                                       /* Remember for later kunmap() */
+                                       kmap_mask |= BIT(seg);
+
                                        if (do_crc)
                                                crypto_shash_update(
                                                        c_tx->mpa_crc_hd,
@@ -543,10 +540,7 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
 
                        if (++seg > (int)MAX_ARRAY) {
                                siw_dbg_qp(tx_qp(c_tx), "to many fragments\n");
-                               if (!is_kva && !c_tx->use_sendpage) {
-                                       siw_unmap_pages(page_array, hdr_len,
-                                                       seg - 1);
-                               }
+                               siw_unmap_pages(page_array, kmap_mask);
                                wqe->processed -= c_tx->bytes_unsent;
                                rv = -EMSGSIZE;
                                goto done_crc;
@@ -597,8 +591,7 @@ sge_done:
        } else {
                rv = kernel_sendmsg(s, &msg, iov, seg + 1,
                                    hdr_len + data_len + trl_len);
-               if (!is_kva)
-                       siw_unmap_pages(page_array, hdr_len, seg);
+               siw_unmap_pages(page_array, kmap_mask);
        }
        if (rv < (int)hdr_len) {
                /* Not even complete hdr pushed or negative rv */