[SCSI] cxgb3i: Outgoing pdus need to observe skb's MAX_SKB_FRAGS
authorKaren Xie <kxie@chelsio.com>
Sat, 14 Feb 2009 05:38:54 +0000 (21:38 -0800)
committerJames Bottomley <James.Bottomley@HansenPartnership.com>
Sun, 22 Feb 2009 02:29:37 +0000 (20:29 -0600)
Need to make sure the outgoing pdu can fit into a single skb.  When
calulating the max. outgoing pdu payload size, take into consideration
of
- data can be held in the skb's fragment list, assume 512 bytes per
  fragment, and
- data can be held in the headroom.

Signed-off-by: Karen Xie <kxie@chelsio.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
drivers/scsi/cxgb3i/cxgb3i_ddp.c
drivers/scsi/cxgb3i/cxgb3i_ddp.h
drivers/scsi/cxgb3i/cxgb3i_iscsi.c
drivers/scsi/cxgb3i/cxgb3i_offload.h
drivers/scsi/cxgb3i/cxgb3i_pdu.c
drivers/scsi/cxgb3i/cxgb3i_pdu.h

index 08f3a09..a83d36e 100644 (file)
@@ -639,10 +639,11 @@ static int ddp_init(struct t3cdev *tdev)
        write_unlock(&cxgb3i_ddp_rwlock);
 
        ddp_log_info("nppods %u (0x%x ~ 0x%x), bits %u, mask 0x%x,0x%x "
-                       "pkt %u,%u.\n",
+                       "pkt %u/%u, %u/%u.\n",
                        ppmax, ddp->llimit, ddp->ulimit, ddp->idx_bits,
                        ddp->idx_mask, ddp->rsvd_tag_mask,
-                       ddp->max_txsz, ddp->max_rxsz);
+                       ddp->max_txsz, uinfo.max_txsz,
+                       ddp->max_rxsz, uinfo.max_rxsz);
        return 0;
 
 free_ddp_map:
@@ -654,8 +655,8 @@ free_ddp_map:
  * cxgb3i_adapter_ddp_init - initialize the adapter's ddp resource
  * @tdev: t3cdev adapter
  * @tformat: tag format
- * @txsz: max tx pkt size, filled in by this func.
- * @rxsz: max rx pkt size, filled in by this func.
+ * @txsz: max tx pdu payload size, filled in by this func.
+ * @rxsz: max rx pdu payload size, filled in by this func.
  * initialize the ddp pagepod manager for a given adapter if needed and
  * setup the tag format for a given iscsi entity
  */
@@ -685,10 +686,12 @@ int cxgb3i_adapter_ddp_init(struct t3cdev *tdev,
                      tformat->sw_bits, tformat->rsvd_bits,
                      tformat->rsvd_shift, tformat->rsvd_mask);
 
-       *txsz = ddp->max_txsz;
-       *rxsz = ddp->max_rxsz;
-       ddp_log_info("ddp max pkt size: %u, %u.\n",
-                    ddp->max_txsz, ddp->max_rxsz);
+       *txsz = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
+                       ddp->max_txsz - ISCSI_PDU_NONPAYLOAD_LEN);
+       *rxsz = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
+                       ddp->max_rxsz - ISCSI_PDU_NONPAYLOAD_LEN);
+       ddp_log_info("max payload size: %u/%u, %u/%u.\n",
+                    *txsz, ddp->max_txsz, *rxsz, ddp->max_rxsz);
        return 0;
 }
 EXPORT_SYMBOL_GPL(cxgb3i_adapter_ddp_init);
index 5c7c4d9..99d7014 100644 (file)
@@ -85,8 +85,9 @@ struct cxgb3i_ddp_info {
        struct sk_buff **gl_skb;
 };
 
+#define ISCSI_PDU_NONPAYLOAD_LEN       312 /* bhs(48) + ahs(256) + digest(8) */
 #define ULP2_MAX_PKT_SIZE      16224
-#define ULP2_MAX_PDU_PAYLOAD   (ULP2_MAX_PKT_SIZE - ISCSI_PDU_NONPAYLOAD_MAX)
+#define ULP2_MAX_PDU_PAYLOAD   (ULP2_MAX_PKT_SIZE - ISCSI_PDU_NONPAYLOAD_LEN)
 #define PPOD_PAGES_MAX         4
 #define PPOD_PAGES_SHIFT       2       /* 4 pages per pod */
 
index f0434b7..fa2a44f 100644 (file)
@@ -403,17 +403,15 @@ static inline int cxgb3i_conn_max_xmit_dlength(struct iscsi_conn *conn)
 {
        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
        struct cxgb3i_conn *cconn = tcp_conn->dd_data;
-       unsigned int max = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
-                                cconn->hba->snic->tx_max_size -
-                                ISCSI_PDU_NONPAYLOAD_MAX);
+       unsigned int max = max(512 * MAX_SKB_FRAGS, SKB_TX_HEADROOM);
 
+       max = min(cconn->hba->snic->tx_max_size, max);
        if (conn->max_xmit_dlength)
-               conn->max_xmit_dlength = min_t(unsigned int,
-                                               conn->max_xmit_dlength, max);
+               conn->max_xmit_dlength = min(conn->max_xmit_dlength, max);
        else
                conn->max_xmit_dlength = max;
        align_pdu_size(conn->max_xmit_dlength);
-       cxgb3i_log_info("conn 0x%p, max xmit %u.\n",
+       cxgb3i_api_debug("conn 0x%p, max xmit %u.\n",
                         conn, conn->max_xmit_dlength);
        return 0;
 }
@@ -428,9 +426,7 @@ static inline int cxgb3i_conn_max_recv_dlength(struct iscsi_conn *conn)
 {
        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
        struct cxgb3i_conn *cconn = tcp_conn->dd_data;
-       unsigned int max = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
-                                cconn->hba->snic->rx_max_size -
-                                ISCSI_PDU_NONPAYLOAD_MAX);
+       unsigned int max = cconn->hba->snic->rx_max_size;
 
        align_pdu_size(max);
        if (conn->max_recv_dlength) {
@@ -440,8 +436,7 @@ static inline int cxgb3i_conn_max_recv_dlength(struct iscsi_conn *conn)
                                         conn->max_recv_dlength, max);
                        return -EINVAL;
                }
-               conn->max_recv_dlength = min_t(unsigned int,
-                                               conn->max_recv_dlength, max);
+               conn->max_recv_dlength = min(conn->max_recv_dlength, max);
                align_pdu_size(conn->max_recv_dlength);
        } else
                conn->max_recv_dlength = max;
index df1eae0..6344b9e 100644 (file)
@@ -225,6 +225,7 @@ struct sge_opaque_hdr {
 /* for TX: a skb must have a headroom of at least TX_HEADER_LEN bytes */
 #define TX_HEADER_LEN \
                (sizeof(struct tx_data_wr) + sizeof(struct sge_opaque_hdr))
+#define SKB_TX_HEADROOM                SKB_MAX_HEAD(TX_HEADER_LEN)
 
 /*
  * get and set private ip for iscsi traffic
index ce7ce8c..17115c2 100644 (file)
 #define cxgb3i_tx_debug(fmt...)
 #endif
 
+/* always allocate rooms for AHS */
+#define SKB_TX_PDU_HEADER_LEN  \
+       (sizeof(struct iscsi_hdr) + ISCSI_MAX_AHS_SIZE)
+static unsigned int skb_extra_headroom;
 static struct page *pad_page;
 
 /*
@@ -146,12 +150,13 @@ static inline void tx_skb_setmode(struct sk_buff *skb, int hcrc, int dcrc)
 
 void cxgb3i_conn_cleanup_task(struct iscsi_task *task)
 {
-       struct iscsi_tcp_task *tcp_task = task->dd_data;
+       struct cxgb3i_task_data *tdata = task->dd_data +
+                                       sizeof(struct iscsi_tcp_task);
 
        /* never reached the xmit task callout */
-       if (tcp_task->dd_data)
-               kfree_skb(tcp_task->dd_data);
-       tcp_task->dd_data = NULL;
+       if (tdata->skb)
+               __kfree_skb(tdata->skb);
+       memset(tdata, 0, sizeof(struct cxgb3i_task_data));
 
        /* MNC - Do we need a check in case this is called but
         * cxgb3i_conn_alloc_pdu has never been called on the task */
@@ -159,28 +164,102 @@ void cxgb3i_conn_cleanup_task(struct iscsi_task *task)
        iscsi_tcp_cleanup_task(task);
 }
 
-/*
- * We do not support ahs yet
- */
+static int sgl_seek_offset(struct scatterlist *sgl, unsigned int sgcnt,
+                               unsigned int offset, unsigned int *off,
+                               struct scatterlist **sgp)
+{
+       int i;
+       struct scatterlist *sg;
+
+       for_each_sg(sgl, sg, sgcnt, i) {
+               if (offset < sg->length) {
+                       *off = offset;
+                       *sgp = sg;
+                       return 0;
+               }
+               offset -= sg->length;
+       }
+       return -EFAULT;
+}
+
+static int sgl_read_to_frags(struct scatterlist *sg, unsigned int sgoffset,
+                               unsigned int dlen, skb_frag_t *frags,
+                               int frag_max)
+{
+       unsigned int datalen = dlen;
+       unsigned int sglen = sg->length - sgoffset;
+       struct page *page = sg_page(sg);
+       int i;
+
+       i = 0;
+       do {
+               unsigned int copy;
+
+               if (!sglen) {
+                       sg = sg_next(sg);
+                       if (!sg) {
+                               cxgb3i_log_error("%s, sg NULL, len %u/%u.\n",
+                                                __func__, datalen, dlen);
+                               return -EINVAL;
+                       }
+                       sgoffset = 0;
+                       sglen = sg->length;
+                       page = sg_page(sg);
+
+               }
+               copy = min(datalen, sglen);
+               if (i && page == frags[i - 1].page &&
+                   sgoffset + sg->offset ==
+                       frags[i - 1].page_offset + frags[i - 1].size) {
+                       frags[i - 1].size += copy;
+               } else {
+                       if (i >= frag_max) {
+                               cxgb3i_log_error("%s, too many pages %u, "
+                                                "dlen %u.\n", __func__,
+                                                frag_max, dlen);
+                               return -EINVAL;
+                       }
+
+                       frags[i].page = page;
+                       frags[i].page_offset = sg->offset + sgoffset;
+                       frags[i].size = copy;
+                       i++;
+               }
+               datalen -= copy;
+               sgoffset += copy;
+               sglen -= copy;
+       } while (datalen);
+
+       return i;
+}
+
 int cxgb3i_conn_alloc_pdu(struct iscsi_task *task, u8 opcode)
 {
+       struct iscsi_conn *conn = task->conn;
        struct iscsi_tcp_task *tcp_task = task->dd_data;
-       struct sk_buff *skb;
+       struct cxgb3i_task_data *tdata = task->dd_data + sizeof(*tcp_task);
+       struct scsi_cmnd *sc = task->sc;
+       int headroom = SKB_TX_PDU_HEADER_LEN;
 
+       tcp_task->dd_data = tdata;
        task->hdr = NULL;
-       /* always allocate rooms for AHS */
-       skb = alloc_skb(sizeof(struct iscsi_hdr) + ISCSI_MAX_AHS_SIZE +
-                       TX_HEADER_LEN,  GFP_ATOMIC);
-       if (!skb)
+
+       /* write command, need to send data pdus */
+       if (skb_extra_headroom && (opcode == ISCSI_OP_SCSI_DATA_OUT ||
+           (opcode == ISCSI_OP_SCSI_CMD &&
+           (scsi_bidi_cmnd(sc) || sc->sc_data_direction == DMA_TO_DEVICE))))
+               headroom += min(skb_extra_headroom, conn->max_xmit_dlength);
+
+       tdata->skb = alloc_skb(TX_HEADER_LEN + headroom, GFP_ATOMIC);
+       if (!tdata->skb)
                return -ENOMEM;
+       skb_reserve(tdata->skb, TX_HEADER_LEN);
 
        cxgb3i_tx_debug("task 0x%p, opcode 0x%x, skb 0x%p.\n",
-                       task, opcode, skb);
+                       task, opcode, tdata->skb);
 
-       tcp_task->dd_data = skb;
-       skb_reserve(skb, TX_HEADER_LEN);
-       task->hdr = (struct iscsi_hdr *)skb->data;
-       task->hdr_max = sizeof(struct iscsi_hdr);
+       task->hdr = (struct iscsi_hdr *)tdata->skb->data;
+       task->hdr_max = SKB_TX_PDU_HEADER_LEN;
 
        /* data_out uses scsi_cmd's itt */
        if (opcode != ISCSI_OP_SCSI_DATA_OUT)
@@ -192,13 +271,13 @@ int cxgb3i_conn_alloc_pdu(struct iscsi_task *task, u8 opcode)
 int cxgb3i_conn_init_pdu(struct iscsi_task *task, unsigned int offset,
                              unsigned int count)
 {
-       struct iscsi_tcp_task *tcp_task = task->dd_data;
-       struct sk_buff *skb = tcp_task->dd_data;
        struct iscsi_conn *conn = task->conn;
-       struct page *pg;
+       struct iscsi_tcp_task *tcp_task = task->dd_data;
+       struct cxgb3i_task_data *tdata = tcp_task->dd_data;
+       struct sk_buff *skb = tdata->skb;
        unsigned int datalen = count;
        int i, padlen = iscsi_padding(count);
-       skb_frag_t *frag;
+       struct page *pg;
 
        cxgb3i_tx_debug("task 0x%p,0x%p, offset %u, count %u, skb 0x%p.\n",
                        task, task->sc, offset, count, skb);
@@ -209,90 +288,94 @@ int cxgb3i_conn_init_pdu(struct iscsi_task *task, unsigned int offset,
                return 0;
 
        if (task->sc) {
-               struct scatterlist *sg;
-               struct scsi_data_buffer *sdb;
-               unsigned int sgoffset = offset;
-               struct page *sgpg;
-               unsigned int sglen;
-
-               sdb = scsi_out(task->sc);
-               sg = sdb->table.sgl;
-
-               for_each_sg(sdb->table.sgl, sg, sdb->table.nents, i) {
-                       cxgb3i_tx_debug("sg %d, page 0x%p, len %u offset %u\n",
-                                       i, sg_page(sg), sg->length, sg->offset);
-
-                       if (sgoffset < sg->length)
-                               break;
-                       sgoffset -= sg->length;
+               struct scsi_data_buffer *sdb = scsi_out(task->sc);
+               struct scatterlist *sg = NULL;
+               int err;
+
+               tdata->offset = offset;
+               tdata->count = count;
+               err = sgl_seek_offset(sdb->table.sgl, sdb->table.nents,
+                                       tdata->offset, &tdata->sgoffset, &sg);
+               if (err < 0) {
+                       cxgb3i_log_warn("tpdu, sgl %u, bad offset %u/%u.\n",
+                                       sdb->table.nents, tdata->offset,
+                                       sdb->length);
+                       return err;
                }
-               sgpg = sg_page(sg);
-               sglen = sg->length - sgoffset;
-
-               do {
-                       int j = skb_shinfo(skb)->nr_frags;
-                       unsigned int copy;
-
-                       if (!sglen) {
-                               sg = sg_next(sg);
-                               sgpg = sg_page(sg);
-                               sgoffset = 0;
-                               sglen = sg->length;
-                               ++i;
+               err = sgl_read_to_frags(sg, tdata->sgoffset, tdata->count,
+                                       tdata->frags, MAX_PDU_FRAGS);
+               if (err < 0) {
+                       cxgb3i_log_warn("tpdu, sgl %u, bad offset %u + %u.\n",
+                                       sdb->table.nents, tdata->offset,
+                                       tdata->count);
+                       return err;
+               }
+               tdata->nr_frags = err;
+
+               if (tdata->nr_frags > MAX_SKB_FRAGS ||
+                   (padlen && tdata->nr_frags == MAX_SKB_FRAGS)) {
+                       char *dst = skb->data + task->hdr_len;
+                       skb_frag_t *frag = tdata->frags;
+
+                       /* data fits in the skb's headroom */
+                       for (i = 0; i < tdata->nr_frags; i++, frag++) {
+                               char *src = kmap_atomic(frag->page,
+                                                       KM_SOFTIRQ0);
+
+                               memcpy(dst, src+frag->page_offset, frag->size);
+                               dst += frag->size;
+                               kunmap_atomic(src, KM_SOFTIRQ0);
                        }
-                       copy = min(sglen, datalen);
-                       if (j && skb_can_coalesce(skb, j, sgpg,
-                                                 sg->offset + sgoffset)) {
-                               skb_shinfo(skb)->frags[j - 1].size += copy;
-                       } else {
-                               get_page(sgpg);
-                               skb_fill_page_desc(skb, j, sgpg,
-                                                  sg->offset + sgoffset, copy);
+                       if (padlen) {
+                               memset(dst, 0, padlen);
+                               padlen = 0;
                        }
-                       sgoffset += copy;
-                       sglen -= copy;
-                       datalen -= copy;
-               } while (datalen);
+                       skb_put(skb, count + padlen);
+               } else {
+                       /* data fit into frag_list */
+                       for (i = 0; i < tdata->nr_frags; i++)
+                               get_page(tdata->frags[i].page);
+
+                       memcpy(skb_shinfo(skb)->frags, tdata->frags,
+                               sizeof(skb_frag_t) * tdata->nr_frags);
+                       skb_shinfo(skb)->nr_frags = tdata->nr_frags;
+                       skb->len += count;
+                       skb->data_len += count;
+                       skb->truesize += count;
+               }
+
        } else {
                pg = virt_to_page(task->data);
 
-               while (datalen) {
-                       i = skb_shinfo(skb)->nr_frags;
-                       frag = &skb_shinfo(skb)->frags[i];
-
-                       get_page(pg);
-                       frag->page = pg;
-                       frag->page_offset = 0;
-                       frag->size = min((unsigned int)PAGE_SIZE, datalen);
-
-                       skb_shinfo(skb)->nr_frags++;
-                       datalen -= frag->size;
-                       pg++;
-               }
+               get_page(pg);
+               skb_fill_page_desc(skb, 0, pg, offset_in_page(task->data),
+                                       count);
+               skb->len += count;
+               skb->data_len += count;
+               skb->truesize += count;
        }
 
        if (padlen) {
                i = skb_shinfo(skb)->nr_frags;
-               frag = &skb_shinfo(skb)->frags[i];
-               frag->page = pad_page;
-               frag->page_offset = 0;
-               frag->size = padlen;
-               skb_shinfo(skb)->nr_frags++;
+               get_page(pad_page);
+               skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, pad_page, 0,
+                                padlen);
+
+               skb->data_len += padlen;
+               skb->truesize += padlen;
+               skb->len += padlen;
        }
 
-       datalen = count + padlen;
-       skb->data_len += datalen;
-       skb->truesize += datalen;
-       skb->len += datalen;
        return 0;
 }
 
 int cxgb3i_conn_xmit_pdu(struct iscsi_task *task)
 {
-       struct iscsi_tcp_task *tcp_task = task->dd_data;
-       struct sk_buff *skb = tcp_task->dd_data;
        struct iscsi_tcp_conn *tcp_conn = task->conn->dd_data;
        struct cxgb3i_conn *cconn = tcp_conn->dd_data;
+       struct iscsi_tcp_task *tcp_task = task->dd_data;
+       struct cxgb3i_task_data *tdata = tcp_task->dd_data;
+       struct sk_buff *skb = tdata->skb;
        unsigned int datalen;
        int err;
 
@@ -300,13 +383,14 @@ int cxgb3i_conn_xmit_pdu(struct iscsi_task *task)
                return 0;
 
        datalen = skb->data_len;
-       tcp_task->dd_data = NULL;
+       tdata->skb = NULL;
        err = cxgb3i_c3cn_send_pdus(cconn->cep->c3cn, skb);
-       cxgb3i_tx_debug("task 0x%p, skb 0x%p, len %u/%u, rv %d.\n",
-                       task, skb, skb->len, skb->data_len, err);
        if (err > 0) {
                int pdulen = err;
 
+       cxgb3i_tx_debug("task 0x%p, skb 0x%p, len %u/%u, rv %d.\n",
+                       task, skb, skb->len, skb->data_len, err);
+
                if (task->conn->hdrdgst_en)
                        pdulen += ISCSI_DIGEST_SIZE;
                if (datalen && task->conn->datadgst_en)
@@ -325,12 +409,14 @@ int cxgb3i_conn_xmit_pdu(struct iscsi_task *task)
                return err;
        }
        /* reset skb to send when we are called again */
-       tcp_task->dd_data = skb;
+       tdata->skb = skb;
        return -EAGAIN;
 }
 
 int cxgb3i_pdu_init(void)
 {
+       if (SKB_TX_HEADROOM > (512 * MAX_SKB_FRAGS))
+               skb_extra_headroom = SKB_TX_HEADROOM;
        pad_page = alloc_page(GFP_KERNEL);
        if (!pad_page)
                return -ENOMEM;
@@ -366,7 +452,9 @@ void cxgb3i_conn_pdu_ready(struct s3_conn *c3cn)
        skb = skb_peek(&c3cn->receive_queue);
        while (!err && skb) {
                __skb_unlink(skb, &c3cn->receive_queue);
-               read += skb_ulp_pdulen(skb);
+               read += skb_rx_pdulen(skb);
+               cxgb3i_rx_debug("conn 0x%p, cn 0x%p, rx skb 0x%p, pdulen %u.\n",
+                               conn, c3cn, skb, skb_rx_pdulen(skb));
                err = cxgb3i_conn_read_pdu_skb(conn, skb);
                __kfree_skb(skb);
                skb = skb_peek(&c3cn->receive_queue);
@@ -377,6 +465,11 @@ void cxgb3i_conn_pdu_ready(struct s3_conn *c3cn)
                cxgb3i_c3cn_rx_credits(c3cn, read);
        }
        conn->rxdata_octets += read;
+
+       if (err) {
+               cxgb3i_log_info("conn 0x%p rx failed err %d.\n", conn, err);
+               iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+       }
 }
 
 void cxgb3i_conn_tx_open(struct s3_conn *c3cn)
index a3f685c..0770b23 100644 (file)
@@ -53,7 +53,7 @@ struct cpl_rx_data_ddp_norss {
 #define ULP2_FLAG_DCRC_ERROR           0x20
 #define ULP2_FLAG_PAD_ERROR            0x40
 
-void cxgb3i_conn_closing(struct s3_conn *);
+void cxgb3i_conn_closing(struct s3_conn *c3cn);
 void cxgb3i_conn_pdu_ready(struct s3_conn *c3cn);
 void cxgb3i_conn_tx_open(struct s3_conn *c3cn);
 #endif