[PATCH] s390: qeth bug fixes

[patch 10/10] s390: qeth bug fixes.

From: Frank Pavlic <pavlic@de.ibm.com>

qeth network driver related changes:
 - due to OSA hardware changes in TCP Segmentation Offload
   support we are able now to pack TSO packets too.
   This fits perfectly in design of qeth buffer handling and
   sending data respectively.
 - remove skb_realloc_headroom from the sending path since
   hard_header_len value provides enough headroom now.
 - device recovery behaviour improvement
 - bug fixed in Enhanced Device Driver Packing functionality

Signed-off-by: Frank Pavlic <pavlic@de.ibm.com>

1 files changed, 105 insertions, 40 deletions

diff --git a/drivers/s390/net/qeth_main.c b/drivers/s390/net/qeth_main.c
index e18bcf9fb588..208127a5033a 100644
--- a/drivers/s390/net/qeth_main.c
+++ b/drivers/s390/net/qeth_main.c
@@ -1,6 +1,6 @@
 /*
  *
- * linux/drivers/s390/net/qeth_main.c ($Revision: 1.210 $)
+ * linux/drivers/s390/net/qeth_main.c ($Revision: 1.214 $)
  *
  * Linux on zSeries OSA Express and HiperSockets support
  *
@@ -12,7 +12,7 @@
  *                        Frank Pavlic (pavlic@de.ibm.com) and
  *                        Thomas Spatzier <tspat@de.ibm.com>
  *
- *    $Revision: 1.210 $         $Date: 2005/04/18 17:27:39 $
+ *    $Revision: 1.214 $         $Date: 2005/05/04 20:19:18 $
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -80,7 +80,7 @@ qeth_eyecatcher(void)
 #include "qeth_eddp.h"
 #include "qeth_tso.h"
 
-#define VERSION_QETH_C "$Revision: 1.210 $"
+#define VERSION_QETH_C "$Revision: 1.214 $"
 static const char *version = "qeth S/390 OSA-Express driver";
 
 /**
@@ -158,6 +158,9 @@ qeth_irq_tasklet(unsigned long);
 static int
 qeth_set_online(struct ccwgroup_device *);
 
+static int
+__qeth_set_online(struct ccwgroup_device *gdev, int recovery_mode);
+
 static struct qeth_ipaddr *
 qeth_get_addr_buffer(enum qeth_prot_versions);
 
@@ -510,10 +513,10 @@ qeth_irq_tasklet(unsigned long data)
         wake_up(&card->wait_q);
 }
 
-static int qeth_stop_card(struct qeth_card *);
+static int qeth_stop_card(struct qeth_card *, int);
 
 static int
-qeth_set_offline(struct ccwgroup_device *cgdev)
+__qeth_set_offline(struct ccwgroup_device *cgdev, int recovery_mode)
 {
         struct qeth_card *card = (struct qeth_card *) cgdev->dev.driver_data;
         int rc = 0;
@@ -523,7 +526,7 @@ qeth_set_offline(struct ccwgroup_device *cgdev)
         QETH_DBF_HEX(setup, 3, &card, sizeof(void *));
 
         recover_flag = card->state;
-        if (qeth_stop_card(card) == -ERESTARTSYS){
+        if (qeth_stop_card(card, recovery_mode) == -ERESTARTSYS){
                 PRINT_WARN("Stopping card %s interrupted by user!\n",
                            CARD_BUS_ID(card));
                 return -ERESTARTSYS;
@@ -540,6 +543,12 @@ qeth_set_offline(struct ccwgroup_device *cgdev)
 }
 
 static int
+qeth_set_offline(struct ccwgroup_device *cgdev)
+{
+        return  __qeth_set_offline(cgdev, 0);
+}
+
+static int
 qeth_wait_for_threads(struct qeth_card *card, unsigned long threads);
 
 
@@ -953,8 +962,8 @@ qeth_recover(void *ptr)
         PRINT_WARN("Recovery of device %s started ...\n",
                    CARD_BUS_ID(card));
         card->use_hard_stop = 1;
-        qeth_set_offline(card->gdev);
-        rc = qeth_set_online(card->gdev);
+        __qeth_set_offline(card->gdev,1);
+        rc = __qeth_set_online(card->gdev,1);
         if (!rc)
                 PRINT_INFO("Device %s successfully recovered!\n",
                            CARD_BUS_ID(card));
@@ -3786,16 +3795,12 @@ static inline int
 qeth_prepare_skb(struct qeth_card *card, struct sk_buff **skb,
                  struct qeth_hdr **hdr, int ipv)
 {
-        int rc = 0;
 #ifdef CONFIG_QETH_VLAN
         u16 *tag;
 #endif
 
         QETH_DBF_TEXT(trace, 6, "prepskb");
 
-        rc = qeth_realloc_headroom(card, skb, sizeof(struct qeth_hdr));
-        if (rc)
-                return rc;
 #ifdef CONFIG_QETH_VLAN
         if (card->vlangrp && vlan_tx_tag_present(*skb) &&
             ((ipv == 6) || card->options.layer2) ) {
@@ -3977,25 +3982,28 @@ qeth_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
 
 static inline void
 __qeth_fill_buffer(struct sk_buff *skb, struct qdio_buffer *buffer,
-                   int *next_element_to_fill)
+                   int is_tso, int *next_element_to_fill)
 {
         int length = skb->len;
         int length_here;
         int element;
         char *data;
-        int first_lap = 1;
+        int first_lap ;
 
         element = *next_element_to_fill;
         data = skb->data;
+        first_lap = (is_tso == 0 ? 1 : 0);
+
         while (length > 0) {
                 /* length_here is the remaining amount of data in this page */
                 length_here = PAGE_SIZE - ((unsigned long) data % PAGE_SIZE);
                 if (length < length_here)
                         length_here = length;
+
                 buffer->element[element].addr = data;
                 buffer->element[element].length = length_here;
                 length -= length_here;
-                if (!length){
+                if (!length) {
                         if (first_lap)
                                 buffer->element[element].flags = 0;
                         else
@@ -4022,17 +4030,35 @@ qeth_fill_buffer(struct qeth_qdio_out_q *queue,
                  struct sk_buff *skb)
 {
         struct qdio_buffer *buffer;
-        int flush_cnt = 0;
+        struct qeth_hdr_tso *hdr;
+        int flush_cnt = 0, hdr_len, large_send = 0;
 
         QETH_DBF_TEXT(trace, 6, "qdfillbf");
+
         buffer = buf->buffer;
         atomic_inc(&skb->users);
         skb_queue_tail(&buf->skb_list, skb);
+
+        hdr  = (struct qeth_hdr_tso *) skb->data;
+        /*check first on TSO ....*/
+        if (hdr->hdr.hdr.l3.id == QETH_HEADER_TYPE_TSO) {
+                int element = buf->next_element_to_fill;
+
+                hdr_len = sizeof(struct qeth_hdr_tso) + hdr->ext.dg_hdr_len;
+                /*fill first buffer entry only with header information */
+                buffer->element[element].addr = skb->data;
+                buffer->element[element].length = hdr_len;
+                buffer->element[element].flags = SBAL_FLAGS_FIRST_FRAG;
+                buf->next_element_to_fill++;
+                skb->data += hdr_len;
+                skb->len  -= hdr_len;
+                large_send = 1;
+        }
         if (skb_shinfo(skb)->nr_frags == 0)
-                __qeth_fill_buffer(skb, buffer,
+                __qeth_fill_buffer(skb, buffer, large_send,
                                    (int *)&buf->next_element_to_fill);
         else
-                __qeth_fill_buffer_frag(skb, buffer, 0,
+                __qeth_fill_buffer_frag(skb, buffer, large_send,
                                         (int *)&buf->next_element_to_fill);
 
         if (!queue->do_pack) {
@@ -4225,6 +4251,25 @@ out:
 }
 
 static inline int
+qeth_get_elements_no(struct qeth_card *card, void *hdr, struct sk_buff *skb)
+{
+        int elements_needed = 0;
+
+        if (skb_shinfo(skb)->nr_frags > 0) {
+                elements_needed = (skb_shinfo(skb)->nr_frags + 1);
+        }
+        if (elements_needed == 0 )
+                elements_needed = 1 + (((((unsigned long) hdr) % PAGE_SIZE)
+                                        + skb->len) >> PAGE_SHIFT);
+        if (elements_needed > QETH_MAX_BUFFER_ELEMENTS(card)){
+                PRINT_ERR("qeth_do_send_packet: invalid size of "
+                          "IP packet. Discarded.");
+                return 0;
+        }
+        return elements_needed;
+}
+
+static inline int
 qeth_send_packet(struct qeth_card *card, struct sk_buff *skb)
 {
         int ipv = 0;
@@ -4266,19 +4311,25 @@ qeth_send_packet(struct qeth_card *card, struct sk_buff *skb)
         if (skb_shinfo(skb)->tso_size)
                 large_send = card->options.large_send;
 
-        if ((rc = qeth_prepare_skb(card, &skb, &hdr, ipv))){
-                QETH_DBF_TEXT_(trace, 4, "pskbe%d", rc);
-                return rc;
-        }
         /*are we able to do TSO ? If so ,prepare and send it from here */
         if ((large_send == QETH_LARGE_SEND_TSO) &&
             (cast_type == RTN_UNSPEC)) {
-                rc = qeth_tso_send_packet(card, skb, queue,
-                                          ipv, cast_type);
-                goto do_statistics;
+                rc = qeth_tso_prepare_packet(card, skb, ipv, cast_type);
+                if (rc) {
+                        card->stats.tx_dropped++;
+                        card->stats.tx_errors++;
+                        dev_kfree_skb_any(skb);
+                        return NETDEV_TX_OK;
+                } 
+                elements_needed++;
+        } else {
+                if ((rc = qeth_prepare_skb(card, &skb, &hdr, ipv))) {
+                        QETH_DBF_TEXT_(trace, 4, "pskbe%d", rc);
+                        return rc;
+                }
+                qeth_fill_header(card, hdr, skb, ipv, cast_type);
         }
 
-        qeth_fill_header(card, hdr, skb, ipv, cast_type);
         if (large_send == QETH_LARGE_SEND_EDDP) {
                 ctx = qeth_eddp_create_context(card, skb, hdr);
                 if (ctx == NULL) {
@@ -4286,7 +4337,7 @@ qeth_send_packet(struct qeth_card *card, struct sk_buff *skb)
                         return -EINVAL;
                 }
         } else {
-                elements_needed = qeth_get_elements_no(card,(void*) hdr, skb);
+                elements_needed += qeth_get_elements_no(card,(void*) hdr, skb);
                 if (!elements_needed)
                         return -EINVAL;
         }
@@ -4297,12 +4348,12 @@ qeth_send_packet(struct qeth_card *card, struct sk_buff *skb)
         else
                 rc = qeth_do_send_packet_fast(card, queue, skb, hdr,
                                               elements_needed, ctx);
-do_statistics:
         if (!rc){
                 card->stats.tx_packets++;
                 card->stats.tx_bytes += skb->len;
 #ifdef CONFIG_QETH_PERF_STATS
-                if (skb_shinfo(skb)->tso_size) {
+                if (skb_shinfo(skb)->tso_size &&
+                   !(large_send == QETH_LARGE_SEND_NO)) {
                         card->perf_stats.large_send_bytes += skb->len;
                         card->perf_stats.large_send_cnt++;
                 }
@@ -7199,7 +7250,7 @@ qeth_wait_for_threads(struct qeth_card *card, unsigned long threads)
 }
 
 static int
-qeth_stop_card(struct qeth_card *card)
+qeth_stop_card(struct qeth_card *card, int recovery_mode)
 {
         int rc = 0;
 
@@ -7212,9 +7263,13 @@ qeth_stop_card(struct qeth_card *card)
         if (card->read.state == CH_STATE_UP &&
             card->write.state == CH_STATE_UP &&
             (card->state == CARD_STATE_UP)) {
-                rtnl_lock();
-                dev_close(card->dev);
-                rtnl_unlock();
+                if(recovery_mode) {
+                        qeth_stop(card->dev);
+                } else {
+                        rtnl_lock();
+                        dev_close(card->dev);
+                        rtnl_unlock();
+                }
                 if (!card->use_hard_stop) {
                         __u8 *mac = &card->dev->dev_addr[0];
                         rc = qeth_layer2_send_delmac(card, mac);
@@ -7386,13 +7441,17 @@ qeth_register_netdev(struct qeth_card *card)
 }
 
 static void
-qeth_start_again(struct qeth_card *card)
+qeth_start_again(struct qeth_card *card, int recovery_mode)
 {
         QETH_DBF_TEXT(setup ,2, "startag");
 
-        rtnl_lock();
-        dev_open(card->dev);
-        rtnl_unlock();
+        if(recovery_mode) {
+                qeth_open(card->dev);
+        } else {
+                rtnl_lock();
+                dev_open(card->dev);
+                rtnl_unlock();
+        }
         /* this also sets saved unicast addresses */
         qeth_set_multicast_list(card->dev);
 }
@@ -7449,7 +7508,7 @@ static void qeth_make_parameters_consistent(struct qeth_card *card)
 
 
 static int
-qeth_set_online(struct ccwgroup_device *gdev)
+__qeth_set_online(struct ccwgroup_device *gdev, int recovery_mode)
 {
         struct qeth_card *card = gdev->dev.driver_data;
         int rc = 0;
@@ -7509,12 +7568,12 @@ qeth_set_online(struct ccwgroup_device *gdev)
  * we can also use this state for recovery purposes*/
         qeth_set_allowed_threads(card, 0xffffffff, 0);
         if (recover_flag == CARD_STATE_RECOVER)
-                qeth_start_again(card);
+                qeth_start_again(card, recovery_mode);
         qeth_notify_processes();
         return 0;
 out_remove:
         card->use_hard_stop = 1;
-        qeth_stop_card(card);
+        qeth_stop_card(card, 0);
         ccw_device_set_offline(CARD_DDEV(card));
         ccw_device_set_offline(CARD_WDEV(card));
         ccw_device_set_offline(CARD_RDEV(card));
@@ -7525,6 +7584,12 @@ out_remove:
         return -ENODEV;
 }
 
+static int
+qeth_set_online(struct ccwgroup_device *gdev)
+{
+        return __qeth_set_online(gdev, 0);
+}
+
 static struct ccw_device_id qeth_ids[] = {
         {CCW_DEVICE(0x1731, 0x01), driver_info:QETH_CARD_TYPE_OSAE},
         {CCW_DEVICE(0x1731, 0x05), driver_info:QETH_CARD_TYPE_IQD},