[PATCH] smc91c92_cs: Reduce stack usage in smc91c92_event()

This patch reduces the stack usage of the function smc91c92_event() in
smc91c92_cs driver from 3540 to 132.  Currently this is the highest stack
user in linux-2.6.12-rc2-mm3.  I used a patched version of gcc 3.4.3 on
i386 with -fno-unit-at-a-time disabled.

The patch has only been compile tested.

Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Acked-by: Randy Dunlap <rddunlap@osdl.org>
Signed-off-by: Yum Rayan <yum.rayan@gmail.com>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 189 insertions, 98 deletions

diff --git a/drivers/net/pcmcia/smc91c92_cs.c b/drivers/net/pcmcia/smc91c92_cs.c
index 85a152173148..8a5e52c40e46 100644
--- a/drivers/net/pcmcia/smc91c92_cs.c
+++ b/drivers/net/pcmcia/smc91c92_cs.c
@@ -127,6 +127,12 @@ struct smc_private {
     int                         rx_ovrn;
 };
 
+struct smc_cfg_mem {
+    tuple_t tuple;
+    cisparse_t parse;
+    u_char buf[255];
+};
+
 /* Special definitions for Megahertz multifunction cards */
 #define MEGAHERTZ_ISR           0x0380
 
@@ -498,14 +504,24 @@ static int mhz_mfc_config(dev_link_t *link)
 {
     struct net_device *dev = link->priv;
     struct smc_private *smc = netdev_priv(dev);
-    tuple_t tuple;
-    cisparse_t parse;
-    u_char buf[255];
-    cistpl_cftable_entry_t *cf = &parse.cftable_entry;
+    struct smc_cfg_mem *cfg_mem;
+    tuple_t *tuple;
+    cisparse_t *parse;
+    cistpl_cftable_entry_t *cf;
+    u_char *buf;
     win_req_t req;
     memreq_t mem;
     int i, k;
 
+    cfg_mem = kmalloc(sizeof(struct smc_cfg_mem), GFP_KERNEL);
+    if (!cfg_mem)
+        return CS_OUT_OF_RESOURCE;
+
+    tuple = &cfg_mem->tuple;
+    parse = &cfg_mem->parse;
+    cf = &parse->cftable_entry;
+    buf = cfg_mem->buf;
+
     link->conf.Attributes |= CONF_ENABLE_SPKR;
     link->conf.Status = CCSR_AUDIO_ENA;
     link->irq.Attributes =
@@ -514,12 +530,12 @@ static int mhz_mfc_config(dev_link_t *link)
     link->io.Attributes2 = IO_DATA_PATH_WIDTH_8;
     link->io.NumPorts2 = 8;
 
-    tuple.Attributes = tuple.TupleOffset = 0;
-    tuple.TupleData = (cisdata_t *)buf;
-    tuple.TupleDataMax = sizeof(buf);
-    tuple.DesiredTuple = CISTPL_CFTABLE_ENTRY;
+    tuple->Attributes = tuple->TupleOffset = 0;
+    tuple->TupleData = (cisdata_t *)buf;
+    tuple->TupleDataMax = 255;
+    tuple->DesiredTuple = CISTPL_CFTABLE_ENTRY;
 
-    i = first_tuple(link->handle, &tuple, &parse);
+    i = first_tuple(link->handle, tuple, parse);
     /* The Megahertz combo cards have modem-like CIS entries, so
        we have to explicitly try a bunch of port combinations. */
     while (i == CS_SUCCESS) {
@@ -532,10 +548,10 @@ static int mhz_mfc_config(dev_link_t *link)
             if (i == CS_SUCCESS) break;
         }
         if (i == CS_SUCCESS) break;
-        i = next_tuple(link->handle, &tuple, &parse);
+        i = next_tuple(link->handle, tuple, parse);
     }
     if (i != CS_SUCCESS)
-        return i;
+        goto free_cfg_mem;
     dev->base_addr = link->io.BasePort1;
 
     /* Allocate a memory window, for accessing the ISR */
@@ -544,7 +560,7 @@ static int mhz_mfc_config(dev_link_t *link)
     req.AccessSpeed = 0;
     i = pcmcia_request_window(&link->handle, &req, &link->win);
     if (i != CS_SUCCESS)
-        return i;
+        goto free_cfg_mem;
     smc->base = ioremap(req.Base, req.Size);
     mem.CardOffset = mem.Page = 0;
     if (smc->manfid == MANFID_MOTOROLA)
@@ -556,6 +572,8 @@ static int mhz_mfc_config(dev_link_t *link)
         && (smc->cardid == PRODID_MEGAHERTZ_EM3288))
         mhz_3288_power(link);
 
+free_cfg_mem:
+    kfree(cfg_mem);
     return i;
 }
 
@@ -563,39 +581,61 @@ static int mhz_setup(dev_link_t *link)
 {
     client_handle_t handle = link->handle;
     struct net_device *dev = link->priv;
-    tuple_t tuple;
-    cisparse_t parse;
-    u_char buf[255], *station_addr;
+    struct smc_cfg_mem *cfg_mem;
+    tuple_t *tuple;
+    cisparse_t *parse;
+    u_char *buf, *station_addr;
+    int rc;
+
+    cfg_mem = kmalloc(sizeof(struct smc_cfg_mem), GFP_KERNEL);
+    if (!cfg_mem)
+        return -1;
+
+    tuple = &cfg_mem->tuple;
+    parse = &cfg_mem->parse;
+    buf = cfg_mem->buf;
 
-    tuple.Attributes = tuple.TupleOffset = 0;
-    tuple.TupleData = buf;
-    tuple.TupleDataMax = sizeof(buf);
+    tuple->Attributes = tuple->TupleOffset = 0;
+    tuple->TupleData = (cisdata_t *)buf;
+    tuple->TupleDataMax = 255;
 
     /* Read the station address from the CIS.  It is stored as the last
        (fourth) string in the Version 1 Version/ID tuple. */
-    tuple.DesiredTuple = CISTPL_VERS_1;
-    if (first_tuple(handle, &tuple, &parse) != CS_SUCCESS)
-        return -1;
+    tuple->DesiredTuple = CISTPL_VERS_1;
+    if (first_tuple(handle, tuple, parse) != CS_SUCCESS) {
+        rc = -1;
+        goto free_cfg_mem;
+    }
     /* Ugh -- the EM1144 card has two VERS_1 tuples!?! */
-    if (next_tuple(handle, &tuple, &parse) != CS_SUCCESS)
-        first_tuple(handle, &tuple, &parse);
-    if (parse.version_1.ns > 3) {
-        station_addr = parse.version_1.str + parse.version_1.ofs[3];
-        if (cvt_ascii_address(dev, station_addr) == 0)
-            return 0;
+    if (next_tuple(handle, tuple, parse) != CS_SUCCESS)
+        first_tuple(handle, tuple, parse);
+    if (parse->version_1.ns > 3) {
+        station_addr = parse->version_1.str + parse->version_1.ofs[3];
+        if (cvt_ascii_address(dev, station_addr) == 0) {
+                rc = 0;
+                goto free_cfg_mem;
+        }
     }
 
     /* Another possibility: for the EM3288, in a special tuple */
-    tuple.DesiredTuple = 0x81;
-    if (pcmcia_get_first_tuple(handle, &tuple) != CS_SUCCESS)
-        return -1;
-    if (pcmcia_get_tuple_data(handle, &tuple) != CS_SUCCESS)
-        return -1;
+    tuple->DesiredTuple = 0x81;
+    if (pcmcia_get_first_tuple(handle, tuple) != CS_SUCCESS) {
+        rc = -1;
+        goto free_cfg_mem;
+    }
+    if (pcmcia_get_tuple_data(handle, tuple) != CS_SUCCESS) {
+        rc = -1;
+        goto free_cfg_mem;
+    }
     buf[12] = '\0';
-    if (cvt_ascii_address(dev, buf) == 0)
-        return 0;
-
-    return -1;
+    if (cvt_ascii_address(dev, buf) == 0) {
+        rc = 0;
+        goto free_cfg_mem;
+   }
+    rc = -1;
+free_cfg_mem:
+   kfree(cfg_mem);
+   return rc;
 }
 
 /*======================================================================
@@ -665,19 +705,29 @@ static int mot_setup(dev_link_t *link)
 static int smc_config(dev_link_t *link)
 {
     struct net_device *dev = link->priv;
-    tuple_t tuple;
-    cisparse_t parse;
-    u_char buf[255];
-    cistpl_cftable_entry_t *cf = &parse.cftable_entry;
+    struct smc_cfg_mem *cfg_mem;
+    tuple_t *tuple;
+    cisparse_t *parse;
+    cistpl_cftable_entry_t *cf;
+    u_char *buf;
     int i;
 
-    tuple.Attributes = tuple.TupleOffset = 0;
-    tuple.TupleData = (cisdata_t *)buf;
-    tuple.TupleDataMax = sizeof(buf);
-    tuple.DesiredTuple = CISTPL_CFTABLE_ENTRY;
+    cfg_mem = kmalloc(sizeof(struct smc_cfg_mem), GFP_KERNEL);
+    if (!cfg_mem)
+        return CS_OUT_OF_RESOURCE;
+
+    tuple = &cfg_mem->tuple;
+    parse = &cfg_mem->parse;
+    cf = &parse->cftable_entry;
+    buf = cfg_mem->buf;
+
+    tuple->Attributes = tuple->TupleOffset = 0;
+    tuple->TupleData = (cisdata_t *)buf;
+    tuple->TupleDataMax = 255;
+    tuple->DesiredTuple = CISTPL_CFTABLE_ENTRY;
 
     link->io.NumPorts1 = 16;
-    i = first_tuple(link->handle, &tuple, &parse);
+    i = first_tuple(link->handle, tuple, parse);
     while (i != CS_NO_MORE_ITEMS) {
         if (i == CS_SUCCESS) {
             link->conf.ConfigIndex = cf->index;
@@ -686,10 +736,12 @@ static int smc_config(dev_link_t *link)
             i = pcmcia_request_io(link->handle, &link->io);
             if (i == CS_SUCCESS) break;
         }
-        i = next_tuple(link->handle, &tuple, &parse);
+        i = next_tuple(link->handle, tuple, parse);
     }
     if (i == CS_SUCCESS)
         dev->base_addr = link->io.BasePort1;
+
+    kfree(cfg_mem);
     return i;
 }
 
@@ -697,41 +749,58 @@ static int smc_setup(dev_link_t *link)
 {
     client_handle_t handle = link->handle;
     struct net_device *dev = link->priv;
-    tuple_t tuple;
-    cisparse_t parse;
+    struct smc_cfg_mem *cfg_mem;
+    tuple_t *tuple;
+    cisparse_t *parse;
     cistpl_lan_node_id_t *node_id;
-    u_char buf[255], *station_addr;
-    int i;
+    u_char *buf, *station_addr;
+    int i, rc;
 
-    tuple.Attributes = tuple.TupleOffset = 0;
-    tuple.TupleData = buf;
-    tuple.TupleDataMax = sizeof(buf);
+    cfg_mem = kmalloc(sizeof(struct smc_cfg_mem), GFP_KERNEL);
+    if (!cfg_mem)
+        return CS_OUT_OF_RESOURCE;
+
+    tuple = &cfg_mem->tuple;
+    parse = &cfg_mem->parse;
+    buf = cfg_mem->buf;
+
+    tuple->Attributes = tuple->TupleOffset = 0;
+    tuple->TupleData = (cisdata_t *)buf;
+    tuple->TupleDataMax = 255;
 
     /* Check for a LAN function extension tuple */
-    tuple.DesiredTuple = CISTPL_FUNCE;
-    i = first_tuple(handle, &tuple, &parse);
+    tuple->DesiredTuple = CISTPL_FUNCE;
+    i = first_tuple(handle, tuple, parse);
     while (i == CS_SUCCESS) {
-        if (parse.funce.type == CISTPL_FUNCE_LAN_NODE_ID)
+        if (parse->funce.type == CISTPL_FUNCE_LAN_NODE_ID)
             break;
-        i = next_tuple(handle, &tuple, &parse);
+        i = next_tuple(handle, tuple, parse);
     }
     if (i == CS_SUCCESS) {
-        node_id = (cistpl_lan_node_id_t *)parse.funce.data;
+        node_id = (cistpl_lan_node_id_t *)parse->funce.data;
         if (node_id->nb == 6) {
             for (i = 0; i < 6; i++)
                 dev->dev_addr[i] = node_id->id[i];
-            return 0;
+            rc = 0;
+            goto free_cfg_mem;
         }
     }
     /* Try the third string in the Version 1 Version/ID tuple. */
-    tuple.DesiredTuple = CISTPL_VERS_1;
-    if (first_tuple(handle, &tuple, &parse) != CS_SUCCESS)
-        return -1;
-    station_addr = parse.version_1.str + parse.version_1.ofs[2];
-    if (cvt_ascii_address(dev, station_addr) == 0)
-        return 0;
+    tuple->DesiredTuple = CISTPL_VERS_1;
+    if (first_tuple(handle, tuple, parse) != CS_SUCCESS) {
+        rc = -1;
+        goto free_cfg_mem;
+    }
+    station_addr = parse->version_1.str + parse->version_1.ofs[2];
+    if (cvt_ascii_address(dev, station_addr) == 0) {
+        rc = 0;
+        goto free_cfg_mem;
+    }
 
-    return -1;
+    rc = -1;
+free_cfg_mem:
+    kfree(cfg_mem);
+    return rc;
 }
 
 /*====================================================================*/
@@ -773,26 +842,36 @@ static int osi_setup(dev_link_t *link, u_short manfid, u_short cardid)
 {
     client_handle_t handle = link->handle;
     struct net_device *dev = link->priv;
-    tuple_t tuple;
-    u_char buf[255];
-    int i;
+    struct smc_cfg_mem *cfg_mem;
+    tuple_t *tuple;
+    u_char *buf;
+    int i, rc;
 
-    tuple.Attributes = TUPLE_RETURN_COMMON;
-    tuple.TupleData = buf;
-    tuple.TupleDataMax = sizeof(buf);
-    tuple.TupleOffset = 0;
+    cfg_mem = kmalloc(sizeof(struct smc_cfg_mem), GFP_KERNEL);
+    if (!cfg_mem)
+        return -1;
+
+    tuple = &cfg_mem->tuple;
+    buf = cfg_mem->buf;
+
+    tuple->Attributes = TUPLE_RETURN_COMMON;
+    tuple->TupleData = (cisdata_t *)buf;
+    tuple->TupleDataMax = 255;
+    tuple->TupleOffset = 0;
 
     /* Read the station address from tuple 0x90, subtuple 0x04 */
-    tuple.DesiredTuple = 0x90;
-    i = pcmcia_get_first_tuple(handle, &tuple);
+    tuple->DesiredTuple = 0x90;
+    i = pcmcia_get_first_tuple(handle, tuple);
     while (i == CS_SUCCESS) {
-        i = pcmcia_get_tuple_data(handle, &tuple);
+        i = pcmcia_get_tuple_data(handle, tuple);
         if ((i != CS_SUCCESS) || (buf[0] == 0x04))
             break;
-        i = pcmcia_get_next_tuple(handle, &tuple);
+        i = pcmcia_get_next_tuple(handle, tuple);
+    }
+    if (i != CS_SUCCESS) {
+        rc = -1;
+        goto free_cfg_mem;
     }
-    if (i != CS_SUCCESS)
-        return -1;
     for (i = 0; i < 6; i++)
         dev->dev_addr[i] = buf[i+2];
 
@@ -814,8 +893,10 @@ static int osi_setup(dev_link_t *link, u_short manfid, u_short cardid)
               inw(link->io.BasePort1 + OSITECH_AUI_PWR),
               inw(link->io.BasePort1 + OSITECH_RESET_ISR));
     }
-
-    return 0;
+    rc = 0;
+free_cfg_mem:
+   kfree(cfg_mem);
+   return rc;
 }
 
 /*======================================================================
@@ -887,9 +968,10 @@ static void smc91c92_config(dev_link_t *link)
     client_handle_t handle = link->handle;
     struct net_device *dev = link->priv;
     struct smc_private *smc = netdev_priv(dev);
-    tuple_t tuple;
-    cisparse_t parse;
-    u_short buf[32];
+    struct smc_cfg_mem *cfg_mem;
+    tuple_t *tuple;
+    cisparse_t *parse;
+    u_char *buf;
     char *name;
     int i, j, rev;
     kio_addr_t ioaddr;
@@ -897,21 +979,29 @@ static void smc91c92_config(dev_link_t *link)
 
     DEBUG(0, "smc91c92_config(0x%p)\n", link);
 
-    tuple.Attributes = tuple.TupleOffset = 0;
-    tuple.TupleData = (cisdata_t *)buf;
-    tuple.TupleDataMax = sizeof(buf);
+    cfg_mem = kmalloc(sizeof(struct smc_cfg_mem), GFP_KERNEL);
+    if (!cfg_mem)
+        goto config_failed;
 
-    tuple.DesiredTuple = CISTPL_CONFIG;
-    i = first_tuple(handle, &tuple, &parse);
-    CS_EXIT_TEST(i, ParseTuple, config_failed);
-    link->conf.ConfigBase = parse.config.base;
-    link->conf.Present = parse.config.rmask[0];
+    tuple = &cfg_mem->tuple;
+    parse = &cfg_mem->parse;
+    buf = cfg_mem->buf;
 
-    tuple.DesiredTuple = CISTPL_MANFID;
-    tuple.Attributes = TUPLE_RETURN_COMMON;
-    if (first_tuple(handle, &tuple, &parse) == CS_SUCCESS) {
-        smc->manfid = parse.manfid.manf;
-        smc->cardid = parse.manfid.card;
+    tuple->Attributes = tuple->TupleOffset = 0;
+    tuple->TupleData = (cisdata_t *)buf;
+    tuple->TupleDataMax = 64;
+
+    tuple->DesiredTuple = CISTPL_CONFIG;
+    i = first_tuple(handle, tuple, parse);
+    CS_EXIT_TEST(i, ParseTuple, config_failed);
+    link->conf.ConfigBase = parse->config.base;
+    link->conf.Present = parse->config.rmask[0];
+
+    tuple->DesiredTuple = CISTPL_MANFID;
+    tuple->Attributes = TUPLE_RETURN_COMMON;
+    if (first_tuple(handle, tuple, parse) == CS_SUCCESS) {
+        smc->manfid = parse->manfid.manf;
+        smc->cardid = parse->manfid.card;
     }
 
     /* Configure card */
@@ -1046,7 +1136,7 @@ static void smc91c92_config(dev_link_t *link)
             printk(KERN_NOTICE "  No MII transceivers found!\n");
         }
     }
-
+    kfree(cfg_mem);
     return;
 
 config_undo:
@@ -1054,6 +1144,7 @@ config_undo:
 config_failed:                  /* CS_EXIT_TEST() calls jump to here... */
     smc91c92_release(link);
     link->state &= ~DEV_CONFIG_PENDING;
+    kfree(cfg_mem);
 
 } /* smc91c92_config */