drivercore: revert addition of of_match to struct device

Commit b826291c, "drivercore/dt: add a match table pointer to struct
device" added an of_match pointer to struct device to cache the
of_match_table entry discovered at driver match time.  This was unsafe
because matching is not an atomic operation with probing a driver.  If
two or more drivers are attempted to be matched to a driver at the
same time, then the cached matching entry pointer could get
overwritten.

This patch reverts the of_match cache pointer and reworks all users to
call of_match_device() directly instead.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/net/fs_enet/fs_enet-main.c b/drivers/net/fs_enet/fs_enet-main.c
index 24cb953900dd..5131e61c358c 100644
--- a/drivers/net/fs_enet/fs_enet-main.c
+++ b/drivers/net/fs_enet/fs_enet-main.c
@@ -998,8 +998,10 @@ static const struct net_device_ops fs_enet_netdev_ops = {
 #endif
 };
 
+static struct of_device_id fs_enet_match[];
 static int __devinit fs_enet_probe(struct platform_device *ofdev)
 {
+        const struct of_device_id *match;
         struct net_device *ndev;
         struct fs_enet_private *fep;
         struct fs_platform_info *fpi;
@@ -1007,14 +1009,15 @@ static int __devinit fs_enet_probe(struct platform_device *ofdev)
         const u8 *mac_addr;
         int privsize, len, ret = -ENODEV;
 
-        if (!ofdev->dev.of_match)
+        match = of_match_device(fs_enet_match, &ofdev->dev);
+        if (!match)
                 return -EINVAL;
 
         fpi = kzalloc(sizeof(*fpi), GFP_KERNEL);
         if (!fpi)
                 return -ENOMEM;
 
-        if (!IS_FEC(ofdev->dev.of_match)) {
+        if (!IS_FEC(match)) {
                 data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
                 if (!data || len != 4)
                         goto out_free_fpi;
@@ -1049,7 +1052,7 @@ static int __devinit fs_enet_probe(struct platform_device *ofdev)
         fep->dev = &ofdev->dev;
         fep->ndev = ndev;
         fep->fpi = fpi;
-        fep->ops = ofdev->dev.of_match->data;
+        fep->ops = match->data;
 
         ret = fep->ops->setup_data(ndev);
         if (ret)