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, 5 insertions, 2 deletions

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index cc6c9b2546a3..64c6b8530615 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -2554,9 +2554,11 @@ static struct pci_driver ipmi_pci_driver = {
 };
 #endif /* CONFIG_PCI */
 
+static struct of_device_id ipmi_match[];
 static int __devinit ipmi_probe(struct platform_device *dev)
 {
 #ifdef CONFIG_OF
+        const struct of_device_id *match;
         struct smi_info *info;
         struct resource resource;
         const __be32 *regsize, *regspacing, *regshift;
@@ -2566,7 +2568,8 @@ static int __devinit ipmi_probe(struct platform_device *dev)
 
         dev_info(&dev->dev, "probing via device tree\n");
 
-        if (!dev->dev.of_match)
+        match = of_match_device(ipmi_match, &dev->dev);
+        if (!match)
                 return -EINVAL;
 
         ret = of_address_to_resource(np, 0, &resource);
@@ -2601,7 +2604,7 @@ static int __devinit ipmi_probe(struct platform_device *dev)
                 return -ENOMEM;
         }
 
-        info->si_type           = (enum si_type) dev->dev.of_match->data;
+        info->si_type           = (enum si_type) match->data;
         info->addr_source       = SI_DEVICETREE;
         info->irq_setup         = std_irq_setup;