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>

2 files changed, 10 insertions, 4 deletions

diff --git a/arch/powerpc/platforms/83xx/suspend.c b/arch/powerpc/platforms/83xx/suspend.c
index 188272934cfb..104faa8aa23c 100644
--- a/arch/powerpc/platforms/83xx/suspend.c
+++ b/arch/powerpc/platforms/83xx/suspend.c
@@ -318,17 +318,20 @@ static const struct platform_suspend_ops mpc83xx_suspend_ops = {
         .end = mpc83xx_suspend_end,
 };
 
+static struct of_device_id pmc_match[];
 static int pmc_probe(struct platform_device *ofdev)
 {
+        const struct of_device_id *match;
         struct device_node *np = ofdev->dev.of_node;
         struct resource res;
         struct pmc_type *type;
         int ret = 0;
 
-        if (!ofdev->dev.of_match)
+        match = of_match_device(pmc_match, &ofdev->dev);
+        if (!match)
                 return -EINVAL;
 
-        type = ofdev->dev.of_match->data;
+        type = match->data;
 
         if (!of_device_is_available(np))
                 return -ENODEV;
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index d5679dc1e20f..01cd2f089512 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -304,8 +304,10 @@ static int __devinit fsl_msi_setup_hwirq(struct fsl_msi *msi,
         return 0;
 }
 
+static const struct of_device_id fsl_of_msi_ids[];
 static int __devinit fsl_of_msi_probe(struct platform_device *dev)
 {
+        const struct of_device_id *match;
         struct fsl_msi *msi;
         struct resource res;
         int err, i, j, irq_index, count;
@@ -316,9 +318,10 @@ static int __devinit fsl_of_msi_probe(struct platform_device *dev)
         u32 offset;
         static const u32 all_avail[] = { 0, NR_MSI_IRQS };
 
-        if (!dev->dev.of_match)
+        match = of_match_device(fsl_of_msi_ids, &dev->dev);
+        if (!match)
                 return -EINVAL;
-        features = dev->dev.of_match->data;
+        features = match->data;
 
         printk(KERN_DEBUG "Setting up Freescale MSI support\n");