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, 3 deletions

diff --git a/arch/sparc/kernel/pci_sabre.c b/arch/sparc/kernel/pci_sabre.c
index 948068a083fc..d1840dbdaa2f 100644
--- a/arch/sparc/kernel/pci_sabre.c
+++ b/arch/sparc/kernel/pci_sabre.c
@@ -452,8 +452,10 @@ static void __devinit sabre_pbm_init(struct pci_pbm_info *pbm,
         sabre_scan_bus(pbm, &op->dev);
 }
 
+static const struct of_device_id sabre_match[];
 static int __devinit sabre_probe(struct platform_device *op)
 {
+        const struct of_device_id *match;
         const struct linux_prom64_registers *pr_regs;
         struct device_node *dp = op->dev.of_node;
         struct pci_pbm_info *pbm;
@@ -463,7 +465,8 @@ static int __devinit sabre_probe(struct platform_device *op)
         const u32 *vdma;
         u64 clear_irq;
 
-        hummingbird_p = op->dev.of_match && (op->dev.of_match->data != NULL);
+        match = of_match_device(sabre_match, &op->dev);
+        hummingbird_p = match && (match->data != NULL);
         if (!hummingbird_p) {
                 struct device_node *cpu_dp;
 
diff --git a/arch/sparc/kernel/pci_schizo.c b/arch/sparc/kernel/pci_schizo.c
index fecfcb2063c8..283fbc329a43 100644
--- a/arch/sparc/kernel/pci_schizo.c
+++ b/arch/sparc/kernel/pci_schizo.c
@@ -1458,11 +1458,15 @@ out_err:
         return err;
 }
 
+static const struct of_device_id schizo_match[];
 static int __devinit schizo_probe(struct platform_device *op)
 {
-        if (!op->dev.of_match)
+        const struct of_device_id *match;
+
+        match = of_match_device(schizo_match, &op->dev);
+        if (!match)
                 return -EINVAL;
-        return __schizo_init(op, (unsigned long) op->dev.of_match->data);
+        return __schizo_init(op, (unsigned long)match->data);
 }
 
 /* The ordering of this table is very important.  Some Tomatillo