PCI: work_on_cpu: use in drivers/pci/pci-driver.c

This uses work_on_cpu(), rather than altering the cpumask of the
thread which we happen to be.

Note the cleanups:

1) I've removed the CONFIG_NUMA test, since dev_to_node() returns -1
   for !CONFIG_NUMA anyway and the compiler will eliminate it.

2) No need to reset mempolicy to default (a bad idea anyway) since
   work_on_cpu is run from a workqueue.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 888191a..c3f76be 100644 (file)
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -16,6 +16,7 @@
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/cpu.h>
 #include "pci.h"
 
 /*
@@ -185,32 +186,43 @@ static const struct pci_device_id *pci_match_device(struct pci_driver *drv,
        return pci_match_id(drv->id_table, dev);
 }
 
+struct drv_dev_and_id {
+       struct pci_driver *drv;
+       struct pci_dev *dev;
+       const struct pci_device_id *id;
+};
+
+static long local_pci_probe(void *_ddi)
+{
+       struct drv_dev_and_id *ddi = _ddi;
+
+       return ddi->drv->probe(ddi->dev, ddi->id);
+}
+
 static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
                          const struct pci_device_id *id)
 {
-       int error;
-#ifdef CONFIG_NUMA
-       /* Execute driver initialization on node where the
-          device's bus is attached to.  This way the driver likely
-          allocates its local memory on the right node without
-          any need to change it. */
-       struct mempolicy *oldpol;
-       cpumask_t oldmask = current->cpus_allowed;
-       int node = dev_to_node(&dev->dev);
+       int error, node;
+       struct drv_dev_and_id ddi = { drv, dev, id };
 
+       /* Execute driver initialization on node where the device's
+          bus is attached to.  This way the driver likely allocates
+          its local memory on the right node without any need to
+          change it. */
+       node = dev_to_node(&dev->dev);
        if (node >= 0) {
+               int cpu;
                node_to_cpumask_ptr(nodecpumask, node);
-               set_cpus_allowed_ptr(current, nodecpumask);
-       }
-       /* And set default memory allocation policy */
-       oldpol = current->mempolicy;
-       current->mempolicy = NULL;      /* fall back to system default policy */
-#endif
-       error = drv->probe(dev, id);
-#ifdef CONFIG_NUMA
-       set_cpus_allowed_ptr(current, &oldmask);
-       current->mempolicy = oldpol;
-#endif
+
+               get_online_cpus();
+               cpu = cpumask_any_and(nodecpumask, cpu_online_mask);
+               if (cpu < nr_cpu_ids)
+                       error = work_on_cpu(cpu, local_pci_probe, &ddi);
+               else
+                       error = local_pci_probe(&ddi);
+               put_online_cpus();
+       } else
+               error = local_pci_probe(&ddi);
        return error;
 }