PCI: Consolidate "next-function" functions

There are several next_fn functions (no_next_fn, next_trad_fn,
next_ari_fn); consolidate them in next_fn() to simplify the code.

[bhelgaas: make next_fn() static, rework control flow]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 21 insertions, 27 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 7b9e691b95b1..2a9958c1556e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1349,31 +1349,31 @@ struct pci_dev *__ref pci_scan_single_device(struct pci_bus *bus, int devfn)
 }
 EXPORT_SYMBOL(pci_scan_single_device);
 
-static unsigned next_ari_fn(struct pci_dev *dev, unsigned fn)
+static unsigned next_fn(struct pci_bus *bus, struct pci_dev *dev, unsigned fn)
 {
-        u16 cap;
-        unsigned pos, next_fn;
+        int pos;
+        u16 cap = 0;
+        unsigned next_fn;
 
-        if (!dev)
-                return 0;
+        if (pci_ari_enabled(bus)) {
+                if (!dev)
+                        return 0;
+                pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
+                if (!pos)
+                        return 0;
 
-        pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
-        if (!pos)
-                return 0;
-        pci_read_config_word(dev, pos + 4, &cap);
-        next_fn = cap >> 8;
-        if (next_fn <= fn)
-                return 0;
-        return next_fn;
-}
+                pci_read_config_word(dev, pos + PCI_ARI_CAP, &cap);
+                next_fn = PCI_ARI_CAP_NFN(cap);
+                if (next_fn <= fn)
+                        return 0;       /* protect against malformed list */
 
-static unsigned next_trad_fn(struct pci_dev *dev, unsigned fn)
-{
-        return (fn + 1) % 8;
-}
+                return next_fn;
+        }
+
+        /* dev may be NULL for non-contiguous multifunction devices */
+        if (!dev || dev->multifunction)
+                return (fn + 1) % 8;
 
-static unsigned no_next_fn(struct pci_dev *dev, unsigned fn)
-{
         return 0;
 }
 
@@ -1406,7 +1406,6 @@ int pci_scan_slot(struct pci_bus *bus, int devfn)
 {
         unsigned fn, nr = 0;
         struct pci_dev *dev;
-        unsigned (*next_fn)(struct pci_dev *, unsigned) = no_next_fn;
 
         if (only_one_child(bus) && (devfn > 0))
                 return 0; /* Already scanned the entire slot */
@@ -1417,12 +1416,7 @@ int pci_scan_slot(struct pci_bus *bus, int devfn)
         if (!dev->is_added)
                 nr++;
 
-        if (pci_ari_enabled(bus))
-                next_fn = next_ari_fn;
-        else if (dev->multifunction)
-                next_fn = next_trad_fn;
-
-        for (fn = next_fn(dev, 0); fn > 0; fn = next_fn(dev, fn)) {
+        for (fn = next_fn(bus, dev, 0); fn > 0; fn = next_fn(bus, dev, fn)) {
                 dev = pci_scan_single_device(bus, devfn + fn);
                 if (dev) {
                         if (!dev->is_added)