powerpc/pseries/iommu: Add ddw_list_new_entry() helper

There are two functions creating direct_window_list entries in a
similar way, so create a ddw_list_new_entry() to avoid duplicity and
simplify those functions.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210817063929.38701-5-leobras.c@gmail.com

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 33d8286..712d166 100644 (file)
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -874,6 +874,21 @@ static u64 find_existing_ddw(struct device_node *pdn, int *window_shift)
        return dma_addr;
 }
 
+static struct direct_window *ddw_list_new_entry(struct device_node *pdn,
+                                               const struct dynamic_dma_window_prop *dma64)
+{
+       struct direct_window *window;
+
+       window = kzalloc(sizeof(*window), GFP_KERNEL);
+       if (!window)
+               return NULL;
+
+       window->device = pdn;
+       window->prop = dma64;
+
+       return window;
+}
+
 static int find_existing_ddw_windows(void)
 {
        int len;
@@ -886,18 +901,15 @@ static int find_existing_ddw_windows(void)
 
        for_each_node_with_property(pdn, DIRECT64_PROPNAME) {
                direct64 = of_get_property(pdn, DIRECT64_PROPNAME, &len);
-               if (!direct64)
-                       continue;
-
-               window = kzalloc(sizeof(*window), GFP_KERNEL);
-               if (!window || len < sizeof(struct dynamic_dma_window_prop)) {
-                       kfree(window);
+               if (!direct64 || len < sizeof(*direct64)) {
                        remove_ddw(pdn, true);
                        continue;
                }
 
-               window->device = pdn;
-               window->prop = direct64;
+               window = ddw_list_new_entry(pdn, direct64);
+               if (!window)
+                       break;
+
                spin_lock(&direct_window_list_lock);
                list_add(&window->list, &direct_window_list);
                spin_unlock(&direct_window_list_lock);
@@ -1307,7 +1319,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
        dev_dbg(&dev->dev, "created tce table LIOBN 0x%x for %pOF\n",
                  create.liobn, dn);
 
-       window = kzalloc(sizeof(*window), GFP_KERNEL);
+       window = ddw_list_new_entry(pdn, ddwprop);
        if (!window)
                goto out_clear_window;
 
@@ -1326,8 +1338,6 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
                goto out_free_window;
        }
 
-       window->device = pdn;
-       window->prop = ddwprop;
        spin_lock(&direct_window_list_lock);
        list_add(&window->list, &direct_window_list);
        spin_unlock(&direct_window_list_lock);