[PATCH v1 06/10] powerpc/pseries/iommu: Add ddw_list_add() helper

[Leonardo Bras]

There are two functions adding DDW to the direct_window_list in a
similar way, so create a ddw_list_add() to avoid duplicity and
simplify those functions.

Also, on enable_ddw(), add list_del() on out_free_window to allow
removing the window from list if any error occurs.

Signed-off-by: Leonardo Bras <leobra...@gmail.com>
---
 arch/powerpc/platforms/pseries/iommu.c | 42 ++++++++++++++++----------
 1 file changed, 26 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c 
b/arch/powerpc/platforms/pseries/iommu.c
index 39617ce0ec83..fcdefcc0f365 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -872,6 +872,24 @@ static u64 find_existing_ddw(struct device_node *pdn)
        return dma_addr;
 }
 
+static struct direct_window *ddw_list_add(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;
+       spin_lock(&direct_window_list_lock);
+       list_add(&window->list, &direct_window_list);
+       spin_unlock(&direct_window_list_lock);
+
+       return window;
+}
+
 static int find_existing_ddw_windows(void)
 {
        int len;
@@ -887,18 +905,11 @@ static int find_existing_ddw_windows(void)
                if (!direct64)
                        continue;
 
-               window = kzalloc(sizeof(*window), GFP_KERNEL);
-               if (!window || len < sizeof(struct dynamic_dma_window_prop)) {
+               window = ddw_list_add(pdn, direct64);
+               if (!window || len < sizeof(*direct64)) {
                        kfree(window);
                        remove_ddw(pdn, true);
-                       continue;
                }
-
-               window->device = pdn;
-               window->prop = direct64;
-               spin_lock(&direct_window_list_lock);
-               list_add(&window->list, &direct_window_list);
-               spin_unlock(&direct_window_list_lock);
        }
 
        return 0;
@@ -1261,7 +1272,8 @@ 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);
+       /* Add new window to existing DDW list */
+       window = ddw_list_add(pdn, ddwprop);
        if (!window)
                goto out_clear_window;
 
@@ -1280,16 +1292,14 @@ 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);
-
        dma_addr = be64_to_cpu(ddwprop->dma_base);
        goto out_unlock;
 
 out_free_window:
+       spin_lock(&direct_window_list_lock);
+       list_del(&window->list);
+       spin_unlock(&direct_window_list_lock);
+
        kfree(window);
 
 out_clear_window:
-- 
2.25.4