Cc: linuxppc-dev@lists.ozlabs.org, linux-ker...@vger.kernel.org,
enable_ddw() currently returns the address of the DMA window, which is
considered invalid if has the value 0x00.
Also, it only considers valid an address returned from find_existing_ddw
if it's not 0x00.
Changing this behavior makes sense, given the users of enable_ddw() only
need to know if direct mapping is possible. It can also allow a DMA window
starting at 0x00 to be used.
This will be helpful for using a DDW with indirect mapping, as the window
address will be different than 0x00, but it will not map the whole
partition.
Signed-off-by: Leonardo Bras <leobra...@gmail.com>
Reviewed-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
arch/powerpc/platforms/pseries/iommu.c | 30 ++++++++++++--------------
1 file changed, 14 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c
b/arch/powerpc/platforms/pseries/iommu.c
index e4c17d27dcf3..bba8584a8f9d 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -849,24 +849,25 @@ static void remove_ddw(struct device_node *np, bool
remove_prop)
np, ret);
}
-static u64 find_existing_ddw(struct device_node *pdn)
+static bool find_existing_ddw(struct device_node *pdn, u64 *dma_addr)
{
struct direct_window *window;
const struct dynamic_dma_window_prop *direct64;
- u64 dma_addr = 0;
+ bool found = false;
spin_lock(&direct_window_list_lock);
/* check if we already created a window and dupe that config if so */
list_for_each_entry(window, &direct_window_list, list) {
if (window->device == pdn) {
direct64 = window->prop;
- dma_addr = be64_to_cpu(direct64->dma_base);
+ *dma_addr = be64_to_cpu(direct64->dma_base);
+ found = true;
break;
}
}
spin_unlock(&direct_window_list_lock);
- return dma_addr;
+ return found;
}
static struct direct_window *ddw_list_new_entry(struct device_node *pdn,
@@ -1129,15 +1130,15 @@ static void reset_dma_window(struct pci_dev *dev,
struct device_node *par_dn)
* pdn: the parent pe node with the ibm,dma_window property
* Future: also check if we can remap the base window for our base page size
*
- * returns the dma offset for use by the direct mapped DMA code.
+ * returns true if can map all pages (direct mapping), false otherwise..
*/
-static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
+static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
{
int len, ret;
struct ddw_query_response query;
struct ddw_create_response create;
int page_shift;
- u64 dma_addr, max_addr;
+ u64 max_addr;
struct device_node *dn;
u32 ddw_avail[DDW_APPLICABLE_SIZE];
struct direct_window *window;
@@ -1148,8 +1149,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
device_node *pdn)
mutex_lock(&direct_window_init_mutex);
- dma_addr = find_existing_ddw(pdn);
- if (dma_addr != 0)
+ if (find_existing_ddw(pdn, &dev->dev.archdata.dma_offset))
goto out_unlock;
/*
@@ -1296,7 +1296,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
device_node *pdn)
list_add(&window->list, &direct_window_list);
spin_unlock(&direct_window_list_lock);
- dma_addr = be64_to_cpu(ddwprop->dma_base);
+ dev->dev.archdata.dma_offset = be64_to_cpu(ddwprop->dma_base);
goto out_unlock;
out_free_window:
@@ -1309,6 +1309,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
device_node *pdn)
kfree(win64->name);
kfree(win64->value);
kfree(win64);
+ win64 = NULL;
out_failed:
if (default_win_removed)
@@ -1322,7 +1323,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
device_node *pdn)
out_unlock:
mutex_unlock(&direct_window_init_mutex);
- return dma_addr;
+ return win64;
}
static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
@@ -1401,11 +1402,8 @@ static bool iommu_bypass_supported_pSeriesLP(struct
pci_dev *pdev, u64 dma_mask)
break;
}
- if (pdn && PCI_DN(pdn)) {
- pdev->dev.archdata.dma_offset = enable_ddw(pdev, pdn);
- if (pdev->dev.archdata.dma_offset)
- return true;
- }
+ if (pdn && PCI_DN(pdn))
+ return enable_ddw(pdev, pdn);
return false;
}
--
2.25.4
