[dpdk-dev] [PATCH] igb_uio: fix build error with kernel < 3.2

[Ferruh Yigit <ferruh.yigit@intel.com>]

Recently added "dma_zalloc_coherent()" call is causing build error
for Linux kernels < 3.2.

compile error:
.../build/build/lib/librte_eal/linuxapp/igb_uio/igb_uio.c:
  In function ‘igbuio_pci_probe’:
.../build/build/lib/librte_eal/linuxapp/igb_uio/igb_uio.c:434:2:
error: implicit declaration of function ‘dma_zalloc_coherent’
  [-Werror=implicit-function-declaration]
  map_addr = dma_zalloc_coherent(&dev->dev, 1024,
  ^

dma_zalloc_coherent() introduced with Linux kernel 3.2, with commit
Linux: 842fa69f3e0c ("include/linux/dma-mapping.h: add dma_zalloc_coherent()")
Since it does not exist for older kernels, causing a build error.

Swithched to dma_alloc_coherent() API to prevent build error.

Fixes: d287e4d41be0 ("igb_uio: map dummy DMA forcing IOMMU domain attachment")

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
 lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
index 41bf6ea..192bd4a 100644
--- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
+++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
@@ -431,8 +431,10 @@ igbuio_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	 * the iommu identity mapping if kernel boots with iommu=pt.
 	 * Note this is not a problem if no IOMMU at all.
 	 */
-	map_addr = dma_zalloc_coherent(&dev->dev, 1024,
-				       &map_dma_addr, GFP_KERNEL);
+	map_addr = dma_alloc_coherent(&dev->dev, 1024, &map_dma_addr,
+			GFP_KERNEL);
+	if (map_addr)
+		memset(map_addr, 0, 1024);
 
 	if (!map_addr)
 		dev_info(&dev->dev, "dma mapping failed\n");
-- 
2.9.3