s390/virtio_ccw: use DMA handle from DMA API

Change and use ccw_device_dma_zalloc() so it returns a virtual address like
before, which can be used to access data. However also pass a new dma32_t
pointer type handle, which correlates to the returned virtual address.
This pointer is used to directly pass/set the DMA handle as returned by the
DMA API.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

2 files changed, 19 insertions, 11 deletions

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 094431a62ad5..1d68db1a3d4e 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -1114,26 +1114,33 @@ static int cio_dma_pool_init(void)
 	return 0;
 }
 
-void *cio_gp_dma_zalloc(struct gen_pool *gp_dma, struct device *dma_dev,
-			size_t size)
+void *__cio_gp_dma_zalloc(struct gen_pool *gp_dma, struct device *dma_dev,
+			  size_t size, dma32_t *dma_handle)
 {
 	dma_addr_t dma_addr;
-	unsigned long addr;
 	size_t chunk_size;
+	void *addr;
 
 	if (!gp_dma)
 		return NULL;
-	addr = gen_pool_alloc(gp_dma, size);
+	addr = gen_pool_dma_alloc(gp_dma, size, &dma_addr);
 	while (!addr) {
 		chunk_size = round_up(size, PAGE_SIZE);
-		addr = (unsigned long) dma_alloc_coherent(dma_dev,
-					 chunk_size, &dma_addr, CIO_DMA_GFP);
+		addr = dma_alloc_coherent(dma_dev, chunk_size, &dma_addr, CIO_DMA_GFP);
 		if (!addr)
 			return NULL;
-		gen_pool_add_virt(gp_dma, addr, dma_addr, chunk_size, -1);
-		addr = gen_pool_alloc(gp_dma, size);
+		gen_pool_add_virt(gp_dma, (unsigned long)addr, dma_addr, chunk_size, -1);
+		addr = gen_pool_dma_alloc(gp_dma, size, dma_handle ? &dma_addr : NULL);
 	}
-	return (void *) addr;
+	if (dma_handle)
+		*dma_handle = (__force dma32_t)dma_addr;
+	return addr;
+}
+
+void *cio_gp_dma_zalloc(struct gen_pool *gp_dma, struct device *dma_dev,
+			size_t size)
+{
+	return __cio_gp_dma_zalloc(gp_dma, dma_dev, size, NULL);
 }
 
 void cio_gp_dma_free(struct gen_pool *gp_dma, void *cpu_addr, size_t size)
diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index a5dba3829769..40c97f873075 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -823,13 +823,14 @@ EXPORT_SYMBOL_GPL(ccw_device_get_chid);
  * the subchannels dma pool. Maximal size of allocation supported
  * is PAGE_SIZE.
  */
-void *ccw_device_dma_zalloc(struct ccw_device *cdev, size_t size)
+void *ccw_device_dma_zalloc(struct ccw_device *cdev, size_t size,
+			    dma32_t *dma_handle)
 {
 	void *addr;
 
 	if (!get_device(&cdev->dev))
 		return NULL;
-	addr = cio_gp_dma_zalloc(cdev->private->dma_pool, &cdev->dev, size);
+	addr = __cio_gp_dma_zalloc(cdev->private->dma_pool, &cdev->dev, size, dma_handle);
 	if (IS_ERR_OR_NULL(addr))
 		put_device(&cdev->dev);
 	return addr;