dmaengine: idxd: cleanup completion record allocation

According to core-api/dma-api-howto.rst, the address from
dma_alloc_coherent is gauranteed to align to the smallest PAGE_SIZE order.
That supercedes the 64B/32B alignment requirement of the completion record.
Remove alignment adjustment code.

Tested-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163517396063.3484297.7494385225280705372.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/idxd/device.c

@@ -135,8 +135,6 @@ int idxd_wq_alloc_resources(struct idxd_wq *wq)
 	struct idxd_device *idxd = wq->idxd;
 	struct device *dev = &idxd->pdev->dev;
 	int rc, num_descs, i;
-	int align;
-	u64 tmp;
 
 	if (wq->type != IDXD_WQT_KERNEL)
 		return 0;
@@ -148,21 +146,13 @@ int idxd_wq_alloc_resources(struct idxd_wq *wq)
 	if (rc < 0)
 		return rc;
 
-	align = idxd->data->align;
-	wq->compls_size = num_descs * idxd->data->compl_size + align;
-	wq->compls_raw = dma_alloc_coherent(dev, wq->compls_size,
-					    &wq->compls_addr_raw, GFP_KERNEL);
-	if (!wq->compls_raw) {
+	wq->compls_size = num_descs * idxd->data->compl_size;
+	wq->compls = dma_alloc_coherent(dev, wq->compls_size, &wq->compls_addr, GFP_KERNEL);
+	if (!wq->compls) {
 		rc = -ENOMEM;
 		goto fail_alloc_compls;
 	}
 
-	/* Adjust alignment */
-	wq->compls_addr = (wq->compls_addr_raw + (align - 1)) & ~(align - 1);
-	tmp = (u64)wq->compls_raw;
-	tmp = (tmp + (align - 1)) & ~(align - 1);
-	wq->compls = (struct dsa_completion_record *)tmp;
-
 	rc = alloc_descs(wq, num_descs);
 	if (rc < 0)
 		goto fail_alloc_descs;
@@ -191,8 +181,7 @@ int idxd_wq_alloc_resources(struct idxd_wq *wq)
  fail_sbitmap_init:
 	free_descs(wq);
  fail_alloc_descs:
-	dma_free_coherent(dev, wq->compls_size, wq->compls_raw,
-			  wq->compls_addr_raw);
+	dma_free_coherent(dev, wq->compls_size, wq->compls, wq->compls_addr);
  fail_alloc_compls:
 	free_hw_descs(wq);
 	return rc;
@@ -207,8 +196,7 @@ void idxd_wq_free_resources(struct idxd_wq *wq)
 
 	free_hw_descs(wq);
 	free_descs(wq);
-	dma_free_coherent(dev, wq->compls_size, wq->compls_raw,
-			  wq->compls_addr_raw);
+	dma_free_coherent(dev, wq->compls_size, wq->compls, wq->compls_addr);
 	sbitmap_queue_free(&wq->sbq);
 }
 

drivers/dma/idxd/idxd.h

@@ -187,9 +187,7 @@ struct idxd_wq {
 		struct dsa_completion_record *compls;
 		struct iax_completion_record *iax_compls;
 	};
-	void *compls_raw;
 	dma_addr_t compls_addr;
-	dma_addr_t compls_addr_raw;
 	int compls_size;
 	struct idxd_desc **descs;
 	struct sbitmap_queue sbq;