usb: dwc2: host: use kmem cache to allocate descriptors

Kmem caches help to get correct boundary for descriptor buffers
which need to be 512 bytes aligned for dwc2 controller.
Two kmem caches are needed for generic descriptors and for
hs isochronous descriptors which doesn't have same size.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 49 insertions, 1 deletions

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 7fd4f41e12a7..b2afe913d559 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -3146,6 +3146,47 @@ int dwc2_hcd_init(struct dwc2_hsotg *hsotg, int irq)
 	if (!hsotg->status_buf)
 		goto error3;
 
+	/*
+	 * Create kmem caches to handle descriptor buffers in descriptor
+	 * DMA mode.
+	 * Alignment must be set to 512 bytes.
+	 */
+	if (hsotg->core_params->dma_desc_enable ||
+	    hsotg->core_params->dma_desc_fs_enable) {
+		hsotg->desc_gen_cache = kmem_cache_create("dwc2-gen-desc",
+				sizeof(struct dwc2_hcd_dma_desc) *
+				MAX_DMA_DESC_NUM_GENERIC, 512, SLAB_CACHE_DMA,
+				NULL);
+		if (!hsotg->desc_gen_cache) {
+			dev_err(hsotg->dev,
+				"unable to create dwc2 generic desc cache\n");
+
+			/*
+			 * Disable descriptor dma mode since it will not be
+			 * usable.
+			 */
+			hsotg->core_params->dma_desc_enable = 0;
+			hsotg->core_params->dma_desc_fs_enable = 0;
+		}
+
+		hsotg->desc_hsisoc_cache = kmem_cache_create("dwc2-hsisoc-desc",
+				sizeof(struct dwc2_hcd_dma_desc) *
+				MAX_DMA_DESC_NUM_HS_ISOC, 512, 0, NULL);
+		if (!hsotg->desc_hsisoc_cache) {
+			dev_err(hsotg->dev,
+				"unable to create dwc2 hs isoc desc cache\n");
+
+			kmem_cache_destroy(hsotg->desc_gen_cache);
+
+			/*
+			 * Disable descriptor dma mode since it will not be
+			 * usable.
+			 */
+			hsotg->core_params->dma_desc_enable = 0;
+			hsotg->core_params->dma_desc_fs_enable = 0;
+		}
+	}
+
 	hsotg->otg_port = 1;
 	hsotg->frame_list = NULL;
 	hsotg->frame_list_dma = 0;
@@ -3169,7 +3210,7 @@ int dwc2_hcd_init(struct dwc2_hsotg *hsotg, int irq)
 	 */
 	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (retval < 0)
-		goto error3;
+		goto error4;
 
 	device_wakeup_enable(hcd->self.controller);
 
@@ -3179,6 +3220,9 @@ int dwc2_hcd_init(struct dwc2_hsotg *hsotg, int irq)
 
 	return 0;
 
+error4:
+	kmem_cache_destroy(hsotg->desc_gen_cache);
+	kmem_cache_destroy(hsotg->desc_hsisoc_cache);
 error3:
 	dwc2_hcd_release(hsotg);
 error2:
@@ -3219,6 +3263,10 @@ void dwc2_hcd_remove(struct dwc2_hsotg *hsotg)
 
 	usb_remove_hcd(hcd);
 	hsotg->priv = NULL;
+
+	kmem_cache_destroy(hsotg->desc_gen_cache);
+	kmem_cache_destroy(hsotg->desc_hsisoc_cache);
+
 	dwc2_hcd_release(hsotg);
 	usb_put_hcd(hcd);