usb: mv_udc: Add bounce buffer

The requests sent to the controller are not properly cache aligned
most of the time, thus implement a simple bounce buffer to avoid
problem with cache.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Lei Wen <leiwen@marvell.com>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Stefano Babic <sbabic@denx.de>

diff --git a/drivers/usb/gadget/mv_udc.c b/drivers/usb/gadget/mv_udc.c
index 8a5593ae0a0c38828504a70a6a5973d8adc4e3d4..7574e31a8f3e8d18fbf7cc0ce7c838f824f656a7 100644 (file)
--- a/drivers/usb/gadget/mv_udc.c
+++ b/drivers/usb/gadget/mv_udc.c
@@ -247,6 +247,71 @@ static int mv_ep_disable(struct usb_ep *ep)
        return 0;
 }
 
+static int mv_bounce(struct mv_ep *ep)
+{
+       uint32_t addr = (uint32_t)ep->req.buf;
+       uint32_t ba;
+
+       /* Input buffer address is not aligned. */
+       if (addr & (ARCH_DMA_MINALIGN - 1))
+               goto align;
+
+       /* Input buffer length is not aligned. */
+       if (ep->req.length & (ARCH_DMA_MINALIGN - 1))
+               goto align;
+
+       /* The buffer is well aligned, only flush cache. */
+       ep->b_len = ep->req.length;
+       ep->b_buf = ep->req.buf;
+       goto flush;
+
+align:
+       /* Use internal buffer for small payloads. */
+       if (ep->req.length <= 64) {
+               ep->b_len = 64;
+               ep->b_buf = ep->b_fast;
+       } else {
+               ep->b_len = roundup(ep->req.length, ARCH_DMA_MINALIGN);
+               ep->b_buf = memalign(ARCH_DMA_MINALIGN, ep->b_len);
+               if (!ep->b_buf)
+                       return -ENOMEM;
+       }
+
+       memcpy(ep->b_buf, ep->req.buf, ep->req.length);
+
+flush:
+       ba = (uint32_t)ep->b_buf;
+       flush_dcache_range(ba, ba + ep->b_len);
+
+       return 0;
+}
+
+static void mv_debounce(struct mv_ep *ep)
+{
+       uint32_t addr = (uint32_t)ep->req.buf;
+       uint32_t ba = (uint32_t)ep->b_buf;
+
+       invalidate_dcache_range(ba, ba + ep->b_len);
+
+       /* Input buffer address is not aligned. */
+       if (addr & (ARCH_DMA_MINALIGN - 1))
+               goto copy;
+
+       /* Input buffer length is not aligned. */
+       if (ep->req.length & (ARCH_DMA_MINALIGN - 1))
+               goto copy;
+
+       /* The buffer is well aligned, only invalidate cache. */
+       return;
+
+copy:
+       memcpy(ep->req.buf, ep->b_buf, ep->req.length);
+
+       /* Large payloads use allocated buffer, free it. */
+       if (ep->req.length > 64)
+               free(ep->b_buf);
+}
+
 static int mv_ep_queue(struct usb_ep *ep,
                struct usb_request *req, gfp_t gfp_flags)
 {
@@ -254,25 +319,27 @@ static int mv_ep_queue(struct usb_ep *ep,
        struct mv_udc *udc = (struct mv_udc *)controller.ctrl->hcor;
        struct ept_queue_item *item;
        struct ept_queue_head *head;
-       unsigned phys;
-       int bit, num, len, in;
+       int bit, num, len, in, ret;
        num = mv_ep->desc->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
        in = (mv_ep->desc->bEndpointAddress & USB_DIR_IN) != 0;
        item = mv_get_qtd(num, in);
        head = mv_get_qh(num, in);
-       phys = (unsigned)req->buf;
        len = req->length;
 
+       ret = mv_bounce(mv_ep);
+       if (ret)
+               return ret;
+
        item->next = TERMINATE;
        item->info = INFO_BYTES(len) | INFO_IOC | INFO_ACTIVE;
-       item->page0 = phys;
-       item->page1 = (phys & 0xfffff000) + 0x1000;
+       item->page0 = (uint32_t)mv_ep->b_buf;
+       item->page1 = ((uint32_t)mv_ep->b_buf & 0xfffff000) + 0x1000;
 
        head->next = (unsigned) item;
        head->info = 0;
 
-       DBG("ept%d %s queue len %x, buffer %x\n",
-                       num, in ? "in" : "out", len, phys);
+       DBG("ept%d %s queue len %x, buffer %p\n",
+           num, in ? "in" : "out", len, mv_ep->b_buf);
 
        if (in)
                bit = EPT_TX(num);
@@ -303,6 +370,9 @@ static void handle_ep_complete(struct mv_ep *ep)
                        num, in ? "in" : "out", item->info, item->page0);
 
        len = (item->info >> 16) & 0x7fff;
+
+       mv_debounce(ep);
+
        ep->req.length -= len;
        DBG("ept%d %s complete %x\n",
                        num, in ? "in" : "out", len);

diff --git a/include/usb/mv_udc.h b/include/usb/mv_udc.h
index c1761b07246d823892a6c41ba87c3c677e536c7f..c71516cf6daa01f56c6bbea77e7bbf221fd603a6 100644 (file)
--- a/include/usb/mv_udc.h
+++ b/include/usb/mv_udc.h
@@ -66,9 +66,13 @@ struct mv_udc {
 
 struct mv_ep {
        struct usb_ep ep;
-       struct usb_request req;
        struct list_head queue;
        const struct usb_endpoint_descriptor *desc;
+
+       struct usb_request req;
+       uint8_t *b_buf;
+       uint32_t b_len;
+       uint8_t b_fast[64] __aligned(ARCH_DMA_MINALIGN);
 };
 
 struct mv_drv {