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 8a5593a..7574e31 100644
--- a/drivers/usb/gadget/mv_udc.c
+++ b/drivers/usb/gadget/mv_udc.c
@@ -247,6 +247,71 @@
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 @@
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 @@
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 c1761b0..c71516c 100644
--- a/include/usb/mv_udc.h
+++ b/include/usb/mv_udc.h
@@ -66,9 +66,13 @@
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 {