libpayload: Make USB transfer functions return amount of bytes

The USB bulk and control transfer functions in libpayload currently
always return 0 for success and 1 for all errors. This is sufficient for
current use cases (essentially just mass storage), but other classes
(like certain Ethernet adapters) need to be able to tell if a transfer
reached the intended amount of bytes, or if it fell short.

This patch slightly changes that USB API to return -1 on errors, and the
amount of transferred bytes on successes. All drivers in the current
libpayload mainline are modified to conform to the new error detection
model. Any third party users of this API will need to adapt their
if (...<controller>->bulk/control(...)) checks to
if (...<controller>->bulk/control(...) < 0) as well.

The host controller drivers for OHCI and EHCI correctly implement the
new behavior. UHCI and the XHCI stub just comply with the new API by
returning 0 or -1, but do not actually count the returned bytes.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/48308
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Reviewed-by: Stefan Reinauer <reinauer@google.com>
Tested-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>

Updated the patch to support XHCI as well.

Change-Id: Ic2ea2810c5edb992cbe185bc9711d2f8f557cae6
(cherry picked from commit e39e2d84762a3804653d950a228ed2269c651458)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6390
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

1 files changed, 42 insertions, 29 deletions

diff --git a/payloads/libpayload/drivers/usb/ohci.c b/payloads/libpayload/drivers/usb/ohci.c
index 0683de3c5d..723b0dbadf 100644
--- a/payloads/libpayload/drivers/usb/ohci.c
+++ b/payloads/libpayload/drivers/usb/ohci.c
@@ -44,7 +44,7 @@ static int ohci_control (usbdev_t *dev, direction_t dir, int drlen, void *devreq
 static void* ohci_create_intr_queue (endpoint_t *ep, int reqsize, int reqcount, int reqtiming);
 static void ohci_destroy_intr_queue (endpoint_t *ep, void *queue);
 static u8* ohci_poll_intr_queue (void *queue);
-static void ohci_process_done_queue(ohci_t *ohci, int spew_debug);
+static int ohci_process_done_queue(ohci_t *ohci, int spew_debug);
 
 #ifdef USB_DEBUG
 static void
@@ -321,13 +321,13 @@ wait_for_ed(usbdev_t *dev, ed_t *head, int pages)
 		usb_debug("Error: ohci: endpoint "
 			"descriptor processing timed out.\n");
 	/* Clear the done queue. */
-	ohci_process_done_queue(OHCI_INST(dev->controller), 1);
+	int result = ohci_process_done_queue(OHCI_INST(dev->controller), 1);
 
 	if (head->head_pointer & 1) {
 		usb_debug("HALTED!\n");
-		return 1;
+		return -1;
 	}
-	return 0;
+	return result;
 }
 
 static void
@@ -355,6 +355,7 @@ static int
 ohci_control (usbdev_t *dev, direction_t dir, int drlen, void *devreq, int dalen,
 	      unsigned char *data)
 {
+	int remaining = dalen;
 	td_t *cur;
 
 	// pages are specified as 4K in OHCI, so don't use getpagesize()
@@ -392,21 +393,21 @@ ohci_control (usbdev_t *dev, direction_t dir, int drlen, void *devreq, int dalen
 		cur->current_buffer_pointer = virt_to_phys(data);
 		pages--;
 		int consumed = (4096 - ((unsigned long)data % 4096));
-		if (consumed >= dalen) {
+		if (consumed >= remaining) {
 			// end of data is within same page
-			cur->buffer_end = virt_to_phys(data + dalen - 1);
-			dalen = 0;
+			cur->buffer_end = virt_to_phys(data + remaining - 1);
+			remaining = 0;
 			/* assert(pages == 0); */
 		} else {
-			dalen -= consumed;
+			remaining -= consumed;
 			data += consumed;
 			pages--;
-			int second_page_size = dalen;
-			if (dalen > 4096) {
+			int second_page_size = remaining;
+			if (remaining > 4096) {
 				second_page_size = 4096;
 			}
 			cur->buffer_end = virt_to_phys(data + second_page_size - 1);
-			dalen -= second_page_size;
+			remaining -= second_page_size;
 			data += second_page_size;
 		}
 	}
@@ -454,7 +455,7 @@ ohci_control (usbdev_t *dev, direction_t dir, int drlen, void *devreq, int dalen
 	OHCI_INST(dev->controller)->opreg->HcControl |= ControlListEnable;
 	OHCI_INST(dev->controller)->opreg->HcCommandStatus = ControlListFilled;
 
-	int failure = wait_for_ed(dev, head,
+	int result = wait_for_ed(dev, head,
 			(dalen==0)?0:(last_page - first_page + 1));
 	/* Wait some frames before and one after disabling list access. */
 	mdelay(4);
@@ -464,7 +465,10 @@ ohci_control (usbdev_t *dev, direction_t dir, int drlen, void *devreq, int dalen
 	/* free memory */
 	ohci_free_ed(head);
 
-	return failure;
+	if (result >= 0)
+		result = dalen - result;
+
+	return result;
 }
 
 /* finalize == 1: if data is of packet aligned size, add a zero length packet */
@@ -472,6 +476,7 @@ static int
 ohci_bulk (endpoint_t *ep, int dalen, u8 *data, int finalize)
 {
 	int i;
+	int remaining = dalen;
 	usb_debug("bulk: %x bytes from %x, finalize: %x, maxpacketsize: %x\n", dalen, data, finalize, ep->maxpacketsize);
 
 	td_t *cur, *next;
@@ -501,28 +506,28 @@ ohci_bulk (endpoint_t *ep, int dalen, u8 *data, int finalize)
                         TD_CC_NOACCESS;
 		cur->current_buffer_pointer = virt_to_phys(data);
 		pages--;
-		if (dalen == 0) {
+		if (remaining == 0) {
 			/* magic TD for empty packet transfer */
 			cur->current_buffer_pointer = 0;
 			cur->buffer_end = 0;
 			/* assert((pages == 0) && finalize); */
 		}
 		int consumed = (4096 - ((unsigned long)data % 4096));
-		if (consumed >= dalen) {
+		if (consumed >= remaining) {
 			// end of data is within same page
-			cur->buffer_end = virt_to_phys(data + dalen - 1);
-			dalen = 0;
+			cur->buffer_end = virt_to_phys(data + remaining - 1);
+			remaining = 0;
 			/* assert(pages == finalize); */
 		} else {
-			dalen -= consumed;
+			remaining -= consumed;
 			data += consumed;
 			pages--;
-			int second_page_size = dalen;
-			if (dalen > 4096) {
+			int second_page_size = remaining;
+			if (remaining > 4096) {
 				second_page_size = 4096;
 			}
 			cur->buffer_end = virt_to_phys(data + second_page_size - 1);
-			dalen -= second_page_size;
+			remaining -= second_page_size;
 			data += second_page_size;
 		}
 		/* One more TD. */
@@ -558,7 +563,7 @@ ohci_bulk (endpoint_t *ep, int dalen, u8 *data, int finalize)
 	OHCI_INST(ep->dev->controller)->opreg->HcControl |= BulkListEnable;
 	OHCI_INST(ep->dev->controller)->opreg->HcCommandStatus = BulkListFilled;
 
-	int failure = wait_for_ed(ep->dev, head,
+	int result = wait_for_ed(ep->dev, head,
 			(dalen==0)?0:(last_page - first_page + 1));
 	/* Wait some frames before and one after disabling list access. */
 	mdelay(4);
@@ -570,12 +575,12 @@ ohci_bulk (endpoint_t *ep, int dalen, u8 *data, int finalize)
 	/* free memory */
 	ohci_free_ed(head);
 
-	if (failure) {
-		/* try cleanup */
+	if (result >= 0)
+		result = dalen - result;
+	else
 		clear_stall(ep);
-	}
 
-	return failure;
+	return result;
 }
 
 
@@ -780,9 +785,11 @@ ohci_poll_intr_queue(void *const q_)
 	return data;
 }
 
-static void
+static int
 ohci_process_done_queue(ohci_t *const ohci, const int spew_debug)
 {
+	/* returns the amount of bytes *not* transmitted for short packets */
+	int result = 0;
 	int i, j;
 
 	/* Temporary queue of interrupt queue TDs (to reverse order). */
@@ -790,7 +797,7 @@ ohci_process_done_queue(ohci_t *const ohci, const int spew_debug)
 
 	/* Check if done head has been written. */
 	if (!(ohci->opreg->HcInterruptStatus & WritebackDoneHead))
-		return;
+		return 0;
 	/* Fetch current done head.
 	   Lsb is only interesting for hw interrupts. */
 	u32 phys_done_queue = ohci->hcca->HccaDoneHead & ~1;
@@ -807,7 +814,11 @@ ohci_process_done_queue(ohci_t *const ohci, const int spew_debug)
 
 		switch (done_td->config & TD_QUEUETYPE_MASK) {
 		case TD_QUEUETYPE_ASYNC:
-			/* Free processed async TDs. */
+			/* Free processed async TDs and count short transfer. */
+			if (done_td->current_buffer_pointer)
+				result += (done_td->buffer_end & 0xfff) -
+						(done_td->current_buffer_pointer
+						& 0xfff) + 1;
 			free((void *)done_td);
 			break;
 		case TD_QUEUETYPE_INTR: {
@@ -864,5 +875,7 @@ ohci_process_done_queue(ohci_t *const ohci, const int spew_debug)
 	}
 	if (spew_debug)
 		usb_debug("processed %d done tds, %d intr tds thereof.\n", i, j);
+
+	return result;
 }