usb-ohci: collect TDs from done list

OHCI HC after using the TDs queues them back to hccaDoneHead. Until
this event the TDs cannot be reused, as there might be references in
the host controller still pending. Recycle all the TDs from the queue
and acknowledge it by clearing the WD bit in interrupt status
register.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>

2 files changed, 133 insertions, 14 deletions

diff --git a/lib/libusb/usb-ohci.c b/lib/libusb/usb-ohci.c
index 45d027c..8d7fdb3 100644
--- a/lib/libusb/usb-ohci.c
+++ b/lib/libusb/usb-ohci.c
@@ -24,6 +24,15 @@
 #define dprintf(_x ...)
 #endif
 
+#undef OHCI_DEBUG_PACKET
+//#define OHCI_DEBUG_PACKET
+#ifdef OHCI_DEBUG_PACKET
+#define dpprintf(_x ...) printf(_x)
+#else
+#define dpprintf(_x ...)
+#endif
+
+
 /*
  * Dump OHCI register
  *
@@ -187,7 +196,7 @@ static inline struct ohci_ed *ohci_pipe_get_ed(struct usb_pipe *pipe)
 {
 	struct ohci_pipe *opipe;
 	opipe = container_of(pipe, struct ohci_pipe, pipe);
-	dprintf("%s: ed is %p\n", __func__, &opipe->ed);
+	dpprintf("%s: ed is %p\n", __func__, &opipe->ed);
 	return &opipe->ed;
 }
 
@@ -195,7 +204,7 @@ static inline long ohci_pipe_get_ed_phys(struct usb_pipe *pipe)
 {
 	struct ohci_pipe *opipe;
 	opipe = container_of(pipe, struct ohci_pipe, pipe);
-	dprintf("%s: ed_phys is %x\n", __func__, opipe->ed_phys);
+	dpprintf("%s: ed_phys is %x\n", __func__, opipe->ed_phys);
 	return opipe->ed_phys;
 }
 
@@ -203,7 +212,7 @@ static inline struct ohci_pipe *ohci_pipe_get_opipe(struct usb_pipe *pipe)
 {
 	struct ohci_pipe *opipe;
 	opipe = container_of(pipe, struct ohci_pipe, pipe);
-	dprintf("%s: opipe is %p\n", __func__, opipe);
+	dpprintf("%s: opipe is %p\n", __func__, opipe);
 	return opipe;
 }
 
@@ -212,7 +221,7 @@ static int ohci_alloc_pipe_pool(struct ohci_hcd *ohcd)
 	struct ohci_pipe *opipe, *curr, *prev;
 	long opipe_phys = 0;
 	unsigned int i, count;
-#ifdef DEBUG
+#ifdef OHCI_DEBUG_PACKET
 	struct usb_pipe *pipe;
 #endif
 
@@ -244,7 +253,7 @@ static int ohci_alloc_pipe_pool(struct ohci_hcd *ohcd)
 		ohcd->end->next = &opipe->pipe;
 	ohcd->end = &prev->pipe;
 
-#ifdef DEBUG
+#ifdef OHCI_DEBUG_PACKET
 	for (i = 0, pipe = ohcd->freelist; pipe; pipe = pipe->next)
 		dprintf("usb-ohci: %d: pipe cur %p ed %p ed_phys %x\n",
 			i++, pipe, ohci_pipe_get_ed(pipe),
@@ -360,10 +369,91 @@ static void ohci_fill_ed(struct ohci_ed *ed, long headp, long tailp,
 
 static long ohci_get_td_phys(struct ohci_td *curr, struct ohci_td *start, long td_phys)
 {
-	//dprintf("position %d\n", curr - start);
+	dpprintf("position %d\n", curr - start);
 	return td_phys + (curr - start) * sizeof(*start);
 }
 
+static long ohci_get_td_virt(struct ohci_td *curr, struct ohci_td *start, long td_virt, long total_count)
+{
+	dpprintf("position %d\n", curr - start);
+	if ( (curr - start) >= total_count) {
+		/* busted position, should ignore this */
+		return 0;
+	}
+	return td_virt + (curr - start) * sizeof(*start);
+}
+
+/* OHCI Spec: 4.4.2.3 HccaDoneHead*/
+static int ohci_process_done_head(struct ohci_hcd *ohcd,
+				struct ohci_td *td_start,
+				long __td_start_phys, long total_count)
+{
+	struct ohci_hcca *hcca;
+	struct ohci_td *td_phys = NULL, *td_start_phys;
+	struct ohci_td *td, *prev_td = NULL;
+	uint32_t reg = 0, start_frame = 0, time = 0, ret = true;
+	long count;
+
+	count = total_count;
+	td_start_phys = (struct ohci_td *) __td_start_phys;
+	hcca = ohcd->hcca;
+	start_frame = hcca->frame_num;
+	time = SLOF_GetTimer() + USB_TIMEOUT;
+	dpprintf("Claiming %ld\n", count);
+
+	while(time > SLOF_GetTimer()) {
+		if (hcca->frame_num != start_frame)
+			break;
+		cpu_relax();
+	}
+	if (hcca->frame_num == start_frame)
+		dprintf("frame not changed %x\n", start_frame);
+
+	time = SLOF_GetTimer() + USB_TIMEOUT;
+	while (count > 0) {
+		while(time > SLOF_GetTimer()) {
+			td_phys = (struct ohci_td *)(uint64_t) le32_to_cpu(hcca->done_head);
+			if (td_phys)
+				break;
+			cpu_relax();
+		}
+		mb();
+		hcca->done_head = 0;
+		mb();
+		td = (struct ohci_td *)(uint64_t) ohci_get_td_virt(td_phys,
+								   td_start_phys,
+								PTR_U32(td_start), total_count);
+
+		while ((td != NULL) && (count > 0)) {
+			count--;
+			dpprintf("Claimed %p(%p) td_start %p count %ld\n",
+				td, td_phys, td_start_phys, count);
+			dpprintf("%s: cbp %08X attr %08X next_td %08X be %08X\n",
+				 __func__,
+				 le32_to_cpu(td->cbp), le32_to_cpu(td->attr),
+				 le32_to_cpu(td->next_td), le32_to_cpu(td->be));
+			mb();
+			reg = (le32_to_cpu(td->attr) & TDA_CC) >> 28;
+			if (reg) {
+				printf("USB: Error %s %p\n", tda_cc_error[reg], td);
+				ret = false;
+			}
+			prev_td = td;
+			td = (struct ohci_td *)(uint64_t) le32_to_cpu(td->next_td);
+			mb();
+			prev_td->attr |= cpu_to_le32(TDA_DONE);
+			prev_td->next_td = 0;
+			mb();
+		}
+		/* clear the WD interrupt status*/
+		write_reg32(&ohcd->regs->intr_status, OHCI_INTR_STATUS_WD);
+		mb();
+		read_reg32(&ohcd->regs->intr_status);
+	}
+	dpprintf("TDs left to be claimed td %p %ld\n", td, count);
+	return ret;
+}
+
 /*
  * OHCI Spec:
  *           4.2 Endpoint Descriptor
@@ -380,7 +470,7 @@ static int ohci_send_ctrl(struct usb_pipe *pipe, struct usb_dev_req *req, void *
 	uint32_t dir, attr = 0;
 	uint32_t time;
 	int ret = true;
-	long req_phys = 0, data_phys = 0, td_next = 0;
+	long req_phys = 0, data_phys = 0, td_next = 0, td_count = 0;
 
 	datalen = le16_to_cpu(req->wLength);
 	dir = (req->bmRequestType & REQT_DIR_IN) ? 1 : 0;
@@ -395,7 +485,7 @@ static int ohci_send_ctrl(struct usb_pipe *pipe, struct usb_dev_req *req, void *
 	attr = TDA_DP_SETUP | TDA_CC | TDA_TOGGLE_DATA0;
 	td_next = ohci_get_td_phys(td + 1, tds, PTR_U32(td_phys));
 	ohci_fill_td(td, td_next, req_phys, sizeof(*req), attr);
-	td++;
+	td++; td_count++;
 
 	if (datalen) {
 		data_phys = SLOF_dma_map_in(data, datalen, true);
@@ -403,14 +493,14 @@ static int ohci_send_ctrl(struct usb_pipe *pipe, struct usb_dev_req *req, void *
 		attr = (dir ? TDA_DP_IN : TDA_DP_OUT) | TDA_TOGGLE_DATA1 | TDA_CC;
 		td_next = ohci_get_td_phys(td + 1, tds, PTR_U32(td_phys));
 		ohci_fill_td(td, td_next, data_phys, datalen, attr);
-		td++;
+		td++; td_count++;
 	}
 
 	attr = 0;
 	attr = (dir ? TDA_DP_OUT : TDA_DP_IN) | TDA_CC | TDA_TOGGLE_DATA1;
 	td_next = ohci_get_td_phys(td + 1, tds, PTR_U32(td_phys));
 	ohci_fill_td(td, td_next, 0, 0, attr);
-	td++;
+	td_count++;
 
 	ed = ohci_pipe_get_ed(pipe);
 	attr = 0;
@@ -443,6 +533,8 @@ static int ohci_send_ctrl(struct usb_pipe *pipe, struct usb_dev_req *req, void *
 	mb();
 	write_reg32(&regs->cntl_head_ed, 0);
 
+	ohci_process_done_head(ohcd, tds, (long)td_phys, td_count);
+
 	SLOF_dma_map_out(req_phys, req, sizeof(struct usb_dev_req));
 	if (datalen)
 		SLOF_dma_map_out(data_phys, data, datalen);
@@ -457,7 +549,7 @@ static int ohci_transfer_bulk(struct usb_pipe *pipe, void *td_ptr,
 	struct ohci_td *td, *tds;
 	struct ohci_regs *regs;
 	struct ohci_hcd *ohcd;
-	long td_phys = 0, td_next, ed_phys, ptr;
+	long td_phys = 0, td_next, ed_phys, ptr, td_count = 0;
 	uint32_t dir, attr = 0, count;
 	size_t len, packet_len;
 	uint32_t time;
@@ -470,7 +562,7 @@ static int ohci_transfer_bulk(struct usb_pipe *pipe, void *td_ptr,
 	}
 
 	dir = (pipe->dir == USB_PIPE_OUT) ? 0 : 1;
-	count = datalen / pipe->mps;
+	count = datalen / OHCI_MAX_BULK_SIZE;
 	if (count > OHCI_MAX_TDS) {
 		printf("usb-ohci: buffer size not supported - %d\n", datalen);
 		ret = false;
@@ -494,12 +586,12 @@ static int ohci_transfer_bulk(struct usb_pipe *pipe, void *td_ptr,
 	attr = 0;
 	attr = (dir ? TDA_DP_IN : TDA_DP_OUT) | TDA_CC;
 	while (len) {
-		packet_len = (pipe->mps < len)? pipe->mps : len;
+		packet_len = (OHCI_MAX_BULK_SIZE < len)? OHCI_MAX_BULK_SIZE : len;
 		td_next = ohci_get_td_phys((td + 1), tds, td_phys);
 		ohci_fill_td(td, td_next, ptr, packet_len, attr);
 		ptr = ptr + packet_len;
 		len = len - packet_len;
-		td++;
+		td++; td_count++;
 	}
 
 	ed = ohci_pipe_get_ed(pipe);
@@ -535,6 +627,8 @@ static int ohci_transfer_bulk(struct usb_pipe *pipe, void *td_ptr,
 	ed->attr |= cpu_to_le32(EDA_SKIP);
 	mb();
 	write_reg32(&regs->bulk_head_ed, 0);
+
+	ohci_process_done_head(ohcd, tds, td_phys, td_count);
 end:
 	return ret;
 }
diff --git a/lib/libusb/usb-ohci.h b/lib/libusb/usb-ohci.h
index b9bcaca..fc24aa8 100644
--- a/lib/libusb/usb-ohci.h
+++ b/lib/libusb/usb-ohci.h
@@ -69,6 +69,7 @@ struct ohci_ed {
 	uint32_t next_ed;
 } __attribute__((packed));
 
+#define TDA_DONE         (1 << 17)
 #define TDA_ROUNDING     (1 << 18)
 #define TDA_DP_SETUP     (0 << 19)
 #define TDA_DP_OUT       (1 << 19)
@@ -78,6 +79,26 @@ struct ohci_ed {
 #define TDA_TOGGLE_DATA1 (1 << 25)
 #define TDA_CC           (0xF << 28)
 
+/* Table 4-7: Completion Codes */
+const char *tda_cc_error[] = {
+	"NOERROR",
+	"CRC",
+	"BITSTUFFING",
+	"DATATOGGLEMISMATCH",
+	"STALL",
+	"DEVICENOTRESPONDING",
+	"PIDCHECKFAILURE",
+	"UNEXPECTEDPID",
+	"DATAOVERRUN",
+	"DATAUNDERRUN",
+	"reserved",
+	"reserved",
+	"BUFFEROVERRUN",
+	"BUFFERUNDERRUN",
+	"NOT ACCESSED",
+	"NOT ACCESSED",
+};
+
 struct ohci_td {
 	uint32_t attr;
 	uint32_t cbp;
@@ -111,6 +132,7 @@ struct ohci_pipe {
 
 #define OHCI_PIPE_POOL_SIZE 4096
 #define OHCI_MAX_TDS        256 /* supports 16k buffers, i.e. 64 * 256 */
+#define OHCI_MAX_BULK_SIZE  4096
 
 struct ohci_hcd {
 	struct ohci_hcca *hcca;
@@ -139,6 +161,9 @@ struct ohci_hcd {
 #define OHCI_CMD_STATUS_CLF   (1 << 1)
 #define OHCI_CMD_STATUS_BLF   (1 << 2)
 
+/* OHCI Interrupt status */
+#define OHCI_INTR_STATUS_WD   (1 << 1)
+
 /* Root Hub Descriptor A bits */
 #define RHDA_NDP                 (0xFF)
 #define RHDA_PSM_INDIVIDUAL      (1 << 8)