Message-Id: <1453781665-4714-7-git-send-email-baolu.lu@linux.intel.com>
Date:	Tue, 26 Jan 2016 12:14:19 +0800
From:	Lu Baolu <baolu.lu@...ux.intel.com>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
	Lu Baolu <baolu.lu@...ux.intel.com>
Subject: [PATCH v6 06/12] usb: dbc: add bulk out and bulk in interfaces

This patch adds interfaces for bulk out and bulk in ops. These
interfaces could be used to implement early printk bootconsole
or hook to various system debuggers.

Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
---
 drivers/usb/early/xhci-dbc.c | 373 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/usb/xhci-dbc.h |  30 ++++
 2 files changed, 403 insertions(+)

diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c
index 6855048..f59c80ef 100644
--- a/drivers/usb/early/xhci-dbc.c
+++ b/drivers/usb/early/xhci-dbc.c
@@ -219,11 +219,21 @@ static void xdbc_dbg_dump_data(char *str)
 	xdbc_dbg_dump_string("String Descriptor:");
 }
 
+static void xdbc_dbg_dump_trb(struct xdbc_trb *trb, char *str)
+{
+	xdbc_trace("DBC trb: %s\n", str);
+	xdbc_trace("@%016llx %08x %08x %08x %08x\n", (u64)__pa(trb),
+				le32_to_cpu(trb->field[0]),
+				le32_to_cpu(trb->field[1]),
+				le32_to_cpu(trb->field[2]),
+				le32_to_cpu(trb->field[3]));
+}
 #else
 static inline void xdbc_trace(const char *fmt, ...) { }
 static inline void xdbc_dump_debug_buffer(void) { }
 static inline void xdbc_dbg_dump_regs(char *str) { }
 static inline void xdbc_dbg_dump_data(char *str) { }
+static inline void xdbc_dbg_dump_trb(struct xdbc_trb *trb, char *str) { }
 #endif	/* DBC_DEBUG */
 
 /*
@@ -334,6 +344,7 @@ static void *xdbc_get_page(dma_addr_t *dma_addr,
 	static char in_ring_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 	static char out_ring_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 	static char table_page[PAGE_SIZE] __aligned(PAGE_SIZE);
+	static char bulk_buf_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 
 	switch (type) {
 	case XDBC_PAGE_EVENT:
@@ -348,6 +359,9 @@ static void *xdbc_get_page(dma_addr_t *dma_addr,
 	case XDBC_PAGE_TABLE:
 		virt = (void *)table_page;
 		break;
+	case XDBC_PAGE_BUFFER:
+		virt = (void *)bulk_buf_page;
+		break;
 	default:
 		return NULL;
 	}
@@ -694,6 +708,12 @@ static int xdbc_mem_init(void)
 	dev_info = cpu_to_le32((XDBC_DEVICE_REV << 16) | XDBC_PRODUCT_ID);
 	writel(dev_info, &xdbcp->xdbc_reg->devinfo2);
 
+	/* get and store the transfer buffer */
+	xdbcp->out_buf = xdbc_get_page(&xdbcp->out_dma,
+			XDBC_PAGE_BUFFER);
+	xdbcp->in_buf = xdbcp->out_buf + XDBC_MAX_PACKET;
+	xdbcp->in_dma = xdbcp->out_dma + XDBC_MAX_PACKET;
+
 	return 0;
 }
 
@@ -789,6 +809,9 @@ static int xdbc_start(void)
 
 	xdbc_trace("root hub port number %d\n", DCST_DPN(status));
 
+	xdbcp->in_ep_state = EP_RUNNING;
+	xdbcp->out_ep_state = EP_RUNNING;
+
 	xdbc_trace("DbC is running now, control 0x%08x\n",
 			readl(&xdbcp->xdbc_reg->control));
 
@@ -882,3 +905,353 @@ int __init early_xdbc_init(char *s)
 
 	return 0;
 }
+
+static void xdbc_queue_trb(struct xdbc_ring *ring,
+		u32 field1, u32 field2, u32 field3, u32 field4)
+{
+	struct xdbc_trb *trb, *link_trb;
+
+	trb = ring->enqueue;
+	trb->field[0] = cpu_to_le32(field1);
+	trb->field[1] = cpu_to_le32(field2);
+	trb->field[2] = cpu_to_le32(field3);
+	trb->field[3] = cpu_to_le32(field4);
+
+	xdbc_dbg_dump_trb(trb, "enqueue trb");
+
+	++(ring->enqueue);
+	if (ring->enqueue >= &ring->segment->trbs[TRBS_PER_SEGMENT - 1]) {
+		link_trb = ring->enqueue;
+		if (ring->cycle_state)
+			link_trb->field[3] |= cpu_to_le32(TRB_CYCLE);
+		else
+			link_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+		ring->enqueue = ring->segment->trbs;
+		ring->cycle_state ^= 1;
+	}
+}
+
+static void xdbc_ring_doorbell(int target)
+{
+	writel(DOOR_BELL_TARGET(target), &xdbcp->xdbc_reg->doorbell);
+}
+
+static void xdbc_handle_port_status(struct xdbc_trb *evt_trb)
+{
+	u32 port_reg;
+
+	port_reg = readl(&xdbcp->xdbc_reg->portsc);
+
+	if (port_reg & PORTSC_CSC) {
+		xdbc_trace("%s: connect status change event\n", __func__);
+		writel(port_reg | PORTSC_CSC, &xdbcp->xdbc_reg->portsc);
+		port_reg = readl(&xdbcp->xdbc_reg->portsc);
+	}
+
+	if (port_reg & PORTSC_PRC) {
+		xdbc_trace("%s: port reset change event\n", __func__);
+		writel(port_reg | PORTSC_PRC, &xdbcp->xdbc_reg->portsc);
+		port_reg = readl(&xdbcp->xdbc_reg->portsc);
+	}
+
+	if (port_reg & PORTSC_PLC) {
+		xdbc_trace("%s: port link status change event\n", __func__);
+		writel(port_reg | PORTSC_PLC, &xdbcp->xdbc_reg->portsc);
+		port_reg = readl(&xdbcp->xdbc_reg->portsc);
+	}
+
+	if (port_reg & PORTSC_CEC) {
+		xdbc_trace("%s: config error change\n", __func__);
+		writel(port_reg | PORTSC_CEC, &xdbcp->xdbc_reg->portsc);
+		port_reg = readl(&xdbcp->xdbc_reg->portsc);
+	}
+}
+
+static void xdbc_handle_tx_event(struct xdbc_trb *evt_trb)
+{
+	u32 comp_code;
+	u32 tx_dma_high, tx_dma_low;
+	u64 in_dma, out_dma;
+	size_t remain_length;
+	int ep_id;
+
+	tx_dma_low = le32_to_cpu(evt_trb->field[0]);
+	tx_dma_high = le32_to_cpu(evt_trb->field[1]);
+	comp_code = GET_COMP_CODE(le32_to_cpu(evt_trb->field[2]));
+	remain_length = EVENT_TRB_LEN(le32_to_cpu(evt_trb->field[2]));
+	ep_id = TRB_TO_EP_ID(le32_to_cpu(evt_trb->field[3]));
+	in_dma = __pa(xdbcp->in_pending);
+	out_dma = __pa(xdbcp->out_pending);
+
+	/*
+	 * Possible Completion Codes for DbC Transfer Event are Success,
+	 * Stall Error, USB Transaction Error, Babble Detected Error,
+	 * TRB Error, Short Packet, Undefined Error, Event Ring Full Error,
+	 * and Vendor Defined Error. TRB error, undefined error and vendor
+	 * defined error will result in HOT/HIT set and be handled the same
+	 * way as Stall error.
+	 */
+	switch (comp_code) {
+	case COMP_SUCCESS:
+		remain_length = 0;
+	case COMP_SHORT_TX:
+		xdbc_trace("%s: endpoint %d remains %d bytes\n", __func__,
+			ep_id, remain_length);
+		break;
+	case COMP_TRB_ERR:
+	case COMP_BABBLE:
+	case COMP_TX_ERR:
+	case COMP_STALL:
+	default:
+		xdbc_trace("%s: endpoint %d halted\n", __func__, ep_id);
+		if (ep_id == XDBC_EPID_OUT)
+			xdbcp->out_ep_state = EP_HALTED;
+		if (ep_id == XDBC_EPID_IN)
+			xdbcp->in_ep_state = EP_HALTED;
+
+		break;
+	}
+
+	if (lower_32_bits(in_dma) == tx_dma_low &&
+			upper_32_bits(in_dma) == tx_dma_high) {
+		xdbcp->in_complete = comp_code;
+		xdbcp->in_complete_length =
+				(remain_length > xdbcp->in_length) ?
+				0 : xdbcp->in_length - remain_length;
+	}
+
+	if (lower_32_bits(out_dma) == tx_dma_low &&
+			upper_32_bits(out_dma) == tx_dma_high) {
+		xdbcp->out_complete = comp_code;
+		xdbcp->out_complete_length =
+				(remain_length > xdbcp->out_length) ?
+				0 : xdbcp->out_length - remain_length;
+	}
+}
+
+static void xdbc_handle_events(void)
+{
+	struct xdbc_trb *evt_trb;
+	bool update_erdp = false;
+
+	evt_trb = xdbcp->evt_ring.dequeue;
+	while ((le32_to_cpu(evt_trb->field[3]) & TRB_CYCLE) ==
+			xdbcp->evt_ring.cycle_state) {
+		/*
+		 * Memory barrier to ensure software sees the trbs
+		 * enqueued by hardware.
+		 */
+		rmb();
+
+		xdbc_dbg_dump_trb(evt_trb, "event trb");
+
+		/* FIXME: Handle more event types. */
+		switch ((le32_to_cpu(evt_trb->field[3]) & TRB_TYPE_BITMASK)) {
+		case TRB_TYPE(TRB_PORT_STATUS):
+			xdbc_handle_port_status(evt_trb);
+			break;
+		case TRB_TYPE(TRB_TRANSFER):
+			xdbc_handle_tx_event(evt_trb);
+			break;
+		default:
+			break;
+		}
+
+		/* advance to the next trb */
+		++(xdbcp->evt_ring.dequeue);
+		if (xdbcp->evt_ring.dequeue ==
+				&xdbcp->evt_seg.trbs[TRBS_PER_SEGMENT]) {
+			xdbcp->evt_ring.dequeue = xdbcp->evt_seg.trbs;
+			xdbcp->evt_ring.cycle_state ^= 1;
+		}
+
+		evt_trb = xdbcp->evt_ring.dequeue;
+		update_erdp = true;
+	}
+
+	/* update event ring dequeue pointer */
+	if (update_erdp)
+		xdbc_write64(__pa(xdbcp->evt_ring.dequeue),
+				&xdbcp->xdbc_reg->erdp);
+}
+
+/*
+ * Check and dispatch events in event ring. It also checks status
+ * of hardware. This function will be called from multiple threads.
+ * An atomic lock is applied to protect the access of event ring.
+ */
+static int xdbc_check_event(void)
+{
+	/* event ring is under checking by other thread? */
+	if (!test_bit(XDBC_ATOMIC_EVENT, &xdbcp->atomic_flags) &&
+			!test_and_set_bit(XDBC_ATOMIC_EVENT,
+			&xdbcp->atomic_flags))
+		return 0;
+
+	xdbc_handle_events();
+
+	test_and_clear_bit(XDBC_ATOMIC_EVENT, &xdbcp->atomic_flags);
+
+	return 0;
+}
+
+#define	BULK_IN_COMPLETED(p)	((xdbcp->in_pending == (p)) && \
+				 xdbcp->in_complete)
+#define	BULK_OUT_COMPLETED(p)	((xdbcp->out_pending == (p)) && \
+				 xdbcp->out_complete)
+
+/*
+ * Wait for a bulk-in or bulk-out transfer completion or timed out.
+ * Return count of the actually transferred bytes or error.
+ */
+static int xdbc_wait_until_bulk_done(struct xdbc_trb *trb, int loops)
+{
+	int timeout = 0;
+	bool read;
+
+	if (trb != xdbcp->in_pending &&
+			trb != xdbcp->out_pending)
+		return -EINVAL;
+
+	read = (trb == xdbcp->in_pending);
+
+	do {
+		if (xdbc_check_event() < 0)
+			break;
+
+		if (read && BULK_IN_COMPLETED(trb)) {
+			if (xdbcp->in_ep_state == EP_HALTED)
+				return -EAGAIN;
+			else
+				return xdbcp->in_complete_length;
+		}
+
+		if (!read && BULK_OUT_COMPLETED(trb)) {
+			if (xdbcp->out_ep_state == EP_HALTED)
+				return -EAGAIN;
+			else
+				return xdbcp->out_complete_length;
+		}
+
+		xdbc_udelay(10);
+	} while ((timeout++ < loops) || !loops);
+
+	return -EIO;
+}
+
+static int xdbc_bulk_transfer(void *data, int size, int loops, bool read)
+{
+	u64 addr;
+	u32 length, control;
+	struct xdbc_trb *trb;
+	struct xdbc_ring *ring;
+	u32 cycle;
+	int ret;
+
+	if (size > XDBC_MAX_PACKET) {
+		xdbc_trace("%s: bad parameter, size %d", __func__, size);
+		return -EINVAL;
+	}
+
+	ring = (read ? &xdbcp->in_ring : &xdbcp->out_ring);
+	trb = ring->enqueue;
+	cycle = ring->cycle_state;
+
+	length = TRB_LEN(size);
+	control = TRB_TYPE(TRB_NORMAL) | TRB_IOC;
+
+	if (cycle)
+		control &= cpu_to_le32(~TRB_CYCLE);
+	else
+		control |= cpu_to_le32(TRB_CYCLE);
+
+	if (read) {
+		memset(xdbcp->in_buf, 0, XDBC_MAX_PACKET);
+		addr = xdbcp->in_dma;
+
+		xdbcp->in_pending = trb;
+		xdbcp->in_length = size;
+		xdbcp->in_complete = 0;
+		xdbcp->in_complete_length = 0;
+	} else {
+		memcpy(xdbcp->out_buf, data, size);
+		addr = xdbcp->out_dma;
+
+		xdbcp->out_pending = trb;
+		xdbcp->out_length = size;
+		xdbcp->out_complete = 0;
+		xdbcp->out_complete_length = 0;
+	}
+
+	xdbc_queue_trb(ring, lower_32_bits(addr),
+			upper_32_bits(addr),
+			length, control);
+
+	/*
+	 * Memory barrier to ensure hardware sees the trbs
+	 * enqueued above.
+	 */
+	wmb();
+	if (cycle)
+		trb->field[3] |= cpu_to_le32(cycle);
+	else
+		trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+	xdbc_ring_doorbell(read ? IN_EP_DOORBELL : OUT_EP_DOORBELL);
+
+	ret = xdbc_wait_until_bulk_done(trb, loops);
+
+	if (read)
+		xdbcp->in_pending = NULL;
+	else
+		xdbcp->out_pending = NULL;
+
+	if (ret > 0) {
+		if (read)
+			memcpy(data, xdbcp->in_buf, size);
+		else
+			memset(xdbcp->out_buf, 0, XDBC_MAX_PACKET);
+	} else {
+		xdbc_trace("%s: bulk %s transfer results in error %d\n",
+				__func__, read ? "in" : "out", ret);
+	}
+
+	return ret;
+}
+
+int xdbc_bulk_read(void *data, int size, int loops)
+{
+	int ret;
+
+	do {
+		if (!test_bit(XDBC_ATOMIC_BULKIN, &xdbcp->atomic_flags) &&
+				!test_and_set_bit(XDBC_ATOMIC_BULKIN,
+				&xdbcp->atomic_flags))
+			break;
+	} while (1);
+
+	ret = xdbc_bulk_transfer(data, size, loops, true);
+
+	test_and_clear_bit(XDBC_ATOMIC_BULKIN, &xdbcp->atomic_flags);
+
+	return ret;
+}
+
+int xdbc_bulk_write(const char *bytes, int size)
+{
+	int ret;
+
+	do {
+		if (!test_bit(XDBC_ATOMIC_BULKOUT, &xdbcp->atomic_flags) &&
+				!test_and_set_bit(XDBC_ATOMIC_BULKOUT,
+				&xdbcp->atomic_flags))
+			break;
+	} while (1);
+
+	ret = xdbc_bulk_transfer((void *)bytes, size, XDBC_LOOPS, false);
+
+	test_and_clear_bit(XDBC_ATOMIC_BULKOUT, &xdbcp->atomic_flags);
+
+	return ret;
+}
diff --git a/include/linux/usb/xhci-dbc.h b/include/linux/usb/xhci-dbc.h
index fc0ef9a..289ba58 100644
--- a/include/linux/usb/xhci-dbc.h
+++ b/include/linux/usb/xhci-dbc.h
@@ -120,8 +120,17 @@ enum xdbc_page_type {
 	XDBC_PAGE_TXIN,
 	XDBC_PAGE_TXOUT,
 	XDBC_PAGE_TABLE,
+	XDBC_PAGE_BUFFER,
 };
 
+enum xdbc_ep_state {
+	EP_DISABLED,
+	EP_RUNNING,
+	EP_HALTED,
+};
+#define	XDBC_EPID_OUT	2
+#define	XDBC_EPID_IN	1
+
 struct xdbc_state {
 	/* pci device info*/
 	u32		bus;
@@ -170,13 +179,34 @@ struct xdbc_state {
 	/* bulk OUT endpoint */
 	struct xdbc_ring	out_ring;
 	struct xdbc_segment	out_seg;
+	void			*out_buf;
+	dma_addr_t		out_dma;
+	struct xdbc_trb		*out_pending;		/* IN */
+	size_t			out_length;		/* IN */
+	u32			out_complete;		/* OUT */
+	size_t			out_complete_length;	/* OUT */
+	enum xdbc_ep_state	out_ep_state;
 
 	/* bulk IN endpoint */
 	struct xdbc_ring	in_ring;
 	struct xdbc_segment	in_seg;
+	void			*in_buf;
+	dma_addr_t		in_dma;
+	struct xdbc_trb		*in_pending;		/* IN */
+	size_t			in_length;		/* IN */
+	u32			in_complete;		/* OUT */
+	size_t			in_complete_length;	/* OUT */
+	enum xdbc_ep_state	in_ep_state;
+
+	/* atomic flags */
+	unsigned long		atomic_flags;
+#define	XDBC_ATOMIC_BULKOUT	0
+#define	XDBC_ATOMIC_BULKIN	1
+#define	XDBC_ATOMIC_EVENT	2
 };
 
 #define	XDBC_MAX_PACKET		1024
+#define	XDBC_LOOPS		1000
 
 /* door bell target */
 #define	OUT_EP_DOORBELL		0
-- 
2.1.4

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