[PATCH v6 06/12] usb: dbc: add bulk out and bulk in interfaces

From: Lu Baolu
Date: Mon Jan 25 2016 - 23:15:38 EST


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@xxxxxxxxxxxxxxx>
---
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