[PATCH] From: Xu Rao <raoxu@uniontech.com> Subject: [PATCH] usb: xhci: Add debugfs support for xHCI port bandwidth

[raoxu <raoxu@uniontech.com>]

From: Xu Rao <raoxu@uniontech.com>

In many projects, you need to obtain the available bandwidth of the
xhci roothub port. Refer to xhci rev1_2 and use the TRB_GET_BW
command to obtain it.

hardware tested:
03:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] Raven USB 3.1
(prog-if 30 [XHCI])
Subsystem: Huawei Technologies Co., Ltd. Raven USB 3.1
Flags: bus master, fast devsel, latency 0, IRQ 30
Memory at c0300000 (64-bit, non-prefetchable) [size=1M]
Capabilities: [48] Vendor Specific Information: Len=08 <?>
Capabilities: [50] Power Management version 3
Capabilities: [64] Express Endpoint, MSI 00
Capabilities: [a0] MSI: Enable- Count=1/8 Maskable- 64bit+
Capabilities: [c0] MSI-X: Enable+ Count=8 Masked-
Kernel driver in use: xhci_hcd

test progress:
1.cd /sys/kernel/debug/usb/xhci/0000:03:00.3
cat port_bandwidth
/sys/kernel/debug/usb/xhci/0000:03:00.3# cat port_bandwidth
port[1] available bw: 79%.
port[2] available bw: 79%.
port[3] available bw: 79%.
port[4] available bw: 79%.
port[5] available bw: 90%.
port[6] available bw: 90%.
port[7] available bw: 90%.
port[8] available bw: 90%.
2.plug in usb video cammer open it
cat port_bandwidth
port[1] available bw: 39%.
port[2] available bw: 39%.
port[3] available bw: 39%.
port[4] available bw: 39%.
port[5] available bw: 90%.
port[6] available bw: 90%.
port[7] available bw: 90%.
port[8] available bw: 90%.

Signed-off-by: Xu Rao <raoxu@uniontech.com>
---
 drivers/usb/host/xhci-debugfs.c | 42 +++++++++++++++++++
 drivers/usb/host/xhci-ring.c    | 14 +++++++
 drivers/usb/host/xhci.c         | 74 +++++++++++++++++++++++++++++++++
 drivers/usb/host/xhci.h         |  7 ++++
 4 files changed, 137 insertions(+)

diff --git a/drivers/usb/host/xhci-debugfs.c b/drivers/usb/host/xhci-debugfs.c
index 1f5ef174abea..573b6c25f3af 100644
--- a/drivers/usb/host/xhci-debugfs.c
+++ b/drivers/usb/host/xhci-debugfs.c
@@ -631,6 +631,46 @@ static void xhci_debugfs_create_ports(struct xhci_hcd *xhci,
 	}
 }

+static int xhci_port_bw_show(struct seq_file *s, void *unused)
+{
+	struct xhci_hcd		*xhci = (struct xhci_hcd *)s->private;
+	unsigned int		num_ports;
+	unsigned int		i;
+	int			ret;
+	u8			bw_table[MAX_HC_PORTS] = {0};
+
+	num_ports = HCS_MAX_PORTS(xhci->hcs_params1);
+
+	/* get roothub port bandwidth */
+	ret = xhci_get_port_bandwidth(xhci, bw_table);
+	if (ret)
+		return ret;
+
+	/* print all roothub ports available bandwidth */
+	for (i = 1; i < num_ports+1; i++)
+		seq_printf(s, "port[%d] available bw: %d%%.\n", i, bw_table[i]);
+
+	return ret;
+}
+
+static int bw_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, xhci_port_bw_show, inode->i_private);
+}
+
+static const struct file_operations bw_fops = {
+	.open			= bw_open,
+	.read			= seq_read,
+	.llseek			= seq_lseek,
+	.release		= single_release,
+};
+
+static void xhci_debugfs_create_bandwidth(struct xhci_hcd *xhci,
+					struct dentry *parent)
+{
+	debugfs_create_file("port_bandwidth", 0644, parent, xhci, &bw_fops);
+}
+
 void xhci_debugfs_init(struct xhci_hcd *xhci)
 {
 	struct device		*dev = xhci_to_hcd(xhci)->self.controller;
@@ -681,6 +721,8 @@ void xhci_debugfs_init(struct xhci_hcd *xhci)
 	xhci->debugfs_slots = debugfs_create_dir("devices", xhci->debugfs_root);

 	xhci_debugfs_create_ports(xhci, xhci->debugfs_root);
+
+	xhci_debugfs_create_bandwidth(xhci, xhci->debugfs_root);
 }

 void xhci_debugfs_exit(struct xhci_hcd *xhci)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 965bffce301e..af1cd4f8ace9 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1867,6 +1867,8 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
 	case TRB_NEC_GET_FW:
 		xhci_handle_cmd_nec_get_fw(xhci, event);
 		break;
+	case TRB_GET_BW:
+		break;
 	default:
 		/* Skip over unknown commands on the event ring */
 		xhci_info(xhci, "INFO unknown command type %d\n", cmd_type);
@@ -4414,6 +4416,18 @@ int xhci_queue_configure_endpoint(struct xhci_hcd *xhci,
 			command_must_succeed);
 }

+/* Queue a get root hub port bandwidth command TRB */
+int xhci_queue_get_rh_port_bw(struct xhci_hcd *xhci,
+		struct xhci_command *cmd, dma_addr_t in_ctx_ptr,
+		u8 dev_speed, u32 slot_id, bool command_must_succeed)
+{
+	return queue_command(xhci, cmd, lower_32_bits(in_ctx_ptr),
+		upper_32_bits(in_ctx_ptr), 0,
+		TRB_TYPE(TRB_GET_BW) | DEV_SPEED_FOR_TRB(dev_speed) |
+		SLOT_ID_FOR_TRB(slot_id),
+		command_must_succeed);
+}
+
 /* Queue an evaluate context command TRB */
 int xhci_queue_evaluate_context(struct xhci_hcd *xhci, struct xhci_command *cmd,
 		dma_addr_t in_ctx_ptr, u32 slot_id, bool command_must_succeed)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 45653114ccd7..84092fe981e8 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3088,6 +3088,80 @@ void xhci_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
 }
 EXPORT_SYMBOL_GPL(xhci_reset_bandwidth);

+/* Get the available bandwidth of the ports under the xhci roothub,
+ * including USB 2.0 port and USB 3.0 port.
+ */
+int xhci_get_port_bandwidth(struct xhci_hcd *xhci, u8 *bw_table)
+{
+	unsigned int		num_ports;
+	unsigned int		i;
+	struct xhci_command	*cmd;
+	dma_addr_t		dma_handle;
+	void			*dma_buf;
+	int			ret;
+	unsigned long		flags;
+	struct device		*dev  = xhci_to_hcd(xhci)->self.sysdev;
+
+	num_ports = HCS_MAX_PORTS(xhci->hcs_params1);
+
+	cmd = xhci_alloc_command(xhci, true, GFP_KERNEL);
+	if (!cmd)
+		return -ENOMEM;
+
+	dma_buf = dma_alloc_coherent(dev, xhci->page_size, &dma_handle,
+					GFP_KERNEL);
+	if (!dma_buf) {
+		xhci_free_command(xhci, cmd);
+		return -ENOMEM;
+	}
+
+	/* get xhci hub usb3 port bandwidth */
+	/* refer to xhci rev1_2 protocol 4.6.15*/
+	spin_unlock_irqrestore(&xhci->lock, flags);
+	ret = xhci_queue_get_rh_port_bw(xhci, cmd, dma_handle, USB_SPEED_SUPER,
+					0, false);
+	if (ret < 0) {
+		spin_unlock_irqrestore(&xhci->lock, flags);
+		goto out;
+	}
+	xhci_ring_cmd_db(xhci);
+	spin_unlock_irqrestore(&xhci->lock, flags);
+
+	wait_for_completion(cmd->completion);
+
+	/* refer to xhci rev1_2 protocol 6.2.6 , byte 0 is reserved */
+	for (i = 1; i < num_ports+1; i++) {
+		if (((u8 *)dma_buf)[i])
+			bw_table[i] = ((u8 *)dma_buf)[i];
+	}
+
+	/* get xhci hub usb2 port bandwidth */
+	/* refer to xhci rev1_2 protocol 4.6.15*/
+	spin_unlock_irqrestore(&xhci->lock, flags);
+	ret = xhci_queue_get_rh_port_bw(xhci, cmd, dma_handle, USB_SPEED_HIGH,
+					0, false);
+	if (ret < 0) {
+		spin_unlock_irqrestore(&xhci->lock, flags);
+		goto out;
+	}
+	xhci_ring_cmd_db(xhci);
+	spin_unlock_irqrestore(&xhci->lock, flags);
+
+	wait_for_completion(cmd->completion);
+
+	/* refer to xhci rev1_2 protocol 6.2.6 , byte 0 is reserved */
+	for (i = 1; i < num_ports+1; i++) {
+		if (((u8 *)dma_buf)[i])
+			bw_table[i] = ((u8 *)dma_buf)[i];
+	}
+
+out:
+	dma_free_coherent(dev, xhci->page_size, dma_buf, dma_handle);
+	xhci_free_command(xhci, cmd);
+
+	return ret;
+}
+
 static void xhci_setup_input_ctx_for_config_ep(struct xhci_hcd *xhci,
 		struct xhci_container_ctx *in_ctx,
 		struct xhci_container_ctx *out_ctx,
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 8c164340a2c3..a137097b0404 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -999,6 +999,9 @@ enum xhci_setup_dev {
 /* bits 16:23 are the virtual function ID */
 /* bits 24:31 are the slot ID */

+/* bits 19:16 are the dev speed */
+#define DEV_SPEED_FOR_TRB(p)    ((p) << 16)
+
 /* Stop Endpoint TRB - ep_index to endpoint ID for this TRB */
 #define SUSPEND_PORT_FOR_TRB(p)		(((p) & 1) << 23)
 #define TRB_TO_SUSPEND_PORT(p)		(((p) & (1 << 23)) >> 23)
@@ -1907,6 +1910,10 @@ int xhci_queue_isoc_tx_prepare(struct xhci_hcd *xhci, gfp_t mem_flags,
 int xhci_queue_configure_endpoint(struct xhci_hcd *xhci,
 		struct xhci_command *cmd, dma_addr_t in_ctx_ptr, u32 slot_id,
 		bool command_must_succeed);
+int xhci_queue_get_rh_port_bw(struct xhci_hcd *xhci,
+		struct xhci_command *cmd, dma_addr_t in_ctx_ptr,
+		u8 dev_speed, u32 slot_id, bool command_must_succeed);
+int xhci_get_port_bandwidth(struct xhci_hcd *xhci, u8 *bw_table);
 int xhci_queue_evaluate_context(struct xhci_hcd *xhci, struct xhci_command *cmd,
 		dma_addr_t in_ctx_ptr, u32 slot_id, bool command_must_succeed);
 int xhci_queue_reset_ep(struct xhci_hcd *xhci, struct xhci_command *cmd,
--
2.43.4