xhci: Store information about roothubs and TTs.

For upcoming patches, we need to keep information about the bandwidth
domains under the xHCI host.  Each root port is a separate primary
bandwidth domain, and each high speed hub's TT (and potentially each port
on a multi-TT hub) is a secondary bandwidth domain.

If the table were in text form, it would look a bit like this:

EP Interval	Sum of Number	Largest Max	Max Packet
		of Packets	Packet Size	Overhead
	0	   N		   mps		  overhead
...
	15	   N		   mps		  overhead

Overhead is the maximum packet overhead (for bit stuffing, CRC, protocol
overhead, etc) for all the endpoints in this interval.  Devices with
different speeds have different max packet overhead.  For example, if
there is a low speed and a full speed endpoint that both have an interval
of 3, we would use the higher overhead (the low speed overhead).  Interval
0 is a bit special, since we really just want to know the sum of the max
ESIT payloads instead of the largest max packet size.  That's stored in
the interval0_esit_payload variable.  For root ports, we also need to keep
track of the number of active TTs.

For each root port, and each TT under a root port, store some information
about the bandwidth consumption.  Dynamically allocate an array of root
port bandwidth information for the number of root ports on the xHCI host.
Each root port stores a list of TTs under the root port.  A single TT hub
only has one entry in the list, but a multi-TT hub will have an entry per
port.

When the USB core says that a USB device is a hub, create one or more
entries in the root port TT list for the hub.  When a device is deleted,
and it is a hub, search through the root port TT list and delete all
TT entries for the hub.  Keep track of which TT entry is associated with a
device under a TT.

LS/FS devices attached directly to the root port will have usb_device->tt
set to the roothub.  Ignore that, and treat it like a primary bandwidth
domain, since there isn't really a high speed bus between the roothub and
the host.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 189 insertions, 1 deletions

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 1755c668ac05..5efb0afff5f6 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -687,7 +687,98 @@ static void xhci_init_endpoint_timer(struct xhci_hcd *xhci,
         ep->xhci = xhci;
 }
 
-/* All the xhci_tds in the ring's TD list should be freed at this point */
+static void xhci_free_tt_info(struct xhci_hcd *xhci,
+                struct xhci_virt_device *virt_dev,
+                int slot_id)
+{
+        struct list_head *tt;
+        struct list_head *tt_list_head;
+        struct list_head *tt_next;
+        struct xhci_tt_bw_info *tt_info;
+
+        /* If the device never made it past the Set Address stage,
+         * it may not have the real_port set correctly.
+         */
+        if (virt_dev->real_port == 0 ||
+                        virt_dev->real_port > HCS_MAX_PORTS(xhci->hcs_params1)) {
+                xhci_dbg(xhci, "Bad real port.\n");
+                return;
+        }
+
+        tt_list_head = &(xhci->rh_bw[virt_dev->real_port - 1].tts);
+        if (list_empty(tt_list_head))
+                return;
+
+        list_for_each(tt, tt_list_head) {
+                tt_info = list_entry(tt, struct xhci_tt_bw_info, tt_list);
+                if (tt_info->slot_id == slot_id)
+                        break;
+        }
+        /* Cautionary measure in case the hub was disconnected before we
+         * stored the TT information.
+         */
+        if (tt_info->slot_id != slot_id)
+                return;
+
+        tt_next = tt->next;
+        tt_info = list_entry(tt, struct xhci_tt_bw_info,
+                        tt_list);
+        /* Multi-TT hubs will have more than one entry */
+        do {
+                list_del(tt);
+                kfree(tt_info);
+                tt = tt_next;
+                if (list_empty(tt_list_head))
+                        break;
+                tt_next = tt->next;
+                tt_info = list_entry(tt, struct xhci_tt_bw_info,
+                                tt_list);
+        } while (tt_info->slot_id == slot_id);
+}
+
+int xhci_alloc_tt_info(struct xhci_hcd *xhci,
+                struct xhci_virt_device *virt_dev,
+                struct usb_device *hdev,
+                struct usb_tt *tt, gfp_t mem_flags)
+{
+        struct xhci_tt_bw_info          *tt_info;
+        unsigned int                    num_ports;
+        int                             i, j;
+
+        if (!tt->multi)
+                num_ports = 1;
+        else
+                num_ports = hdev->maxchild;
+
+        for (i = 0; i < num_ports; i++, tt_info++) {
+                struct xhci_interval_bw_table *bw_table;
+
+                tt_info = kzalloc(sizeof(*tt_info), mem_flags);
+                if (!tt_info)
+                        goto free_tts;
+                INIT_LIST_HEAD(&tt_info->tt_list);
+                list_add(&tt_info->tt_list,
+                                &xhci->rh_bw[virt_dev->real_port - 1].tts);
+                tt_info->slot_id = virt_dev->udev->slot_id;
+                if (tt->multi)
+                        tt_info->ttport = i+1;
+                bw_table = &tt_info->bw_table;
+                for (j = 0; j < XHCI_MAX_INTERVAL; j++)
+                        INIT_LIST_HEAD(&bw_table->interval_bw[j].endpoints);
+        }
+        return 0;
+
+free_tts:
+        xhci_free_tt_info(xhci, virt_dev, virt_dev->udev->slot_id);
+        return -ENOMEM;
+}
+
+
+/* All the xhci_tds in the ring's TD list should be freed at this point.
+ * Should be called with xhci->lock held if there is any chance the TT lists
+ * will be manipulated by the configure endpoint, allocate device, or update
+ * hub functions while this function is removing the TT entries from the list.
+ */
 void xhci_free_virt_device(struct xhci_hcd *xhci, int slot_id)
 {
         struct xhci_virt_device *dev;
@@ -709,6 +800,8 @@ void xhci_free_virt_device(struct xhci_hcd *xhci, int slot_id)
                         xhci_free_stream_info(xhci,
                                         dev->eps[i].stream_info);
         }
+        /* If this is a hub, free the TT(s) from the TT list */
+        xhci_free_tt_info(xhci, dev, slot_id);
 
         if (dev->ring_cache) {
                 for (i = 0; i < dev->num_rings_cached; i++)
@@ -926,6 +1019,36 @@ int xhci_setup_addressable_virt_dev(struct xhci_hcd *xhci, struct usb_device *ud
         xhci_dbg(xhci, "Set root hub portnum to %d\n", port_num);
         xhci_dbg(xhci, "Set fake root hub portnum to %d\n", dev->fake_port);
 
+        /* Find the right bandwidth table that this device will be a part of.
+         * If this is a full speed device attached directly to a root port (or a
+         * decendent of one), it counts as a primary bandwidth domain, not a
+         * secondary bandwidth domain under a TT.  An xhci_tt_info structure
+         * will never be created for the HS root hub.
+         */
+        if (!udev->tt || !udev->tt->hub->parent) {
+                dev->bw_table = &xhci->rh_bw[port_num - 1].bw_table;
+        } else {
+                struct xhci_root_port_bw_info *rh_bw;
+                struct xhci_tt_bw_info *tt_bw;
+
+                rh_bw = &xhci->rh_bw[port_num - 1];
+                /* Find the right TT. */
+                list_for_each_entry(tt_bw, &rh_bw->tts, tt_list) {
+                        if (tt_bw->slot_id != udev->tt->hub->slot_id)
+                                continue;
+
+                        if (!dev->udev->tt->multi ||
+                                        (udev->tt->multi &&
+                                         tt_bw->ttport == dev->udev->ttport)) {
+                                dev->bw_table = &tt_bw->bw_table;
+                                dev->tt_info = tt_bw;
+                                break;
+                        }
+                }
+                if (!dev->tt_info)
+                        xhci_warn(xhci, "WARN: Didn't find a matching TT\n");
+        }
+
         /* Is this a LS/FS device under an external HS hub? */
         if (udev->tt && udev->tt->hub->parent) {
                 slot_ctx->tt_info = cpu_to_le32(udev->tt->hub->slot_id |
@@ -1552,6 +1675,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
         kfree(xhci->usb2_ports);
         kfree(xhci->usb3_ports);
         kfree(xhci->port_array);
+        kfree(xhci->rh_bw);
 
         xhci->page_size = 0;
         xhci->page_shift = 0;
@@ -1822,6 +1946,12 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags)
         if (!xhci->port_array)
                 return -ENOMEM;
 
+        xhci->rh_bw = kzalloc(sizeof(*xhci->rh_bw)*num_ports, flags);
+        if (!xhci->rh_bw)
+                return -ENOMEM;
+        for (i = 0; i < num_ports; i++)
+                INIT_LIST_HEAD(&xhci->rh_bw[i].tts);
+
         /*
          * For whatever reason, the first capability offset is from the
          * capability register base, not from the HCCPARAMS register.
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 7da3b139c8dd..1657041c19cf 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2990,6 +2990,14 @@ int xhci_update_hub_device(struct usb_hcd *hcd, struct usb_device *hdev,
         }
 
         spin_lock_irqsave(&xhci->lock, flags);
+        if (hdev->speed == USB_SPEED_HIGH &&
+                        xhci_alloc_tt_info(xhci, vdev, hdev, tt, GFP_ATOMIC)) {
+                xhci_dbg(xhci, "Could not allocate xHCI TT structure.\n");
+                xhci_free_command(xhci, config_cmd);
+                spin_unlock_irqrestore(&xhci->lock, flags);
+                return -ENOMEM;
+        }
+
         xhci_slot_copy(xhci, config_cmd->in_ctx, vdev->out_ctx);
         ctrl_ctx = xhci_get_input_control_ctx(xhci, config_cmd->in_ctx);
         ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index ec4817003a56..eee47c8a6ee8 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -774,6 +774,26 @@ struct xhci_virt_ep {
         bool                    skip;
 };
 
+enum xhci_overhead_type {
+        LS_OVERHEAD_TYPE = 0,
+        FS_OVERHEAD_TYPE,
+        HS_OVERHEAD_TYPE,
+};
+
+struct xhci_interval_bw {
+        unsigned int            num_packets;
+        /* How many endpoints of each speed are present. */
+        unsigned int            overhead[3];
+};
+
+#define XHCI_MAX_INTERVAL       16
+
+struct xhci_interval_bw_table {
+        unsigned int            interval0_esit_payload;
+        struct xhci_interval_bw interval_bw[XHCI_MAX_INTERVAL];
+};
+
+
 struct xhci_virt_device {
         struct usb_device               *udev;
         /*
@@ -800,6 +820,30 @@ struct xhci_virt_device {
         struct list_head                cmd_list;
         u8                              fake_port;
         u8                              real_port;
+        struct xhci_interval_bw_table   *bw_table;
+        struct xhci_tt_bw_info          *tt_info;
+};
+
+/*
+ * For each roothub, keep track of the bandwidth information for each periodic
+ * interval.
+ *
+ * If a high speed hub is attached to the roothub, each TT associated with that
+ * hub is a separate bandwidth domain.  The interval information for the
+ * endpoints on the devices under that TT will appear in the TT structure.
+ */
+struct xhci_root_port_bw_info {
+        struct list_head                tts;
+        unsigned int                    num_active_tts;
+        struct xhci_interval_bw_table   bw_table;
+};
+
+struct xhci_tt_bw_info {
+        struct list_head                tt_list;
+        int                             slot_id;
+        int                             ttport;
+        struct xhci_interval_bw_table   bw_table;
+        int                             active_eps;
 };
 
 
@@ -1268,6 +1312,8 @@ struct xhci_hcd {
         int slot_id;
         /* Internal mirror of the HW's dcbaa */
         struct xhci_virt_device *devs[MAX_HC_SLOTS];
+        /* For keeping track of bandwidth domains per roothub. */
+        struct xhci_root_port_bw_info   *rh_bw;
 
         /* DMA pools */
         struct dma_pool *device_pool;
@@ -1508,6 +1554,10 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd);
 irqreturn_t xhci_msi_irq(int irq, struct usb_hcd *hcd);
 int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev);
 void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev);
+int xhci_alloc_tt_info(struct xhci_hcd *xhci,
+                struct xhci_virt_device *virt_dev,
+                struct usb_device *hdev,
+                struct usb_tt *tt, gfp_t mem_flags);
 int xhci_alloc_streams(struct usb_hcd *hcd, struct usb_device *udev,
                 struct usb_host_endpoint **eps, unsigned int num_eps,
                 unsigned int num_streams, gfp_t mem_flags);