[PATCH 5/6] usb: xhci-mtk: supports bandwidth scheduling with multi-TT

Chunfeng Yun
2018-08-29T02:55:17Z

Supports LowSpeed and FullSpeed INT/ISOC bandwidth scheduling
with USB multi-TT

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
drivers/usb/host/xhci-mtk-sch.c | 247 ++++++++++++++++++++++++++++++++++++++--
drivers/usb/host/xhci-mtk.h | 21 ++++
2 files changed, 258 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
index 7efd890..36050a1 100644
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -80,10 +80,98 @@ static u32 get_esit(struct xhci_ep_ctx *ep_ctx)
return esit;
}

+static struct mu3h_sch_tt *find_tt(struct usb_device *udev)
+{
+ struct usb_tt *utt = udev->tt;
+ struct mu3h_sch_tt *tt, **tt_index, **ptt;
+ unsigned int port;
+ bool allocated_index = false;
+
+ if (!utt)
+ return NULL; /* Not below a TT */
+
+ /*
+ * Find/create our data structure.
+ * For hubs with a single TT, we get it directly.
+ * For hubs with multiple TTs, there's an extra level of pointers.
+ */
+ tt_index = NULL;
+ if (utt->multi) {
+ tt_index = utt->hcpriv;
+ if (!tt_index) { /* Create the index array */
+ tt_index = kcalloc(utt->hub->maxchild,
+ sizeof(*tt_index), GFP_KERNEL);
+ if (!tt_index)
+ return ERR_PTR(-ENOMEM);
+ utt->hcpriv = tt_index;
+ allocated_index = true;
+ }
+ port = udev->ttport - 1;
+ ptt = &tt_index[port];
+ } else {
+ port = 0;
+ ptt = (struct mu3h_sch_tt **) &utt->hcpriv;
+ }
+
+ tt = *ptt;
+ if (!tt) { /* Create the mu3h_sch_tt */
+ tt = kzalloc(sizeof(*tt), GFP_KERNEL);
+ if (!tt) {
+ if (allocated_index) {
+ utt->hcpriv = NULL;
+ kfree(tt_index);
+ }
+ return ERR_PTR(-ENOMEM);
+ }
+ INIT_LIST_HEAD(&tt->ep_list);
+ tt->usb_tt = utt;
+ tt->tt_port = port;
+ *ptt = tt;
+ }
+
+ return tt;
+}
+
+/* Release the TT above udev, if it's not in use */
+static void drop_tt(struct usb_device *udev)
+{
+ struct usb_tt *utt = udev->tt;
+ struct mu3h_sch_tt *tt, **tt_index, **ptt;
+ int i, cnt;
+
+ if (!utt || !utt->hcpriv)
+ return; /* Not below a TT, or never allocated */
+
+ cnt = 0;
+ if (utt->multi) {
+ tt_index = utt->hcpriv;
+ ptt = &tt_index[udev->ttport - 1];
+ /* How many entries are left in tt_index? */
+ for (i = 0; i < utt->hub->maxchild; ++i)
+ cnt += !!tt_index[i];
+ } else {
+ tt_index = NULL;
+ ptt = (struct mu3h_sch_tt **)&utt->hcpriv;
+ }
+
+ tt = *ptt;
+ if (!tt || !list_empty(&tt->ep_list))
+ return; /* never allocated , or still in use*/
+
+ *ptt = NULL;
+ kfree(tt);
+
+ if (cnt == 1) {
+ utt->hcpriv = NULL;
+ kfree(tt_index);
+ }
+}
+
static struct mu3h_sch_ep_info *create_sch_ep(struct usb_device *udev,
struct usb_host_endpoint *ep, struct xhci_ep_ctx *ep_ctx)
{
struct mu3h_sch_ep_info *sch_ep;
+ struct mu3h_sch_tt *tt = NULL;
u32 len_bw_budget_table;
size_t mem_size;

@@ -101,6 +189,15 @@ static struct mu3h_sch_ep_info *create_sch_ep(struct usb_device *udev,
if (!sch_ep)
return ERR_PTR(-ENOMEM);

+ if (is_fs_or_ls(udev->speed)) {
+ tt = find_tt(udev);
+ if (IS_ERR(tt)) {
+ kfree(sch_ep);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+
+ sch_ep->sch_tt = tt;
sch_ep->ep = ep;

return sch_ep;
@@ -128,6 +225,8 @@ static void setup_sch_info(struct usb_device *udev,
CTX_TO_MAX_ESIT_PAYLOAD(le32_to_cpu(ep_ctx->tx_info));

sch_ep->esit = get_esit(ep_ctx);
+ sch_ep->ep_type = ep_type;
+ sch_ep->maxpkt = maxpkt;
sch_ep->offset = 0;
sch_ep->burst_mode = 0;
sch_ep->repeat = 0;
@@ -197,8 +296,13 @@ static void setup_sch_info(struct usb_device *udev,
}
} else if (is_fs_or_ls(udev->speed)) {
sch_ep->pkts = 1; /* at most one packet for each microframe */
+
+ /*
+ * num_budget_microframes and cs_count will be updated when
+ * check TT for INT_OUT_EP, ISOC/INT_IN_EP type
+ */
sch_ep->cs_count = DIV_ROUND_UP(maxpkt, FS_PAYLOAD_MAX);
- sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
+ sch_ep->num_budget_microframes = sch_ep->cs_count;
sch_ep->bw_cost_per_microframe =
(maxpkt < FS_PAYLOAD_MAX) ? maxpkt : FS_PAYLOAD_MAX;

@@ -212,7 +316,13 @@ static void setup_sch_info(struct usb_device *udev,
} else { /* INT_IN_EP or ISOC_IN_EP */
bwb_table[0] = 0; /* start split */
bwb_table[1] = 0; /* idle */
- for (i = 2; i < sch_ep->num_budget_microframes; i++)
+ /*
+ * due to cs_count will be updated according to cs
+ * position, assign all remainder budget array
+ * elements as @bw_cost_per_microframe, but only first
+ * @num_budget_microframes elements will be used later
+ */
+ for (i = 2; i < TT_MICROFRAMES_MAX; i++)
bwb_table[i] = sch_ep->bw_cost_per_microframe;
}
}
@@ -264,6 +374,96 @@ static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
}
}

+static int check_sch_tt(struct usb_device *udev,
+ struct mu3h_sch_ep_info *sch_ep, u32 offset)
+{
+ struct mu3h_sch_tt *tt = sch_ep->sch_tt;
+ u32 extra_cs_count;
+ u32 fs_budget_start;
+ u32 start_ss, last_ss;
+ u32 start_cs, last_cs;
+ int i;
+
+ start_ss = offset % 8;
+ fs_budget_start = (start_ss + 1) % 8;
+
+ if (sch_ep->ep_type == ISOC_OUT_EP) {
+ last_ss = start_ss + sch_ep->cs_count - 1;
+
+ /*
+ * usb_20 spec section11.18:
+ * must never schedule Start-Split in Y6
+ */
+ if (!(start_ss == 7 || last_ss < 6))
+ return -ERANGE;
+
+ for (i = 0; i < sch_ep->cs_count; i++)
+ if (test_bit(offset + i, tt->split_bit_map))
+ return -ERANGE;
+
+ } else {
+ u32 cs_count = DIV_ROUND_UP(sch_ep->maxpkt, FS_PAYLOAD_MAX);
+
+ /*
+ * usb_20 spec section11.18:
+ * must never schedule Start-Split in Y6
+ */
+ if (start_ss == 6)
+ return -ERANGE;
+
+ /* one uframe for ss + one uframe for idle */
+ start_cs = (start_ss + 2) % 8;
+ last_cs = start_cs + cs_count - 1;
+
+ if (last_cs > 7)
+ return -ERANGE;
+
+ if (sch_ep->ep_type == ISOC_IN_EP)
+ extra_cs_count = (last_cs == 7) ? 1 : 2;
+ else /* ep_type : INTR IN / INTR OUT */
+ extra_cs_count = (fs_budget_start == 6) ? 1 : 2;
+
+ cs_count += extra_cs_count;
+ if (cs_count > 7)
+ cs_count = 7; /* HW limit */
+
+ for (i = 0; i < cs_count + 2; i++) {
+ if (test_bit(offset + i, tt->split_bit_map))
+ return -ERANGE;
+ }
+
+ sch_ep->cs_count = cs_count;
+ /* one for ss, the other for idle */
+ sch_ep->num_budget_microframes = cs_count + 2;
+
+ /*
+ * if interval=1, maxp >752, num_budge_micoframe is larger
+ * than sch_ep->esit, will overstep boundary
+ */
+ if (sch_ep->num_budget_microframes > sch_ep->esit)
+ sch_ep->num_budget_microframes = sch_ep->esit;
+ }
+
+ return 0;
+}
+
+static void update_sch_tt(struct usb_device *udev,
+ struct mu3h_sch_ep_info *sch_ep)
+{
+ struct mu3h_sch_tt *tt = sch_ep->sch_tt;
+ u32 base, num_esit;
+ int i, j;
+
+ num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
+ for (i = 0; i < num_esit; i++) {
+ base = sch_ep->offset + i * sch_ep->esit;
+ for (j = 0; j < sch_ep->num_budget_microframes; j++)
+ set_bit(base + j, tt->split_bit_map);
+ }
+
+ list_add_tail(&sch_ep->tt_endpoint, &tt->ep_list);
+}
+
static int check_sch_bw(struct usb_device *udev,
struct mu3h_sch_bw_info *sch_bw, struct mu3h_sch_ep_info *sch_ep)
{
@@ -273,6 +473,10 @@ static int check_sch_bw(struct usb_device *udev,
u32 min_index;
u32 worst_bw;
u32 bw_boundary;
+ u32 min_num_budget;
+ u32 min_cs_count;
+ bool tt_offset_ok = false;
+ int ret;

esit = sch_ep->esit;

@@ -282,26 +486,30 @@ static int check_sch_bw(struct usb_device *udev,
*/
min_bw = ~0;
min_index = 0;
+ min_cs_count = sch_ep->cs_count;
+ min_num_budget = sch_ep->num_budget_microframes;
for (offset = 0; offset < esit; offset++) {
+ if (is_fs_or_ls(udev->speed)) {
+ ret = check_sch_tt(udev, sch_ep, offset);
+ if (ret)
+ continue;
+ else
+ tt_offset_ok = true;
+ }
+
if ((offset + sch_ep->num_budget_microframes) > sch_ep->esit)
break;

- /*
- * usb_20 spec section11.18:
- * must never schedule Start-Split in Y6
- */
- if (is_fs_or_ls(udev->speed) && (offset % 8 == 6))
- continue;
-
worst_bw = get_max_bw(sch_bw, sch_ep, offset);
if (min_bw > worst_bw) {
min_bw = worst_bw;
min_index = offset;
+ min_cs_count = sch_ep->cs_count;
+ min_num_budget = sch_ep->num_budget_microframes;
}
if (min_bw == 0)
break;
}
- sch_ep->offset = min_index;

bw_boundary = (udev->speed == USB_SPEED_SUPER)
? SS_BW_BOUNDARY : HS_BW_BOUNDARY;
@@ -310,6 +518,18 @@ static int check_sch_bw(struct usb_device *udev,
if (min_bw > bw_boundary)
return -ERANGE;

+ sch_ep->offset = min_index;
+ sch_ep->cs_count = min_cs_count;
+ sch_ep->num_budget_microframes = min_num_budget;
+
+ if (is_fs_or_ls(udev->speed)) {
+ /* all offset for tt is not ok*/
+ if (!tt_offset_ok)
+ return -ERANGE;
+
+ update_sch_tt(udev, sch_ep);
+ }
+
/* update bus bandwidth info */
update_bus_bw(sch_bw, sch_ep, 1);

@@ -415,6 +635,9 @@ int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
ret = check_sch_bw(udev, sch_bw, sch_ep);
if (ret) {
xhci_err(xhci, "Not enough bandwidth!\n");
+ if (is_fs_or_ls(udev->speed))
+ drop_tt(udev);
+
kfree(sch_ep);
return -ENOSPC;
}
@@ -466,6 +689,10 @@ void xhci_mtk_drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
if (sch_ep->ep == ep) {
update_bus_bw(sch_bw, sch_ep, 0);
list_del(&sch_ep->endpoint);
+ if (is_fs_or_ls(udev->speed)) {
+ list_del(&sch_ep->tt_endpoint);
+ drop_tt(udev);
+ }
kfree(sch_ep);
break;
}
diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index f8864fc..8be8c5f 100644
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -20,6 +20,19 @@
#define XHCI_MTK_MAX_ESIT 64

/**
+ * @split_bit_map: used to avoid split microframes overlay
+ * @ep_list: Endpoints using this TT
+ * @usb_tt: usb TT related
+ * @tt_port: TT port number
+ */
+struct mu3h_sch_tt {
+ DECLARE_BITMAP(split_bit_map, XHCI_MTK_MAX_ESIT);
+ struct list_head ep_list;
+ struct usb_tt *usb_tt;
+ int tt_port;
+};
+
+/**
* struct mu3h_sch_bw_info: schedule information for bandwidth domain
*
* @bus_bw: array to keep track of bandwidth already used at each uframes
@@ -41,6 +54,10 @@ struct mu3h_sch_bw_info {
* (@repeat==1) scheduled within the interval
* @bw_cost_per_microframe: bandwidth cost per microframe
* @endpoint: linked into bandwidth domain which it belongs to
+ * @tt_endpoint: linked into mu3h_sch_tt's list which it belongs to
+ * @sch_tt: mu3h_sch_tt linked into
+ * @ep_type: endpoint type
+ * @maxpkt: max packet size of endpoint
* @ep: address of usb_host_endpoint struct
* @offset: which uframe of the interval that transfer should be
* scheduled first time within the interval
@@ -64,6 +81,10 @@ struct mu3h_sch_ep_info {
u32 num_budget_microframes;
u32 bw_cost_per_microframe;
struct list_head endpoint;
+ struct list_head tt_endpoint;
+ struct mu3h_sch_tt *sch_tt;
+ u32 ep_type;
+ u32 maxpkt;
void *ep;
/*
* mtk xHCI scheduling information put into reserved DWs
--
1.9.1