[PATCH 2/2] usb: xhci-mtk: improve split scheduling by separate IN/OUT budget
From: Chunfeng Yun
Date: Wed Aug 30 2023 - 14:53:12 EST
Calculate the IN/OUT budget separately to improve the bandwidth schedule,
meanwhile should avoid Start-Split token overlap between IN and OUT
endpoints, and take into account the FS/LS bandwidth boundary in each
microframe and also in each FS frame.
Calculate the budget for SS of OUT eps and CS of IN eps, but not include
extra-cs, and always add at most extra-cs allowed.
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
drivers/usb/host/xhci-mtk-sch.c | 305 ++++++++++++++++++++++++++++----
drivers/usb/host/xhci-mtk.h | 13 +-
2 files changed, 278 insertions(+), 40 deletions(-)
diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
index 93d962b159b4..6c63c346f154 100644
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -19,6 +19,11 @@
#define HS_BW_BOUNDARY 6144
/* usb2 spec section11.18.1: at most 188 FS bytes per microframe */
#define FS_PAYLOAD_MAX 188
+#define LS_PAYLOAD_MAX 18
+/* section 11.18.1, per fs frame */
+#define FS_BW_BOUNDARY 1157
+#define LS_BW_BOUNDARY 144
+
/*
* max number of microframes for split transfer, assume extra-cs budget is 0
* for fs isoc in : 1 ss + 1 idle + 6 cs (roundup(1023/188))
@@ -437,6 +442,23 @@ static u32 get_max_bw(struct mu3h_sch_bw_info *sch_bw,
return max_bw;
}
+/*
+ * for OUT: get first SS consumed bw;
+ * for IN: get first CS consumed bw;
+ */
+static u16 get_fs_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
+{
+ struct mu3h_sch_tt *tt = sch_ep->sch_tt;
+ u16 fs_bw;
+
+ if (sch_ep->ep_type == ISOC_OUT_EP || sch_ep->ep_type == INT_OUT_EP)
+ fs_bw = tt->fs_bus_bw_out[XHCI_MTK_BW_INDEX(offset)];
+ else /* skip ss + idle */
+ fs_bw = tt->fs_bus_bw_in[XHCI_MTK_BW_INDEX(offset + CS_OFFSET)];
+
+ return fs_bw;
+}
+
static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
struct mu3h_sch_ep_info *sch_ep, bool used)
{
@@ -455,40 +477,117 @@ static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
}
}
-static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
+static int check_ls_budget_microframes(struct mu3h_sch_ep_info *sch_ep, int offset)
+{
+ struct mu3h_sch_tt *tt = sch_ep->sch_tt;
+ int i;
+
+ if (sch_ep->speed != USB_SPEED_LOW)
+ return 0;
+
+ if (sch_ep->ep_type == INT_OUT_EP)
+ i = XHCI_MTK_BW_INDEX(offset);
+ else if (sch_ep->ep_type == INT_IN_EP)
+ i = XHCI_MTK_BW_INDEX(offset + CS_OFFSET); /* skip ss + idle */
+ else
+ return -EINVAL;
+
+ if (tt->ls_bus_bw[i] + sch_ep->maxpkt > LS_PAYLOAD_MAX)
+ return -ESCH_BW_OVERFLOW;
+
+ return 0;
+}
+
+static int check_fs_budget_microframes(struct mu3h_sch_ep_info *sch_ep, int offset)
{
struct mu3h_sch_tt *tt = sch_ep->sch_tt;
u32 tmp;
- int base;
+ int i, k;
+
+ /*
+ * for OUT eps, will transfer exactly assigned length of data,
+ * so can't allocate more than 188 bytes;
+ * but it's not for IN eps, usually it can't receive full
+ * 188 bytes in a uframe, if it not assign full 188 bytes,
+ * can add another one;
+ */
+ for (i = 0; i < sch_ep->num_budget_microframes; i++) {
+ k = XHCI_MTK_BW_INDEX(offset + i);
+ if (sch_ep->ep_type == ISOC_OUT_EP || sch_ep->ep_type == INT_OUT_EP)
+ tmp = tt->fs_bus_bw_out[k] + sch_ep->bw_budget_table[i];
+ else /* ep_type : ISOC IN / INTR IN */
+ tmp = tt->fs_bus_bw_in[k];
+
+ if (tmp > FS_PAYLOAD_MAX)
+ return -ESCH_BW_OVERFLOW;
+ }
+
+ return 0;
+}
+
+static int check_fs_budget_frames(struct mu3h_sch_ep_info *sch_ep, int offset)
+{
+ struct mu3h_sch_tt *tt = sch_ep->sch_tt;
+ u32 head, tail;
int i, j, k;
+ /* bugdet scheduled may cross at most two fs frames */
+ j = XHCI_MTK_BW_INDEX(offset) / UFRAMES_PER_FRAME;
+ k = XHCI_MTK_BW_INDEX(offset + sch_ep->num_budget_microframes - 1) / UFRAMES_PER_FRAME;
+
+ if (j != k) {
+ head = tt->fs_frame_bw[j];
+ tail = tt->fs_frame_bw[k];
+ } else {
+ head = tt->fs_frame_bw[j];
+ tail = 0;
+ }
+
+ j = roundup(offset, UFRAMES_PER_FRAME);
+ for (i = 0; i < sch_ep->num_budget_microframes; i++) {
+ if ((offset + i) < j)
+ head += sch_ep->bw_budget_table[i];
+ else
+ tail += sch_ep->bw_budget_table[i];
+ }
+
+ if (head > FS_BW_BOUNDARY || tail > FS_BW_BOUNDARY)
+ return -ESCH_BW_OVERFLOW;
+
+ return 0;
+}
+
+static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
+{
+ int i, base;
+ int ret = 0;
+
for (i = 0; i < sch_ep->num_esit; i++) {
base = offset + i * sch_ep->esit;
- /*
- * Compared with hs bus, no matter what ep type,
- * the hub will always delay one uframe to send data
- */
- for (j = 0; j < sch_ep->num_budget_microframes; j++) {
- k = XHCI_MTK_BW_INDEX(base + j);
- tmp = tt->fs_bus_bw[k] + sch_ep->bw_budget_table[j];
- if (tmp > FS_PAYLOAD_MAX)
- return -ESCH_BW_OVERFLOW;
- }
+ ret = check_ls_budget_microframes(sch_ep, base);
+ if (ret)
+ goto err;
+
+ ret = check_fs_budget_microframes(sch_ep, base);
+ if (ret)
+ goto err;
+
+ ret = check_fs_budget_frames(sch_ep, base);
+ if (ret)
+ goto err;
}
- return 0;
+err:
+ return ret;
}
-static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
+static int check_ss_and_cs(struct mu3h_sch_ep_info *sch_ep, u32 offset)
{
u32 start_ss, last_ss;
u32 start_cs, last_cs;
- if (!sch_ep->sch_tt)
- return 0;
-
- start_ss = offset % 8;
+ start_ss = offset % UFRAMES_PER_FRAME;
if (sch_ep->ep_type == ISOC_OUT_EP) {
last_ss = start_ss + sch_ep->cs_count - 1;
@@ -501,6 +600,7 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
return -ESCH_SS_Y6;
} else {
+ /* maxpkt <= 1023, cs <= 6 */
u32 cs_count = DIV_ROUND_UP(sch_ep->maxpkt, FS_PAYLOAD_MAX);
/*
@@ -511,7 +611,7 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
return -ESCH_SS_Y6;
/* one uframe for ss + one uframe for idle */
- start_cs = (start_ss + CS_OFFSET) % 8;
+ start_cs = (start_ss + CS_OFFSET) % UFRAMES_PER_FRAME;
last_cs = start_cs + cs_count - 1;
if (last_cs > 7)
return -ESCH_CS_OVERFLOW;
@@ -525,25 +625,149 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
}
+ return 0;
+}
+
+/*
+ * when isoc-out transfers 188 bytes in a uframe, and send isoc/intr's
+ * ss token in the uframe, may cause 'bit stuff error' in downstream
+ * port;
+ * when isoc-out transfer less than 188 bytes in a uframe, shall send
+ * isoc-in's ss after isoc-out's ss (but hw can't ensure the sequence,
+ * so just avoid overlap).
+ */
+static int check_isoc_ss_overlap(struct mu3h_sch_ep_info *sch_ep, u32 offset)
+{
+ struct mu3h_sch_tt *tt = sch_ep->sch_tt;
+ int base;
+ int i, j, k;
+
+ if (!tt)
+ return 0;
+
+ for (i = 0; i < sch_ep->num_esit; i++) {
+ base = offset + i * sch_ep->esit;
+
+ if (sch_ep->ep_type == ISOC_OUT_EP) {
+ for (j = 0; j < sch_ep->num_budget_microframes; j++) {
+ k = XHCI_MTK_BW_INDEX(base + j + CS_OFFSET);
+ /* use cs to indicate existence of in-ss @(base+j) */
+ if (tt->fs_bus_bw_in[k])
+ return -ESCH_SS_OVERLAP;
+ }
+ } else if (sch_ep->ep_type == ISOC_IN_EP || sch_ep->ep_type == INT_IN_EP) {
+ k = XHCI_MTK_BW_INDEX(base);
+ /* only check IN's ss */
+ if (tt->fs_bus_bw_out[k])
+ return -ESCH_SS_OVERLAP;
+ }
+ }
+
+ return 0;
+}
+
+static int check_sch_tt_budget(struct mu3h_sch_ep_info *sch_ep, u32 offset)
+{
+ int ret;
+
+ ret = check_ss_and_cs(sch_ep, offset);
+ if (ret)
+ return ret;
+
+ ret = check_isoc_ss_overlap(sch_ep, offset);
+ if (ret)
+ return ret;
+
return check_fs_bus_bw(sch_ep, offset);
}
+/* allocate microframes in the ls/fs frame */
+static int alloc_sch_portion_of_frame(struct mu3h_sch_ep_info *sch_ep)
+{
+ struct mu3h_sch_bw_info *sch_bw = sch_ep->bw_info;
+ const u32 bw_boundary = get_bw_boundary(sch_ep->speed);
+ u32 bw_max, fs_bw_min;
+ u32 offset, offset_min;
+ u16 fs_bw;
+ int frames;
+ int i, j;
+ int ret;
+
+ frames = sch_ep->esit / UFRAMES_PER_FRAME;
+
+ for (i = 0; i < UFRAMES_PER_FRAME; i++) {
+ fs_bw_min = FS_PAYLOAD_MAX;
+ offset_min = XHCI_MTK_MAX_ESIT;
+
+ for (j = 0; j < frames; j++) {
+ offset = (i + j * UFRAMES_PER_FRAME) % sch_ep->esit;
+
+ ret = check_sch_tt_budget(sch_ep, offset);
+ if (ret)
+ continue;
+
+ /* check hs bw domain */
+ bw_max = get_max_bw(sch_bw, sch_ep, offset);
+ if (bw_max > bw_boundary) {
+ ret = -ESCH_BW_OVERFLOW;
+ continue;
+ }
+
+ /* use best-fit between frames */
+ fs_bw = get_fs_bw(sch_ep, offset);
+ if (fs_bw < fs_bw_min) {
+ fs_bw_min = fs_bw;
+ offset_min = offset;
+ }
+
+ if (!fs_bw_min)
+ break;
+ }
+
+ /* use first-fit between microframes in a frame */
+ if (offset_min < XHCI_MTK_MAX_ESIT)
+ break;
+ }
+
+ if (offset_min == XHCI_MTK_MAX_ESIT)
+ return -ESCH_BW_OVERFLOW;
+
+ sch_ep->offset = offset_min;
+
+ return 0;
+}
+
static void update_sch_tt(struct mu3h_sch_ep_info *sch_ep, bool used)
{
struct mu3h_sch_tt *tt = sch_ep->sch_tt;
+ u16 *fs_bus_bw;
u32 base;
- int i, j, k;
+ int i, j, k, f;
+ if (sch_ep->ep_type == ISOC_OUT_EP || sch_ep->ep_type == INT_OUT_EP)
+ fs_bus_bw = tt->fs_bus_bw_out;
+ else
+ fs_bus_bw = tt->fs_bus_bw_in;
for (i = 0; i < sch_ep->num_esit; i++) {
base = sch_ep->offset + i * sch_ep->esit;
for (j = 0; j < sch_ep->num_budget_microframes; j++) {
k = XHCI_MTK_BW_INDEX(base + j);
- if (used)
- tt->fs_bus_bw[k] += (u16)sch_ep->bw_budget_table[j];
- else
- tt->fs_bus_bw[k] -= (u16)sch_ep->bw_budget_table[j];
+ f = k / UFRAMES_PER_FRAME;
+ if (used) {
+ if (sch_ep->speed == USB_SPEED_LOW)
+ tt->ls_bus_bw[k] += (u8)sch_ep->bw_budget_table[j];
+
+ fs_bus_bw[k] += (u16)sch_ep->bw_budget_table[j];
+ tt->fs_frame_bw[f] += (u16)sch_ep->bw_budget_table[j];
+ } else {
+ if (sch_ep->speed == USB_SPEED_LOW)
+ tt->ls_bus_bw[k] -= (u8)sch_ep->bw_budget_table[j];
+
+ fs_bus_bw[k] -= (u16)sch_ep->bw_budget_table[j];
+ tt->fs_frame_bw[f] -= (u16)sch_ep->bw_budget_table[j];
+ }
}
}
@@ -566,7 +790,8 @@ static int load_ep_bw(struct mu3h_sch_bw_info *sch_bw,
return 0;
}
-static int check_sch_bw(struct mu3h_sch_ep_info *sch_ep)
+/* allocate microframes for hs/ss/ssp */
+static int alloc_sch_microframes(struct mu3h_sch_ep_info *sch_ep)
{
struct mu3h_sch_bw_info *sch_bw = sch_ep->bw_info;
const u32 bw_boundary = get_bw_boundary(sch_ep->speed);
@@ -574,16 +799,12 @@ static int check_sch_bw(struct mu3h_sch_ep_info *sch_ep)
u32 worst_bw;
u32 min_bw = ~0;
int min_index = -1;
- int ret = 0;
/*
* Search through all possible schedule microframes.
* and find a microframe where its worst bandwidth is minimum.
*/
for (offset = 0; offset < sch_ep->esit; offset++) {
- ret = check_sch_tt(sch_ep, offset);
- if (ret)
- continue;
worst_bw = get_max_bw(sch_bw, sch_ep, offset);
if (worst_bw > bw_boundary)
@@ -593,21 +814,29 @@ static int check_sch_bw(struct mu3h_sch_ep_info *sch_ep)
min_bw = worst_bw;
min_index = offset;
}
-
- /* use first-fit for LS/FS */
- if (sch_ep->sch_tt && min_index >= 0)
- break;
-
- if (min_bw == 0)
- break;
}
if (min_index < 0)
- return ret ? ret : -ESCH_BW_OVERFLOW;
+ return -ESCH_BW_OVERFLOW;
sch_ep->offset = min_index;
- return load_ep_bw(sch_bw, sch_ep, true);
+ return 0;
+}
+
+static int check_sch_bw(struct mu3h_sch_ep_info *sch_ep)
+{
+ int ret;
+
+ if (sch_ep->sch_tt)
+ ret = alloc_sch_portion_of_frame(sch_ep);
+ else
+ ret = alloc_sch_microframes(sch_ep);
+
+ if (ret)
+ return ret;
+
+ return load_ep_bw(sch_ep->bw_info, sch_ep, true);
}
static void destroy_sch_ep(struct xhci_hcd_mtk *mtk, struct usb_device *udev,
diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index ef8af20b5e88..865b55e23b15 100644
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -30,12 +30,21 @@
#define XHCI_MTK_MAX_ESIT (1 << 6)
#define XHCI_MTK_BW_INDEX(x) ((x) & (XHCI_MTK_MAX_ESIT - 1))
+#define UFRAMES_PER_FRAME 8
+#define XHCI_MTK_FRAMES_CNT (XHCI_MTK_MAX_ESIT / UFRAMES_PER_FRAME)
+
/**
- * @fs_bus_bw: array to keep track of bandwidth already used for FS
+ * @fs_bus_bw_out: save bandwidth used by FS/LS OUT eps in each uframes
+ * @fs_bus_bw_in: save bandwidth used by FS/LS IN eps in each uframes
+ * @ls_bus_bw: save bandwidth used by LS eps in each uframes
+ * @fs_frame_bw: save bandwidth used by FS/LS eps in each FS frames
* @ep_list: Endpoints using this TT
*/
struct mu3h_sch_tt {
- u32 fs_bus_bw[XHCI_MTK_MAX_ESIT];
+ u16 fs_bus_bw_out[XHCI_MTK_MAX_ESIT];
+ u16 fs_bus_bw_in[XHCI_MTK_MAX_ESIT];
+ u8 ls_bus_bw[XHCI_MTK_MAX_ESIT];
+ u16 fs_frame_bw[XHCI_MTK_FRAMES_CNT];
struct list_head ep_list;
};
--
2.18.0