Support USB interrupt schedules on OHCI and UHCI.

The existing code always checks for USB "interrupt in" events every
millisecond.  Although that's okay, it consumes extra bandwidth.  This
change interrupt checks to be scheduled according to their requested
interval time.

8 files changed, 79 insertions, 36 deletions

diff --git a/src/clock.c b/src/clock.c
index e32bf1b7..5a30e352 100644
--- a/src/clock.c
+++ b/src/clock.c
@@ -54,8 +54,6 @@
  * TSC timer
  ****************************************************************/
 
-#define PIT_TICK_RATE 1193180   // Underlying HZ of PIT
-#define PIT_TICK_INTERVAL 65536 // Default interval for 18.2Hz timer
 #define TICKS_PER_DAY (u32)((u64)60*60*24*PIT_TICK_RATE / PIT_TICK_INTERVAL)
 #define CALIBRATE_COUNT 0x800   // Approx 1.7ms
 
diff --git a/src/usb-ohci.c b/src/usb-ohci.c
index 6ad1dbc1..2d33fa98 100644
--- a/src/usb-ohci.c
+++ b/src/usb-ohci.c
@@ -149,12 +149,18 @@ ohci_init(void *data)
 
     // Allocate memory
     struct ohci_hcca *hcca = memalign_high(256, sizeof(*hcca));
+    struct ohci_ed *intr_ed = malloc_high(sizeof(*intr_ed));
     struct ohci_ed *control_ed = malloc_high(sizeof(*control_ed));
-    if (!hcca || !control_ed) {
+    if (!hcca || !intr_ed || !control_ed) {
         dprintf(1, "No ram for ohci init\n");
-        return;
+        goto free;
     }
     memset(hcca, 0, sizeof(*hcca));
+    memset(intr_ed, 0, sizeof(*intr_ed));
+    intr_ed->hwINFO = ED_SKIP;
+    int i;
+    for (i=0; i<ARRAY_SIZE(hcca->int_table); i++)
+        hcca->int_table[i] = (u32)intr_ed;
     memset(control_ed, 0, sizeof(*control_ed));
     control_ed->hwINFO = ED_SKIP;
     cntl->ohci.control_ed = control_ed;
@@ -170,7 +176,9 @@ ohci_init(void *data)
 
 err:
     stop_ohci(cntl);
+free:
     free(hcca);
+    free(intr_ed);
     free(control_ed);
 }
 
@@ -245,18 +253,21 @@ struct ohci_pipe {
 };
 
 struct usb_pipe *
-ohci_alloc_intr_pipe(u32 endp, int period)
+ohci_alloc_intr_pipe(u32 endp, int frameexp)
 {
     if (! CONFIG_USB_OHCI)
         return NULL;
 
-    dprintf(7, "ohci_alloc_intr_pipe %x %d\n", endp, period);
+    dprintf(7, "ohci_alloc_intr_pipe %x %d\n", endp, frameexp);
+    if (frameexp > 5)
+        frameexp = 5;
     struct usb_s *cntl = endp2cntl(endp);
     int maxpacket = endp2maxsize(endp);
     int lowspeed = endp2speed(endp);
     int devaddr = endp2devaddr(endp) | (endp2ep(endp) << 7);
-    // XXX - just grab 20 for now.
-    int count = 20;
+    // Determine number of entries needed for 2 timer ticks.
+    int ms = 1<<frameexp;
+    int count = DIV_ROUND_UP(PIT_TICK_INTERVAL * 1000 * 2, PIT_TICK_RATE * ms);
     struct ohci_pipe *pipe = malloc_low(sizeof(*pipe));
     struct ohci_td *tds = malloc_low(sizeof(*tds) * count);
     void *data = malloc_low(maxpacket * count);
@@ -267,7 +278,6 @@ ohci_alloc_intr_pipe(u32 endp, int period)
     ed->hwHeadP = (u32)&tds[0];
     ed->hwTailP = (u32)&tds[count-1];
     ed->hwINFO = devaddr | (maxpacket << 16) | (lowspeed ? ED_LOWSPEED : 0);
-    ed->hwNextED = 0;
 
     int i;
     for (i=0; i<count-1; i++) {
@@ -277,11 +287,20 @@ ohci_alloc_intr_pipe(u32 endp, int period)
         tds[i].hwBE = tds[i].hwCBP + maxpacket - 1;
     }
 
-    // XXX - need schedule - just add to primary list for now.
+    // Add to interrupt schedule.
     barrier();
     struct ohci_hcca *hcca = (void*)cntl->ohci.regs->hcca;
-    for (i=0; i<ARRAY_SIZE(hcca->int_table); i++)
-        hcca->int_table[i] = (u32)ed;
+    if (frameexp == 0) {
+        // Add to existing interrupt entry.
+        struct ohci_ed *intr_ed = (void*)hcca->int_table[0];
+        ed->hwNextED = intr_ed->hwNextED;
+        intr_ed->hwNextED = (u32)ed;
+    } else {
+        int startpos = 1<<(frameexp-1);
+        ed->hwNextED = hcca->int_table[startpos];
+        for (i=startpos; i<ARRAY_SIZE(hcca->int_table); i+=ms)
+            hcca->int_table[i] = (u32)ed;
+    }
 
     pipe->data = data;
     pipe->count = count;
diff --git a/src/usb-ohci.h b/src/usb-ohci.h
index 5a4f735a..7ff84f6b 100644
--- a/src/usb-ohci.h
+++ b/src/usb-ohci.h
@@ -6,7 +6,7 @@ struct usb_s;
 void ohci_init(void *data);
 int ohci_control(u32 endp, int dir, const void *cmd, int cmdsize
                  , void *data, int datasize);
-struct usb_pipe *ohci_alloc_intr_pipe(u32 endp, int period);
+struct usb_pipe *ohci_alloc_intr_pipe(u32 endp, int frameexp);
 int ohci_poll_intr(struct usb_pipe *pipe, void *data);
 
 
diff --git a/src/usb-uhci.c b/src/usb-uhci.c
index d98c08b0..950ec6a3 100644
--- a/src/usb-uhci.c
+++ b/src/usb-uhci.c
@@ -36,9 +36,15 @@ configure_uhci(struct usb_s *cntl)
     // Allocate ram for schedule storage
     struct uhci_td *term_td = malloc_high(sizeof(*term_td));
     struct uhci_framelist *fl = memalign_high(sizeof(*fl), sizeof(*fl));
-    struct uhci_qh *data_qh = malloc_low(sizeof(*data_qh));
+    struct uhci_qh *intr_qh = malloc_high(sizeof(*intr_qh));
+    struct uhci_qh *data_qh = malloc_high(sizeof(*data_qh));
     struct uhci_qh *term_qh = malloc_high(sizeof(*term_qh));
-    if (!term_td || !fl || !data_qh || !term_qh) {
+    if (!term_td || !fl || !intr_qh || !data_qh || !term_qh) {
+        free(term_td);
+        free(fl);
+        free(intr_qh);
+        free(data_qh);
+        free(term_qh);
         dprintf(1, "No ram for uhci init\n");
         return;
     }
@@ -58,11 +64,14 @@ configure_uhci(struct usb_s *cntl)
     data_qh->link = (u32)term_qh | UHCI_PTR_QH;
     cntl->uhci.qh = data_qh;
 
-    // Set schedule to point to primary queue head
+    // Set schedule to point to primary intr queue head
+    memset(intr_qh, 0, sizeof(*intr_qh));
+    intr_qh->element = UHCI_PTR_TERM;
+    intr_qh->link = (u32)data_qh | UHCI_PTR_QH;
     int i;
-    for (i=0; i<ARRAY_SIZE(fl->links); i++) {
-        fl->links[i] = (u32)data_qh | UHCI_PTR_QH;
-    }
+    for (i=0; i<ARRAY_SIZE(fl->links); i++)
+        fl->links[i] = (u32)intr_qh | UHCI_PTR_QH;
+    cntl->uhci.framelist = fl;
 
     // Set the frame length to the default: 1 ms exactly
     outb(USBSOF_DEFAULT, cntl->uhci.iobase + USBSOF);
@@ -229,26 +238,28 @@ uhci_control(u32 endp, int dir, const void *cmd, int cmdsize
 }
 
 struct usb_pipe *
-uhci_alloc_intr_pipe(u32 endp, int period)
+uhci_alloc_intr_pipe(u32 endp, int frameexp)
 {
     if (! CONFIG_USB_UHCI)
         return NULL;
 
-    dprintf(7, "uhci_alloc_intr_pipe %x %d\n", endp, period);
+    dprintf(7, "uhci_alloc_intr_pipe %x %d\n", endp, frameexp);
+    if (frameexp > 10)
+        frameexp = 10;
     struct usb_s *cntl = endp2cntl(endp);
     int maxpacket = endp2maxsize(endp);
     int lowspeed = endp2speed(endp);
     int devaddr = endp2devaddr(endp) | (endp2ep(endp) << 7);
-    // XXX - just grab 20 for now.
-    int count = 20;
+    // Determine number of entries needed for 2 timer ticks.
+    int ms = 1<<frameexp;
+    int count = DIV_ROUND_UP(PIT_TICK_INTERVAL * 1000 * 2, PIT_TICK_RATE * ms);
     struct uhci_qh *qh = malloc_low(sizeof(*qh));
     struct uhci_td *tds = malloc_low(sizeof(*tds) * count);
-    if (!qh || !tds)
-        return NULL;
-    if (maxpacket > sizeof(tds[0].data))
-        // XXX - free qh/tds
+    if (!qh || !tds || maxpacket > sizeof(tds[0].data)) {
+        free(qh);
+        free(tds);
         return NULL;
-
+    }
     qh->element = (u32)tds;
     int toggle = 0;
     int i;
@@ -266,10 +277,19 @@ uhci_alloc_intr_pipe(u32 endp, int period)
     qh->next_td = &tds[0];
     qh->pipe.endp = endp;
 
-    // XXX - need schedule - just add to primary list for now.
-    struct uhci_qh *data_qh = cntl->uhci.qh;
-    qh->link = data_qh->link;
-    data_qh->link = (u32)qh | UHCI_PTR_QH;
+    // Add to interrupt schedule.
+    struct uhci_framelist *fl = cntl->uhci.framelist;
+    if (frameexp == 0) {
+        // Add to existing interrupt entry.
+        struct uhci_qh *intr_qh = (void*)(fl->links[0] & ~UHCI_PTR_BITS);
+        qh->link = intr_qh->link;
+        intr_qh->link = (u32)qh | UHCI_PTR_QH;
+    } else {
+        int startpos = 1<<(frameexp-1);
+        qh->link = fl->links[startpos];
+        for (i=startpos; i<ARRAY_SIZE(fl->links); i+=ms)
+            fl->links[i] = (u32)qh | UHCI_PTR_QH;
+    }
 
     return &qh->pipe;
 }
diff --git a/src/usb-uhci.h b/src/usb-uhci.h
index 5de7da0d..03ac9cd8 100644
--- a/src/usb-uhci.h
+++ b/src/usb-uhci.h
@@ -8,7 +8,7 @@ struct usb_s;
 void uhci_init(void *data);
 int uhci_control(u32 endp, int dir, const void *cmd, int cmdsize
                  , void *data, int datasize);
-struct usb_pipe *uhci_alloc_intr_pipe(u32 endp, int period);
+struct usb_pipe *uhci_alloc_intr_pipe(u32 endp, int frameexp);
 int uhci_poll_intr(struct usb_pipe *pipe, void *data);
 
 
diff --git a/src/usb.c b/src/usb.c
index 9a61f126..3d59faf6 100644
--- a/src/usb.c
+++ b/src/usb.c
@@ -35,12 +35,16 @@ struct usb_pipe *
 alloc_intr_pipe(u32 endp, int period)
 {
     struct usb_s *cntl = endp2cntl(endp);
+    // Find the exponential period of the requested time.
+    if (period <= 0)
+        period = 1;
+    int frameexp = __fls(period);
     switch (cntl->type) {
     default:
     case USB_TYPE_UHCI:
-        return uhci_alloc_intr_pipe(endp, period);
+        return uhci_alloc_intr_pipe(endp, frameexp);
     case USB_TYPE_OHCI:
-        return ohci_alloc_intr_pipe(endp, period);
+        return ohci_alloc_intr_pipe(endp, frameexp);
     }
 }
 
diff --git a/src/usb.h b/src/usb.h
index cc71c31a..8b9c5f1e 100644
--- a/src/usb.h
+++ b/src/usb.h
@@ -11,7 +11,7 @@ struct usb_s {
     union {
         struct {
             u16 iobase;
-            void *qh;
+            void *qh, *framelist;
         } uhci;
         struct {
             struct ohci_regs *regs;
diff --git a/src/util.h b/src/util.h
index 60a72599..429590ce 100644
--- a/src/util.h
+++ b/src/util.h
@@ -245,6 +245,8 @@ void serial_setup(void);
 void lpt_setup(void);
 
 // clock.c
+#define PIT_TICK_RATE 1193180   // Underlying HZ of PIT
+#define PIT_TICK_INTERVAL 65536 // Default interval for 18.2Hz timer
 static inline int check_time(u64 end) {
     return (s64)(rdtscll() - end) > 0;
 }