Batch free USB pipes on OHCI controllers.

Instead of unregistering each control "endpoint descriptor" after it
is used, keep them around for later users.  Free all unused
descriptors in one batch at the end of initialization.  This should
slightly optimize boot time, and it requires less overall interaction
with the controller.

This also makes the descriptor free code more compliant with the spec.
The descriptor lists will only be modified after the list processing
has been disabled on the controller.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

diff --git a/src/usb-ohci.c b/src/usb-ohci.c
index 9107db2bcd2af68e76fc7ceb9656d7dd4d1c73c6..7a437ad6cb0c3cb615626c8d71a400492dd1cc02 100644 (file)
--- a/src/usb-ohci.c
+++ b/src/usb-ohci.c
@@ -19,6 +19,14 @@ struct usb_ohci_s {
     struct ohci_regs *regs;
 };
 
+struct ohci_pipe {
+    struct ohci_ed ed;
+    struct usb_pipe pipe;
+    void *data;
+    int count;
+    struct ohci_td *tds;
+};
+
 
 /****************************************************************
  * Root hub
@@ -109,6 +117,56 @@ check_ohci_ports(struct usb_ohci_s *cntl)
  * Setup
  ****************************************************************/
 
+// Wait for next USB frame to start - for ensuring safe memory release.
+static void
+ohci_waittick(struct usb_ohci_s *cntl)
+{
+    barrier();
+    struct ohci_hcca *hcca = (void*)cntl->regs->hcca;
+    u32 startframe = hcca->frame_no;
+    u64 end = calc_future_tsc(1000 * 5);
+    for (;;) {
+        if (hcca->frame_no != startframe)
+            break;
+        if (check_tsc(end)) {
+            warn_timeout();
+            return;
+        }
+        yield();
+    }
+}
+
+static void
+ohci_free_pipes(struct usb_ohci_s *cntl)
+{
+    dprintf(7, "ohci_free_pipes %p\n", cntl);
+
+    u32 creg = readl(&cntl->regs->control);
+    if (creg & (OHCI_CTRL_CLE|OHCI_CTRL_BLE)) {
+        writel(&cntl->regs->control, creg & ~(OHCI_CTRL_CLE|OHCI_CTRL_BLE));
+        ohci_waittick(cntl);
+    }
+
+    u32 *pos = &cntl->regs->ed_controlhead;
+    for (;;) {
+        struct ohci_ed *next = (void*)*pos;
+        if (!next)
+            break;
+        struct ohci_pipe *pipe = container_of(next, struct ohci_pipe, ed);
+        if (pipe->pipe.cntl != &cntl->usb) {
+            *pos = next->hwNextED;
+            free(pipe);
+        } else {
+            pos = &next->hwNextED;
+        }
+    }
+
+    writel(&cntl->regs->ed_controlcurrent, 0);
+    writel(&cntl->regs->ed_bulkcurrent, 0);
+    writel(&cntl->regs->control, creg);
+    cntl->usb.freelist = NULL;
+}
+
 static int
 start_ohci(struct usb_ohci_s *cntl, struct ohci_hcca *hcca)
 {
@@ -192,6 +250,7 @@ configure_ohci(void *data)
 
     int count = check_ohci_ports(cntl);
     free_pipe(cntl->usb.defaultpipe);
+    ohci_free_pipes(cntl);
     if (! count)
         goto err;
     return;
@@ -260,74 +319,13 @@ wait_ed(struct ohci_ed *ed)
     }
 }
 
-// Wait for next USB frame to start - for ensuring safe memory release.
-static void
-ohci_waittick(struct usb_ohci_s *cntl)
-{
-    barrier();
-    struct ohci_hcca *hcca = (void*)cntl->regs->hcca;
-    u32 startframe = hcca->frame_no;
-    u64 end = calc_future_tsc(1000 * 5);
-    for (;;) {
-        if (hcca->frame_no != startframe)
-            break;
-        if (check_tsc(end)) {
-            warn_timeout();
-            return;
-        }
-        yield();
-    }
-}
-
-static void
-signal_freelist(struct usb_ohci_s *cntl)
-{
-    u32 v = readl(&cntl->regs->control);
-    if (v & OHCI_CTRL_CLE) {
-        writel(&cntl->regs->control, v & ~(OHCI_CTRL_CLE|OHCI_CTRL_BLE));
-        ohci_waittick(cntl);
-        writel(&cntl->regs->ed_controlcurrent, 0);
-        writel(&cntl->regs->ed_bulkcurrent, 0);
-        writel(&cntl->regs->control, v);
-    } else {
-        ohci_waittick(cntl);
-    }
-}
-
-struct ohci_pipe {
-    struct ohci_ed ed;
-    struct usb_pipe pipe;
-    void *data;
-    int count;
-    struct ohci_td *tds;
-};
-
 void
-ohci_free_pipe(struct usb_pipe *p)
+ohci_free_pipe(struct usb_pipe *pipe)
 {
-    if (! CONFIG_USB_OHCI)
-        return;
-    dprintf(7, "ohci_free_pipe %p\n", p);
-    struct ohci_pipe *pipe = container_of(p, struct ohci_pipe, pipe);
-    struct usb_ohci_s *cntl = container_of(
-        pipe->pipe.cntl, struct usb_ohci_s, usb);
-
-    u32 *pos = &cntl->regs->ed_controlhead;
-    for (;;) {
-        struct ohci_ed *next = (void*)*pos;
-        if (!next) {
-            // Not found?!  Exit without freeing.
-            warn_internalerror();
-            return;
-        }
-        if (next == &pipe->ed) {
-            *pos = next->hwNextED;
-            signal_freelist(cntl);
-            free(pipe);
-            return;
-        }
-        pos = &next->hwNextED;
-    }
+    // Add to controller's free list.
+    struct usb_s *cntl = pipe->cntl;
+    pipe->freenext = cntl->freelist;
+    cntl->freelist = pipe;
 }
 
 struct usb_pipe *
@@ -339,7 +337,17 @@ ohci_alloc_control_pipe(struct usb_pipe *dummy)
         dummy->cntl, struct usb_ohci_s, usb);
     dprintf(7, "ohci_alloc_control_pipe %p\n", &cntl->usb);
 
-    // Allocate a queue head.
+    if (cntl->usb.freelist) {
+        // Use previously allocated queue head.
+        struct ohci_pipe *pipe = container_of(cntl->usb.freelist
+                                              , struct ohci_pipe, pipe);
+        cntl->usb.freelist = pipe->pipe.freenext;
+
+        memcpy(&pipe->pipe, dummy, sizeof(pipe->pipe));
+        return &pipe->pipe;
+    }
+
+    // Allocate a new queue head.
     struct ohci_pipe *pipe = malloc_tmphigh(sizeof(*pipe));
     if (!pipe) {
         warn_noalloc();

diff --git a/src/usb.h b/src/usb.h
index 8b2af405d917916319eaee35bf5c066d1ce50cbb..cc32eb75d8667b848a7828d73e359ed7d598de36 100644 (file)
--- a/src/usb.h
+++ b/src/usb.h
@@ -6,7 +6,10 @@
 
 // Information on a USB end point.
 struct usb_pipe {
-    struct usb_s *cntl;
+    union {
+        struct usb_s *cntl;
+        struct usb_pipe *freenext;
+    };
     u64 path;
     u8 type;
     u8 ep;
@@ -20,6 +23,7 @@ struct usb_pipe {
 // Common information for usb controllers.
 struct usb_s {
     struct usb_pipe *defaultpipe;
+    struct usb_pipe *freelist;
     struct mutex_s resetlock;
     struct pci_device *pci;
     int busid;