PERFORCE change 139166 for review
Hans Petter Selasky
hselasky at FreeBSD.org
Tue Apr 1 14:11:56 PDT 2008
http://perforce.freebsd.org/chv.cgi?CH=139166
Change 139166 by hselasky at hselasky_laptop001 on 2008/04/01 21:11:23
To solve the following three problems I have to make a set of
BUS-DMA related changes. Commit 3/3
P1) I should pass a valid lock function to "bus_dma_tag_create".
P2) Currently the error code EINPROGRESS is not handled at all, when
returned by "bus_dmamap_load". I have created a new condition variable
that will be used to wait for the done callback.
P3) Ensure that all USB page caches on an USB transfer are loaded
in serial, mostly in case of page bouncing.
Changes in "usb_transfer.c" from the top:
1) Use new function "usbd_dma_tag_setup" to initialise the
USB DMA structures.
2) New arguments for "usbd_dma_tag_unsetup()".
3) Factored out code into "usbd_bdma_get_next_xfer()".
4) Modifications to "usbd_bdma_work_loop" so that P3 is solved. The idea is that
the calls to "usbd_pc_load_mem()" are moved outside the main loop and
the state of the current frame buffer to load is stored in
the "usbd_memory_info" structure. When "info->dma_currframe == info->dma_nframes" all
frames have been loaded.
5) Some modifications to "usbd_bdma_done_event()" because the BUS-DMA abstraction is
now less USB-specific.
Affected files ...
.. //depot/projects/usb/src/sys/dev/usb/usb_transfer.c#123 edit
Differences ...
==== //depot/projects/usb/src/sys/dev/usb/usb_transfer.c#123 (text+ko) ====
@@ -63,6 +63,7 @@
static void usbd_premature_callback(struct usbd_xfer *xfer, usbd_status_t error);
static void usbd_pipe_enter_wrapper(struct usbd_xfer *xfer);
static void usbd_bdma_work_loop(struct usbd_memory_info *info);
+static void usbd_bdma_done_event(struct usbd_dma_parent_tag *udpt);
static void usbd_callback_intr_sched(struct usbd_memory_info *info);
static void usbd_callback_intr_td_sub(struct usbd_xfer **xfer, uint8_t dropcount);
static void usbd_callback_intr_td(void *arg);
@@ -814,7 +815,8 @@
if (parm->buf) {
for (x = 0; x != n_frbuffers; x++) {
- xfer->frbuffers[x].xfer = xfer;
+ xfer->frbuffers[x].tag_parent =
+ &(xfer->usb_root->dma_parent_tag);
if (xfer->flags_int.bdma_enable &&
(parm->bufsize_max > 0)) {
@@ -943,8 +945,11 @@
info->usb_mtx = &(udev->bus->mtx);
info->priv_mtx = priv_mtx;
- info->dma_tag_p = parm.dma_tag_p;
- info->dma_tag_max = parm.dma_tag_max;
+
+ usbd_dma_tag_setup(&(info->dma_parent_tag),
+ parm.dma_tag_p, udev->bus->dma_parent_tag[0].tag,
+ priv_mtx, &usbd_bdma_done_event, info, 32, parm.dma_tag_max);
+
info->bus = udev->bus;
LIST_INIT(&(info->done_head));
@@ -1231,8 +1236,7 @@
}
/* free all DMA tags */
- usbd_dma_tag_unsetup(info->dma_tag_p,
- info->dma_tag_max);
+ usbd_dma_tag_unsetup(&(info->dma_parent_tag));
/*
* free the "memory_base" last, hence the "info" structure is
@@ -1801,7 +1805,7 @@
info = xfer->usb_root;
/*
- * Only call the BUS-DMA work loop when it is not busy
+ * Only call the BUS-DMA work loop when it is not busy:
*/
if (info->dma_refcount == 0) {
usbd_bdma_work_loop(info);
@@ -1841,9 +1845,31 @@
}
/*------------------------------------------------------------------------*
+ * usbd_bdma_get_next_xfer
+ *
+ * This function will advance the "dma_curr_xfer" pointer to the next
+ * USB transfer in the queue.
+ *------------------------------------------------------------------------*/
+static void
+usbd_bdma_get_next_xfer(struct usbd_memory_info *info)
+{
+ struct usbd_xfer *xfer;
+
+ xfer = info->dma_curr_xfer;
+
+ /* prepare next USB transfer to load, if any */
+ info->dma_curr_xfer =
+ LIST_PREV(&(info->dma_head), xfer, dma_list);
+ LIST_REMOVE(xfer, dma_list);
+ xfer->dma_list.le_prev = NULL;
+ return;
+}
+
+/*------------------------------------------------------------------------*
* usbd_bdma_work_loop
*
- * This function handles loading of virtual buffers into DMA.
+ * This function handles loading of virtual buffers into DMA and is
+ * only called when "dma_refcount" is zero.
*------------------------------------------------------------------------*/
static void
usbd_bdma_work_loop(struct usbd_memory_info *info)
@@ -1860,44 +1886,69 @@
xfer = info->dma_curr_xfer;
if (xfer) {
- /* prepare next USB transfer to load, if any */
- info->dma_curr_xfer =
- LIST_PREV(&(info->dma_head), xfer, dma_list);
- LIST_REMOVE(xfer, dma_list);
- xfer->dma_list.le_prev = NULL;
+
+ /* prevent recursion by increasing the DMA refcount */
+
+ info->dma_refcount = 2;
- /* check for DMA error */
+ /* check for errors */
if (!xfer->flags_int.open) {
+ /* get next xfer */
+ usbd_bdma_get_next_xfer(info);
+
/* we got cancelled */
-
- info->dma_refcount++;
usbd_premature_callback(xfer,
USBD_ERR_CANCELLED);
- info->dma_refcount--;
} else if (info->dma_error) {
- /* prevent recursion by increasing refcount */
-
- info->dma_refcount++;
+ /* get next xfer */
+ usbd_bdma_get_next_xfer(info);
/* report error */
-
usbd_premature_callback(xfer,
USBD_ERR_DMA_LOAD_FAILED);
- info->dma_refcount--;
+ } else if (info->dma_currframe != info->dma_nframes) {
+
+ if (info->dma_currframe == 0) {
+ /* special case */
+ usbd_pc_load_mem(xfer->frbuffers,
+ info->dma_frlength_0);
+ } else {
+ /* default case */
+ nframes = info->dma_currframe;
+ usbd_pc_load_mem(xfer->frbuffers + nframes,
+ xfer->frlengths[nframes]);
+ }
+
+ /* advance frame index */
+ info->dma_currframe++;
+ /* check if callback has decremented refcount */
+ if (--(info->dma_refcount) == 0) {
+ /* we are complete */
+ goto load_complete;
+ } else {
+ /* wait for callback */
+ return;
+ }
} else {
+
+ /* get next xfer */
+ usbd_bdma_get_next_xfer(info);
+
/* go ahead */
usbd_bdma_pre_sync(xfer);
/* finally start the hardware */
usbd_pipe_enter_wrapper(xfer);
+ }
+
+ info->dma_refcount = 0;
- }
} else {
/* get first USB transfer */
info->dma_curr_xfer =
@@ -1915,7 +1966,6 @@
}
/* reset BUS-DMA load state */
- info->dma_refcount = 1;
info->dma_error = 0;
if (xfer->flags_int.isochronous_xfr) {
@@ -1949,44 +1999,53 @@
xfer->frbuffers[0].isread = isread;
}
+ /*
+ * Setup the "page_start" pointer which points to an array of
+ * USB pages where information about the physical address of a
+ * page will be stored. Also initialise the "isread" field of
+ * the USB page caches.
+ */
xfer->frbuffers[0].page_start = pg;
- usbd_pc_load_mem(xfer->frbuffers, frlength_0);
+ info->dma_nframes = nframes;
+ info->dma_currframe = 0;
+ info->dma_frlength_0 = frlength_0;
pg += (frlength_0 / USB_PAGE_SIZE);
pg += 2;
while (--nframes > 0) {
xfer->frbuffers[nframes].isread = isread;
-
xfer->frbuffers[nframes].page_start = pg;
- usbd_pc_load_mem(xfer->frbuffers + nframes,
- xfer->frlengths[nframes]);
-
pg += (xfer->frlengths[nframes] / USB_PAGE_SIZE);
pg += 2;
}
- if (--(info->dma_refcount) == 0) {
- /* we are complete */
- goto load_complete;
- }
- return;
+ goto load_complete;
}
/*------------------------------------------------------------------------*
* usbd_bdma_done_event
*
* This function is called when the BUS-DMA has loaded virtual memory
- * into DMA, if any
+ * into DMA, if any.
*------------------------------------------------------------------------*/
-void
-usbd_bdma_done_event(struct usbd_memory_info *info)
+static void
+usbd_bdma_done_event(struct usbd_dma_parent_tag *udpt)
{
+ struct usbd_memory_info *info;
+
+ info = udpt->info;
+
mtx_assert(info->priv_mtx, MA_OWNED);
+ /* copy error */
+ info->dma_error = udpt->dma_error;
+
+ /* check refcount */
if (--(info->dma_refcount) == 0) {
+ /* call work loop */
usbd_bdma_work_loop(info);
}
return;
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