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Optimise allocation of USB DMA structures. By default don't double map

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allocations if only one element should be allocated per page
cache. Make one allocation per element compile time configurable. Fix
a comment while at it.

Suggested by:	ian @
MFC after:	1 week
This commit is contained in:
Hans Petter Selasky 2015-02-02 11:32:15 +00:00
parent add9e3e5d3
commit 8b1ce3297a
2 changed files with 28 additions and 4 deletions
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1
sys/conf/options
View File

@ -651,6 +651,7 @@ USB_HOST_ALIGN opt_usb.h
USB_REQ_DEBUG opt_usb.h
USB_TEMPLATE opt_usb.h
USB_VERBOSE opt_usb.h
USB_DMA_SINGLE_ALLOC opt_usb.h
USB_EHCI_BIG_ENDIAN_DESC opt_usb.h
U3G_DEBUG opt_u3g.h
UKBD_DFLT_KEYMAP opt_ukbd.h

31
sys/dev/usb/usb_transfer.c
View File

@ -237,7 +237,11 @@ usbd_transfer_setup_sub_malloc(struct usb_setup_params *parm,
n_obj = 1;
} else {
/* compute number of objects per page */
#ifdef USB_DMA_SINGLE_ALLOC
n_obj = 1;
#else
n_obj = (USB_PAGE_SIZE / size);
#endif
/*
* Compute number of DMA chunks, rounded up
* to nearest one:
@ -273,15 +277,33 @@ usbd_transfer_setup_sub_malloc(struct usb_setup_params *parm,
&parm->curr_xfer->xroot->dma_parent_tag;
}
if (ppc) {
*ppc = parm->xfer_page_cache_ptr;
if (ppc != NULL) {
if (n_obj != 1)
*ppc = parm->xfer_page_cache_ptr;
else
*ppc = parm->dma_page_cache_ptr;
}
r = count; /* set remainder count */
z = n_obj * size; /* set allocation size */
pc = parm->xfer_page_cache_ptr;
pg = parm->dma_page_ptr;
for (x = 0; x != n_dma_pc; x++) {
if (n_obj == 1) {
/*
* Avoid mapping memory twice if only a single object
* should be allocated per page cache:
*/
for (x = 0; x != n_dma_pc; x++) {
if (usb_pc_alloc_mem(parm->dma_page_cache_ptr,
pg, z, align)) {
return (1); /* failure */
}
/* Make room for one DMA page cache and "n_dma_pg" pages */
parm->dma_page_cache_ptr++;
pg += n_dma_pg;
}
} else {
for (x = 0; x != n_dma_pc; x++) {
if (r < n_obj) {
/* compute last remainder */
@ -294,7 +316,7 @@ usbd_transfer_setup_sub_malloc(struct usb_setup_params *parm,
}
/* Set beginning of current buffer */
buf = parm->dma_page_cache_ptr->buffer;
/* Make room for one DMA page cache and one page */
/* Make room for one DMA page cache and "n_dma_pg" pages */
parm->dma_page_cache_ptr++;
pg += n_dma_pg;
@ -314,6 +336,7 @@ usbd_transfer_setup_sub_malloc(struct usb_setup_params *parm,
}
mtx_unlock(pc->tag_parent->mtx);
}
}
}
parm->xfer_page_cache_ptr = pc;