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Utilize bus_dma(9) functions more efficiently. 

pcscp(4) is the first device driver I wrote about five years ago,
but I still have to learn about bus_dma(9) implementation...
This commit is contained in:
tsutsui 2003-10-19 10:25:42 +00:00
parent fa6713d480
commit 8d36037f37
1 changed files with 6 additions and 30 deletions
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36
sys/dev/pci/pcscp.c
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@ -1,4 +1,4 @@
/* $NetBSD: pcscp.c,v 1.25 2003/10/12 04:12:23 tsutsui Exp $ */
/* $NetBSD: pcscp.c,v 1.26 2003/10/19 10:25:42 tsutsui Exp $ */
/*-
* Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
@ -46,7 +46,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pcscp.c,v 1.25 2003/10/12 04:12:23 tsutsui Exp $");
__KERNEL_RCSID(0, "$NetBSD: pcscp.c,v 1.26 2003/10/19 10:25:42 tsutsui Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@ -271,8 +271,8 @@ pcscp_attach(parent, self, aux)
#define MDL_SEG_OFFSET 0x0FFF
#define MDL_SIZE (MAXPHYS / MDL_SEG_SIZE + 1) /* no hardware limit? */
if (bus_dmamap_create(esc->sc_dmat, MAXPHYS, MDL_SIZE, MAXPHYS, 0,
BUS_DMA_NOWAIT, &esc->sc_xfermap)) {
if (bus_dmamap_create(esc->sc_dmat, MAXPHYS, MDL_SIZE, MDL_SEG_SIZE,
MDL_SEG_SIZE, BUS_DMA_NOWAIT, &esc->sc_xfermap)) {
printf("%s: can't create DMA maps\n", sc->sc_dev.dv_xname);
return;
}
@ -525,7 +525,6 @@ pcscp_dma_setup(sc, addr, len, datain, dmasize)
u_int32_t *mdl;
int error, nseg, seg;
bus_addr_t s_offset, s_addr;
long rest, count;
WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
@ -566,40 +565,17 @@ pcscp_dma_setup(sc, addr, len, datain, dmasize)
nseg = dmap->dm_nsegs;
/* the first segment is possibly not aligned with 4k MDL boundary */
count = dmap->dm_segs[0].ds_len;
s_addr = dmap->dm_segs[0].ds_addr;
s_offset = s_addr & MDL_SEG_OFFSET;
s_addr -= s_offset;
rest = MDL_SEG_SIZE - s_offset;
/* set the first MDL and offset */
WRITE_DMAREG(esc, DMA_SPA, s_offset);
*mdl++ = htole32(s_addr);
count -= rest;
/* rests of the first dmamap segment */
while (count > 0) {
s_addr += MDL_SEG_SIZE;
*mdl++ = htole32(s_addr);
count -= MDL_SEG_SIZE;
}
/* the rest dmamap segments are aligned with 4k boundary */
for (seg = 1; seg < nseg; seg++) {
count = dmap->dm_segs[seg].ds_len;
s_addr = dmap->dm_segs[seg].ds_addr;
/* first 4kbyte of each dmamap segment */
*mdl++ = htole32(s_addr);
count -= MDL_SEG_SIZE;
/* trailing contiguous 4k frames of each dmamap segments */
while (count > 0) {
s_addr += MDL_SEG_SIZE;
*mdl++ = htole32(s_addr);
count -= MDL_SEG_SIZE;
}
}
for (seg = 1; seg < nseg; seg++)
*mdl++ = htole32(dmap->dm_segs[seg].ds_addr);
return 0;
}