Coherent4.2.10/conf/hai/src/haisg.c
#include <sys/coherent.h>
#include <sys/cmn_err.h>
#include <sys/buf.h>
#include <sys/mmu.h>
#include <sys/haiscsi.h>
#define LOCAL static
#if defined(__GNUC__)
#define Register
#else
#define Register register
#endif
#define min(a, b) (((a) < (b)) ? (a) : (b))
#if __USE_PROTO__
size_t ukbuftosgl(vaddr_t ukbuf,
size_t ukbufsize,
haisgsegm_p sglist,
size_t segcount)
#else
size_t
ukbuftosgl(ukbuf, ukbufsize, sglist, segcount)
vaddr_t ukbuf;
size_t ukbufsize;
haisgsegm_p sglist;
size_t segcount;
#endif
{
haisgsegm_p sg_seg;
paddr_t newsegstart;
size_t newsegsize;
if (!(sg_seg = sglist) || !segcount) {
cmn_err(CE_WARN, "hai: ukbuftosgl() with empty segment list.");
return NULL;
} /* if */
/*
* Create the first segment in the list. Zero the size entry
* and defer setting it correctly until the top of the loop.
*/
sg_seg->sgs_segstart = vtop(ukbuf);
sg_seg->sgs_segsize = 0;
newsegsize = NBPC - (sg_seg->sgs_segstart & (NBPC - 1));
if (newsegsize > ukbufsize)
newsegsize = ukbufsize;
for ( ; ; ) {
/*
* Now adjust the size of the current entry and of the buffer
* if there isn't any more buffer left then we're done.
*/
sg_seg->sgs_segsize += newsegsize;
ukbufsize -= newsegsize;
if (ukbufsize == 0)
break;
/*
* Adjust the pointer to the virtual buffer and figure out the
* page of physical memory that it points to. Also compute the
* size of the buffer within the page.
*/
ukbuf += newsegsize;
newsegstart = vtop(ukbuf);
newsegsize = min(ukbufsize, NBPC);
/*
* If the page is discontiguous then we have to start a new
* segment. As before set the size of the new segment to 0,
* defering setting it correctly until the top of the loop.
*/
if (newsegstart != sg_seg->sgs_segstart + sg_seg->sgs_segsize) {
/*
* Make sure that we don't use too many segments!
*/
if (--segcount <= 0) {
cmn_err(CE_WARN, "hai: out of segments creating sglist.");
return 0;
}
++sg_seg;
sg_seg->sgs_segstart = newsegstart;
sg_seg->sgs_segsize = 0;
} /* if */
} /* for */
return sg_seg - sglist + 1;
} /* ukbuftosgl() */
#if __USE_PROTO__
size_t sysgbuftosgl(paddr_t sysgbuf,
size_t sysgbufsize,
haisgsegm_p sglist,
size_t segcount)
#else
size_t
sysgbuftosgl(sysgbuf, sysgbufsize, sglist, segcount)
paddr_t sysgbuf;
size_t sysgbufsize;
haisgsegm_p sglist;
size_t segcount;
#endif
{
haisgsegm_p sg_seg;
paddr_t newsegstart;
size_t newsegsize;
if (!(sg_seg = sglist) || segcount == 0) {
cmn_err(CE_WARN, "hai: sysgbuftosgl() with empty segment list.");
return NULL;
} /* if */
/*
* Create the first segment in the list. Zero the size entry
* and defer setting it correctly until the top of the loop.
*/
sg_seg->sgs_segstart = P2P(sysgbuf);
sg_seg->sgs_segsize = 0;
newsegsize = NBPC - (sg_seg->sgs_segstart & (NBPC - 1));
if (newsegsize > sysgbufsize)
newsegsize = sysgbufsize;
for ( ; ; ) {
/*
* Now adjust the size of the current entry and of the buffer
* if there isn't any more buffer left then we're done.
*/
sg_seg->sgs_segsize += newsegsize;
sysgbufsize -= newsegsize;
if (sysgbufsize == 0)
break;
/*
* Adjust the pointer to the virtual buffer and figure out the
* page of physical memory that it points to. Also compute the
* size of the buffer within the page.
*/
sysgbuf += newsegsize;
newsegstart = P2P(sysgbuf);
newsegsize = min(sysgbufsize, NBPC);
/*
* If the page is discontiguous then we have to start a new
* segment. As before set the size of the new segment to 0,
* defering setting it correctly until the top of the loop.
*/
if (newsegstart != sg_seg->sgs_segstart + sg_seg->sgs_segsize) {
/*
* Make sure that we don't use too many segments!
*/
if (--segcount <= 0) {
cmn_err(CE_WARN, "hai: out of segments creating sglist.");
return 0;
} /* if */
++sg_seg;
sg_seg->sgs_segstart = newsegstart;
sg_seg->sgs_segsize = 0;
} /* if */
} /* for */
return sg_seg - sglist + 1;
} /* sysgbuftosgl() */
#if __USE_PROTO__
int addbuftosgl(paddr_t sysgaddr,
size_t bufsize,
haisgsegm_p seg,
size_t segcount)
#else
int
addbuftosgl(sysgaddr, bufsize, seg, segcount)
paddr_t sysgaddr;
size_t bufsize;
haisgsegm_p seg;
size_t segcount;
#endif
{
/*
* Start by saving the end of the list for possible undo operation.
*/
haisgsegm_p start_seg = seg;
paddr_t undo_segstart = seg->sgs_segstart;
size_t undo_segsize = seg->sgs_segsize;
haisgsegm_p stop_seg = seg + segcount;
size_t bytescopied;
paddr_t physaddr;
paddr_t segend;
int retval;
/*
* Setup the first element of an empty scatter/gather list here.
*/
if (seg->sgs_segstart == NULL) {
seg->sgs_segstart = P2P(sysgaddr);
seg->sgs_segsize = 0;
} /* if */
bytescopied = 0;
while (bufsize > 0) {
seg->sgs_segsize += bytescopied;
sysgaddr += bytescopied;
physaddr = P2P(sysgaddr);
segend = seg->sgs_segstart + seg->sgs_segsize;
if (physaddr != segend) {
if (++seg >= stop_seg)
break;
seg->sgs_segstart = physaddr;
seg->sgs_segsize = 0;
} /* if */
bytescopied = NBPC - ((unsigned) segend & (NBPC - 1));
if (bytescopied > bufsize)
bytescopied = bufsize;
seg->sgs_segsize += bytescopied;
bufsize -= bytescopied;
} /* while */
if (bufsize > 0) {
seg = start_seg;
seg->sgs_segstart = undo_segstart;
seg->sgs_segsize = undo_segsize;
retval = -1;
} /* if */
else
retval = seg - start_seg;
if (++seg < stop_seg) {
seg->sgs_segstart = NULL;
seg->sgs_segsize = 0;
} /* if */
return retval;
} /* addbuftosgl() */
#if __USE_PROTO__
int buftosglist(buf_t *bp, size_t bufcount, haisgsegm_p seg, size_t segcount)
#else
int buftosglist(bp, bufcount, seg, segcount)
buf_t *bp;
size_t bufcount;
haisgsegm_p seg;
size_t segcount;
#endif
{
size_t index;
size_t segsused;
/*
* Set up the initial segment to have the physical address of the first
* buffer and 0 size. This way addbuftosgl() works properly.
*/
seg->sgs_segstart = NULL;
seg->sgs_segsize = 0;
for (index = 0; index < segcount; ) {
/*
* Add this segment to the scatter gather list. resid is the
* number of bytes that could not be fit in if we run out of
* segments.
*/
segsused = addbuftosgl(bp->b_paddr + bp->b_count - bp->b_resid,
bp->b_resid,
seg + index,
segcount - index);
if (segsused == -1)
break;
else
index += segsused;
bp = bp->b_actf;
if (!bp || bp->b_resid != bp->b_count || --bufcount)
break;
} /* for */
return index;
} /* buftosglist() */
/* End of file */