d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make pass(4) handle misaligned buffers of MAXPHYS size.

Browse Source 
Since we are already using malloc()+copyin()/copyout() for smaller data
blocks, and since new asynchronous API does it always, I see no reason
to keep this ugly artificial size/alignment limitation in old API.

Tape applications suffer enough from the MAXPHYS limitations by itself,
and additional alignment requirement, often halving effectively usable
block size, does not help.

It would be good to use unmapped I/O here instead, but it require some
HBA drivers polishing first to support non-BIO unmapped buffers.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
This commit is contained in:
Alexander Motin 2019-12-23 20:41:55 +00:00
parent 5ab1cb52b2
commit c389a786dd
1 changed files with 10 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
sys/cam/cam_periph.c
View File

@ -786,6 +786,7 @@ cam_periph_mapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo,
u_int8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
u_int32_t lengths[CAM_PERIPH_MAXMAPS];
u_int32_t dirs[CAM_PERIPH_MAXMAPS];
bool misaligned[CAM_PERIPH_MAXMAPS];
bzero(mapinfo, sizeof(*mapinfo));
if (maxmap == 0)
@ -897,6 +898,12 @@ cam_periph_mapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo,
* have to unmap any previously mapped buffers.
*/
for (i = 0; i < numbufs; i++) {
if (lengths[i] > maxmap) {
printf("cam_periph_mapmem: attempt to map %lu bytes, "
"which is greater than %lu\n",
(long)(lengths[i]), (u_long)maxmap);
return (E2BIG);
}
/*
* The userland data pointer passed in may not be page
@ -906,15 +913,8 @@ cam_periph_mapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo,
* whatever extra space is necessary to make it to the page
* boundary.
*/
if ((lengths[i] +
(((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK)) > maxmap){
printf("cam_periph_mapmem: attempt to map %lu bytes, "
"which is greater than %lu\n",
(long)(lengths[i] +
(((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK)),
(u_long)maxmap);
return(E2BIG);
}
misaligned[i] = (lengths[i] +
(((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK) > MAXPHYS);
}
/*
@ -938,7 +938,7 @@ cam_periph_mapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo,
* small allocations malloc is backed by UMA, and so much
* cheaper on SMP systems.
*/
if (lengths[i] <= periph_mapmem_thresh &&
if ((lengths[i] <= periph_mapmem_thresh || misaligned[i]) &&
ccb->ccb_h.func_code != XPT_MMC_IO) {
*data_ptrs[i] = malloc(lengths[i], M_CAMPERIPH,
M_WAITOK);