On Wed, 5 Dec 2012, Jim Harris wrote:
On Tue, Dec 4, 2012 at 2:36 PM, Jeff Roberson <jrober...@jroberson.net>
wrote:
http://people.freebsd.org/~jeff/loadccb.diff
This patch consolidates all of the functions that map cam
control blocks for DMA into one central function. This change
is a precursor to adding new features to the I/O stack. It is
mostly mechanical. If you are running current on a raid or scsi
card, especially if it is a lesser used one, I would really like
you to apply this patch and report back any problems. If it
works you should notice nothing. If it doesn't work you will
probably panic immediately on I/O or otherwise no I/O will
happen.
+int
+bus_dmamap_load_ccb(bus_dma_tag_t dmat, bus_dmamap_t map, union ccb *ccb,
+ bus_dmamap_callback_t *callback, void *callback_arg,
+ int flags)
+{
+ struct ccb_ataio *ataio;
+ struct ccb_scsiio *csio;
+ struct ccb_hdr *ccb_h;
+ void *data_ptr;
+ uint32_t dxfer_len;
+ uint16_t sglist_cnt;
+
+ ccb_h = &ccb->ccb_h;
+ if ((ccb_h->flags & CAM_DIR_MASK) == CAM_DIR_NONE) {
+ callback(callback_arg, NULL, 0, 0);
+ }
+
I think you need to return here after invoking the callback. Otherwise you
drop through and then either invoke the callback again or call
bus_dmamap_load (which will in turn invoke the callback again).
This fix allows the ahci.c change to go back to:
Thanks Jim. That was silly of me. I have decided to move this work to a
branch and keep expanding on it. I'll solicit more testing once the
branch is closer to the ultimate goal.
Thanks,
Jeff
Index: sys/dev/ahci/ahci.c
===================================================================
--- sys/dev/ahci/ahci.c (revision 243900)
+++ sys/dev/ahci/ahci.c (working copy)
@@ -1667,23 +1667,9 @@
(ccb->ataio.cmd.flags & (CAM_ATAIO_CONTROL |
CAM_ATAIO_NEEDRESULT)))
ch->aslots |= (1 << slot->slot);
slot->dma.nsegs = 0;
- /* If request moves data, setup and load SG list */
- if ((ccb->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_NONE) {
- void *buf;
- bus_size_t size;
-
- slot->state = AHCI_SLOT_LOADING;
- if (ccb->ccb_h.func_code == XPT_ATA_IO) {
- buf = ccb->ataio.data_ptr;
- size = ccb->ataio.dxfer_len;
- } else {
- buf = ccb->csio.data_ptr;
- size = ccb->csio.dxfer_len;
- }
- bus_dmamap_load(ch->dma.data_tag, slot->dma.data_map,
- buf, size, ahci_dmasetprd, slot, 0);
- } else
- ahci_execute_transaction(slot);
+ slot->state = AHCI_SLOT_LOADING;
+ bus_dmamap_load_ccb(ch->dma.data_tag, slot->dma.data_map, ccb,
+ ahci_dmasetprd, slot, 0);
}
/* Locked by busdma engine. */
This is almost what you head earlier, but adding back setting of the slot's
state to AHCI_SLOT_LOADING, to cover the case where the load is deferred.
It seems OK to do this even in case where no load is actually happening
(i.e. CAM_DIR_NONE).
-Jim
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