timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.
The old timeout()/untimeout() API has been removed from the kernel.
- `flags' is now gone, replaced with `xs_control' and `xs_status'.
- Massive cleanup of the control flags. Now we explicitly say that
a job is to complete asynchronously, rather than relying on side-effects,
and use a new flag to now that device discovery is being performed.
- Do SCSI device discovery interrupt-driven.
- the cap field is a u_int8_t, so none of the defined flags would fit in.
Looks like nobody had a drive using 16 bytes commands.
- the ACAP_DRQ_* flags are all wrong. Just remove them and use the definitions
from ata/atareg.h, there's no need to duplicate theses. The effect of this
was that we were always polling for the command phase, even for drives
with interrupt DRQ. This didn't break until the code was changed to support
shared interrupts.
Should fix the lookup problems or 'boot hangs' reported by some users, and
kern/7111.
"device_q" TAILQ entries. The former is for use by the adapter driver,
as it sees fit. The latter is for the scsipi middle layer to track
pending xfers per device.
- Add a pending_xfers queue to scsipi_link, to track pending xfers per
device.
- Grow scsipi_link's flags to int, and add SDEV_WAITDRAIN, to indicate that
we're waiting for the pending_xfers queue to empty.
scsi_base.c to scsipi_base.c. Rename the functions from scsi_verbose.c
too, and rename the file itself. Cleaup includes too (scsi_*.h should not
be #included in scsipi_*.h files, which are supposed to be
common to atapi and scsi).
struct scsipi_adapter; they were not used.
Add a scsipi_ioctl entry point to struct scsipi_adapter. This will be
used to issue ioctl commands to the host adapters.
Inspired by PR #6090, from Matt Jacob.
scsipi_xfer structures.
When scsipi_execute_xs() calls the driver's scsi_cmd function, it assumes
that it can still dereference a pointer to the scsipi_xfer struct. Since
scsipi_done() has already been called, which in turn has called
scsipi_free_xs(), the struct has already been returned the structure to
the pool! In other words, xs->flags has been compromised, but we are still
testing it.
These changes resolve the problem by doing the following:
- In scsipi_execute_xs(), if the hardware driver's scsi_cmd function
returns SUCCESSFULLY_QUEUED, set a new flag (SCSI_ASYNCREQ) in xs->flags.
Since the request will be handled asynchronously, we will need the
scsipi_xfer struct to be freed in scsipi_done().
If the hardware driver's scsi_cmd function returns COMPLETE, we now
simply return any actual errors, or 0 if none occurred. (Previously,
we may have returned EJUSTRETURN, of which the sole effect was to
avoid freeing the scsipi_xfer struct in our caller.)
- In scsipi_done(), only free the scsipi_xfer struct for async requests.
The contents of the struct will otherwise remain valid until the
function that initiated the transfer frees it.
With this change, responsibility for freeing the struct now lies in two
places, depending on the type of the request:
- For synchronous requests, the routine calling scsipi_execute_xs()
must clean up.
- For asynchronous requests, scsipi_done() cleans up (as it always has).
[Note: this change also corrects a problem with sddump(): scsipi_done()
was attempting to return a static scsipi_xfer struct to the pool! Since
dumps are performed synchronously, we now handle this correctly.]
This solution was provided by Jason Thorpe, after I got him to look at
some related (but insufficient) attempts of my own.
-store printable product ID in cd's and sd's softc, use it as "typename"
-for this, add a "destination buffer length" argument to scsipi_strvis()
-return ATAPI device type for ATAPI devices
drivers' sense handlers to return. Coincidentally one of them ends up
being ERESTARTSYS.
2) Add a SCSI_URGENT flag to xs structure- this allows host adapters that
do command tagging to do the right thing wrt a tag.
fix 'cd' driver's NCD_SCSI bogosity (was using testing wrong macro!)
clean up in various ways:
* make common atapi_mode_{sense,select}() functions.
* put ATAPI data structures in more sensible headers, split up by
device type.
* include headers a bit more carefully.
* pass flags to attachment-specific cd functions, and use them.
* get rid of SCSI bits in scsipi_base.h's scsipi_make_xs(), move
them into the correct place in scsi_base.c.
* fix minor typo in struct name in scsipiconf.h (which was apparently
never used except in a #define later in the same file).
* use __attribute__ to force 4-byte alignment for xs command store,
so that architectures trying to bus_space_write_multi_N() (where
N > 1) that data to a controller won't lose.
* clean up a few comments in typos, and make a few #defines easier to
understand/maintain.
* rename cd_link.h to cdvar.h (via repository copy). This is exactly
what a 'var' file is supposed to be.
to be reloaded every time it is checked. This avoids a condition where
it can be cached in a register in such a way that updates to the flags in
an interrupt handler to not be noticed, which in turn causes the process
doing the i/o to sleep forever. Bug report and suggested fix from
Hiroshi HORIMOTO <horimoto@cs-yuugao.cs.sist.ac.jp>, PR $4460.
- Indent with tab of width 8.
- Use four column to indent continuation line.
- Fold long line if possible.
- Use return (xx) instead of return xx.
- Compare pointer against NULL instead of testing like boolean.
- Delete whitespace at the end of line.
- Delete whitespace in front of function call operator.
- Delete whitespace after cast.
- Dereference a pointer to function explicitly.
- Add an empty line after local variable declaration.
- Use NULL instead of (char *)0.
- Dont use block for single statement.
(currently only CD-ROM drives on i386). The sys/dev/scsipi system provides 2
busses to which devices can attach (scsibus and atapibus). This needed to
change some include files and structure names in the low level scsi drivers.
