from the amr_linux. This simplifies the amr_linux shim and puts the
smarts into amr.c.
I tested this with 2 amr controllers in one box. It seems to work
okay with them.
The real problem was that ioctl handlers needed to call amr_wait_command()
with the list lock held. This not only solves the completion race, it also
prevents bounce buffer corruption that could arise from amr_start() being
called without the proper locks held.
Discussed with: ps
MFC After: 3 days
the completion of the command can occur before tsleep is called and
the command ends up blocking forever since the wakeup has already
been called.
Submitted by: ups
routines.
- Add or replace cpu_spinwait() with DELAY(1) to a few of the busy
loops when reading from the controller to work around firmware bugs
which can crash the controller.
This is important with MegaLib, when issuing a GET_REBUILD_PROG since
it returns an error if the drive is not in rebuild state.
This will be MFC'ed shortly.
Submitted by: ps
Reviewed by: scottl
Found by: ambrisko
Linux LSI MegaRaid tools can run on FreeBSD until Linux emulation.
Add in the Linux IOCTL shim and create the megadev0 device so
Linux LSI MegaRaid tools can run on FreeBSD until Linux emulation.
Add glue to build the modules but don't tie it into the build
yet until I test it from the CVS repo. via the mirror on an
amd64 machine.
Tie this into the Linux32 emulation on amd64 so the tools can
run on amd64 kernel.
Cleaned up by: ps (amr_linux.c)
1. Implement a large set of ioctl shims so that the Linux management apps
from LSI will work. This includes infrastructure to support adding, deleting
and rescanning arrays at runtime. This is based on work from Doug Ambrosko,
heavily augmented by LSI and Yahoo.
2. Implement full 64-bit DMA support. Systems with more than 4GB of RAM
can now operate without the cost of bounce buffers. Cards that cannot do
64-bit DMA will automatically revert to using bounce buffers. This option
can be forced off by setting the 'hw.amr.force_sg32" tunable in the loader.
It should only be turned off for debugging purposes. This work was sponsored
by Yahoo.
3. Streamline the command delivery and interrupt handler paths after
much discussion with Dell and LSI. The logic now closely matches the
intended design, making it both more robust and much faster. Certain
i/o failures under heavy load should be fixed with this.
4. Optimize the locking. In the interrupt handler, the card can be checked
for completed commands without any locks held, due to the handler being
implicitely serialized and there being no need to look at any shared data.
Only grab the lock to return the command structure to the free pool. A
small optimization can still be made to collect all of the completions
together and then free them together under a single lock.
Items 3 and 4 significantly increase the performance of the driver. On an
LSI 320-2X card, transactions per second went from 13,000 to 31,000 in my
testing with these changes. However, these changes are still fairly
experimental and shouldn't be merged to 6.x until there is more testing.
Thanks to Doug Ambrosko, LSI, Dell, and Yahoo for contributing towards
this.
with no associated data. Also revert previous changes that allocate off
of the stack instead of using malloc, as it's not needed. Many thanks to
LSI for investigating and fixing these problems.
Submitted by: rajeshpr @ lsil . com
- Introduce the amr_io_lock to control access to command queues, bio queues,
and the hardware.
- Eliminate the taskqueue and do all completion processing in the ithread.
- Assign a static slot number to each command instead of doing a linear
search for free slots each time a command is needed.
- Modify the interrupt handler to more closely match what Linux does, for
safety.
properly support bounce buffers and resource shortages. This allows the
driver to work properly and reliably with more than 4GB of RAM. Of the
three data paths that exist in the driver, (block, CAM, ioctl), the ioctl
path has not been well tested with these changes due to difficulty with
finding an application that uses it that actually works.
Sponsored by: The FreeBSD Foundation and FreeBSD Systems, Inc.
Introduce d_version field in struct cdevsw, this must always be
initialized to D_VERSION.
Flip sense of D_NOGIANT flag to D_NEEDGIANT, this involves removing
four D_NOGIANT flags and adding 145 D_NEEDGIANT flags.
Previously the "struct disk" were owned by the device driver and this
gave us problems when the device disappared and the users of that device
were not immediately disappearing.
Now the struct disk is allocate with a new call, disk_alloc() and owned
by geom_disk and just abandonned by the device driver when disk_create()
is called.
Unfortunately, this results in a ton of "s/\./->/" changes to device
drivers.
Since I'm doing the sweep anyway, a couple of other API improvements
have been carried out at the same time:
The Giant awareness flag has been flipped from DISKFLAG_NOGIANT to
DISKFLAG_NEEDSGIANT
A version number have been added to disk_create() so that we can detect,
report and ignore binary drivers with old ABI in the future.
Manual page update to follow shortly.
