linux.git/drivers/scsi/aacraid, branch v2.6.19

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12+00:00

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells 
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

[PATCH] missing include (free_irq() use)

2006-09-24T22:55:03+00:00

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

[SCSI] aacraid: remove scsi_remove_device

2006-09-24T01:10:10+00:00

Received from Mark Salyzyn:

Until the system is stabilized, I am suggesting the enclosed
modification to prevent the driver from tickling the panic. Once sysfs
and friends are stabilized, the patch may be backed out. We have yet to
evaluate if we really want to relinquish existing Scsi Devices in any
case, holding on to them as configuration of arrays comes and goes makes
some sense as well. As a result, we have opted to pull the lines rather
than comment them in legacy.

Signed-off-by: Mark Haverkamp 
Signed-off-by: James Bottomley

[SCSI] aacraid: merge rx and rkt code

2006-09-24T01:09:42+00:00

Received from Mark Salyzyn:

The only real difference between the rkt and rx platform modules is the
offset of the message registers. This patch recognizes this similarity
and simplifies the driver to reduce it's code footprint and to improve
maintainability by reducing the code duplication.

Visibly, the 'rkt.c' portion of this patch looks more complicated than
it really is. View it as retaining the rkt-only specifics of the
interface.

Signed-off-by: Mark Haverkamp 
Signed-off-by: James Bottomley

[SCSI] aacraid: expose physical devices

2006-09-24T01:09:03+00:00

Received from Mark Salyzyn:

I am placing this functionality into an insmod parameter. Normally the physical
components are exported to sg, and are blocked from showing up in sd.

Note that the pass-through I/O path via the driver through the Firmware to the
physical disks is not an optimized path, the card is designed for Hardware
RAID, elevator sorting and caching. This should not be used as a means for
utilizing the aacraid based controllers as a generic scsi/SATA/SAS controller,
performance should suck by a few percentage points, any RAID meta-data on the
drives will confuse the controller about who owns the drives and there is a
high risk of destroying content in both directions. Unreliable and for
experimentation or strange controlled circumstances only.

Signed-off-by: Mark Haverkamp 
Signed-off-by: James Bottomley

[SCSI] aacraid: misc cleanup

2006-09-24T01:08:26+00:00

Received from Mark Salyzyn:

Basically cleanup, nothing here will have an affect. Adjusting some
error codes, removing superfluous definitions and code fragments.

Signed-off-by: Mark Haverkamp 
Signed-off-by: James Bottomley

[SCSI] aacraid: Reset adapter in recovery timeout

2006-08-19T20:35:11+00:00

Received from Mark Salyzyn

If the adapter is in blinkled (Firmware Assert) when error recovery
timeout actions have been triggered, perform an adapter warm reset and
restart the initialization.

Signed-off-by: Mark Haverkamp 
Signed-off-by: James Bottomley

[SCSI] aacraid: Check for unlikely errors

2006-08-19T20:33:45+00:00

Received from Mark Salyzyn

The enclosed patch cleans up some code fragments, adds some paranoia
(unproven causes of potential driver failures).

Signed-off-by: Mark Haverkamp 
Signed-off-by: James Bottomley

[SCSI] aacraid: Restart adapter on firmware assert (Update 2)

2006-08-19T20:33:13+00:00

Received from Mark Salyzyn

If the adapter should be in a blinkled (Firmware Assert) state when the
driver loads, we will perform a warm restart of the Adapter Firmware to
see if we can rescue the adapter. Possible causes of a blinkled can
occur on some early release motherboard BIOSes, transitory PCI bus
problems on embedded systems or non-x86 based architectures, transitory
startup failures of early release drives or transitory hardware
failures; some of which can bite the adapter later at runtime. Future
enhancements will include recovery during runtime.

Fixed extra whitespace space issue.

Signed-off-by: Mark Haverkamp 
Signed-off-by: James Bottomley

[SCSI] aacraid: interruptible ioctl

2006-08-19T20:32:57+00:00

Received from Mark Salyzyn

This patch allows the FSACTL_SEND_LARGE_FIB, FSACTL_SENDFIB and
FSACTL_SEND_RAW_SRB ioctl calls into the aacraid driver to be
interruptible. Only necessary if the adapter and/or the management
software has gone into some sort of misbehavior and the system is being
rebooted, thus permitting the user management software applications to
be killed relatively cleanly. The FIB queue resource is held out of the
free queue until the adapter finally, if ever, completes the command.

Signed-off-by: Mark Haverkamp 
Signed-off-by: James Bottomley