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 <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
kbuild includes this automatically these days.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
The hptiop just got merged with a horrible amount of really bad ioctl
code that is against the standards for new scsi drivers. This patch
backs it out (and fixes a small bug where scsi_add_host is called to
early). We can re-add proper APIs once we agree on them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
IOP reset message should be posted to inbound message register
instead of outbound message register.
Signed-off-by: HighPoint Linux Team <linux@highpoint-tech.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Updates:
- don't bypass SYNCHRONIZE_CACHE command
- return SCSI_MLQUEUE_HOST_BUSY when no free request slots
- move scsi_remove_host() to the begin of hpt_remove(), or it will
not work after resources being released.
Signed-off-by: HighPoint Linux Team <linux@highpoint-tech.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
HighPoint RocketRAID 3220/3320 series 8 channel PCI-X SATA RAID Host
Adapters.
Fixes from original submission:
Merge Andrew Morton's patches:
- Provide locking for global list
- Fix debug printks
- uninline function with multiple callsites
- coding style fixups
- remove unneeded casts of void*
- kfree(NULL) is legal
- Don't "succeed" if register_chrdev() failed - otherwise we'll later
unregister a not-registered chrdev.
- Don't return from hptiop_do_ioctl() with the spinlock held.
- uninline __hpt_do_ioctl()
Update for Arjan van de Ven's comments:
- put all asm/ includes after the linux/ ones
- replace mdelay with msleep
- add pci posting flush
- do not set pci command reqister in map_pci_bar
- do not try merging sg elements in hptiop_buildsgl()
- remove unused outstandingcommands member from hba structure
- remove unimplemented hptiop_abort() handler
- remove typedef u32 hpt_id_t
Other updates:
- fix endianess
Signed-off-by: HighPoint Linux Team <linux@highpoint-tech.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
David Howells