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)
Check copy_to_user() return value in drivers/scsi/megaraid.c::megadev_ioctl()
This gets rid of this little warning:
drivers/scsi/megaraid.c:3661: warning: ignoring return value of 'copy_to_user', declared with attribute warn_unused_result
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: "Ju, Seokmann" <Seokmann.Ju@lsil.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- Replace scsi_device_types array API with scsi_device_type function API.
Gets rid of a lot of common code, as well as being easier to use.
- Add the new device types in SPC4 r05a, and rename some of the older ones.
- Reformat the printing of inquiry data; now fits on one line and
includes PQ.
I think I've addressed all the feedback from the previous versions. My
current test box prints:
scsi 2:0:1:0: Direct access HP 18.2G ATLAS10K3_18_SCA HP05 PQ: 0 ANSI: 2
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Various scsi drivers use scsi_cmnd.buffer and scsi_cmnd.bufflen in their
queuecommand functions. Those fields are internal storage for the
midlayer only and are used to restore the original payload after
request_buffer and request_bufflen have been overwritten for EH. Using
the buffer and bufflen fields means they do very broken things in error
handling.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
drivers/scsi/megaraid.c: In function `mega_internal_command':
drivers/scsi/megaraid.c:4474: warning: unused variable `flags'
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Replace all occurences of 0xff.. in calls to function pci_set_dma_mask()
and pci_set_consistant_dma_mask() with the corresponding DMA_xBIT_MASK from
linux/dma-mapping.h.
Signed-off-by: Matthias Gehre <M.Gehre@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Attached patch fixes problem that cause kobject_register failure
during loading. Kobject_register would fail when there are more than
1 module with same module name. This patch will change module name of
megaraid_legacy from 'megaraid' to 'megaraid_legacy'.
Signed-Off-by: Seokmann Ju <seokmann.ju@lsil.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
the scsi layer is using semaphores in a mutex way, this patch converts
these into using mutexes instead
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This merge is pretty extensive. The conflict is over the new
req->retries parameter, so I had to change the prototype to
scsi_setup_blk_pc_cmnd() and the usage in sd, sr and st.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch fixes
- PCI ID overlap issue
- node name changed to 'megaraid_legacy'
I hope this patch addresses concerns brought by Daniel Drake.
Signed-off by: Seokmann Ju <seokmann.ju@enginio.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
The SCSI megaraid drive goes to great effort to kmap
the scatterlist buffer (if used), but then uses the
wrong pointer when copying to it afterward.
Signed-off-by: Mark Lord <lkml@rtr.ca>
Acked by: Ju, Seokmann <Seokmann.Ju@engenio.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This fixes locking in megaraid.c, namely:
(1) make sure megaraid_queue release the adapter lock by changing the
code to have a single return
(2) remove the errornous scsi_assign_lock call
Testing by Burton Windle.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Burton Windle <bwindle@fint.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
just take the adapter lock in megaraid_queue. Additional benefit is
that we can get rid of the awkward conditional locking in
mega_internal_command.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Some Legacy megaraid cards can't actually cope with the scatter/gather
version of the READ CAPACITY command (which is what we now send them
since altering all SCSI internal I/O to go via the block layer). Fix
this (and a few other broken megaraid driver assumptions) by sending
the non-sg version of the command if the sg list only has a single
element.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Now we can change the pci core to always set this pointer, as pci drivers
should use it, not the driver core callback.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We never look at it except for the old megaraid driver that abuses it
for sending internal commands. That usage can be fixed easily because
those internal commands are single-threaded by a mutex and we can easily
use a completion there.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
David Howells