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)
All on stack DECLARE_COMPLETIONs should be replaced by:
DECLARE_COMPLETION_ONSTACK
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Making structs const prevents accidental bugs and with the proper debug
options they're protected against corruption.
Signed-off-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (44 commits)
[ARM] 3541/2: workaround for PXA27x erratum E7
[ARM] nommu: provide a way for correct control register value selection
[ARM] 3705/1: add supersection support to ioremap()
[ARM] 3707/1: iwmmxt: use the generic thread notifier infrastructure
[ARM] 3706/2: ep93xx: add cirrus logic edb9315a support
[ARM] 3704/1: format IOP Kconfig with tabs, create more consistency
[ARM] 3703/1: Add help description for ARCH_EP80219
[ARM] 3678/1: MMC: Make OMAP MMC work
[ARM] 3677/1: OMAP: Update H2 defconfig
[ARM] 3676/1: ARM: OMAP: Fix dmtimers and timer32k to compile on OMAP1
[ARM] Add section support to ioremap
[ARM] Fix sa11x0 SDRAM selection
[ARM] Set bit 4 on section mappings correctly depending on CPU
[ARM] 3666/1: TRIZEPS4 [1/5] core
ARM: OMAP: Multiplexing for 24xx GPMC wait pin monitoring
ARM: OMAP: Fix SRAM to use MT_MEMORY instead of MT_DEVICE
ARM: OMAP: Update dmtimers
ARM: OMAP: Make clock variables static
ARM: OMAP: Fix GPMC compilation when DEBUG is defined
ARM: OMAP: Mux updates for external DMA and GPIO
...
- DMA CSR register is cleared by reading on omap1, but on
omap2 it is cleard by writing to it.
- DMA TOUT interrupt does not exist on omap24xx, rename it
- Add SECURE and MISALIGNED errors by default for omap24xx
- Add defines for external DMA request lines
Signed-off-by: Tony Lindgren <tony@atomide.com>
this patch converts drivers/usb to kzalloc usage.
Compile tested with allyes config.
I think there was a bug in drivers/usb/gadget/inode.c because
it used sizeof(*data) for the kmalloc() and sizeof(data) for
the memset(), since sizeof(data) just returns the size for a pointer.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This allows us to eliminate the casts in the drivers, and eventually
remove the use of the device_driver function pointer methods for
platform device drivers.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Convert everyone who uses platform_bus_type to include
linux/platform_device.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Ensure the the device_driver and usb_gadget_driver
have their .owner fields initialised to associate
the module owner to the driver.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When a USB device is put into suspend mode, the current drawn from VBUS
has to be less than 500 uA. Some transceivers need to be put into a
special power-saving mode to accomplish this, and won't have a separate
OTG driver handling that.
This adds a suspend method to the "otg_transceiver" struct -- misnamed,
it's not only for OTG -- and calls it from the OMAP UDC driver.
Signed-off-by: Juha Yrj?l? <juha.yrjola@nokia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The change to make DMA work two bytes at a time omitted an important
tweak that affects the file_storage gadget: it needs to recognize when
the host writes an odd number of bytes. (The network layer ignores
such extra bytes.)
This patch resolves that issue by checking the relevant bit and adjusting
the rx byte count, so that for example a legal 13 byte request doesn't
morph into an illegal 14 byte one any more.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In PM v1, all devices were called at SUSPEND_DISABLE level. Then
all devices were called at SUSPEND_SAVE_STATE level, and finally
SUSPEND_POWER_DOWN level. However, with PM v2, to maintain
compatibility for platform devices, I arranged for the PM v2
suspend/resume callbacks to call the old PM v1 suspend/resume
callbacks three times with each level in order so that existing
drivers continued to work.
Since this is obsolete infrastructure which is no longer necessary,
we can remove it. Here's an (untested) patch to do exactly that.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Minor OMAP updates that somehow got dropped from previous patches.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Greg,
This patch fixes the kmalloc() flags argument type in USB
subsystem; hopefully all of its occurences. The patch was
made against patch-2.6.12-git2 from Jun 20.
Cleanup of flags for kmalloc() in USB subsystem.
Signed-off-by: Olav Kongas <ok@artecdesign.ee>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
More omap_udc updates:
* OMAP 1710 updates
- new UDC bit for clearing endpoint toggle, affecting CLEAR_HALT
- new OTG bits affecting wakeup
* Fix the bug Vladimir noted, that IN-DMA transfer code path kicks in
for under 1024 bytes (not "up to 1024 bytes")
* Handle transceiver setup more intelligently
- use transceiver whenever one's available; this can be handy
for GPIO based, loopback, or transceiverless configs
- cleanup correctly after the "unrecognized HMC" case
* DMA performance tweaks
- allow burst/pack for memory access
- use 16 bit DMA access most of the time on TIPB
* Add workarounds for some DMA errata (not observed "in the wild"):
- DMA CSAC/CDAC reads returning zero
- RX/TX DMA config registers bit 12 always reads as zero (TI patch)
* More "sparse" warnings removed, notably "changing" the SETUP packet
to return data in USB byteorder (an API change, null effect on OMAP
except for these warnings).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Various USB patches, mostly for portability:
- Fifo mode 1 didn't work previously (oopsed), so now it's fixed and
(why not) defines even more endpoints for composite devices.
- OMAP 1710 doesn't have an internal transceiver.
- Small PM update: if the USB link is suspended, don't disconnect on
entry to deep sleep.
- Be more correct about handling zero length control reads. OMAP
seems to mis-handle that protocol peculiarity though; best avoided.
- Platform device resources (for UDC and OTG controllers) now use
physical addresses, so /proc/iomem is more consistent.
- Minor cleanups, notably (by volume) for "sparse" NULL warnings.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
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