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)
WARNING: drivers/net/cs89x0.o - Section mismatch: reference to .init.data:version from .text between 'init_module' (at offset 0x13d8) and 'net_get_stats'
WARNING: drivers/net/cs89x0.o - Section mismatch: reference to .init.text: from .text between 'init_module' (at offset 0x1634) and 'net_get_stats'
WARNING: drivers/net/cs89x0.o - Section mismatch: reference to .init.text: from .text between 'init_module' (at offset 0x1a1f) and 'net_get_stats'
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch adds support for the Intel IXDP2351 to the CS89x0 driver.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
cs89x0 inconsistently used 'int' and 'u32' for device register data.
As the cs89x0 is a 16-bit chip, change the I/O accessors over to 'u16'.
(Spotted by Deepak Saxena.)
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There's an ifdef in cs89x0.c that seems to have been the wrong way round
since it was merged (and noone seems to have noticed) -- the IXDP2x01
doesn't support ISA-style DMA, but when building for IXDP2x01, cs89x0's
ALLOW_DMA is set to 1, and when building for another platform, ALLOW_DMA is
set to 0.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The Kconfig symbol for pnx0105 was recently renamed to ARCH_PNX010X.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: dmitry pervushin <dpervushin@ru.mvista.com>
Cc: <dsaxena@plexity.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Implement readwords/writewords that use readword/writeword, and switch the
rest of the driver over to use these.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: dmitry pervushin <dpervushin@ru.mvista.com>
Cc: <dsaxena@plexity.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Implement suitable versions of the readword/writeword macros for ixdp2x01 and
pnx0501. Handle the 32-bit spacing of the registers in these functions
instead of in the header file.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: dmitry pervushin <dpervushin@ru.mvista.com>
Cc: <dsaxena@plexity.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Reverse the order of readreg/writereg and readword/writeword in the
file, so that we can make readreg/writereg use readword/writeword.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: dmitry pervushin <dpervushin@ru.mvista.com>
Cc: <dsaxena@plexity.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Switch all occurences of inw/outw in the driver over to readword/writeword.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: dmitry pervushin <dpervushin@ru.mvista.com>
Cc: <dsaxena@plexity.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
readword() and writeword() take a 'struct net_device *' and deref its
->base_addr member. Make them take the base_addr directly instead, so
that we can switch the other occurences of inw/outw in the file over
to readword/writeword as well.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: dmitry pervushin <dpervushin@ru.mvista.com>
Cc: <dsaxena@plexity.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Jon Ringle
This patch gives support for the CS8900A ethernet chip on the Comdial MP1000
Signed-off-by: Jon Ringle
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
cs89x0 talks a lot at boot. Seems like debug leftover. This patch
downgrades printks to KERN_DEBUG. While we're at it, make these messages a
bit less obscure.
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch is to provide support for cs89x0-based network device on
Philips' pnx0105 board.
Signed-off-by: dmitry pervushin <dpervushin@ru.mvista.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
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!
