kernel_optimize_test/include/asm-powerpc
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
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)
2006-10-05 15:10:12 +01:00
..
iseries [POWERPC] Merge iSeries i/o operations with the rest 2006-09-22 15:19:58 +10:00
8253pit.h
a.out.h [PATCH] powerpc: Merge include/asm-ppc*/a.out.h into include/asm-powerpc 2005-09-21 19:21:08 +10:00
abs_addr.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
agp.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
asm-compat.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
atomic.h power: improve inline asm memory constraints 2006-07-08 15:00:28 -07:00
auxvec.h [PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel 2005-11-11 22:25:39 +11:00
backlight.h [PATCH] powermac: More powermac backlight fixes 2006-07-31 13:28:45 -07:00
bitops.h power: improve inline asm memory constraints 2006-07-08 15:00:28 -07:00
bootx.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
btext.h [PATCH] powerpc: Unify udbg (#2) 2006-01-09 14:49:54 +11:00
bug.h [PATCH] Let WARN_ON/WARN_ON_ONCE return the condition 2006-09-29 09:18:06 -07:00
bugs.h
byteorder.h [PATCH] powerpc: merge byteorder.h 2005-09-28 15:42:53 +10:00
cache.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
cacheflush.h [PATCH] powerpc: Merge cacheflush.h and cache.h 2005-11-10 13:09:22 +11:00
checksum.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
compat.h [PATCH] powerpc signal __user annotations 2006-02-08 01:03:46 -05:00
cputable.h [POWERPC] powerpc: PA6T cputable entry, PVR value 2006-09-13 18:39:52 +10:00
cputime.h [PATCH] powerpc: implement missing jiffies64_to_cputime64() 2006-07-05 09:39:54 -07:00
current.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
dbdma.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
delay.h [POWERPC] Fix mdelay badness on shared processor partitions 2006-06-21 15:01:33 +10:00
div64.h
dma-mapping.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
dma.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
eeh_event.h [PATCH] powerpc/pseries: clear PCI failure counter if no new failures 2006-04-22 18:46:13 +10:00
eeh.h [POWERPC] Fix MMIO ops to provide expected barrier behaviour 2006-09-13 22:08:26 +10:00
elf.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc 2006-06-22 22:11:30 -07:00
emergency-restart.h
errno.h
fcntl.h
firmware.h [POWERPC] implement BEGIN/END_FW_FTR_SECTION 2006-10-03 16:50:21 +10:00
floppy.h [PATCH] irq-flags: POWERPC: Use the new IRQF_ constants 2006-07-02 13:58:47 -07:00
fs_pd.h POWERPC: Get rid of remapping the whole immr 2006-09-21 22:37:58 +04:00
futex.h [POWERPC] Implement PowerPC futex_atomic_cmpxchg_inatomic(). 2006-09-13 18:28:41 +10:00
grackle.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
hardirq.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
heathrow.h powerpc: Fix some #ifndef __KERNEL__ that should be #ifdef 2006-01-09 15:14:05 +11:00
hvcall.h [POWERPC] powerpc: Instrument Hypervisor Calls 2006-09-13 18:39:53 +10:00
hvconsole.h [PATCH] powerpc: hvc_console updates 2006-03-28 16:45:26 +11:00
hvcserver.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
hw_irq.h [PATCH] genirq: add ->retrigger() irq op to consolidate hw_irq_resend() 2006-06-29 10:26:23 -07:00
i8259.h [POWERPC] Add new interrupt mapping core and change platforms to use it 2006-07-03 21:36:01 +10:00
ibmebus.h [POWERPC] Constify & voidify get_property() 2006-07-31 15:55:04 +10:00
ide.h [POWERPC] clean up ide io accessors 2006-09-20 14:06:18 +10:00
immap_86xx.h [POWERPC] Add 8641 Register space and IRQ definitions. 2006-06-21 15:01:28 +10:00
immap_qe.h [POWERPC] Add QUICC Engine (QE) infrastructure 2006-10-04 15:24:27 +10:00
io.h [PATCH] restore parport_pc probing on powermac 2006-10-03 08:03:41 -07:00
ioctl.h
ioctls.h powerpc: remove duplicate ioctl definitions 2005-11-01 14:36:30 +11:00
iommu.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc 2006-06-22 22:11:30 -07:00
ipc.h
ipcbuf.h [PATCH] powerpc: Keep fixing merged ipcbuf.h 2005-11-03 16:58:17 +11:00
ipic.h fix file specification in comments 2006-10-03 23:01:26 +02:00
irq_regs.h IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 2006-10-05 15:10:12 +01:00
irq.h IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 2006-10-05 15:10:12 +01:00
irqflags.h [PATCH] lockdep: irqtrace subsystem, core 2006-07-03 15:27:03 -07:00
Kbuild [HEADERS] One line per header in Kbuild files to reduce conflicts 2006-09-19 12:43:58 +01:00
kdebug.h [PATCH] Notify page fault call chain for powerpc 2006-06-26 09:58:22 -07:00
kdump.h [POWERPC] kdump: Support kernels having 64k page size. 2006-09-13 18:30:04 +10:00
kexec.h [POWERPC] Make crash.c work on 32-bit and 64-bit 2006-08-17 16:41:10 +10:00
keylargo.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
kmap_types.h
kprobes.h [PATCH] kprobes: handle symbol resolution when <module:.symbol> is specified 2006-10-02 07:57:16 -07:00
linkage.h
lmb.h [PATCH] powerpc: Remove calculation of io hole 2006-03-22 15:04:30 +11:00
local.h
lppaca.h [POWERPC] Update lppaca offset comments 2006-08-08 17:08:58 +10:00
machdep.h [POWERPC] Add new interrupt mapping core and change platforms to use it 2006-07-03 21:36:01 +10:00
macio.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
mc146818rtc.h
mediabay.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
mman.h [PATCH] add asm-generic/mman.h 2006-02-15 15:32:22 -08:00
mmu_context.h [POWERPC] Correct the MAX_CONTEXT definition 2006-06-29 16:16:15 +10:00
mmu.h [POWERPC] powerpc: Initialise ppc_md htab pointers earlier 2006-06-28 11:59:47 +10:00
mmzone.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
module.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
mpc85xx.h POWERPC: Add support for the mpc8560 eval board 2006-09-21 22:31:26 +04:00
mpc86xx.h [POWERPC] Use mpc8641hpcn PIC base address from dev tree. 2006-08-25 14:32:13 +10:00
mpic.h [POWERPC] Support for "weird" MPICs and fixup mpc7448_hpc2 2006-08-30 14:29:42 +10:00
msgbuf.h
mutex.h [PATCH] mutex subsystem, add default include/asm-*/mutex.h files 2006-01-09 15:59:19 -08:00
namei.h
nvram.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
of_device.h typo fixes: mecanism -> mechanism 2006-06-30 18:20:44 +02:00
ohare.h powerpc: Fix some #ifndef __KERNEL__ that should be #ifdef 2006-01-09 15:14:05 +11:00
oprofile_impl.h [PATCH] powerpc: Remove oprofile spinlock backtrace code 2006-03-29 13:44:16 +11:00
paca.h Merge branch 'linux-2.6' 2006-09-14 07:07:18 +10:00
page_32.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
page_64.h [PATCH] powerpc: Fix pagetable bloat for hugepages 2006-04-28 15:02:51 +10:00
page.h [POWERPC] Remove DISCONTIGMEM cruft from page.h 2006-09-22 15:19:58 +10:00
param.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
parport.h [PATCH] powerpc: parallel port init fix 2006-01-11 14:49:24 +11:00
pci-bridge.h Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
pci.h [PATCH] 64bit resource: change pci core and arch code to use resource_size_t 2006-06-27 09:24:00 -07:00
percpu.h [PATCH] lockdep: add per_cpu_offset() 2006-07-03 15:27:00 -07:00
pgalloc.h [POWERPC] hugepage BUG fix 2006-08-24 10:07:23 +10:00
pgtable-4k.h [PATCH] Standardize pxx_page macros 2006-09-26 08:48:51 -07:00
pgtable-64k.h powerpc: Use 64k pages without needing cache-inhibited large pages 2006-06-15 10:45:18 +10:00
pgtable.h [PATCH] Standardize pxx_page macros 2006-09-26 08:48:51 -07:00
pmac_feature.h [PATCH] powerpc: Kill _machine and hard-coded platform numbers 2006-03-28 23:15:54 +11:00
pmac_low_i2c.h [PATCH] 3/5 powerpc: Add platform functions interpreter 2006-01-09 15:47:18 +11:00
pmac_pfunc.h typo fixes: mecanism -> mechanism 2006-06-30 18:20:44 +02:00
pmc.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
poll.h [PATCH] POLLRDHUP/EPOLLRDHUP handling for half-closed devices notifications 2006-03-25 08:22:56 -08:00
posix_types.h
ppc_asm.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
ppc-pci.h [POWERPC] EEH: enable MMIO/DMA on frozen slot 2006-09-21 22:59:14 +10:00
processor.h [POWERPC] Add briq support to CHRP 2006-07-07 20:19:15 +10:00
prom.h [POWERPC] Define of_read_ulong helper 2006-09-20 15:09:48 +10:00
pSeries_reconfig.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
ptrace.h [PATCH] Add regs_return_value() helper 2006-10-02 07:57:16 -07:00
qe_ic.h [POWERPC] Add QUICC Engine (QE) infrastructure 2006-10-04 15:24:27 +10:00
qe.h [POWERPC] Add QUICC Engine (QE) infrastructure 2006-10-04 15:24:27 +10:00
reg_8xx.h [PATCH] powerpc: Merge cacheflush.h and cache.h 2005-11-10 13:09:22 +11:00
reg.h [POWERPC] powerpc: PA6T cputable entry, PVR value 2006-09-13 18:39:52 +10:00
resource.h
rtas.h [POWERPC] Add a helper for calculating RTAS "config_addr" parameters 2006-08-25 13:27:35 +10:00
rtc.h powerpc: Make set_rtc_time() return error code from lower-level function 2005-10-22 15:57:55 +10:00
rwsem.h [PATCH] lockdep: remove RWSEM_DEBUG remnants 2006-07-03 15:27:01 -07:00
scatterlist.h [PATCH] powerpc: merge scatterlist.h 2005-10-27 16:45:52 +10:00
seccomp.h powerpc: Fix some #ifndef __KERNEL__ that should be #ifdef 2006-01-09 15:14:05 +11:00
sections.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
semaphore.h Merge ../linux-2.6 by hand 2005-10-31 13:37:12 +11:00
sembuf.h
serial.h powerpc: Introduce a new config symbol to control 16550 early debug code 2006-01-10 16:19:05 +11:00
setup.h
shmbuf.h
shmparam.h
sigcontext.h powerpc: merge sigcontext.h 2005-11-03 16:24:25 +11:00
siginfo.h
signal.h [PATCH] irq-flags: POWERPC: Use the new IRQF_ constants 2006-07-02 13:58:47 -07:00
smp.h IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 2006-10-05 15:10:12 +01:00
smu.h [POWERPC] powermac: Constify & voidify get_property() 2006-07-31 15:55:05 +10:00
socket.h [AF_UNIX]: Datagram getpeersec 2006-06-29 16:58:06 -07:00
sockios.h
sparsemem.h [PATCH] powerpc: sanitize header files for user space includes 2006-01-09 15:13:08 +11:00
spinlock_types.h [PATCH] powerpc: merge include/asm-ppc*/spinlock_types.h into include/asm-powerpc/spinlock_types.h 2005-09-21 19:21:09 +10:00
spinlock.h [PATCH] Directed yield: direct yield of spinlocks for powerpc 2006-10-01 00:39:22 -07:00
spu_csa.h [POWERPC] spufs: one more fix for 64k pages 2006-06-21 15:01:32 +10:00
spu_priv1.h [POWERPC] spufs: fix spu irq affinity setting 2006-06-21 15:01:31 +10:00
spu.h [POWERPC] spufs: add infrastructure for finding elf objects 2006-10-05 09:21:02 +10:00
sstep.h powerpc: Make single-stepping emulation (mostly) usable on 32-bit 2005-10-28 22:48:08 +10:00
stat.h powerpc: merge stat.h 2005-11-03 16:02:23 +11:00
statfs.h [PATCH] powerpc: merge include/asm-ppc*/statfs.h into include/asm-powerpc/statfs.h 2005-09-21 19:21:10 +10:00
string.h powerpc: fix strncasecmp prototype 2006-03-25 09:41:40 -08:00
synch.h [PATCH] powerpc: newline for ISYNC_ON_SMP 2006-02-24 14:06:00 +11:00
syscalls.h [PATCH] powerpc: declare arch syscalls in <asm/syscalls.h> 2006-03-27 14:48:22 +11:00
systbl.h [POWERPC] Unify ppc syscall tables 2006-06-21 15:01:32 +10:00
system.h [POWERPC] Cleanup include/asm-powerpc/xmon.h 2006-10-04 14:52:17 +10:00
tce.h [PATCH] powerpc: kill union tce_entry 2006-04-29 18:07:54 +10:00
termbits.h [PATCH] Add CMSPAR to termbits.h for powerpc and alpha 2006-05-26 11:55:46 -07:00
termios.h powerpc: use asm-generic/termios.h 2005-11-01 14:36:55 +11:00
thread_info.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
time.h [POWERPC] Add powerpc get/set_rtc_time interface to new generic rtc class 2006-10-02 17:48:47 +10:00
timex.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
tlb.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
tlbflush.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
todc.h [POWERPC] todc: add support for Time-Of-Day-Clock 2006-06-29 16:22:46 +10:00
topology.h [PATCH] sched: introduce child field in sched_domain 2006-10-03 08:04:06 -07:00
tsi108_irq.h [POWERPC] Update mpc7448hpc2 board irq support using device tree 2006-08-23 15:51:18 +10:00
tsi108.h [POWERPC] Update mpc7448hpc2 board irq support using device tree 2006-08-23 15:51:18 +10:00
types.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
uaccess.h powerpc: Fix incorrect might_sleep in __get_user/__put_user on kernel addresses 2006-05-03 23:06:46 +10:00
ucc_fast.h [POWERPC] Add QUICC Engine (QE) infrastructure 2006-10-04 15:24:27 +10:00
ucc_slow.h [POWERPC] Add QUICC Engine (QE) infrastructure 2006-10-04 15:24:27 +10:00
ucc.h [POWERPC] Add QUICC Engine (QE) infrastructure 2006-10-04 15:24:27 +10:00
ucontext.h powerpc: merge ucontext.h 2005-11-03 16:59:17 +11:00
udbg.h [POWERPC] Add udbg support for RTAS console 2006-06-28 11:59:48 +10:00
unaligned.h
uninorth.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
unistd.h [PATCH] rename the provided execve functions to kernel_execve 2006-10-02 07:57:23 -07:00
user.h
vdso_datapage.h [PATCH] powerpc: Kill _machine and hard-coded platform numbers 2006-03-28 23:15:54 +11:00
vdso.h [PATCH] powerpc: Make the vDSO functions set error code (#2) 2005-11-16 14:05:11 +11:00
vga.h [PATCH] vgacon: make VGA_MAP_MEM take size, remove extra use 2006-06-22 15:05:58 -07:00
vio.h [POWERPC] Constify & voidify get_property() 2006-07-31 15:55:04 +10:00
xmon.h [POWERPC] Fix xmon=off and cleanup xmon initialisation 2006-10-04 14:52:22 +10:00
xor.h