Commit Graph

614 Commits

Author SHA1 Message Date
Paul Mackerras
9216ad8cb7 powerpc/32: Generate miboot images with ARCH=powerpc
Miboot images are apparently still used on some old 32-bit powermacs,
so build them with ARCH=powerpc if we're 32-bit and powermac support
is enabled.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-15 13:00:08 +11:00
Linus Torvalds
3e2b32b693 Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6 2006-01-14 10:42:40 -08:00
Paul Mackerras
d5f079000b [PATCH] powerpc: Recognize /chaos bridge on old pmacs as PCI
The first generation of PCI powermacs had a host bridge called /chaos
which was for all intents and purposes a PCI host bridge, but has a
device_type of "vci" in the device tree (presumably it's not really
PCI at the hardware level or something).

The OF parsing stuff in arch/powerpc/kernel/prom_parse.c currently
doesn't recognize it as a PCI bridge, which means that controlfb.c
can't get its device addresses.

This makes prom_parse.c recognize a device_type of "vci" as indicating
a PCI host bridge.  With this, controlfb works again.

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 15:08:50 +11:00
Paul Mackerras
b4e7de0f35 powerpc: Avoid unaligned loads and stores in boot memcpy code
The 601 processor will generate an alignment exception for accesses
which cross a page boundary.  In the boot wrapper code, OF is still
handling all exceptions, and it doesn't have an alignment exception
handler that emulates the instruction and continues.

This changes the memcpy and memmove routines in the boot wrapper to
avoid doing unaligned accesses.  If the source and destination are
misaligned with respect to each other, we just copy one byte at a
time.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 15:06:51 +11:00
Paul Mackerras
66a45dd362 powerpc: Make COFF zImages for old 32-bit powermacs
This adds code to build zImage.coff and/or zImage.initrd.coff when
CONFIG_PPC32 and CONFIG_PPC_PMAC are defined.  It also restructures
the OF client code and adds some workarounds for OF quirks on the
older machines.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 15:04:06 +11:00
David Woodhouse
575e321606 [PATCH] powerpc: Make CHRP build again
This makes CHRP build again, although it's untested because my Pegasos
is currently in pieces.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 13:19:18 +11:00
Dave C Boutcher
91dc182ca6 [PATCH] powerpc: special-case ibm,suspend-me RTAS call
Handle the ibm,suspend-me RTAS call specially.  It needs
to be wrapped in a set of synchronization hypervisor calls
(H_Join).  When the H_Join calls are made on all CPUs, the
intent is that only one will return with H_Continue, meaning
that he is the "last man standing".  That CPU then issues the
ibm,suspend-me call.  What is interesting, of course, is that
the CPU running when the rtas syscall is made, may NOT be the
CPU that ultimately executes the ibm,suspend-me rtas call.

Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 12:04:25 +11:00
Kumar Gala
7d13d21ae8 [PATCH] powerpc: Add MPC834x SYS board to arch/powerpc
Add the first MPC83xx board that uses a flat device tree to arch/powerpc.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 11:13:24 +11:00
Kumar Gala
eed3200108 [PATCH] powerpc: Add FSL SOC library and setup code
Parse the flat device tree for devices on Freescale SOC's that we know
about (gianfar, gianfar_mdio, i2c, mpc83xx_wdt).  We need to setup
platform devices and platform data for these devices to match arch/ppc
usage.

Also add a helper function (get_immrbase) that reports the base
address of the MMIO registers on the SOC.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 11:13:22 +11:00
Kumar Gala
b8e383d592 [PATCH] powerpc: Allow for ppc_md restart, power_off, and halt to be NULL
On a number of embedded reference boards there isn't always a
way to reset, power_off, or halt the board.  Rather than having
each board implement a spin loop just let the generic code do
it.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 11:12:23 +11:00
Andy Whitcroft
7a45fb19ce [PATCH] powerpc: oprofile cpu type names clash with other code
In 2.6.15-git6 a change was commited in the oprofile support in
the powerpc architecture.  It introduced the powerpc_oprofile_type
which contains the define G4.  This causes a name clash with the
existing wacom usb tablet driver.

      CC [M]  drivers/usb/input/wacom.o
    drivers/usb/input/wacom.c:98: error: conflicting types for `G4'
    include/asm/cputable.h:37: error: previous declaration of `G4'
      CC [M]  drivers/usb/mon/mon_text.o
    make[3]: *** [drivers/usb/input/wacom.o] Error 1
    make[2]: *** [drivers/usb/input] Error 2

The elements of an enum declared in global scope are effectivly
global identifiers themselves.  As such we need to ensure the names
are unique.  This patch updates the later oprofile support to use
unique names.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 11:12:16 +11:00
Paul Mackerras
80f15dc703 powerpc: Provide a suitable AT_PLATFORM value
The glibc folks want to use AT_PLATFORM to select between possible
alternative versions of shared libraries.  This commit makes the kernel
supply an AT_PLATFORM string that indicates what class of processor
we are running on.  Processors with the same set of user-level
instructions and roughly the same instruction scheduling characteristics
are given the same AT_PLATFORM value; for example, 821, 823 and 860
are all reported as "ppc823", and 7447, 7447A, 7448, 7450, 7451, 7455
are all called "ppc7450".

The intention is that the AT_PLATFORM values match the values that
gcc accepts for the -mcpu= option.  For values which are numeric
(e.g. -mcpu=750), "ppc" has been prepended.

This also adds a PPC_FEATURE_BOOKE bit to the AT_HWCAP value and sets
it for the 440 family and the Freescale 85xx family.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 10:11:39 +11:00
Russell King
2f53a80fc0 [PATCH] Add vio_bus_type probe and remove methods
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13 11:26:07 -08:00
Russell King
79f9fb8886 [PATCH] Add of_platform_bus_type probe and remove methods
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13 11:26:06 -08:00
David Gibson
3356bb9f7b [PATCH] powerpc: Remove lppaca structure from the PACA
At present the lppaca - the structure shared with the iSeries
hypervisor and phyp - is contained within the PACA, our own low-level
per-cpu structure.  This doesn't have to be so, the patch below
removes it, making a separate array of lppaca structures.

This saves approximately 500*NR_CPUS bytes of image size and kernel
memory, because we don't need aligning gap between the Linux and
hypervisor portions of every PACA.  On the other hand it means an
extra level of dereference in many accesses to the lppaca.

The patch also gets rid of several places where we assign the paca
address to a local variable for no particular reason.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:17:39 +11:00
David Gibson
e58c3495e6 [PATCH] powerpc: Cleanup LOADADDR etc. asm macros
This patch consolidates the variety of macros used for loading 32 or
64-bit constants in assembler (LOADADDR, LOADBASE, SET_REG_TO_*).  The
idea is to make the set of macros consistent across 32 and 64 bit and
to make it more obvious which is the appropriate one to use in a given
situation.  The new macros and their semantics are described in the
comments in ppc_asm.h.

In the process, we change several places that were unnecessarily using
immediate loads on ppc64 to use the GOT/TOC.  Likewise we cleanup a
couple of places where we were clumsily subtracting PAGE_OFFSET with
asm instructions to use assemble-time arithmetic or the toreal() macro
instead.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:16:23 +11:00
Tom Rini
135f0b17a7 [PATCH] powerpc/boot: Better use of defaultimage-
The following reworks how defaultimage- is used.  We default to zImage
here and then override it on platforms that need something more (uImage
in the future) or less (vmlinux on iSeries).

Signed-off-by: Tom Rini <trini@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:14:28 +11:00
Dave C Boutcher
610d91511f [PATCH] powerpc: Add support for changing properties from userspace
Add support to reconfigure the device tree through the existing
proc filesystem interface.  Add "add_property", "remove_property",
and "update_property" commands to the existing interface.

Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:12:41 +11:00
Dave C Boutcher
ecaa8b0ff3 [PATCH] powerpc: Add of_find_property function
Add an of_find_property function that returns a struct property
given a property name.  Then change the get_property function to
use that routine internally.

Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:11:57 +11:00
Dave C Boutcher
088186ded4 [PATCH] powerpc: Add/remove/update properties in firmware device tree
Add support for updating and removing device tree
properties.  Since we hand out pointers to properties with gay
abandon, we can't just free the property storage.  Instead we
move deleted, or the old copy of an updated property, to a
"dead properties" list.

Also note, its not feasable to kref device tree properties.
we call get_property() all over the kernel in a wild variety
of contexts.

One consequence of this change is that we now take a
read_lock(&devtree_lock) when doing get_property().

Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:02:50 +11:00
Tom Rini
9e1c72a4e4 [PATCH] Remove bzImage target
Since the documentation no longer tells people to 'make bzImage', and
with the previous patch nothing more than 'make' is required to get the
right bootable images (just like on i386 now), this removes the bzImage
-> zImage target redirect on ARCH=powerpc

Signed-off-by: Tom Rini <trini@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 20:56:00 +11:00
Linus Torvalds
45bfe98bd7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc-merge
Fix up delete/modify conflict of arch/ppc/kernel/process.c by hand (it's
gone, gone, gone).

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 10:21:22 -08:00
Al Viro
0cec6fd137 [PATCH] powerpc: task_stack_page()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:08:57 -08:00
Al Viro
b5e2fc1c62 [PATCH] powerpc: task_thread_info()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:08:57 -08:00
Paul Mackerras
624cee31bc powerpc: make ARCH=ppc use arch/powerpc/kernel/process.c
Commit 5388fb1025 made signal_32.c
use discard_lazy_cpu_state, which broke ARCH=ppc because that
uses the common signal_32.c but has its own process.c.  Make ARCH=ppc
use the common process.c to fix this and to reduce the amount
of duplicated code.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 21:22:34 +11:00
Arnd Bergmann
8fce10a3c9 [PATCH] powerpc: cell namespace cleanup
These symbols are only used in the file that they are defined in,
so they should not be in the global namespace.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:39:14 +11:00
Arnd Bergmann
b0da985644 [PATCH] powerpc: xmon namespace cleanups
These symbols are only used in the file that they are defined in,
so they should not be in the global namespace.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:39:14 +11:00
Arnd Bergmann
ff38e7c80a [PATCH] powerpc: pmac namespace cleanup
pmac_setup_arch is only used in the file that it is defined in,
so it should not be in the global namespace.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:39:13 +11:00
Arnd Bergmann
8446196ade [PATCH] powerpc: pseries namespace cleanup
These symbols are only used in the file that they are defined in,
so they should not be in the global namespace.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:39:13 +11:00
Olof Johansson
b07dfab3e3 [PATCH] powerpc: minor dart driver cleanup
Rpn is assigned every time in the loop, no need to increase it too.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:39:13 +11:00
Stephen Rothwell
9623b5d3d3 [PATCH] powerpc: small pci cleanups
pcibios_claim_one_bus is not needed on iSeries and phbs_remap_io can be
mode static.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:30 +11:00
Stephen Rothwell
9bd7ea60b1 [PATCH] powerpc: clean up iommu.h a bit
There was a function declared for CONFIG_PSERIES which no longer exists
and the two function declarations for CONFIG_ISERIES have been moved
into an include file in platforms/iseries since they are defined and
used only there.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:30 +11:00
Stephen Rothwell
ee2cdecec4 [PATCH] powerpc: iSeries fixes for build with no PCI
This reverts part of "ppc64 iSeries: allow build with no PCI"
(145d01e428) which affected generic code
and applies a fix in the arch specific code.

Commit "partly merge iseries do_IRQ"
(5fee9b3b39eb55c7e3619a3b36ceeabffeb8f144) introduced iSeries_get_irq
which was only available if CONFIG_PCI is set.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:30 +11:00
Stephen Rothwell
f9cb83ac1f [PATCH] powerpc: eliminate bitfields from ItLpNaca
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:30 +11:00
Stephen Rothwell
677f8c0d04 [PATCH] powerpc: remove bitfields from HvLpEvent
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:29 +11:00
Kumar Gala
cbbcf34011 [PATCH] powerpc: Fixed memory reserve map layout
powerpc: Fixed memory reserve map layout

The memory reserve map is suppose to be a pair of 64-bit integers
to represent each region.  On ppc32 the code was treating the
pair as two 32-bit integers.  Additional the prom_init code was
producing the wrong layout on ppc32.

Added a simple check to try to provide backwards compatibility.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:29 +11:00
Olof Johansson
ea183a957a [PATCH] powerpc: remove warning in EEH code
Remove warning in eeh code about mixed variables and code.

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:29 +11:00
Paul Mackerras
5388fb1025 [PATCH] powerpc: Avoid potential FP corruption with preempt and UP
Heikki Lindholm pointed out that there was a potential race with the
lazy CPU state (FP, VR, EVR) stuff if preempt is enabled.  The race
is that in the process of restoring FP state on sigreturn, the task
gets preempted by a user task that wants to use the FPU.  It will take
an FP unavailable exception, which will write the current FPU state
to the thread_struct, overwriting the values which sigreturn has
stored.  Note that this can only happen on UP since we don't implement
lazy CPU state on SMP.

The fix is to flush the lazy CPU state before updating the
thread_struct.  To do this we re-use the flush_lazy_cpu_state()
function from process.c.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-12 20:09:29 +11:00
Randy Dunlap
a941564458 [PATCH] capable/capability.h (arch/)
arch: Use <linux/capability.h> where capable() is used.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 18:42:14 -08:00
Keshavamurthy Anil S
eb3a72921c [PATCH] kprobes: fix race in recovery of reentrant probe
There is a window where a probe gets removed right after the probe is hit
on some different cpu.  In this case probe handlers can't find a matching
probe instance related to break address.  In this case we need to read the
original instruction at break address to see if that is not a break/int3
instruction and recover safely.

Previous code had a bug where we were not checking for the above race in
case of reentrant probes and the below patch fixes this race.

Tested on IA64, Powerpc, x86_64.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 18:42:12 -08:00
Michael Ellerman
97b1b99974 [PATCH] powerpc: Don't build crash.c for PPC32
arch/powerpc/kernel/crash.c isn't safe for PPC32 (yet?), so don't build it.

Built with CONFIG_KEXEC=y for pmac32_defconfig, pseries_defconfig,
and g5_defconfig.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11 19:52:05 +11:00
Kumar Gala
886c98d786 [PATCH] powerpc: Fix clean_files in arch/powerpc/boot Makefile
clean-files was being set twice rather than being appended to.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11 16:28:13 +11:00
Michael Ellerman
c9c47b6e27 [PATCH] powerpc: Remove redundant setting of htab_address
iSeries doesn't need to set the htab_address explicitly, htab_initialize()
will do it for us later.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11 15:35:46 +11:00
Michael Ellerman
7eb5476f68 [PATCH] powerpc: Add ibm,pft-size to iSeries device tree
To make iSeries just a teensy bit less special, create ibm,pft-size properties
in the iSeries device tree. We can then rely on htab_dt_scan_pftsize() to set
ppc64_pft_size for us.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11 15:35:40 +11:00
Kumar Gala
0e5e39bfd8 [PATCH] powerpc: Add some missing .gitignore's
ignore generated files under arch/powerpc

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11 15:35:35 +11:00
Kumar Gala
08264cbc9f [PATCH] powerpc: Updated Kconfig and Makefiles for 83xx support
Updated Kconfig & Makefiles in prep for adding support for the Freescale
MPC83xx family of processors to arch/powerpc.  Moved around some config
options that are more globally applicable to other PowerPC processors.
Added a temporary config option (83xx) to match existing arch/ppc support
for the MPC83xx line.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11 15:35:29 +11:00
Geoff Levand
7f52eb0093 [PATCH] spufs: Suspend/restore MFC DMA operations at SPU context switch.
The SPE Book IV indicates that MFC DMA operations must be
suspended and restored on SPU context switch (in Step 8).

This patch adds that operation, which is missing from the
current spufs implementation.

Signed-off-by: Masato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11 15:35:11 +11:00
Haren Myneni
f6cc82fc0b [PATCH] powerpc: fix for compile problem in kdump code when SMP disabled
This patch fixes the compilation error (shown below) when CONFIG_SMP=n.
    arch/powerpc/kernel/crash.c: In function `crash_kexec_prepare_cpus':
    arch/powerpc/kernel/crash.c:236: error: implicit declaration of
    function `smp_release_cpus'

Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11 15:33:55 +11:00
Paul Mackerras
6bac953fa4 powerpc: Fix compile error when CONFIG_PROC_VMCORE is not defined
We were getting elfcorehdr_addr undefined in this case.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11 15:30:07 +11:00
Anton Blanchard
7a0268fa1a [PATCH] powerpc/64: per cpu data optimisations
The current ppc64 per cpu data implementation is quite slow. eg:

        lhz 11,18(13)           /* smp_processor_id() */
        ld 9,.LC63-.LCTOC1(30)  /* per_cpu__variable_name */
        ld 8,.LC61-.LCTOC1(30)  /* __per_cpu_offset */
        sldi 11,11,3            /* form index into __per_cpu_offset */
        mr 10,9
        ldx 9,11,8              /* __per_cpu_offset[smp_processor_id()] */
        ldx 0,10,9              /* load per cpu data */

5 loads for something that is supposed to be fast, pretty awful. One
reason for the large number of loads is that we have to synthesize 2
64bit constants (per_cpu__variable_name and __per_cpu_offset).

By putting __per_cpu_offset into the paca we can avoid the 2 loads
associated with it:

        ld 11,56(13)            /* paca->data_offset */
        ld 9,.LC59-.LCTOC1(30)  /* per_cpu__variable_name */
        ldx 0,9,11              /* load per cpu data

Longer term we can should be able to do even better than 3 loads.
If per_cpu__variable_name wasnt a 64bit constant and paca->data_offset
was in a register we could cut it down to one load. A suggestion from
Rusty is to use gcc's __thread extension here. In order to do this we
would need to free up r13 (the __thread register and where the paca
currently is). So far Ive had a few unsuccessful attempts at doing that :)

The patch also allocates per cpu memory node local on NUMA machines.
This patch from Rusty has been sitting in my queue _forever_ but stalled
when I hit the compiler bug. Sorry about that.

Finally I also only allocate per cpu data for possible cpus, which comes
straight out of the x86-64 port. On a pseries kernel (with NR_CPUS == 128)
and 4 possible cpus we see some nice gains:

             total       used       free     shared    buffers cached
Mem:       4012228     212860    3799368          0          0 162424

             total       used       free     shared    buffers cached
Mem:       4016200     212984    3803216          0          0 162424

A saving of 3.75MB. Quite nice for smaller machines. Note: we now have
to be careful of per cpu users that touch data for !possible cpus.

At this stage it might be worth making the NUMA and possible cpu
optimisations generic, but per cpu init is done so early we have to be
careful that all architectures have their possible map setup correctly.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11 14:49:45 +11:00