r5 does contain the value to be updated, so lets use r5 all way long
for that. It makes the code more readable.
To avoid confusion, it is better to use adde instead of addc
The first addition is useless. Its only purpose is to clear carry.
As r4 is a signed int that is always positive, this can be done by
using srawi instead of srwi
Let's also remove the comment about bdnz having no overhead as it
is not correct on all powerpc, at least on MPC8xx
In the last part, in our situation, the remaining quantity of bytes
to be proceeded is between 0 and 3. Therefore, we can base that part
on the value of bit 31 and bit 30 of r4 instead of anding r4 with 3
then proceding on comparisons and substractions.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
csum_partial_copy_generic() does the same as copy_tofrom_user and also
calculates the checksum during the copy. Unlike copy_tofrom_user(),
the existing version of csum_partial_copy_generic() doesn't take
benefit of the cache.
This patch is a rewrite of csum_partial_copy_generic() based on
copy_tofrom_user().
The previous version of csum_partial_copy_generic() was handling
errors. Now we have the checksum wrapper functions to handle the error
case like in powerpc64 so we can make the error case simple:
just return -EFAULT.
copy_tofrom_user() only has r12 available => we use it for the
checksum r7 and r8 which contains pointers to error feedback are used,
so we stack them.
On a TCP benchmark using socklib on the loopback interface on which
checksum offload and scatter/gather have been deactivated, we get
about 20% performance increase.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
In several architectures, ip_fast_csum() is inlined
There are functions like ip_send_check() which do nothing
much more than calling ip_fast_csum().
Inlining ip_fast_csum() allows the compiler to optimise better
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[scottwood: whitespace and cast fixes]
Signed-off-by: Scott Wood <oss@buserror.net>
The powerpc64 checksum wrapper functions adds csum_and_copy_to_user()
which otherwise is implemented in include/net/checksum.h by using
csum_partial() then copy_to_user()
Those two wrapper fonctions are also applicable to powerpc32 as it is
based on the use of csum_partial_copy_generic() which also
exists on powerpc32
This patch renames arch/powerpc/lib/checksum_wrappers_64.c to
arch/powerpc/lib/checksum_wrappers.c and
makes it non-conditional to CONFIG_WORD_SIZE
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
csum_tcpudp_magic is now an inline function, so there is
nothing to export
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
The enable_kernel_*() functions leave the relevant MSR bits enabled
until we exit the kernel sometime later. Create disable versions
that wrap the kernel use of FP, Altivec VSX or SPE.
While we don't want to disable it normally for performance reasons
(MSR writes are slow), it will be used for a debug boot option that
does this and catches bad uses in other areas of the kernel.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
memset() uses instruction dcbz to speed up clearing by not wasting time
loading cache line with data that will be overwritten.
Some platform like mpc52xx do no have cache active at startup and
can therefore not use memset(). Allthough no part of the code
explicitly uses memset(), GCC may make calls to it.
This patch modifies memset() such that at startup, memset()
unconditionally skip the optimised bloc that uses dcbz instruction.
Once the initial MMU is set up, in machine_init() we patch memset()
by replacing this inconditional jump by a NOP
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
memcpy() uses instruction dcbz to speed up copy by not wasting time
loading cache line with data that will be overwritten.
Some platform like mpc52xx do no have cache active at startup and
can therefore not use memcpy(). Allthough no part of the code
explicitly uses memcpy(), GCC makes calls to it.
This patch modifies memcpy() such that at startup, memcpy()
unconditionally jumps to generic_memcpy() which doesn't use
the dcbz instruction.
Once the initial MMU is set up, in machine_init() we patch memcpy()
by replacing this inconditional jump by a NOP
Reported-by: Michal Sojka <sojkam1@fel.cvut.cz>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds a few optimisations in memcpy functions by using
lbzu/stbu instead of lxb/stb and by re-ordering insn inside a loop
to reduce latency due to loading
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
cacheable_memcpy uses dcbz instruction and is more efficient than
memcpy when the destination is in RAM. If the destination is in an
io area, memcpy_toio() is normally used, not memcpy
This patch renames memcpy as generic_memcpy, and renames
cacheable_memcpy as memcpy
On MPC885, we get approximatly 7% increase of the transfer rate
on an FTP reception
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
cacheable_memzero() which has become the new memset() and the old
memset() are quite similar, so just merge them.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
cacheable_memzero uses dcbz instruction and is more efficient than
memset(0) when the destination is in RAM
This patch renames memset as generic_memset, and defines memset
as a prolog to cacheable_memzero. This prolog checks if the byte
to set is 0. If not, it falls back to generic_memcpy()
cacheable_memzero disappears as it is not referenced anywhere anymore
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
This partially reverts
commit 'powerpc: Remove duplicate cacheable_memcpy/memzero functions
("b05ae4ee602b7dc90771408ccf0972e1b3801a35")'
Functions cacheable_memcpy/memzero are more efficient than
memcpy/memset as they use the dcbz instruction which avoids refill
of the cacheline with the data that we will overwrite.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
csum_tcpudp_magic() is only a few instructions, and does modify
really few registers. So it is not worth having it as a separate
function and suffer function branching and saving of volatile
registers.
This patch makes it inline by use of the already existing
csum_tcpudp_nofold() function.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
- Disable the 32-bit vdso when building LE, so we can build with a 64-bit only
toolchain.
- EEH fixes from Gavin & Richard.
- Enable the sys_kcmp syscall from Laurent.
- Sysfs control for fastsleep workaround from Shreyas.
- Expose OPAL events as an irq chip by Alistair.
- MSI ops moved to pci_controller_ops by Daniel.
- Fix for kernel to userspace backtraces for perf from Anton.
- Merge pseries and pseries_le defconfigs from Cyril.
- CXL in-kernel API from Mikey.
- OPAL prd driver from Jeremy.
- Fix for DSCR handling & tests from Anshuman.
- Powernv flash mtd driver from Cyril.
- Dynamic DMA Window support on powernv from Alexey.
- LLVM clang fixes & workarounds from Anton.
- Reworked version of the patch to abort syscalls when transactional.
- Fix the swap encoding to support 4TB, from Aneesh.
- Various fixes as usual.
- Freescale updates from Scott: Highlights include more 8xx optimizations, an
e6500 hugetlb optimization, QMan device tree nodes, t1024/t1023 support, and
various fixes and cleanup.
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Merge tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux
Pull powerpc updates from Michael Ellerman:
- disable the 32-bit vdso when building LE, so we can build with a
64-bit only toolchain.
- EEH fixes from Gavin & Richard.
- enable the sys_kcmp syscall from Laurent.
- sysfs control for fastsleep workaround from Shreyas.
- expose OPAL events as an irq chip by Alistair.
- MSI ops moved to pci_controller_ops by Daniel.
- fix for kernel to userspace backtraces for perf from Anton.
- merge pseries and pseries_le defconfigs from Cyril.
- CXL in-kernel API from Mikey.
- OPAL prd driver from Jeremy.
- fix for DSCR handling & tests from Anshuman.
- Powernv flash mtd driver from Cyril.
- dynamic DMA Window support on powernv from Alexey.
- LLVM clang fixes & workarounds from Anton.
- reworked version of the patch to abort syscalls when transactional.
- fix the swap encoding to support 4TB, from Aneesh.
- various fixes as usual.
- Freescale updates from Scott: Highlights include more 8xx
optimizations, an e6500 hugetlb optimization, QMan device tree nodes,
t1024/t1023 support, and various fixes and cleanup.
* tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (180 commits)
cxl: Fix typo in debug print
cxl: Add CXL_KERNEL_API config option
powerpc/powernv: Fix wrong IOMMU table in pnv_ioda_setup_bus_dma()
powerpc/mm: Change the swap encoding in pte.
powerpc/mm: PTE_RPN_MAX is not used, remove the same
powerpc/tm: Abort syscalls in active transactions
powerpc/iommu/ioda2: Enable compile with IOV=on and IOMMU_API=off
powerpc/include: Add opal-prd to installed uapi headers
powerpc/powernv: fix construction of opal PRD messages
powerpc/powernv: Increase opal-irqchip initcall priority
powerpc: Make doorbell check preemption safe
powerpc/powernv: pnv_init_idle_states() should only run on powernv
macintosh/nvram: Remove as unused
powerpc: Don't use gcc specific options on clang
powerpc: Don't use -mno-strict-align on clang
powerpc: Only use -mtraceback=no, -mno-string and -msoft-float if toolchain supports it
powerpc: Only use -mabi=altivec if toolchain supports it
powerpc: Fix duplicate const clang warning in user access code
vfio: powerpc/spapr: Support Dynamic DMA windows
vfio: powerpc/spapr: Register memory and define IOMMU v2
...
The -mabi=altivec option is not recognised on LLVM, so use call cc-option
to check for support.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We have a powerpc specific global called mem_init_done which is "set on
boot once kmalloc can be called".
But that's not *quite* true. We set it at the bottom of mem_init(), and
rely on the fact that mm_init() calls kmem_cache_init() immediately
after that, and nothing is running in parallel.
So replace it with the generic and 100% correct slab_is_available().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If CONFIG_SMP=n, <linux/smp.h> does not include <asm/smp.h>, causing:
drivers/cpufreq/ppc-corenet-cpufreq.c: In function 'corenet_cpufreq_cpu_init':
drivers/cpufreq/ppc-corenet-cpufreq.c:173:3: error: implicit declaration of function 'get_hard_smp_processor_id' [-Werror=implicit-funcuresh E. Warrier" <warrier@linux.vnet.ibm.com>
X-Patchwork-Id: 443703
Message-Id: <54EE5989.7010800@linux.vnet.ibm.com>
To: linuxppc-dev@ozlabs.org
Date: Wed, 25 Feb 2015 17:23:53 -0600
Export __spin_yield so that the arch_spin_unlock() function can
be invoked from a module. This will be required for modules where
we want to take a lock that is also is acquired in hypervisor
real mode. Because we want to avoid running any lockdep code
(which may not be safe in real mode), this lock needs to be
an arch_spinlock_t instead of a normal spinlock.
Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
These functions are only used from one place each. If the cacheable_*
versions really are more efficient, then those changes should be
migrated into the common code instead.
NOTE: The old routines are just flat buggy on kernels that support
hardware with different cacheline sizes.
Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The kfree() function tests whether its argument is NULL and then returns
immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As our various loops (copy, string, crypto etc) get more complicated,
we want to share implementations between userspace (eg glibc) and
the kernel. We also want to write userspace test harnesses to put
in tools/testing/selftest.
One gratuitous difference between userspace and the kernel is the
VSX register definitions - the kernel uses vsrX whereas gcc uses
vsX.
Change the kernel to match userspace.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As our various loops (copy, string, crypto etc) get more complicated,
we want to share implementations between userspace (eg glibc) and
the kernel. We also want to write userspace test harnesses to put
in tools/testing/selftest.
One gratuitous difference between userspace and the kernel is the
VMX register definitions - the kernel uses vrX whereas both gcc and
glibc use vX.
Change the kernel to match userspace.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
I noticed ksm spending quite a lot of time in memcmp on a large
KVM box. The current memcmp loop is very unoptimised - byte at a
time compares with no loop unrolling. We can do much much better.
Optimise the loop in a few ways:
- Unroll the byte at a time loop
- For large (at least 32 byte) comparisons that are also 8 byte
aligned, use an unrolled modulo scheduled loop using 8 byte
loads. This is similar to our glibc memcmp.
A simple microbenchmark testing 10000000 iterations of an 8192 byte
memcmp was used to measure the performance:
baseline: 29.93 s
modified: 1.70 s
Just over 17x faster.
v2: Incorporated some suggestions from Segher:
- Use andi. instead of rdlicl.
- Convert bdnzt eq, to bdnz. It's just duplicating the earlier compare
and was a relic from a previous version.
- Don't use cr5, we have plans to use that CR field for fast local
atomics.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In the Makefile, string.o (which is generated from string.S) is
included into the list of objects being built unconditionally
(obj-y) in line 12.
Additionally, if CONFIG_PPC64 is set, it is included again in
line 17.
This patch removes the latter unnecessary inclusion.
Signed-off-by: Andreas Ruprecht <rupran@einserver.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Although we are now selecting NO_BOOTMEM, we still have some traces of
bootmem lying around. That is because even with NO_BOOTMEM there is
still a shim that converts bootmem calls into memblock calls, but
ultimately we want to remove all traces of bootmem.
Most of the patch is conversions from alloc_bootmem() to
memblock_virt_alloc(). In general a call such as:
p = (struct foo *)alloc_bootmem(x);
Becomes:
p = memblock_virt_alloc(x, 0);
We don't need the cast because memblock_virt_alloc() returns a void *.
The alignment value of zero tells memblock to use the default alignment,
which is SMP_CACHE_BYTES, the same value alloc_bootmem() uses.
We remove a number of NULL checks on the result of
memblock_virt_alloc(). That is because memblock_virt_alloc() will panic
if it can't allocate, in exactly the same way as alloc_bootmem(), so the
NULL checks are and always have been redundant.
The memory returned by memblock_virt_alloc() is already zeroed, so we
remove several memsets of the result of memblock_virt_alloc().
Finally we convert a few uses of __alloc_bootmem(x, y, MAX_DMA_ADDRESS)
to just plain memblock_virt_alloc(). We don't use memblock_alloc_base()
because MAX_DMA_ADDRESS is ~0ul on powerpc, so limiting the allocation
to that is pointless, 16XB ought to be enough for anyone.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit be96f63375 ("powerpc: Split out instruction analysis
part of emulate_step()") added some calls to do_fp_load()
and do_fp_store(), which fail to compile on configs with
CONFIG_PPC_FPU=n and CONFIG_PPC_EMULATE_SSTEP=y. This fixes
the compile by adding #ifdef CONFIG_PPC_FPU around the code
that calls these functions.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Added in 2008, but has never had any in-tree users, and no other
architectures provide it.
Signed-off-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The size field of the op.type word is now the total number of bytes
to be loaded or stored.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This extends the instruction emulation done by analyse_instr() and
emulate_step() to handle a few more instructions that are found in
the kernel.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This splits out the instruction analysis part of emulate_step() into
a separate analyse_instr() function, which decodes the instruction,
but doesn't execute any load or store instructions. It does execute
integer instructions and branches which can be executed purely by
updating register values in the pt_regs struct. For other instructions,
it returns the instruction type and other details in a new
instruction_op struct. emulate_step() then uses that information
to execute loads, stores, cache operations, mfmsr, mtmsr[d], and
(on 64-bit) sc instructions.
The reason for doing this is so that the KVM code can use it instead
of having its own separate instruction emulation code. Possibly the
alignment interrupt handler could also use this.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move the lib symbol exports closer to their function definitions
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Similar to the previous commit which described why we need to add a
barrier to arch_spin_is_locked(), we have a similar problem with
spin_unlock_wait().
We need a barrier on entry to ensure any spinlock we have previously
taken is visibly locked prior to the load of lock->slock.
It's also not clear if spin_unlock_wait() is intended to have ACQUIRE
semantics. For now be conservative and add a barrier on exit to give it
ACQUIRE semantics.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
There are still a few occurences where it remains, because it helps to
explain something that persists.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
memmove may be called from module code copy_pages(btrfs), and it may
call memcpy, which may call back to C code, so it needs to use
_GLOBAL_TOC to set up r2 correctly.
This fixes following error when I tried to boot an le guest:
Vector: 300 (Data Access) at [c000000073f97210]
pc: c000000000015004: enable_kernel_altivec+0x24/0x80
lr: c000000000058fbc: enter_vmx_copy+0x3c/0x60
sp: c000000073f97490
msr: 8000000002009033
dar: d000000001d50170
dsisr: 40000000
current = 0xc0000000734c0000
paca = 0xc00000000fff0000 softe: 0 irq_happened: 0x01
pid = 815, comm = mktemp
enter ? for help
[c000000073f974f0] c000000000058fbc enter_vmx_copy+0x3c/0x60
[c000000073f97510] c000000000057d34 memcpy_power7+0x274/0x840
[c000000073f97610] d000000001c3179c copy_pages+0xfc/0x110 [btrfs]
[c000000073f97660] d000000001c3c248 memcpy_extent_buffer+0xe8/0x160 [btrfs]
[c000000073f97700] d000000001be4be8 setup_items_for_insert+0x208/0x4a0 [btrfs]
[c000000073f97820] d000000001be50b4 btrfs_insert_empty_items+0xf4/0x140 [btrfs]
[c000000073f97890] d000000001bfed30 insert_with_overflow+0x70/0x180 [btrfs]
[c000000073f97900] d000000001bff174 btrfs_insert_dir_item+0x114/0x2f0 [btrfs]
[c000000073f979a0] d000000001c1f92c btrfs_add_link+0x10c/0x370 [btrfs]
[c000000073f97a40] d000000001c20e94 btrfs_create+0x204/0x270 [btrfs]
[c000000073f97b00] c00000000026d438 vfs_create+0x178/0x210
[c000000073f97b50] c000000000270a70 do_last+0x9f0/0xe90
[c000000073f97c20] c000000000271010 path_openat+0x100/0x810
[c000000073f97ce0] c000000000272ea8 do_filp_open+0x58/0xd0
[c000000073f97dc0] c00000000025ade8 do_sys_open+0x1b8/0x300
[c000000073f97e30] c00000000000a008 syscall_exit+0x0/0x7c
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This fixes some bugs in emulate_step(). First, the setting of the carry
bit for the arithmetic right-shift instructions was not correct on 64-bit
machines because we were masking with a mask of type int rather than
unsigned long. Secondly, the sld (shift left doubleword) instruction was
using the wrong instruction field for the register containing the shift
count.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit cd64d1697c ("powerpc: mtmsrd not defined") added a check for
CONFIG_PPC_CPU were a check for CONFIG_PPC_FPU was clearly intended.
Fixes: cd64d1697c ("powerpc: mtmsrd not defined")
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
__clear_user and copy_page load from the TOC and are also exported
to modules. This means we have to use _GLOBAL_TOC() so that we
create the global entry point that sets up the TOC.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This series adds support for building the powerpc 64-bit
LE kernel using the new ABI v2. We already supported
running ABI v2 userspace programs but this adds support
for building the kernel itself using the new ABI.
Unaligned stores take alignment exceptions on POWER7 running in little-endian.
This is a dumb little-endian base memcpy that prevents unaligned stores.
Once booted the feature fixup code switches over to the VMX copy loops
(which are already endian safe).
The question is what we do before that switch over. The base 64bit
memcpy takes alignment exceptions on POWER7 so we can't use it as is.
Fixing the causes of alignment exception would slow it down, because
we'd need to ensure all loads and stores are aligned either through
rotate tricks or bytewise loads and stores. Either would be bad for
all other 64bit platforms.
[ I simplified the loop a bit - Anton ]
Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
If an assembly function that calls back into c code is exported to
modules, we need to ensure r2 is setup correctly. There are only
two places crazy enough to do it (two of which are my fault).
Signed-off-by: Anton Blanchard <anton@samba.org>
Some of the assembler files in lib/ make use of the fact that in the
ELFv1 ABI, the caller guarantees to provide stack space to save the
parameter registers r3 ... r10. This guarantee is no longer present
in ELFv2 for functions that have no variable argument list and no
more than 8 arguments.
Change the affected routines to temporarily store registers in the
red zone and/or the top of their own stack frame (in the space
provided to save r31 .. r29, which is actually not used in these
routines).
In opal_query_takeover, simply always allocate a stack frame;
the routine is not performance critical.
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
