linux.git/arch/powerpc/Makefile, branch v3.12.45

powerpc: Fix 64 bit builds with binutils 2.24

2014-06-09T13:53:56+00:00

commit 7998eb3dc700aaf499f93f50b3d77da834ef9e1d upstream.

With binutils 2.24, various 64 bit builds fail with relocation errors
such as

arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x165ee): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_base_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o
arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x16602): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_end_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o

The assembler maintainer says:

 I changed the ABI, something that had to be done but unfortunately
 happens to break the booke kernel code.  When building up a 64-bit
 value with lis, ori, shl, oris, ori or similar sequences, you now
 should use @high and @higha in place of @h and @ha.  @h and @ha
 (and their associated relocs R_PPC64_ADDR16_HI and R_PPC64_ADDR16_HA)
 now report overflow if the value is out of 32-bit signed range.
 ie. @h and @ha assume you're building a 32-bit value. This is needed
 to report out-of-range -mcmodel=medium toc pointer offsets in @toc@h
 and @toc@ha expressions, and for consistency I did the same for all
 other @h and @ha relocs.

Replacing @h with @high in one strategic location fixes the relocation
errors. This has to be done conditionally since the assembler either
supports @h or @high but not both.

Signed-off-by: Guenter Roeck 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Jiri Slaby

powerpc/e500: Set -mcpu flag for 32-bit e500

2013-08-21T01:49:56+00:00

Unlike 64-bit, we don't currently support multiplatform between e500
and non-e500, so the -mcpu is not configurable at this time.

-msoft-float is specified when testing for -mcpu=8540 because otherwise
some older toolchains will fail with "error: E500 and FPRs not
supported".

Signed-off-by: Scott Wood

powerpc/booke64: Use appropriate -mcpu

2013-08-21T00:55:36+00:00

By default use -mcpu=powerpc64 rather than -mtune=power7

Add options for e5500/e6500, with fallbacks for older compilers.

Hide the POWER cpu options in booke configs.

Signed-off-by: Scott Wood

powerpc/85xx: Remove -Wa,-me500

2013-08-21T00:53:10+00:00

This caused lwsync to be converted to sync on 64-bit (on 32-bit lwsync
is generated at runtime, and so wasn't affected).  Not using lwsync
caused a significant slowdown on certain workloads.

Setting this flag for any e500-enabled build is also not friendly to
multiplatform kernels.

Signed-off-by: Scott Wood

Revert "powerpc/e500: Update compilation flags with core specific options"

2013-08-14T05:00:28+00:00

This reverts commit c8db32c8669f7de05b820ee4934926405af52188.

The commit breaks the build of all my 64-bit embedded configs. It
looks like gcc-4.7.3 doesn't know about e5500. Additionally it
incorrectly does -mcpu=e5500 on a config that has both e5500 and A2
support enabled.

Signed-off-by: Benjamin Herrenschmidt 
---

powerpc/e500: Update compilation flags with core specific options

2013-08-07T23:49:44+00:00

If CONFIG_E500 is enabled, the compilation flags are updated
specifying the target core -mcpu=e5500/e500mc/8540
Also remove -Wa,-me500, being incompatible with -mcpu=e5500/e6500
The assembler option is redundant if the -mcpu= flag is set.
The patch fixes the kernel compilation problem for e5500/e6500
when using gcc option -mcpu=e5500/e6500.

Signed-off-by: Catalin Udma 
Signed-off-by: Scott Wood

powerpc: Avoid load of static chain register when calling nested functions through a pointer on 64bit

2013-01-10T06:01:27+00:00

The ppc64 ABI has a static chain register (r11) which is only used
when calling nested functions through a pointer. Considering that
we take a dim view of nested functions in the kernel, we have a lot
of unnecessary overhead here.

gcc 4.7 has an option to disable loading of r11 so lets use it.

If hell freezes over and hipsters manage to litter the kernel
with nested functions, gcc will give us an error message and
won't simply compile bad code:

    You cannot take the address of a nested function if you use
    the -mno-pointers-to-nested-functions option.

Furthermore our kernel module trampolines don't setup the static
chain register so adding this option and forcing gcc to error out
makes even more sense.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Build kernel with -mcmodel=medium

2013-01-10T06:00:31+00:00

Finally remove the two level TOC and build with -mcmodel=medium.

Unfortunately we can't build modules with -mcmodel=medium due to
the tricks the kernel module loader plays with percpu data:

# -mcmodel=medium breaks modules because it uses 32bit offsets from
# the TOC pointer to create pointers where possible. Pointers into the
# percpu data area are created by this method.
#
# The kernel module loader relocates the percpu data section from the
# original location (starting with 0xd...) to somewhere in the base
# kernel percpu data space (starting with 0xc...). We need a full
# 64bit relocation for this to work, hence -mcmodel=large.

On older kernels we fall back to the two level TOC (-mminimal-toc)

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Relocate prom_init.c on 64bit

2013-01-10T06:00:25+00:00

The ppc64 kernel can get loaded at any address which means
our very early init code in prom_init.c must be relocatable. We do
this with a pretty nasty RELOC() macro that we wrap accesses of
variables with. It is very fragile and sometimes we forget to add a
RELOC() to an uncommon path or sometimes a compiler change breaks it.

32bit has a much more elegant solution where we build prom_init.c
with -mrelocatable and then process the relocations manually.
Unfortunately we can't do the equivalent on 64bit and we would
have to build the entire kernel relocatable (-pie), resulting in a
large increase in kernel footprint (megabytes of relocation data).
The relocation data will be marked __initdata but it still creates
more pressure on our already tight memory layout at boot.

Alan Modra pointed out that the 64bit ABI is relocatable even
if we don't build with -pie, we just need to relocate the TOC.
This patch implements that idea and relocates the TOC entries of
prom_init.c. An added bonus is there are very few relocations to
process which helps keep boot times on simulators down.

gcc does not put 64bit integer constants into the TOC but to be
safe we may want a build time script which passes through the
prom_init.c TOC entries to make sure everything looks reasonable.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Add a powerpc implementation of SHA-1

2013-01-10T03:43:45+00:00

This patch adds a crypto driver which provides a powerpc accelerated
implementation of SHA-1, accelerated in that it is written in asm.

Original patch by Paul, minor fixups for upstream by moi.

Lightly tested on 64-bit with the test program here:

 http://michael.ellerman.id.au/files/junkcode/sha1test.c

Seems to work, and is "not slower" than the generic version.

Needs testing on 32-bit.

Signed-off-by: Paul Mackerras 
Signed-off-by: Michael Ellerman 
Signed-off-by: Benjamin Herrenschmidt