powerpc/powermac: Use early_* IO variants in via_calibrate_decr()

On a powermac platform, via the call path:

start_kernel()
time_init()
ppc_md.calibrate_decr() (pmac_calibrate_decr)
via_calibrate_decr()

ioremap() and iounmap() are called. The unmap can enable interrupts
unexpectedly (cond_resched() in vunmap_pmd_range()), which causes a
warning later in the boot sequence in start_kernel().

Use the early_* variants of these IO functions to prevent this.

The issue is pre-existing, but is surfaced by commit 721255b9826b
("genirq: Use a maple tree for interrupt descriptor management").

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230706010816.72682-1-bgray@linux.ibm.com

powerpc: Add missing headers

Don't inherit headers "by chances" from asm/prom.h, asm/mpc52xx.h,
asm/pci.h etc...

Include the needed headers, and remove asm/prom.h when it was
needed exclusively for pulling necessary headers.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/be8bdc934d152a7d8ee8d1a840d5596e2f7d85e0.1646767214.git.christophe.leroy@csgroup.eu

mm: don't include asm/pgtable.h if linux/mm.h is already included

Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once. For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the
functions involving page table manipulations, e.g. pte_alloc() and
pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h>
in the files that include <linux/mm.h>.

The include statements in such cases are remove with a simple loop:

for f in $(git grep -l "include <linux/mm.h>") ; do
sed -i -e '/include <asm\/pgtable.h>/ d' $f
done

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: Adopt nvram module for PPC64

Adopt nvram module to reduce code duplication. This means CONFIG_NVRAM
becomes available to PPC64 builds. Previously it was only available to
PPC32 builds because it depended on CONFIG_GENERIC_NVRAM.

The IOC_NVRAM_GET_OFFSET ioctl as implemented on PPC64 validates the
offset returned by pmac_get_partition(). Do the same in the nvram module.

Note that the old PPC32 generic_nvram module lacked this test.
So when CONFIG_PPC32 && CONFIG_PPC_PMAC, the IOC_NVRAM_GET_OFFSET ioctl
would have returned 0 (always). But when CONFIG_PPC64 && CONFIG_PPC_PMAC,
the IOC_NVRAM_GET_OFFSET ioctl would have returned -1 (which is -EPERM)
when the requested partition was not found.

With this patch, the result is now -EINVAL on both PPC32 and PPC64 when
the requested PowerMac NVRAM partition is not found. This is a userspace-
visible change, in the non-existent partition case, which would be in
an error path for an IOC_NVRAM_GET_OFFSET ioctl syscall.

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

macintosh: Use common code to access RTC

Now that the 68k Mac port has adopted the via-pmu driver, the same RTC
code can be shared between m68k and powerpc. Replace duplicated code in
arch/powerpc and arch/m68k with common RTC accessors for Cuda and PMU.

Drop the problematic WARN_ON which was introduced in commit 22db552b50fa
("powerpc/powermac: Fix rtc read/write functions").

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/powermac: Add missing include of header pmac.h

The header `pmac.h` was not included, leading to the following warnings,
treated as error with W=1:

arch/powerpc/platforms/powermac/time.c:69:13: error: no previous prototype for ‘pmac_time_init’ [-Werror=missing-prototypes]
arch/powerpc/platforms/powermac/time.c:207:15: error: no previous prototype for ‘pmac_get_boot_time’ [-Werror=missing-prototypes]
arch/powerpc/platforms/powermac/time.c:222:6: error: no previous prototype for ‘pmac_get_rtc_time’ [-Werror=missing-prototypes]
arch/powerpc/platforms/powermac/time.c:240:5: error: no previous prototype for ‘pmac_set_rtc_time’ [-Werror=missing-prototypes]
arch/powerpc/platforms/powermac/time.c:259:12: error: no previous prototype for ‘via_calibrate_decr’ [-Werror=missing-prototypes]
arch/powerpc/platforms/powermac/time.c:311:13: error: no previous prototype for ‘pmac_calibrate_decr’ [-Werror=missing-prototypes]

The function `via_calibrate_decr` was made static to silence a warning.

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/powermac: Fix rtc read/write functions

As Mathieu pointed out, my conversion to time64_t was incorrect and
resulted in negative times to be read from the RTC. The problem is
that during the conversion from a byte array to a time64_t, the
'unsigned char' variable holding the top byte gets turned into a
negative signed 32-bit integer before being assigned to the 64-bit
variable for any times after 1972.

This changes the logic to cast to an unsigned 32-bit number first for
the Macintosh time and then convert that to the Unix time, which then
gives us a time in the documented 1904..2040 year range. I decided not
to use the longer 1970..2106 range that other drivers use, for
consistency with the literal interpretation of the register, but that
could be easily changed if we decide we want to support any Mac after
2040.

Just to be on the safe side, I'm also adding a WARN_ON that will
trigger if either the year 2040 has come and is observed by this
driver, or we run into an RTC that got set back to a pre-1970 date for
some reason (the two are indistinguishable).

For the RTC write functions, Andreas found another problem: both
pmu_request() and cuda_request() are varargs functions, so changing
the type of the arguments passed into them from 32 bit to 64 bit
breaks the API for the set_rtc_time functions. This changes it back to
32 bits.

The same code exists in arch/m68k/ and is patched in an identical way
now in a separate patch.

Fixes: 5bfd643583b2 ("powerpc: use time64_t in read_persistent_clock")
Reported-by: Mathieu Malaterre <malat@debian.org>
Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc: use time64_t in update_persistent_clock

update_persistent_clock() is deprecated because it suffers from overflow
in 2038 on 32-bit architectures. This changes powerpc to use the
update_persistent_clock64() replacement, and to pass down 64-bit
timestamps consistently.

This is now simpler, as we no longer have to worry about the offset
numbers in tm_year and tm_mon that are different between the Linux
conventions and RTAS.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc: use time64_t in read_persistent_clock

Looking through the remaining users of the deprecated mktime()
function, I found the powerpc rtc handlers, which use it in
place of rtc_tm_to_time64().

To clean this up, I'm changing over the read_persistent_clock()
function to the read_persistent_clock64() variant, and change
all the platform specific handlers along with it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Disintegrate asm/system.h for PowerPC

Disintegrate asm/system.h for PowerPC.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
cc: linuxppc-dev@lists.ozlabs.org

treewide: Convert uses of struct resource to resource_size(ptr)

Several fixes as well where the +1 was missing.

Done via coccinelle scripts like:

@@
struct resource *ptr;
@@

- ptr->end - ptr->start + 1
+ resource_size(ptr)

and some grep and typing.

Mostly uncompiled, no cross-compilers.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

of: add 'of_' prefix to machine_is_compatible()

machine is compatible is an OF-specific call. It should have
the of_ prefix to protect the global namespace.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Michal Simek <monstr@monstr.eu>

powerpc/powermac: Add missing of_node_put

This patch fixes some unbalanced OF node references in the
powermac code

Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc: Guard from_rtc_time() in platforms/powermac/time.c

from_rtc_time() is only called when one of 3 CONFIG options are defined.
Guard the declaration appropriately.

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] powermac: Fix warning in time.c

arch/powerpc/platforms/powermac/time.c:88: warning: 'to_rtc_time' defined but not used

This fixes the warning by making the relevant code depend on the
users.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Generic time suspend/resume code

This removes the time suspend/restore code that was done through
a PMU notifier in arch/platforms/powermac/time.c.

Instead, introduce arch/powerpc/sysdev/timer.c which creates a sys
device and handles time of day suspend/resume through that.

This should probably be replaced by using the generic RTC framework
but for now it gets rid of the arcane powermac specific hack.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[PATCH] powerpc: Kill _machine and hard-coded platform numbers

This removes statically assigned platform numbers and reworks the
powerpc platform probe code to use a better mechanism. With this,
board support files can simply declare a new machine type with a
macro, and implement a probe() function that uses the flattened
device-tree to detect if they apply for a given machine.

We now have a machine_is() macro that replaces the comparisons of
_machine with the various PLATFORM_* constants. This commit also
changes various drivers to use the new macro instead of looking at
_machine.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[PATCH] powerpc: Remove device_node addrs/n_addr

The pre-parsed addrs/n_addrs fields in struct device_node are finally
gone. Remove the dodgy heuristics that did that parsing at boot and
remove the fields themselves since we now have a good replacement with
the new OF parsing code. This patch also fixes a bunch of drivers to use
the new code instead, so that at least pmac32, pseries, iseries and g5
defconfigs build.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: Remove __init from a function used in suspend/resume.

Suspend/resume on powermacs uses the pmac_get_boot_time function,
so it can't be marked as __init.

Signed-off-by: Paul Mackerras <paulus@samba.org>

[PATCH] powerpc: kill ppc64 rtc.c, use genrtc instead

This moves the rtas RTC callbacks to rtas-rtc.c in arch/powerpc/kernel,
and kills the rest of arch/ppc64/kernel/rtc.c which was just a duplicate
of the genrtc functionality. Also enable build of genrtc for
CONFIG_PPC64 (it just works are we already have the required callbacks)
and enable it in all defconfigs.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[PATCH] powerpc: vdso fixes (take #2)

This fixes various errors in the new functions added in the vDSO's,
I've now verified all functions on both 32 and 64 bits vDSOs. It also
fix a sign extension bug getting the initial time of day at boot that
could cause the monotonic clock value to be completely on bogus for
64 bits applications (with either the vDSO or the syscall) on
powermacs.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: Don't limit pmac_get_rtc_time to return only positive values

If the machine's clock is set to a bogus value, this check resulted
in userland waiting effectively forever for the RTC value to change,
so remove the check.

Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: Merge in 64-bit powermac support.

This brings in a lot of changes from arch/ppc64/kernel/pmac_*.c to
arch/powerpc/platforms/powermac/*.c and makes various minor tweaks
elsewhere. On the powermac we now initialize ppc_md by copying
the whole pmac_md structure into it, which required some changes in
the ordering of initializations of individual fields of it.

Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: Fix some bugs in the new merged time code

I had the sense of the test for when to use the old 601-style RTC
registers inverted. pmac_calibrate_decr and via_calibrate_decr
weren't setting ppc_tb_freq, on which all the further calculations
depended. Lastly, update_gtod was losing the top 32 bits of
the new tb_to_xs value.

Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: Merge time.c and asm/time.h.

We now use the merged time.c for both 32-bit and 64-bit compilation
with ARCH=powerpc, and for ARCH=ppc64, but not for ARCH=ppc32.
This removes setup_default_decr (folds its function into time_init)
and moves wakeup_decrementer into time.c. This also makes an
asm-powerpc/rtc.h.

Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: Merge machdep.h

A few things change for consistency between ppc32 and ppc64:
idle functions return void; *_get_boot_time functions return
unsigned long (i.e. time_t) rather than filling in a struct rtc_time
(since that's useful to the callers and easier for pmac to
generate); *_get_rtc_time and *_set_rtc_time functions take
a struct rtc_time; irq_canonicalize is gone; nvram_sync returns
void.

Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: Bring in some changes made to arch/ppc and include/asm-ppc64

Recent commits upstream have changed files which are currently
duplicated in arch/powerpc and include/asm-powerpc. This updates
them with the corresponding changes.

Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: rename powermac files to remove pmac_ prefix

Since the files are now in arch/powerpc/platforms/powermac, the
pmac_ prefix that they had is redundant.

Signed-off-by: Paul Mackerras <paulus@samba.org>