30 Oct, 2009
1 commit
-
Signed-off-by: Benjamin Herrenschmidt
24 Sep, 2009
1 commit
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Some System p configurations can already have more than 16 nodes so we
need to increase NODES_SHIFT. I chose 256 to give us some room to grow in the
future, although we can look at something smaller if the memory bloat is
considered too much.Unless we clamp MAX_ACTIVE_REGIONS we end up with 300kB of extra bloat in
early_node_map in mm/page_alloc.c:< 6144 early_node_map
> 307200 early_node_mapdue to:
#if MAX_NUMNODES >= 32
/* If there can be many nodes, allow up to 50 holes per node */
#define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
#else
/* By default, allow up to 256 distinct regions */
#define MAX_ACTIVE_REGIONS 256Since our memory is mostly contiguous it seems reasonable to keep this
at 256 for now. I also set 32bit to 32 to save space (is there any chance
a 32bit system will have more than 32 discontiguous memory ranges?).Even with that fixed we have a few data structures that grow:
< 896 bootmem_node_data
> 14336 bootmem_node_data< 1280 node_devices
> 20480 node_devices< 25088 kmalloc_caches
> 59648 kmalloc_caches< 1632 hstates
> 21792 hstatesSigned-off-by: Anton Blanchard
Signed-off-by: Benjamin Herrenschmidt
21 Sep, 2009
1 commit
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Bye-bye Performance Counters, welcome Performance Events!
In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)This patch has been generated via the following script:
FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')
sed -i \
-e 's/PERF_EVENT_/PERF_RECORD_/g' \
-e 's/PERF_COUNTER/PERF_EVENT/g' \
-e 's/perf_counter/perf_event/g' \
-e 's/nb_counters/nb_events/g' \
-e 's/swcounter/swevent/g' \
-e 's/tpcounter_event/tp_event/g' \
$FILESfor N in $(find . -name perf_counter.[ch]); do
M=$(echo $N | sed 's/perf_counter/perf_event/g')
mv $N $M
doneFILES=$(find . -name perf_event.*)
sed -i \
-e 's/COUNTER_MASK/REG_MASK/g' \
-e 's/COUNTER/EVENT/g' \
-e 's/\/event_id/g' \
-e 's/counter/event/g' \
-e 's/Counter/Event/g' \
$FILES... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.( NOTE: 'counters' are still the proper terminology when we deal
with hardware registers - and these sed scripts are a bit
over-eager in renaming them. I've undone some of that, but
in case there's something left where 'counter' would be
better than 'event' we can undo that on an individual basis
instead of touching an otherwise nicely automated patch. )Suggested-by: Stephane Eranian
Acked-by: Peter Zijlstra
Acked-by: Paul Mackerras
Reviewed-by: Arjan van de Ven
Cc: Mike Galbraith
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
Cc: Steven Rostedt
Cc: Benjamin Herrenschmidt
Cc: David Howells
Cc: Kyle McMartin
Cc: Martin Schwidefsky
Cc: "David S. Miller"
Cc: Thomas Gleixner
Cc: "H. Peter Anvin"
Cc:
LKML-Reference:
Signed-off-by: Ingo Molnar
16 Sep, 2009
1 commit
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* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (134 commits)
powerpc/nvram: Enable use Generic NVRAM driver for different size chips
powerpc/iseries: Fix oops reading from /proc/iSeries/mf/*/cmdline
powerpc/ps3: Workaround for flash memory I/O error
powerpc/booke: Don't set DABR on 64-bit BookE, use DAC1 instead
powerpc/perf_counters: Reduce stack usage of power_check_constraints
powerpc: Fix bug where perf_counters breaks oprofile
powerpc/85xx: Fix SMP compile error and allow NULL for smp_ops
powerpc/irq: Improve nanodoc
powerpc: Fix some late PowerMac G5 with PCIe ATI graphics
powerpc/fsl-booke: Use HW PTE format if CONFIG_PTE_64BIT
powerpc/book3e: Add missing page sizes
powerpc/pseries: Fix to handle slb resize across migration
powerpc/powermac: Thermal control turns system off too eagerly
powerpc/pci: Merge ppc32 and ppc64 versions of phb_scan()
powerpc/405ex: support cuImage via included dtb
powerpc/405ex: provide necessary fixup function to support cuImage
powerpc/40x: Add support for the ESTeem 195E (PPC405EP) SBC
powerpc/44x: Add Eiger AMCC (AppliedMicro) PPC460SX evaluation board support.
powerpc/44x: Update Arches defconfig
powerpc/44x: Update Arches dts
...Fix up conflicts in drivers/char/agp/uninorth-agp.c
28 Aug, 2009
2 commits
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Signed-off-by: FUJITA Tomonori
Signed-off-by: Benjamin Herrenschmidt -
Signed-off-by: FUJITA Tomonori
Acked-by: Becky Bruce
Signed-off-by: Benjamin Herrenschmidt
20 Aug, 2009
2 commits
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This contains all the bits that didn't fit in previous patches :-) This
includes the actual exception handlers assembly, the changes to the
kernel entry, other misc bits and wiring it all up in Kconfig.Signed-off-by: Benjamin Herrenschmidt
-
The current definitions set ranges and defaults for 32 and 64-bit
only using "PPC_STD_MMU" which means hash based MMU. This uselessly
restrict the usefulness for the upcoming 64-bit BookE port, but more
than that, it's broken on 32-bit since the only 32-bit platform
supporting multiple page sizes currently is 44x which does -not-
have PPC_STD_MMU_32 set.This fixes it by using PPC64 and PPC32 instead.
Signed-off-by: Benjamin Herrenschmidt
14 Aug, 2009
1 commit
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Now that percpu allows arbitrary embedding of the first chunk,
powerpc64 can easily be converted to dynamic percpu allocator.
Convert it. powerpc supports several large page sizes. Cap atom_size
at 1M. There isn't much to gain by going above that anyway.Signed-off-by: Tejun Heo
Cc: Benjamin Herrenschmidt
04 Jul, 2009
1 commit
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Pull linus#master to merge PER_CPU_DEF_ATTRIBUTES and alpha build fix
changes. As alpha in percpu tree uses 'weak' attribute instead of
inline assembly, there's no need for __used attribute.Conflicts:
arch/alpha/include/asm/percpu.h
arch/mn10300/kernel/vmlinux.lds.S
include/linux/percpu-defs.h
26 Jun, 2009
1 commit
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Based on initial work from: Dale Farnsworth
Add the low level irq tracing hooks for 32-bit powerpc needed
to enable full lockdep functionality.The approach taken to deal with the code in entry_32.S is that
we don't trace all the transitions of MSR:EE when we just turn
it off to peek at TI_FLAGS without races. Only when we are
calling into C code or returning from exceptions with a state
that have changed from what lockdep thinks.There's a little bugger though: If we take an exception that
keeps interrupts enabled (such as an alignment exception) while
interrupts are enabled, we will call trace_hardirqs_on() on the
way back spurriously. Not a big deal, but to get rid of it would
require remembering in pt_regs that the exception was one of the
type that kept interrupts enabled which we don't know at this
stage. (Well, we could test all cases for regs->trap but that
sucks too much).Signed-off-by: Benjamin Herrenschmidt
Tested-by: Kumar Gala
24 Jun, 2009
1 commit
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This patch makes most !CONFIG_HAVE_SETUP_PER_CPU_AREA archs use
dynamic percpu allocator. The first chunk is allocated using
embedding helper and 8k is reserved for modules. This ensures that
the new allocator behaves almost identically to the original allocator
as long as static percpu variables are concerned, so it shouldn't
introduce much breakage.s390 and alpha use custom SHIFT_PERCPU_PTR() to work around addressing
range limit the addressing model imposes. Unfortunately, this breaks
if the address is specified using a variable, so for now, the two
archs aren't converted.The following architectures are affected by this change.
* sh
* arm
* cris
* mips
* sparc(32)
* blackfin
* avr32
* parisc (broken, under investigation)
* m32r
* powerpc(32)As this change makes the dynamic allocator the default one,
CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is replaced with its invert -
CONFIG_HAVE_LEGACY_PER_CPU_AREA, which is added to yet-to-be converted
archs. These archs implement their own setup_per_cpu_areas() and the
conversion is not trivial.* powerpc(64)
* sparc(64)
* ia64
* alpha
* s390Boot and batch alloc/free tests on x86_32 with debug code (x86_32
doesn't use default first chunk initialization). Compile tested on
sparc(32), powerpc(32), arm and alpha.Kyle McMartin reported that this change breaks parisc. The problem is
still under investigation and he is okay with pushing this patch
forward and fixing parisc later.[ Impact: use dynamic allocator for most archs w/o custom percpu setup ]
Signed-off-by: Tejun Heo
Acked-by: Rusty Russell
Acked-by: David S. Miller
Acked-by: Benjamin Herrenschmidt
Acked-by: Martin Schwidefsky
Reviewed-by: Christoph Lameter
Cc: Paul Mundt
Cc: Russell King
Cc: Mikael Starvik
Cc: Ralf Baechle
Cc: Bryan Wu
Cc: Kyle McMartin
Cc: Matthew Wilcox
Cc: Grant Grundler
Cc: Hirokazu Takata
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Cc: Heiko Carstens
Cc: Ingo Molnar
18 Jun, 2009
1 commit
-
This enables the perf_counter subsystem on 32-bit powerpc. Since we
don't have any support for hardware counters on 32-bit powerpc yet,
only software counters can be used.Besides selecting HAVE_PERF_COUNTERS for 32-bit powerpc as well as
64-bit, the main thing this does is add an implementation of
set_perf_counter_pending(). This needs to arrange for
perf_counter_do_pending() to be called when interrupts are enabled.
Rather than add code to local_irq_restore as 64-bit does, the 32-bit
set_perf_counter_pending() generates an interrupt by setting the
decrementer to 1 so that a decrementer interrupt will become pending
in 1 or 2 timebase ticks (if a decrementer interrupt isn't already
pending). When interrupts are enabled, timer_interrupt() will be
called, and some new code in there calls perf_counter_do_pending().
We use a per-cpu array of flags to indicate whether we need to call
perf_counter_do_pending() or not.This introduces a couple of new Kconfig symbols: PPC_HAVE_PMU_SUPPORT,
which is selected by processor families for which we have hardware PMU
support (currently only PPC64), and PPC_PERF_CTRS, which enables the
powerpc-specific perf_counter back-end.Signed-off-by: Paul Mackerras
Cc: Peter Zijlstra
Cc: linuxppc-dev@ozlabs.org
Cc: benh@kernel.crashing.org
LKML-Reference:
Signed-off-by: Ingo Molnar
15 Jun, 2009
2 commits
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This makes 32-bit powerpc use the generic atomic64_t implementation.
Signed-off-by: Paul Mackerras
Signed-off-by: Benjamin Herrenschmidt -
Currently we are wasting time calling the generic calibrate_delay()
function. We don't need it since our implementation of __delay() is
based on the CPU timebase. So instead, we use our own small
implementation that initializes loops_per_jiffy to something sensible
to make the few users like spinlock debug be happySigned-off-by: Benjamin Herrenschmidt
09 Jun, 2009
1 commit
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This patch includes the basic infrastructure to use swiotlb
bounce buffering on 32-bit powerpc. It is not yet enabled on
any platforms. Probably the most interesting bit is the
addition of addr_needs_map to dma_ops - we need this as
a dma_op because the decision of whether or not an addr
can be mapped by a device is device-specific.Signed-off-by: Becky Bruce
Acked-by: Kumar Gala
Signed-off-by: Benjamin Herrenschmidt
29 May, 2009
1 commit
27 May, 2009
2 commits
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The implementation we just revived has issues, such as using a
Kconfig-defined virtual address area in kernel space that nothing
actually carves out (and thus will overlap whatever is there),
or having some dependencies on being self contained in a single
PTE page which adds unnecessary constraints on the kernel virtual
address space.This fixes it by using more classic PTE accessors and automatically
locating the area for consistent memory, carving an appropriate hole
in the kernel virtual address space, leaving only the size of that
area as a Kconfig option. It also brings some dma-mask related fixes
from the ARM implementation which was almost identical initially but
grew its own fixes.Signed-off-by: Benjamin Herrenschmidt
-
This reverts commit 33f00dcedb0e22cdb156a23632814fc580fcfcf8.
While it was a good idea to try to use the mm/vmalloc.c allocator instead
of our own (in fact, ours is itself a dup on an old variant of the vmalloc
one), unfortunately, the approach is terminally busted since
dma_alloc_coherent() can be called at interrupt time or in atomic contexts
and there's little chances we'll make the code in mm/vmalloc.c cope with\ that :-(Until we can get the generic code to forbid that idiocy and fix all
drivers abusing it, we pretty much have no choice but revert to
our custom virtual space allocator.There's also a problem with SMP safety since freeing such mapping
would require an IPI which cannot be done at interrupt time.However, right now, I don't think we support any platform that is
both SMP and has non-coherent DMA (don't laugh, I know such things
do exist !) so we can sort that out later.Signed-off-by: Benjamin Herrenschmidt
21 May, 2009
1 commit
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So select GENERIC_HARDIRQS_NO__DO_IRQ to disable it.
Signed-off-by: Michael Ellerman
Signed-off-by: Benjamin Herrenschmidt
03 May, 2009
1 commit
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The powerpc kernel always requires an Open Firmware like device tree
to supply device information. On systems without OF, this comes from
a flattened device tree blob. This blob is usually generated by dtc,
a tool which compiles a text description of the device tree into the
flattened format used by the kernel. Sometimes, the bootwrapper makes
small changes to the pre-compiled device tree blob (e.g. filling in
the size of RAM). To do this it uses the libfdt library.Because these are only used on powerpc, the code for both these tools
is included under arch/powerpc/boot (these were imported and are
periodically updated from the upstream dtc tree).However, the microblaze architecture, currently being prepared for
merging to mainline also uses dtc to produce device tree blobs. A few
other archs have also mentioned some interest in using dtc.
Therefore, this patch moves dtc and libfdt from arch/powerpc into
scripts, where it can be used by any architecture.The vast bulk of this patch is a literal move, the rest is adjusting
the various Makefiles to use dtc and libfdt correctly from their new
locations.Signed-off-by: David Gibson
Signed-off-by: Linus Torvalds
15 Apr, 2009
1 commit
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Now that shmem's divisions by zero and SHMEM_MAX_BYTES are fixed,
let powerpc 256kB pages coexist with CONFIG_SHMEM again.Signed-off-by: Hugh Dickins
Signed-off-by: Paul Mackerras
07 Apr, 2009
2 commits
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commit 28794d34ecb6815a3fa0a4256027c9b081a17c5f ("powerpc/kconfig: Kill
PPC_MULTIPLATFORM") broke KEXEC, by making it dependent on BOOK3S, while it
should be PPC_BOOK3S.Signed-off-by: Geert Uytterhoeven
Signed-off-by: Paul Mackerras
04 Apr, 2009
1 commit
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* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits)
trivial: Update my email address
trivial: NULL noise: drivers/mtd/tests/mtd_*test.c
trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h
trivial: Fix misspelling of "Celsius".
trivial: remove unused variable 'path' in alloc_file()
trivial: fix a pdlfush -> pdflush typo in comment
trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL
trivial: wusb: Storage class should be before const qualifier
trivial: drivers/char/bsr.c: Storage class should be before const qualifier
trivial: h8300: Storage class should be before const qualifier
trivial: fix where cgroup documentation is not correctly referred to
trivial: Give the right path in Documentation example
trivial: MTD: remove EOL from MODULE_DESCRIPTION
trivial: Fix typo in bio_split()'s documentation
trivial: PWM: fix of #endif comment
trivial: fix typos/grammar errors in Kconfig texts
trivial: Fix misspelling of firmware
trivial: cgroups: documentation typo and spelling corrections
trivial: Update contact info for Jochen Hein
trivial: fix typo "resgister" -> "register"
...
01 Apr, 2009
1 commit
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CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and
s390. This patch implements it for the rest of the architectures by
filling the pages with poison byte patterns after free_pages() and
verifying the poison patterns before alloc_pages().This generic one cannot detect invalid page accesses immediately but
invalid read access may cause invalid dereference by poisoned memory and
invalid write access can be detected after a long delay.Signed-off-by: Akinobu Mita
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Mar, 2009
1 commit
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The recent addition of CONFIG_LOWMEM_CAM_BOOL and
CONFIG_LOWMEM_CAM_NUM cause the latter to show up in configs
that do not need it during 'make oldconfig'. Make LOWMEM_CAM_NUM
depend on FSL_BOOKE.Signed-off-by: Josh Boyer
Signed-off-by: Kumar Gala
30 Mar, 2009
1 commit
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Signed-off-by: Matt LaPlante
Acked-by: Randy Dunlap
Signed-off-by: Jiri Kosina
11 Mar, 2009
1 commit
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CONFIG_PPC_MULTIPLATFORM is a remain of the pre-powerpc days and isn't
really meaningful anymore. It was basically equivalent to PPC64 || 6xx.This removes it along with the following changes:
- 32-bit platforms that relied on PPC32 && PPC_MULTIPLATFORM now rely
on 6xx which is what they want anyway.- A new symbol, PPC_BOOK3S, is defined that represent compliance with
the "Server" variant of the architecture. This is set when either 6xx
or PPC64 is set and open the door for future BOOK3E 64-bit.- 64-bit platforms that relied on PPC64 && PPC_MULTIPLATFORM now use
PPC64 && PPC_BOOK3S- A separate and selectable CONFIG_PPC_OF_BOOT_TRAMPOLINE option is now
used to control the use of prom_init.cSigned-off-by: Benjamin Herrenschmidt
03 Mar, 2009
1 commit
23 Feb, 2009
5 commits
-
This patch rewrites consistent dma allocations support to use vmalloc
layer to allocate virtual memory space from vmalloc pool and get rid
of CONFIG_CONSISTENT_{START,SIZE}.This greatly simplifies the code by effectively removing a custom
allocator we had for virtual space.Signed-off-by: Ilya Yanok
Signed-off-by: Benjamin Herrenschmidt -
This patch gets function graph tracing working with dynamic function
tracer on PowerPC32.Acked-by: Benjamin Herrenschmidt
Signed-off-by: Steven Rostedt
Signed-off-by: Benjamin Herrenschmidt -
This patch ports the function graph tracer for PowerPC, but only
for static function tracing.Acked-by: Benjamin Herrenschmidt
Signed-off-by: Steven Rostedt
Signed-off-by: Benjamin Herrenschmidt -
This is the port of the function graph tracer to PowerPC with
dynamic tracing.Geoff Lavand tested on PS3.
Tested-by: Geoff Levand
Acked-by: Benjamin Herrenschmidt
Signed-off-by: Steven Rostedt
Signed-off-by: Benjamin Herrenschmidt -
This is a port of the function graph tracer that was written by
Frederic Weisbecker for the x86.This only works for PPC64 at the moment and only for static tracing.
PPC32 and dynamic function graph tracing support will come later.The trace produces a visual calling of functions:
# tracer: function_graph
#
# CPU DURATION FUNCTION CALLS
# | | | | | | |
0) 2.224 us | }
0) ! 271.024 us | }
0) ! 320.080 us | }
0) ! 324.656 us | }
0) ! 329.136 us | }
0) | .put_prev_task_fair() {
0) | .update_curr() {
0) 2.240 us | .update_min_vruntime();
0) 6.512 us | }
0) 2.528 us | .__enqueue_entity();
0) + 15.536 us | }
0) | .pick_next_task_fair() {
0) 2.032 us | .__pick_next_entity();
0) 2.064 us | .__clear_buddies();
0) | .set_next_entity() {
0) 2.672 us | .__dequeue_entity();
0) 6.864 us | }Geoff Lavand tested on PS3.
Tested-by: Geoff Levand
Acked-by: Benjamin Herrenschmidt
Signed-off-by: Steven Rostedt
Signed-off-by: Benjamin Herrenschmidt
15 Feb, 2009
1 commit
-
This patch adds support for 256KB pages on ppc44x-based boards.
For simplification of implementation with 256KB pages we still assume
2-level paging. As a side effect this leads to wasting extra memory space
reserved for PTE tables: only 1/4 of pages allocated for PTEs are
actually used. But this may be an acceptable trade-off to achieve the
high performance we have with big PAGE_SIZEs in some applications (e.g.
RAID).Also with 256KB PAGE_SIZE we increase THREAD_SIZE up to 32KB to minimize
the risk of stack overflows in the cases of on-stack arrays, which size
depends on the page size (e.g. multipage BIOs, NTFS, etc.).With 256KB PAGE_SIZE we need to decrease the PKMAP_ORDER at least down
to 9, otherwise all high memory (2 ^ 10 * PAGE_SIZE == 256MB) we'll be
occupied by PKMAP addresses leaving no place for vmalloc. We do not
separate PKMAP_ORDER for 256K from 16K/64K PAGE_SIZE here; actually that
value of 10 in support for 16K/64K had been selected rather intuitively.
Thus now for all cases of PAGE_SIZE on ppc44x (including the default, 4KB,
one) we have 512 pages for PKMAP.Because ELF standard supports only page sizes up to 64K, then you should
use binutils later than 2.17.50.0.3 with '-zmax-page-size' set to 256K
for building applications, which are to be run with the 256KB-page sized
kernel. If using the older binutils, then you should patch them like follows:--- binutils/bfd/elf32-ppc.c.orig
+++ binutils/bfd/elf32-ppc.c-#define ELF_MAXPAGESIZE 0x10000
+#define ELF_MAXPAGESIZE 0x40000One more restriction we currently have with 256KB page sizes is inability
to use shmem safely, so, for now, the 256KB is available only if you turn
the CONFIG_SHMEM option off (another variant is to use BROKEN).
Though, if you need shmem with 256KB pages, you can always remove the !SHMEM
dependency in 'config PPC_256K_PAGES', and use the workaround available here:
http://lkml.org/lkml/2008/12/19/20Signed-off-by: Yuri Tikhonov
Signed-off-by: Ilya Yanok
Signed-off-by: Josh Boyer
29 Jan, 2009
3 commits
-
The FSL PCI code depends on PCI quirks being enabled to function
properly. We can ensure this by doing a select in Kconfig of
PCI_QUIRKS.Signed-off-by: Kumar Gala
-
On booke processors, the code that maps low memory only uses up to three
CAM entries, even though there are sixteen and nothing else uses them.Make this number configurable in the advanced options menu along with max
low memory size. If one wants 1 GB of lowmem, then it's typically
necessary to have four CAM entries.Signed-off-by: Trent Piepho
Signed-off-by: Kumar Gala -
The code that maps kernel low memory would only use page sizes up to 256
MB. On E500v2 pages up to 4 GB are supported.However, a page must be aligned to a multiple of the page's size. I.e.
256 MB pages must aligned to a 256 MB boundary. This was enforced by a
requirement that the physical and virtual addresses of the start of lowmem
be aligned to 256 MB. Clearly requiring 1GB or 4GB alignment to allow
pages of that size isn't acceptable.To solve this, I simply have adjust_total_lowmem() take alignment into
account when it decides what size pages to use. Give it PAGE_OFFSET =
0x7000_0000, PHYSICAL_START = 0x3000_0000, and 2GB of RAM, and it will map
pages like this:
PA 0x3000_0000 VA 0x7000_0000 Size 256 MB
PA 0x4000_0000 VA 0x8000_0000 Size 1 GB
PA 0x8000_0000 VA 0xC000_0000 Size 256 MB
PA 0x9000_0000 VA 0xD000_0000 Size 256 MB
PA 0xA000_0000 VA 0xE000_0000 Size 256 MBBecause the lowmem mapping code now takes alignment into account,
PHYSICAL_ALIGN can be lowered from 256 MB to 64 MB. Even lower might be
possible. The lowmem code will work down to 4 kB but it's possible some of
the boot code will fail before then. Poor alignment will force small pages
to be used, which combined with the limited number of TLB1 pages available,
will result in very little memory getting mapped. So alignments less than
64 MB probably aren't very useful anyway.Signed-off-by: Trent Piepho
Signed-off-by: Kumar Gala
28 Jan, 2009
1 commit
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Remove some leftover cruft from the arch/ppc days
Signed-off-by: Josh Boyer
Acked-by: Kumar Gala
Signed-off-by: Benjamin Herrenschmidt