Commit Graph

76 Commits

Author SHA1 Message Date
Russell King b9b32bf70f ARM: use linker magic for vectors and vector stubs
Use linker magic to create the vectors and vector stubs: we can tell the
linker to place them at an appropriate VMA, but keep the LMA within the
kernel.  This gets rid of some unnecessary symbol manipulation, and
have the linker calculate the relocations appropriately.

Cc: <stable@vger.kernel.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-07-31 21:34:24 +01:00
Stephen Rothwell 40b313608a Finally eradicate CONFIG_HOTPLUG
Ever since commit 45f035ab9b ("CONFIG_HOTPLUG should be always on"),
it has been basically impossible to build a kernel with CONFIG_HOTPLUG
turned off.  Remove all the remaining references to it.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03 14:20:18 -07:00
Marc Zyngier 0394e1f605 ARM: KVM: enforce maximum size for identity mapped code
We're about to move to an init procedure where we rely on the
fact that the init code fits in a single page. Make sure we
align the idmap text on a vector alignment, and that the code is
not bigger than a single page.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-04-28 22:23:09 -07:00
Christoffer Dall 9e9a367c29 ARM: Section based HYP idmap
Add a method (hyp_idmap_setup) to populate a hyp pgd with an
identity mapping of the code contained in the .hyp.idmap.text
section.

Offer a method to drop this identity mapping through
hyp_idmap_teardown.

Make all the above depend on CONFIG_ARM_VIRT_EXT and CONFIG_ARM_LPAE.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23 13:29:09 -05:00
Pawel Moll dad5451a32 ARM: 7605/1: vmlinux.lds: Move .notes section next to the rodata
The .notes, being read-only data by nature, were placed between
read-write .data and .bss. This was harmful in case of the XIP
kernel, as being placed in the RAM range, most likely far
from the ROM address, was inflating the XIP images.

Moving the .notes at the end of the read-only section
(consisting of .text, .rodata and unwind info) fixes the problem.

Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Tested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-12-16 10:04:24 +00:00
Stephen Boyd ee951c630c ARM: 7568/1: Sort exception table at compile time
Add the ARM machine identifier to sortextable and select the
config option so that we can sort the exception table at compile
time. sortextable relies on a section named __ex_table existing
in the vmlinux, but ARM's linker script places the exception
table in the data section. Give the exception table its own
section so that sortextable can find it.

This allows us to skip the sorting step during boot.

Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-11-04 10:31:16 +00:00
David Brown 9973290ce2 ARM: 7428/1: Prevent KALLSYM size mismatch on ARM.
ARM builds seem to be plagued by an occasional build error:

    Inconsistent kallsyms data
    This is a bug - please report about it
    Try "make KALLSYMS_EXTRA_PASS=1" as a workaround

The problem has to do with alignment of some sections by the linker.
The kallsyms data is built in two passes by first linking the kernel
without it, and then linking the kernel again with the symbols
included.  Normally, this just shifts the symbols, without changing
their order, and the compression used by the kallsyms gives the same
result.

On non SMP, the per CPU data is empty.  Depending on the where the
alignment ends up, it can come out as either:

   +-------------------+
   | last text segment |
   +-------------------+
   /* padding */
   +-------------------+     <- L1_CACHE_BYTES alignemnt
   | per cpu (empty)   |
   +-------------------+
__per_cpu_end:
   /* padding */
__data_loc:
   +-------------------+     <- THREAD_SIZE alignment
   | data              |
   +-------------------+

or

   +-------------------+
   | last text segment |
   +-------------------+
   /* padding */
   +-------------------+     <- L1_CACHE_BYTES alignemnt
   | per cpu (empty)   |
   +-------------------+
__per_cpu_end:
   /* no padding */
__data_loc:
   +-------------------+     <- THREAD_SIZE alignment
   | data              |
   +-------------------+

if the alignment satisfies both.  Because symbols that have the same
address are sorted by 'nm -n', the second case will be in a different
order than the first case.  This changes the compression, changing the
size of the kallsym data, causing the build failure.

The KALLSYMS_EXTRA_PASS=1 workaround usually works, but it is still
possible to have the alignment change between the second and third
pass.  It's probably even possible for it to never reach a fixedpoint.

The problem only occurs on non-SMP, when the per-cpu data is empty,
and when the data segment has alignment (and immediately follows the
text segments).  Fix this by only including the per_cpu section on
SMP, when it is not empty.

Signed-off-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-06-22 22:54:18 +01:00
Marc Zyngier b8b9987ffd ARM: 7320/1: Fix proc_info table alignment
With an admittedly exotic choice of configuration options
(CC_OPTIMIZE_FOR_SIZE, THUMB2, some other size-minimizing ones)
and compiler, the proc_info table can end up being misaligned,
and the kernel being unbootable (Error: unrecognized/unsupported
processor variant).

Forcing the alignement to 4 bytes in the linker script fixes the
issue.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-02-09 16:25:37 +00:00
Will Deacon 972da06470 ARM: 7290/1: vmlinux.lds.S: align the exception fixup table to a 4-byte boundary
The exception fixup table is currently aligned to a 32-byte boundary.
Whilst this won't cause any problems, the exception_table_entry
structures contain only a pair of unsigned longs, so 4-byte alignment
is all that is required. If the table was walked from start to end,
cacheline alignment may bring some performance benefits, but since a
binary search is used, the access pattern is random and will not benefit
from a stricter alignment.

Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-01-23 10:20:04 +00:00
Will Deacon f0d5375e3c ARM: 7289/1: vmlinux.lds.S: do not hardcode cacheline size as 32 bytes
The linker script assumes a cacheline size of 32 bytes when aligning
the .data..cacheline_aligned and .data..percpu sections.

This patch updates the script to use L1_CACHE_BYTES, which should be set
to 64 on platforms that require it.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-01-23 10:20:04 +00:00
Will Deacon 8903826d0c ARM: idmap: populate identity map pgd at init time using .init.text
When disabling and re-enabling the MMU, it is necessary to take out an
identity mapping for the code that manipulates the SCTLR in order to
avoid it disappearing from under our feet. This is useful when soft
rebooting and returning from CPU suspend.

This patch allocates a set of page tables during boot and populates them
with an identity mapping for the .idmap.text section. This means that
users of the identity map do not need to manage their own pgd and can
instead annotate their functions with __idmap or, in the case of assembly
code, place them in the correct section.

Acked-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-12-06 14:04:14 +00:00
Russell King bdf4e94823 Merge branch 'misc' into for-linus
Conflicts:
	arch/arm/mach-integrator/integrator_ap.c
2011-10-25 08:19:59 +01:00
Simon Glass 87e040b645 ARM: 7017/1: Use generic BUG() handler
ARM uses its own BUG() handler which makes its output slightly different
from other archtectures.

One of the problems is that the ARM implementation doesn't report the function
with the BUG() in it, but always reports the PC being in __bug(). The generic
implementation doesn't have this problem.

Currently we get something like:

kernel BUG at fs/proc/breakme.c:35!
Unable to handle kernel NULL pointer dereference at virtual address 00000000
...
PC is at __bug+0x20/0x2c

With this patch it displays:

kernel BUG at fs/proc/breakme.c:35!
Internal error: Oops - undefined instruction: 0 [#1] PREEMPT SMP
...
PC is at write_breakme+0xd0/0x1b4

This implementation uses an undefined instruction to implement BUG, and sets up
a bug table containing the relevant information. Many versions of gcc do not
support %c properly for ARM (inserting a # when they shouldn't) so we work
around this using distasteful macro magic.

v1: Initial version to replace existing ARM BUG() implementation with something
more similar to other architectures.

v2: Add Thumb support, remove backtrace whitespace output changes. Change to
use macros instead of requiring the asm %d flag to work (thanks to
Dave Martin <dave.martin@linaro.org>)

v3: Remove old BUG() implementation in favor of this one.
Remove the Backtrace: message (will submit this separately).
Use ARM_EXIT_KEEP() so that some architectures can dump exit text at link time
thanks to Stephen Boyd <sboyd@codeaurora.org> (although since we always
define GENERIC_BUG this might be academic.)
Rebase to linux-2.6.git master.

v4: Allow BUGS in modules (these were not reported correctly in v3)
(thanks to Stephen Boyd <sboyd@codeaurora.org> for suggesting that.)
Remove __bug() as this is no longer needed.

v5: Add %progbits as the section flags.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17 09:13:41 +01:00
Russell King 6760b10960 ARM: fix vmlinux.lds.S discarding sections
We are seeing linker errors caused by sections being discarded, despite
the linker script trying to keep them.  The result is (eg):

`.exit.text' referenced in section `.alt.smp.init' of drivers/built-in.o: defined in discarded section `.exit.text' of drivers/built-in.o
`.exit.text' referenced in section `.alt.smp.init' of net/built-in.o: defined in discarded section `.exit.text' of net/built-in.o

This is the relevent part of the linker script (reformatted to make it
clearer):
| SECTIONS
| {
| /*
| * unwind exit sections must be discarded before the rest of the
| * unwind sections get included.
| */
| /DISCARD/ : {
| *(.ARM.exidx.exit.text)
| *(.ARM.extab.exit.text)
| }
| ...
| .exit.text : {
| *(.exit.text)
| *(.memexit.text)
| }
| ...
| /DISCARD/ : {
| *(.exit.text)
| *(.memexit.text)
| *(.exit.data)
| *(.memexit.data)
| *(.memexit.rodata)
| *(.exitcall.exit)
| *(.discard)
| *(.discard.*)
| }
| }

Now, this is what the linker manual says about discarded output sections:

|    The special output section name `/DISCARD/' may be used to discard
| input sections.  Any input sections which are assigned to an output
| section named `/DISCARD/' are not included in the output file.

No questions, no exceptions. It doesn't say "unless they are listed
before the /DISCARD/ section." Now, this is what asn-generic/vmlinux.lds.S
says:
| /*
|  * Default discarded sections.
|  *
|  * Some archs want to discard exit text/data at runtime rather than
|  * link time due to cross-section references such as alt instructions,
|  * bug table, eh_frame, etc. DISCARDS must be the last of output
|  * section definitions so that such archs put those in earlier section
|  * definitions.
|  */

And guess what - the list _always_ includes .exit.text etc.

Now, what's actually happening is that the linker is reading the script,
and it finds the first /DISCARD/ output section at the beginning of the
script. It continues reading the script, and finds the 'DISCARD' macro
at the end, which having been postprocessed results in another
/DISCARD/ output section. As the linker already contains the earlier
/DISCARD/ output section, it adds it to that existing section, so it
effectively is placed at the start. This can be seen by using the -M
option to ld:

| Linker script and memory map
|
|                 0xc037c080                jiffies = jiffies_64
|
| /DISCARD/
|  *(.ARM.exidx.exit.text)
|  *(.ARM.extab.exit.text)
|  *(.exit.text)
|  *(.memexit.text)
|  *(.exit.data)
|  *(.memexit.data)
|  *(.memexit.rodata)
|  *(.exitcall.exit)
|  *(.discard)
|  *(.discard.*)
|
|                 0xc0008000                . = 0xc0008000
|
| .head.text      0xc0008000      0x1d0
|                 0xc0008000                _text = .
|  *(.head.text)
|  .head.text     0xc0008000      0x1d0 arch/arm/kernel/head.o
|                 0xc0008000                stext
|
| .text           0xc0008200   0x2d78d0
|                 0xc0008200                _stext = .
|                 0xc0008200                __exception_text_start = .
|  *(.exception.text)
|  .exception.text
| ...

As you can see, all the discarded sections are grouped together - and
as a result of it being the first output section, they all appear before
any other section.

The result is that not only is the unwind information discarded (as
intended), but also the .exit.text, despite us wanting to have the
.exit.text preserved.

We can't move the unwind information elsewhere, because it'll then be
included even when we do actually discard the .exit.text (and similar)
sections.

So, work around this by avoiding the generic DISCARDS macro, and instead
conditionalize the sections to be discarded ourselves.  This avoids the
ambiguity in how the linker assigns input sections to output sections,
making our script less dependent on undocumented linker behaviour.

Reported-by: Rob Herring <robherring2@gmail.com>
Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-20 23:42:31 +01:00
Russell King e2f81844ef ARM: vmlinux.lds: use _text and _stext the same way as x86
x86 uses _text to mark the start of the kernel image including the
head text, and _stext to mark the start of the .text section.  Change
our vmlinux.lds to conform.  An audit of the places which use _stext
and _text in arch/arm indicates no users of either symbol are impacted
by this change.  It does mean a slight change to /proc/iomem output.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-07 23:36:34 +01:00
Russell King 3835d69a6c ARM: vmlinux.lds: move init sections between text and data sections
Place the init sections between the text and data sections.  This
means all code is grouped together at the beginning of the kernel
image, and all data is at the end of the image.  This avoids problems
with the 24-bit branch instruction relocations becoming invalid with
large initramfs images.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-07 23:36:31 +01:00
Russell King 43fc9d2fa5 ARM: vmlinux.lds: remove .rodata/.rodata1 from main .text segment
RODATA() already handles these sections, so allow it to take care
of them for us.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-07 23:36:28 +01:00
Russell King 1604d79d37 ARM: vmlinux.lds: rearrange .init output section
Keep the various linker tables as separate output sections rather
than combining them together into one big .init section.  This
makes the 'vmlinux' easier to see what is placed where.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-07 23:35:41 +01:00
Russell King 39df88872f ARM: vmlinux.lds: move discarded sections to beginning
Rather than scattering the discarded sections throughout the linker
file, move them to the start.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-07 23:35:38 +01:00
Tejun Heo 0415b00d17 percpu: Always align percpu output section to PAGE_SIZE
Percpu allocator honors alignment request upto PAGE_SIZE and both the
percpu addresses in the percpu address space and the translated kernel
addresses should be aligned accordingly.  The calculation of the
former depends on the alignment of percpu output section in the kernel
image.

The linker script macros PERCPU_VADDR() and PERCPU() are used to
define this output section and the latter takes @align parameter.
Several architectures are using @align smaller than PAGE_SIZE breaking
percpu memory alignment.

This patch removes @align parameter from PERCPU(), renames it to
PERCPU_SECTION() and makes it always align to PAGE_SIZE.  While at it,
add PCPU_SETUP_BUG_ON() checks such that alignment problems are
reliably detected and remove percpu alignment comment recently added
in workqueue.c as the condition would trigger BUG way before reaching
there.

For um, this patch raises the alignment of percpu area.  As the area
is in .init, there shouldn't be any noticeable difference.

This problem was discovered by David Howells while debugging boot
failure on mn10300.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: user-mode-linux-devel@lists.sourceforge.net
2011-03-24 18:50:09 +01:00
Linus Torvalds 16d8775700 Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (91 commits)
  ARM: 6806/1: irq: introduce entry and exit functions for chained handlers
  ARM: 6781/1: Thumb-2: Work around buggy Thumb-2 short branch relocations in gas
  ARM: 6747/1: P2V: Thumb2 support
  ARM: 6798/1: aout-core: zero thread debug registers in a.out core dump
  ARM: 6796/1: Footbridge: Fix I/O mappings for NOMMU mode
  ARM: 6784/1: errata: no automatic Store Buffer drain on Cortex-A9
  ARM: 6772/1: errata: possible fault MMU translations following an ASID switch
  ARM: 6776/1: mach-ux500: activate fix for errata 753970
  ARM: 6794/1: SPEAr: Append UL to device address macros.
  ARM: 6793/1: SPEAr: Remove unused *_SIZE macros from spear*.h files
  ARM: 6792/1: SPEAr: Replace SIZE macro's with SZ_4K macros
  ARM: 6791/1: SPEAr3xx: Declare device structures after shirq code
  ARM: 6790/1: SPEAr: Clock Framework: Rename usbd clock and align apb_clk entry
  ARM: 6789/1: SPEAr3xx: Rename sdio to sdhci
  ARM: 6788/1: SPEAr: Include mach/hardware.h instead of mach/spear.h
  ARM: 6787/1: SPEAr: Reorder #includes in .h & .c files.
  ARM: 6681/1: SPEAr: add debugfs support to clk API
  ARM: 6703/1: SPEAr: update clk API support
  ARM: 6679/1: SPEAr: make clk API functions more generic
  ARM: 6737/1: SPEAr: formalized timer support
  ...
2011-03-16 19:03:06 -07:00
Russell King 05e3475451 Merge branch 'p2v' into devel
Conflicts:
	arch/arm/kernel/module.c
	arch/arm/mach-s5pv210/sleep.S
2011-03-16 23:35:27 +00:00
Linus Torvalds 79d8a8f736 Merge branch 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu, x86: Add arch-specific this_cpu_cmpxchg_double() support
  percpu: Generic support for this_cpu_cmpxchg_double()
  alpha: use L1_CACHE_BYTES for cacheline size in the linker script
  percpu: align percpu readmostly subsection to cacheline

Fix up trivial conflict in arch/x86/kernel/vmlinux.lds.S due to the
percpu alignment having changed ("x86: Reduce back the alignment of the
per-CPU data section")
2011-03-16 08:22:41 -07:00
Russell King a9ad21fed0 ARM: Keep exit text/data around for SMP_ON_UP
When SMP_ON_UP is used and the spinlocks are inlined, we end up with
inline spinlocks in the exit code, with references from the SMP
alternatives section to the exit sections.  This causes link time
errors.  Avoid this by placing the exit sections in the init-discarded
region.

Cc: <stable@kernel.org>
Tested-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-21 19:29:27 +00:00
Pawel Moll dc810efb0c ARM: 6740/1: Place correctly notes section in the linker script
Commit 18991197b4 added --build-id
linker option when toolchain supports it. ARM one does, but for some
reason places the section at 0 when linker script doesn't mention it
explicitly.

The 1e621a8e37 worked around the problem
removing this section from binary image with explicit objcopy options,
but it still exists in vmlinux, confusing tools like debuggers and perf.

This problem was discussed here:
http://lists.infradead.org/pipermail/linux-arm-kernel/2010-May/015994.html
http://lists.infradead.org/pipermail/linux-arm-kernel/2010-May/015994.html
but the proposed changes to the linker script were substantial.

This patch simply places NOTES (36 bytes long, at least when compiled
with CodeSourcery toolchain) between data and bss, which seem to be
the right place (and suggested by the sample linker script in
include/asm-generic/vmlinux.lds.h).

It is enough to place it correctly in vmlinux (so debuggers are happy):

Section Headers:
  [11] .data             PROGBITS        c07ce000 7ce000 020fc0 00  WA  0   0 32
  [12] .notes            NOTE            c07eefc0 7eefc0 000024 00  AX  0   0  4
  [13] .bss              NOBITS          c07ef000 7eefe4 01e628 00  WA  0   0 32
Program Headers:
  LOAD           0x008000 0xc0008000 0xc0008000 0x7e6fe4 0x805628 RWE 0x8000
  NOTE           0x7eefc0 0xc07eefc0 0xc07eefc0 0x00024 0x00024 R E 0x4
Section to Segment mapping:
  Segment Sections...
   00     <...> .data .notes .bss
   01     .notes

and to get it exposed as /sys/kernel/notes used by perf tools.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-21 19:29:25 +00:00
Russell King dc21af99fa ARM: P2V: introduce phys_to_virt/virt_to_phys runtime patching
This idea came from Nicolas, Eric Miao produced an initial version,
which was then rewritten into this.

Patch the physical to virtual translations at runtime.  As we modify
the code, this makes it incompatible with XIP kernels, but allows us
to achieve this with minimal loss of performance.

As many translations are of the form:

	physical = virtual + (PHYS_OFFSET - PAGE_OFFSET)
	virtual = physical - (PHYS_OFFSET - PAGE_OFFSET)

we generate an 'add' instruction for __virt_to_phys(), and a 'sub'
instruction for __phys_to_virt().  We calculate at run time (PHYS_OFFSET
- PAGE_OFFSET) by comparing the address prior to MMU initialization with
where it should be once the MMU has been initialized, and place this
constant into the above add/sub instructions.

Once we have (PHYS_OFFSET - PAGE_OFFSET), we can calculate the real
PHYS_OFFSET as PAGE_OFFSET is a build-time constant, and save this for
the C-mode PHYS_OFFSET variable definition to use.

At present, we are unable to support Realview with Sparsemem enabled
as this uses a complex mapping function, and MSM as this requires a
constant which will not fit in our math instruction.

Add a module version magic string for this feature to prevent
incompatible modules being loaded.

Tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-17 23:27:32 +00:00
Tejun Heo 19df0c2fef percpu: align percpu readmostly subsection to cacheline
Currently percpu readmostly subsection may share cachelines with other
percpu subsections which may result in unnecessary cacheline bounce
and performance degradation.

This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR()
linker macros, makes each arch linker scripts specify its cacheline
size and use it to align percpu subsections.

This is based on Shaohua's x86 only patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Shaohua Li <shaohua.li@intel.com>
2011-01-25 14:26:50 +01:00
Russell King 4073723acb Merge branch 'misc' into devel
Conflicts:
	arch/arm/Kconfig
	arch/arm/common/Makefile
	arch/arm/kernel/Makefile
	arch/arm/kernel/smp.c
2011-01-06 22:32:52 +00:00
Russell King daf8741675 ARM: implement support for read-mostly sections
As our SMP implementation uses MESI protocols.  Grouping together data
which is mostly only read together means that we avoid unnecessary
cache line bouncing when this code shares a cache line with other data.

In other words, cache lines associated with read-mostly data are
expected to spend most of their time in shared state.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-05 08:39:36 +00:00
Rabin Vincent 61b5cb1c3b ARM: place C irq handlers in IRQ_ENTRY for ftrace
When FUNCTION_GRAPH_TRACER is enabled, place do_IRQ() and friends in the
IRQ_ENTRY section so that the irq-related features of the function graph
tracer work.

Signed-off-by: Rabin Vincent <rabin@rab.in>
2010-11-19 21:43:26 +05:30
Tony Lindgren 88d927e948 ARM: 6465/1: Fix data abort accessing proc_info from __lookup_processor_type
Commit 5085f3ff45 added better support for
CONFIG_HOTPLUG_CPU by keeping proc_info around. However, depending on
the Kconfig options selected, this can make the booting fail mysteriously
early on.

Turns out a data abort can happen in __lookup_processor in ldmia r5 {r3, r4}.
When it happens the address loaded to r5 is not aligned. Fix the problem by
aligning proc_info.

Reported-by: Anand Gadiyar <gadiyar@ti.com>
Tested-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-27 21:40:29 +01:00
Russell King a0a55682b8 Merge branch 'hotplug' into devel
Conflicts:
	arch/arm/kernel/head-common.S
2010-10-18 22:34:47 +01:00
Russell King 5085f3ff45 ARM: hotplug cpu: Keep processor information, startup code & __lookup_processor_type
When hotplug CPU is enabled, we need to keep the list of supported CPUs,
their setup functions, and __lookup_processor_type in place so that we
can find and initialize secondary CPUs.  Move these into the __CPUINIT
section.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-08 10:07:32 +01:00
Russell King 74b0ec0708 ARM: vmlinux.lds: Move unwind tables into _stext.._etext
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-08 10:02:25 +01:00
Russell King f00ec48fad ARM: Allow SMP kernels to boot on UP systems
UP systems do not implement all the instructions that SMP systems have,
so in order to boot a SMP kernel on a UP system, we need to rewrite
parts of the kernel.

Do this using an 'alternatives' scheme, where the kernel code and data
is modified prior to initialization to replace the SMP instructions,
thereby rendering the problematical code ineffectual.  We use the linker
to generate a list of 32-bit word locations and their replacement values,
and run through these replacements when we detect a UP system.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-04 20:23:36 +01:00
Jeremy Kerr 2b0d8c251b ARM: 5880/1: arm: use generic infrastructure for early params
The ARM setup code includes its own parser for early params, there's
also one in the generic init code.

This patch removes __early_init (and related code) from
arch/arm/kernel/setup.c, and changes users to the generic early_init
macro instead.

The generic macro takes a char * argument, rather than char **, so we
need to update the parser functions a little.

Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-15 21:39:13 +00:00
Alan Jenkins e3f28c1333 ARM: use unified discard definition in linker script
Commit 023bf6f "linker script: unify usage of discard definition"
changed the linker scripts for all architectures except for ARM.
I can find no discussion about this ommision, so here are the changes
for ARM.

These changes are exactly parallel to the ia64 case.

"ia64 is notable because it first throws away some ia64 specific
 subsections and then include the rest of the sections into the final
 image, so those sections must be discarded before the inclusion."

Not boot-tested.  In build testing, the modified linker script generated
an identical vmlinux file.

[I would like to be able to rely on this unified discard definition.
 I want to sort the kernel symbol tables to allow faster symbol
 resolution during module loading. The simplest way appears to be
 to generate sorted versions from vmlinux.o, link them in to vmlinux,
 _and discard the original unsorted tables_.

 This work is driven by my x86 netbook, but it is implemented at a
 generic level. It is possible it will benefit some ARM systems also.]

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by-without-testing: Tejun Heo <tj@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-12-15 16:28:18 +10:30
Nelson Elhage 78d7530ac3 ARM: Clean up linker script using new linker script macros.
This patch is mostly a straightforward translation. The primary side
effect to the resulting vmlinux should be to increase the alignment on
the initramfs to the standard PAGE_SIZE from 32 bytes.

Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-11-23 20:33:38 +00:00
Tim Abbott 2abc1c50b6 ARM: convert to use __HEAD and HEAD_TEXT macros.
This has the consequence of changing the section name used for head
code from ".text.head" to ".head.text".  Since this commit changes all
users in the architecture, this change should be harmless.

The .text.head output section is eliminated and the head text code is
included at the start of the .init output section.

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-11-23 20:33:34 +00:00
Russell King ae19ffbadc Merge branch 'master' into for-linus 2009-09-22 21:01:40 +01:00
Linus Walleij bc581770cf ARM: 5580/2: ARM TCM (Tightly-Coupled Memory) support v3
This adds the TCM interface to Linux, when active, it will
detect and report TCM memories and sizes early in boot if
present, introduce generic TCM memory handling, provide a
generic TCM memory pool and select TCM memory for the U300
platform.

See the Documentation/arm/tcm.txt for documentation.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-09-15 22:11:05 +01:00
Tejun Heo c43768cbb7 Merge branch 'master' into for-next
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
2009-07-04 07:13:18 +09:00
Linus Walleij f6430a938d [ARM] 5565/2: Use PAGE_SIZE and RO_DATA() in link script
Update the link script for ARM to use PAGE_SIZE instead of hard-
coded 4096. Also the old RODATA macro is deprecated
for the RO_DATA(PAGE_SIZE) macro. As a consequence the PAGE_SIZE
was changed from (1UL << PAGE_SHIFT) to (_AC(1,UL) << PAGE_SHIFT)
because the linker does not understand the "UL" suffix to numeric
constants.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-06-25 14:00:59 +01:00
Tejun Heo 405d967dc7 linker script: throw away .discard section
x86 throws away .discard section but no other archs do.  Also,
.discard is not thrown away while linking modules.  Make every arch
and module linking throw it away.  This will be used to define dummy
variables for percpu declarations and definitions.

This patch is based on Ivan Kokshaysky's alpha percpu patch.

[ Impact: always throw away everything in .discard ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
2009-06-24 15:13:38 +09:00
Catalin Marinas 7436127ce9 [ARM] 5557/1: Discard some ARM.ex*.*exit.text sections when !HOTPLUG or !HOTPLUG_CPU
Not discarding these sections when hotplug isn't available prevents the
kernel from building.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-06-19 16:44:21 +01:00
Catalin Marinas 8c7e65742f arm: Provide _sdata and __bss_stop in the vmlinux.lds.S file
_sdata and __bss_stop are common symbols defined by many architectures
and made available to the kernel via asm-generic/sections.h. Kmemleak
uses these symbols when scanning the data sections.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-05-30 14:00:17 +01:00
Linus Torvalds 0fe41b8982 Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (422 commits)
  [ARM] 5435/1: fix compile warning in sanity_check_meminfo()
  [ARM] 5434/1: ARM: OMAP: Fix mailbox compile for 24xx
  [ARM] pxa: fix the bad assumption that PCMCIA sockets always start with 0
  [ARM] pxa: fix Colibri PXA300 and PXA320 LCD backlight pins
  imxfb: Fix TFT mode
  i.MX21/27: remove ifdef CONFIG_FB_IMX
  imxfb: add clock support
  mxc: add arch_reset() function
  clkdev: add possibility to get a clock based on the device name
  i.MX1: remove fb support from mach-imx
  [ARM] pxa: build arch/arm/plat-pxa/mfp.c only when PXA3xx or ARCH_MMP defined
  Gemini: Add support for Teltonika RUT100
  Gemini: gpiolib based GPIO support v2
  MAINTAINERS: add myself as Gemini architecture maintainer
  ARM: Add Gemini architecture v3
  [ARM] OMAP: Fix compile for omap2_init_common_hw()
  MAINTAINERS: Add myself as Faraday ARM core variant maintainer
  ARM: Add support for FA526 v2
  [ARM] acorn,ebsa110,footbridge,integrator,sa1100: Convert asm/io.h to linux/io.h
  [ARM] collie: fix two minor formatting nits
  ...
2009-03-28 14:03:14 -07:00
Tejun Heo 19390c4d03 linker script: define __per_cpu_load on all SMP capable archs
Impact: __per_cpu_load available on all SMP capable archs

Percpu now requires three symbols to be defined - __per_cpu_load,
__per_cpu_start and __per_cpu_end.  There were three archs which
didn't have it.  Update them as follows.

* powerpc: can use generic PERCPU() macro.  Compile tested for
  powerpc32, compile/boot tested for powerpc64.

* ia64: can use generic PERCPU_VADDR() macro.  __phys_per_cpu_start is
  identical to __per_cpu_load.  Compile tested and symbol table looks
  identical after the change except for the additional __per_cpu_load.

* arm: added explicit __per_cpu_load definition.  Currently uses
  unified .init output section so can't use the generic macro.  Dunno
  whether the unified .init ouput section is required by arch
  peculiarity so I left it alone.  Please break it up and use PERCPU()
  if possible.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Pat Gefre <pfg@sgi.com>
Cc: Russell King <rmk@arm.linux.org.uk>
2009-03-10 16:27:48 +09:00
Catalin Marinas bff595c15c [ARM] 5383/2: unwind: Add core support for ARM stack unwinding
This patch adds the main functionality for parsing the stack unwinding
information generated by the ARM EABI toolchains. The unwinding
information consists of an index with a pair of words per function and a
table with unwinding instructions. For more information, see "Exception
Handling ABI for the ARM Architecture" at:

http://infocenter.arm.com/help/topic/com.arm.doc.subset.swdev.abi/index.html

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-19 11:26:24 +00:00
Tejun Heo 74e7904559 linker script: add missing .data.percpu.page_aligned
arm, arm/mach-integrator and powerpc were missing
.data.percpu.page_aligned in their percpu output section definitions.
Add it.

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-17 15:26:32 +09:00