linux-stable.git/arch/arm/kernel/vmlinux.lds.S, branch v2.6.38 Linux kernel stable tree ARM: Keep exit text/data around for SMP_ON_UP 2011-02-21T19:29:27+00:00 Russell King rmk+kernel@arm.linux.org.uk 2011-02-21T10:13:36+00:00 a9ad21fed09cb95d34af9474be0831525b30c4c6 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> 
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>
ARM: 6740/1: Place correctly notes section in the linker script 2011-02-21T19:29:25+00:00 Pawel Moll pawel.moll@arm.com 2011-02-16T17:54:01+00:00 dc810efb0ca5702c9d96782b99282d4b4383e877 Commit 18991197b4b588255ccabf472ebc84db7b66a19c 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 1e621a8e3752367d4aae78a8ab00a18fb2793f34 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> 
Commit 18991197b4b588255ccabf472ebc84db7b66a19c 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 1e621a8e3752367d4aae78a8ab00a18fb2793f34 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>
Merge branch 'misc' into devel 2011-01-06T22:32:52+00:00 Russell King rmk+kernel@arm.linux.org.uk 2011-01-06T22:32:52+00:00 4073723acb9cdcdbe4df9c0e0c376c65d1697e43 Conflicts: arch/arm/Kconfig arch/arm/common/Makefile arch/arm/kernel/Makefile arch/arm/kernel/smp.c 
Conflicts:
	arch/arm/Kconfig
	arch/arm/common/Makefile
	arch/arm/kernel/Makefile
	arch/arm/kernel/smp.c
ARM: implement support for read-mostly sections 2010-12-05T08:39:36+00:00 Russell King rmk+kernel@arm.linux.org.uk 2010-12-04T17:08:32+00:00 daf8741675562197d4fb4c4e9d773f53494203a5 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> 
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>
ARM: place C irq handlers in IRQ_ENTRY for ftrace 2010-11-19T16:13:26+00:00 Rabin Vincent rabin@rab.in 2010-10-07T15:21:58+00:00 61b5cb1c3bff8875d2fd289c7b6ac344f95261fa 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> 
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>
ARM: 6465/1: Fix data abort accessing proc_info from __lookup_processor_type 2010-10-27T20:40:29+00:00 Tony Lindgren tony@atomide.com 2010-10-26T18:52:21+00:00 88d927e94805ebeec11ec7687df7789b954e334e Commit 5085f3ff458521045f7e43da62b8c30ea7df2e82 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> 
Commit 5085f3ff458521045f7e43da62b8c30ea7df2e82 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>
Merge branch 'hotplug' into devel 2010-10-18T21:34:47+00:00 Russell King rmk+kernel@arm.linux.org.uk 2010-10-18T21:34:47+00:00 a0a55682b83fd5f012afadcf415b030d7424ae68 Conflicts: arch/arm/kernel/head-common.S 
Conflicts:
	arch/arm/kernel/head-common.S
ARM: hotplug cpu: Keep processor information, startup code & __lookup_processor_type 2010-10-08T09:07:32+00:00 Russell King rmk+kernel@arm.linux.org.uk 2010-10-01T14:37:05+00:00 5085f3ff458521045f7e43da62b8c30ea7df2e82 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> 
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>
ARM: vmlinux.lds: Move unwind tables into _stext.._etext 2010-10-08T09:02:25+00:00 Russell King rmk+kernel@arm.linux.org.uk 2010-10-01T13:26:56+00:00 74b0ec0708e7c8c530079b737f32c55597d062cc Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: Allow SMP kernels to boot on UP systems 2010-10-04T19:23:36+00:00 Russell King rmk+kernel@arm.linux.org.uk 2010-09-04T09:47:48+00:00 f00ec48fadf5e37e7889f14cff900aa70d18b644 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> 
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>