linux.git/arch/mips/kernel/head.S, branch v3.14 Linux kernel source tree MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code 2013-07-14T23:36:51+00:00 Paul Gortmaker paul.gortmaker@windriver.com 2013-06-18T13:38:59+00:00 078a55fc824c1633b3a507e4ad48b4637c1dfc18 commit 3747069b25e419f6b51395f48127e9812abc3596 upstream. The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. Here, we remove all the MIPS __cpuinit from C code and __CPUINIT from asm files. MIPS is interesting in this respect, because there are also uasm users hiding behind their own renamed versions of the __cpuinit macros. [1] https://lkml.org/lkml/2013/5/20/589 [ralf@linux-mips.org: Folded in Paul's followup fix.] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5494/ Patchwork: https://patchwork.linux-mips.org/patch/5495/ Patchwork: https://patchwork.linux-mips.org/patch/5509/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
commit 3747069b25e419f6b51395f48127e9812abc3596 upstream.

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
and are flagged as __cpuinit  -- so if we remove the __cpuinit from
the arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
related content into no-ops as early as possible, since that will get
rid of these warnings.  In any case, they are temporary and harmless.

Here, we remove all the MIPS __cpuinit from C code and __CPUINIT
from asm files.  MIPS is interesting in this respect, because there
are also uasm users hiding behind their own renamed versions of the
__cpuinit macros.

[1] https://lkml.org/lkml/2013/5/20/589

[ralf@linux-mips.org: Folded in Paul's followup fix.]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5494/
Patchwork: https://patchwork.linux-mips.org/patch/5495/
Patchwork: https://patchwork.linux-mips.org/patch/5509/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Move gas macro MAPPED_KERNEL_SETUP_TLB to IP27-specific code. 2013-06-21T16:07:00+00:00 Ralf Baechle ralf@linux-mips.org 2013-06-13T10:32:32+00:00 23946ef1658dc7f3d8e2fbdbb2110b4cc4267654 It's IP27-specific and can only cause trouble in head.S. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
It's IP27-specific and can only cause trouble in head.S.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Whitespace cleanup. 2013-02-01T09:00:22+00:00 Ralf Baechle ralf@linux-mips.org 2013-01-22T11:59:30+00:00 7034228792cc561e79ff8600f02884bd4c80e287 Having received another series of whitespace patches I decided to do this once and for all rather than dealing with this kind of patches trickling in forever. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Don't include <asm/page.h> unnecessarily. 2012-12-28T16:04:04+00:00 Ralf Baechle ralf@linux-mips.org 2012-12-28T14:01:10+00:00 348dd600c3db6ac6fa270e0d0c9f9380dacf8064 So far we're jumping through hoops to keep the file usable from assembler source but it's getting just too painful. Turns out that many uses of <asm/page.h> are unnecessary anyway, so just remove those. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
So far we're jumping through hoops to keep the file usable from assembler
source but it's getting just too painful.  Turns out that many uses of
<asm/page.h> are unnecessary anyway, so just remove those.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Avoid potential hazard on Context register 2009-11-02T11:00:07+00:00 Ralf Baechle ralf@linux-mips.org 2009-10-13T21:23:28+00:00 c2ea1d56eaf084c66177eb5658ff4065e79b36ea set_saved_sp reads Context register. Avoid reading stale value from earlier incomplete write. Issue found and fixed for head.S by Chris Dearman <chris@mips.com>. Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
set_saved_sp reads Context register. Avoid reading stale value from
earlier incomplete write.

Issue found and fixed for head.S by Chris Dearman <chris@mips.com>.

Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Avoid clobbering struct pt_regs in kthreads 2009-08-03T16:52:41+00:00 David Daney ddaney@caviumnetworks.com 2009-07-08T17:07:50+00:00 484889fc85a223ef56edc31828b86751b2296b7c The resume() implementation octeon_switch.S examines the saved cp0_status register. We were clobbering the entire pt_regs structure in kernel threads leading to random crashes. When switching away from a kernel thread, the saved cp0_status is examined and if bit 30 is set it is cleared and the CP2 state saved into the pt_regs structure. Since the kernel thread stack overlaid the pt_regs structure this resulted in a corrupt stack. When the kthread with the corrupt stack was resumed, it could crash if it used any of the data in the stack that was clobbered. We fix it by moving the kernel thread stack down so it doesn't overlay pt_regs. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
The resume() implementation octeon_switch.S examines the saved cp0_status
register.  We were clobbering the entire pt_regs structure in kernel
threads leading to random crashes.

When switching away from a kernel thread, the saved cp0_status is examined
and if bit 30 is set it is cleared and the CP2 state saved into the pt_regs
structure.  Since the kernel thread stack overlaid the pt_regs structure
this resulted in a corrupt stack.  When the kthread with the corrupt stack
was resumed, it could crash if it used any of the data in the stack that was
clobbered.

We fix it by moving the kernel thread stack down so it doesn't overlay
pt_regs.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[MIPS] IP27: Fix build errors if CONFIG_MAPPED_KERNEL=y 2008-10-06T00:22:29+00:00 Ralf Baechle ralf@linux-mips.org 2008-10-03T21:43:38+00:00 fd3d2764ee5aad862e51c21b8239561acdea8c2f Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[MIPS] Fix loads of section missmatches 2008-03-12T14:14:41+00:00 Ralf Baechle ralf@linux-mips.org 2008-03-08T09:56:28+00:00 234fcd1484a66158b561b36b421547f0ab85fee9 Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[MIPS] Fix build after b0rked changes to <linux/init.h>. 2008-02-01T14:48:43+00:00 Ralf Baechle ralf@linux-mips.org 2008-01-30T12:14:59+00:00 a055917e1b4ad337c293205377277ffc78c69c57 Commit 312b1485fb509c9bc32eda28ad29537896658cb8 made __INIT_REFOK expand into .section .section ".ref.text", "ax". Since the assembler doesn't tolerate stuttering in the source that broke all MIPS builds. Since with this change Sam downgraded __INIT_REFOK the best fix is to get replace it by the modern days operator. With MIPS the only user of __INIT_REFOK and __INITDATA_REFOK (which was equally broken) being unused anyway these can be deleted but that's subject of a separate commit. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Commit 312b1485fb509c9bc32eda28ad29537896658cb8 made __INIT_REFOK expand
into .section .section ".ref.text", "ax".  Since the assembler doesn't
tolerate stuttering in the source that broke all MIPS builds.

Since with this change Sam downgraded __INIT_REFOK the best fix is to
get replace it by the modern days operator.  With MIPS the only user
of __INIT_REFOK and __INITDATA_REFOK (which was equally broken) being
unused anyway these can be deleted but that's subject of a separate
commit.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[MIPS] Fix CONFIG_BOOT_RAW. 2008-01-07T15:32:04+00:00 Ralf Baechle ralf@linux-mips.org 2008-01-07T15:09:50+00:00 ba820c5c51296343be202c9afb072b7b943099cb This was broken by 017e3a492683b32d17dcd1b13b279745cc656073 (lmo) / 396a2ae08e5080b140330645743ab2567f6bc426 (kernel.org). Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
This was broken by 017e3a492683b32d17dcd1b13b279745cc656073 (lmo) /
396a2ae08e5080b140330645743ab2567f6bc426 (kernel.org).

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>