linux.git/arch/mips/kernel/head.S, branch v5.6

MIPS/head: Store ELF appended dtb in a global variable too

2018-09-25T23:27:24+00:00

Since commit 15f37e158892 ("MIPS: store the appended
dtb address in a variable"),
in kernels with MIPS_RAW_APPENDED_DTB=y, the early boot code detects
the dtb and stores it in the 'fw_passed_dtb' variable.

However, the dtb is not stored in 'fw_passed_dtb' in kernels with
MIPS_ELF_APPENDED_DTB=y.

Under MIPS_ELF_APPENDED_DTB=y, the dtb is also located in the
__appended_dtb section, so we just need to update the #ifdef.

This will allow to access the dtb in a more uniform way.

Fixes: 15f37e158892 ("MIPS: store the appended dtb address in a variable")
Signed-off-by: Yasha Cherikovsky 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/20803/
Cc: Ralf Baechle 
Cc: Paul Burton 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org

MIPS/head: Add comments after #endif and #else

2018-09-25T23:27:19+00:00

It makes the code more readable, especially in the nested ifdefs.

Signed-off-by: Yasha Cherikovsky 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/20802/
Cc: Ralf Baechle 
Cc: Paul Burton 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org

MIPS: head: Reorder instructions missing a delay slot

2017-06-27T21:35:21+00:00

In this sequence the 'move' is assumed in the delay slot of the 'beq',
but head.S is in reorder mode and the former gets pushed one 'nop'
farther by the assembler.

The corrected behavior made booting with an UHI supplied dtb erratic.

Fixes: 15f37e158892 ("MIPS: store the appended dtb address in a variable")
Signed-off-by: Karl Beldan 
Reviewed-by: James Hogan 
Cc: Jonas Gorski 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16614/
Signed-off-by: Ralf Baechle

MIPS: store the appended dtb address in a variable

2016-08-02T12:00:16+00:00

Instead of rewriting the arguments to match the UHI spec, store the
address of a appended or UHI supplied dtb in fw_supplied_dtb.

That way the original bootloader arugments are kept intact while still
making the use of an appended dtb invisible for mach code.

Mach code can still find out if it is an appended dtb by comparing
fw_arg1 with fw_supplied_dtb.

Signed-off-by: Jonas Gorski 
Cc: Kevin Cernekee 
Cc: Florian Fainelli 
Cc: John Crispin 
Cc: Paul Burton 
Cc: James Hogan 
Cc: Alban Bedel 
Cc: Daniel Gimpelevich 
Cc: Antony Pavlov 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13699/
Signed-off-by: Ralf Baechle

MIPS: Remove redundant asm/pgtable-bits.h inclusions

2016-05-13T13:30:25+00:00

asm/pgtable-bits.h is included in 2 assembly files and thus has to
ifdef around C code, however nothing defined by the header is used
in either of the assembly files that include it.

Remove the redundant inclusions such that asm/pgtable-bits.h doesn't
need to #ifdef around C code, for cleanliness and in preparation for
later patches which will add more C.

Signed-off-by: Paul Burton 
Reviewed-by: James Hogan 
Cc: Maciej W. Rozycki 
Cc: Jonas Gorski 
Cc: Alex Smith 
Cc: Kirill A. Shutemov 
Cc: Andrew Morton 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13114/
Signed-off-by: Ralf Baechle

MIPS: Call relocate_kernel if CONFIG_RELOCATABLE=y

2016-05-13T12:02:03+00:00

If CONFIG_RELOCATABLE is enabled, call relocate_kernel.

This function will return the entry point of the relocated kernel if
copy/relocate is sucessful or the original entry point if not. The stack
pointer must then be pointed into the new image.

Signed-off-by: Matt Redfearn 
Cc: Jonas Gorski 
Cc: linux-mips@linux-mips.org
Cc: kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12984/
Signed-off-by: Ralf Baechle

MIPS: Add support for vmlinux.bin appended dtb

2015-06-21T19:54:14+00:00

Add support for detecting a vmlinux.bin appended dtb and overriding
the boot arguments to match the UHI interface.

Due to the PERCPU section being empty for !SMP, but still modifying
the current address by aligning it to the page size, do not define
it for !SMP builds to allow __appended_dtb to still point to
the actual end of the data.

Signed-off-by: Jonas Gorski 
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: John Crispin 
Cc: Kevin Cernekee 
Cc: Florian Fainelli 
Cc: Aaro Koskinen 
Cc: Markos Chandras 
Cc: Andrew Bresticker 
Cc: Daniel Schwierzeck 
Cc: Paul Burton 
Cc: James Hartley 
Patchwork: https://patchwork.linux-mips.org/patch/9739/
Signed-off-by: Ralf Baechle

MIPS: MT: Remove SMTC support

2014-05-23T22:07:01+00:00

Nobody is maintaining SMTC anymore and there also seems to be no userbase.
Which is a pity - the SMTC technology primarily developed by Kevin D.
Kissell  is an ingenious demonstration for the MT
ASE's power and elegance.

Based on Markos Chandras  patch
https://patchwork.linux-mips.org/patch/6719/ which while very similar did
no longer apply cleanly when I tried to merge it plus some additional
post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to
merge once upon a time.

Signed-off-by: Ralf Baechle

MIPS: malta: Add support for SMP EVA

2014-03-26T22:09:20+00:00

Allow secondary cores to program their segment control registers
during smp bootstrap code. This enables EVA on Malta SMP
configurations

Signed-off-by: Markos Chandras

MIPS: Delete cpuinit/CPUINIT usage from MIPS code

2013-07-14T23:36:51+00:00

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 
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