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: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NSteven J. Hill <sjhill@mips.com>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <sjhill@mips.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/4781/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Thanks to current_pt_regs() there is no need to use the dark MIPS magic.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

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

Function tracing is currently broken for all 32 bit MIPS platforms.
When tracing is enabled, the kernel immediately hangs on boot.
This is a result of commit b732d439
that changes the kernel/trace/Kconfig file so that is no longer
forces FRAME_POINTER when FUNCTION_TRACING is enabled.

MIPS frame pointers are generally considered to be useless because
they cannot be used to unwind the stack. Unfortunately the MIPS
function tracing code has bugs that are masked by the use of frame
pointers. This commit fixes the bugs so that MIPS frame pointers
don't need to be enabled.

The bugs are a result of the odd calling sequence used to call the trace
routine. This calling sequence is inserted into every traceable function
when the tracing CONFIG option is enabled. This sequence is generated
for 32bit MIPS platforms by the compiler via the "-pg" flag.

Part of the sequence is "addiu sp,sp,-8" in the delay slot after every
call to the trace routine "_mcount" (some legacy thing where 2 arguments
used to be pushed on the stack). The _mcount routine is expected to
adjust the sp by +8 before returning.  So when not disabled, the original
jalr and addiu will be there, so _mcount has to adjust sp.

The problem is that when tracing is disabled for a function, the
"jalr _mcount" instruction is replaced with a nop, but the
"addiu sp,sp,-8" is still executed and the stack pointer is left
trashed. When frame pointers are enabled the problem is masked
because any access to the stack is done through the frame
pointer and the stack pointer is restored from the frame pointer when
the function returns.

This patch writes two nops starting at the address of the "jalr _mcount"
instruction whenever tracing is disabled. This means that the
"addiu sp,sp.-8" will be converted to a nop along with the "jalr".  When
disabled, there will be two nops.

This is SMP safe because the first time this happens is during
ftrace_init() which is before any other processor has been started.
Subsequent calls to enable/disable tracing when other CPUs ARE running
will still be safe because the enable will only change the first nop
to a "jalr" and the disable, while writing 2 nops, will only be changing
the "jalr". This patch also stops using stop_machine() to call the
tracer enable/disable routines and calls them directly because the
routines are SMP safe.

When the kernel first boots we have to be able to handle the gcc
generated jalr, addui sequence until ftrace_init gets a chance to run
and change the sequence. At this point mcount just adjusts the stack
and returns. When ftrace_init runs, we convert the jalr/addui to nops.
Then whenever tracing is enabled we convert the first nop to a "jalr
mcount+8". The mcount+8 entry point skips the stack adjust.

[ralf@linux-mips.org: Folded in  Steven Rostedt's build fix.]
Signed-off-by: NAl Cooper <alcooperx@gmail.com>
Cc: rostedt@goodmis.org
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4806/
Patchwork: https://patchwork.linux-mips.org/patch/4841/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

In the printk, the variable t euqals to NULL, so there is no t->index.
Use v->tc->index instead.

[ralf@linux-mips.org: Use opportunity of changing this line anyway to make
this line whitespacely correct.]
Signed-off-by: NCong Ding <dinggnu@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4792/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

CONFIG_HOTPLUG is going away as an option.  As a result, the __dev*
markings need to be removed.

This change removes the use of __devinit, __devexit_p, __devinitdata,
and __devexit from these drivers.

Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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

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

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

Commit 4be3d2f3 ("MIPS: perf: Add XLP
support for hardware perf.") added UNSUPPORTED_PERF_EVENT_ID which was
removed a while back.

Cc: Zi Shen Lim <zlim@netlogicmicro.com>
Cc: Jayachandran C <jchandra@broadcom.com>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Cc: John Crispin <blogic@openwrt.org>
Cc: Zi Shen Lim <zlim@netlogicmicro.com>
Signed-off-by: NManuel Lauss <manuel.lauss@gmail.com>
Acked-by: NJayachandran C <jchandra@broadcom.com>
Patchwork: https://patchwork.linux-mips.org/patch/4730/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Nobody seems to be interested anymore and upstream also never had an
ethernet driver.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

 Our FP emulator is hardcoded for the MIPS IV FP instruction set and does
not match the FP ISA with the general ISA.  However for the few MIPS IV FP
instructions that use the COP1X major opcode it relies on the Coprocessor
Unusable exception to be delivered as a COP1 rather than COP3 exception.
This includes indexed transfer (LDXC1, etc.) and FP multiply-accumulate
(MADD.D, etc.) instructions.

 All the MIPS I, II, III and IV processors and some newer chips that do not
implement the FPU use the COP3 exception however.  Therefore I believe the
kernel should follow and redirect any COP3 Unusable traps to the emulator
unless an actual FPU part or core is present.

 This is a change that implements it.  Any minor opcode encodings that are
not recognised as valid FP instructions are rejected by the emulator and
will result in a SIGILL signal being delivered as they currently do.  We
do not support vendor-specific coprocessor 3 implementations supported
with MIPS I and MIPS II ISA processors; we never set CP0.Status.CU3.

[Ralf: On MIPS IV processors the kernel always enables the XX bit which
replaces the CU3 bit off earlier architecture revisions.]

 If matching between the CPU and the FPU ISA is considered required one
day, this can still be done in the emulator itself.  I think the CpU
exception dispatcher is not the right place to do this anyway, as there
are further differences between MIPS I, MIPS II, MIPS III, MIPS IV and
MIPS32 FP ISAs.

 Corresponding explanation of this implementation is included within the
change itself.
Signed-off-by: NMaciej W. Rozycki <macro@codesourcery.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/project/linux-mips/list/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When poweroff machine, kernel_power_off() call disable_nonboot_cpus().
And if we have HOTPLUG_CPU configured, disable_nonboot_cpus() is not an
empty function but attempt to actually disable the nonboot cpus. Since
system state is SYSTEM_POWER_OFF, play_dead() won't be called and thus
disable_nonboot_cpus() hangs. Therefore, we make this patch to avoid
poweroff failure.
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Signed-off-by: NHongliang Tao <taohl@lemote.com>
Signed-off-by: NHua Yan <yanh@lemote.com>
Cc: Yong Zhang <yong.zhang@windriver.com>
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/4211/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When CONFIG_UIDGID_STRICT_TYPE_CHECKS is enabled, plain integer checking
between different uids/gids is explicitely turned into a build failure
by making the k{uid,gid}_t types a structure containing a value:

arch/mips/kernel/mips-mt-fpaff.c: In function 'check_same_owner':
arch/mips/kernel/mips-mt-fpaff.c:53:22: error: invalid operands to
binary == (have 'kuid_t' and 'kuid_t')
arch/mips/kernel/mips-mt-fpaff.c:54:15: error: invalid operands to
binary == (have 'kuid_t' and 'kuid_t')

In order to ensure proper comparison between uids, using the helper
function uid_eq() which performs the right thing whenever this config
option is turned on or off.
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
Patchwork: https://patchwork.linux-mips.org/patch/4717/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Manuel Lauss <manuel.lauss@gmail.com> writes:

I introduced it as a fallback because early revisions of Alchemy hardware
we shipped had a non-functional 32kHz timer and had to rely on the r4k
timer instead.  Previously the r4k timer was initialized regardless, but
it's useless with the "wait" instruction.

So long story short:   I need either the on-chip 32kHz timer OR the r4k
timer if the 32kHz one is unusable, but not both, and r4k timer is useless
when au1k_idle is in use.

The current in-kernel Alchemy boards all work with the 32kHz timer, so I'm
not against removing R4K_LIB symbols.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Manuel Lauss <manuel.lauss@gmail.com> writes:

I introduced it as a fallback because early revisions of Alchemy hardware
we shipped had a non-functional 32kHz timer and had to rely on the r4k
timer instead.  Previously the r4k timer was initialized regardless, but
it's useless with the "wait" instruction.

So long story short:   I need either the on-chip 32kHz timer OR the r4k
timer if the 32kHz one is unusable, but not both, and r4k timer is useless
when au1k_idle is in use.

The current in-kernel Alchemy boards all work with the 32kHz timer, so I'm
not against removing R4K_LIB symbols.
Signed-off-by: NSteven J. Hill <sjhill@mips.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

[ralf@linux-mips.org: Original patch by Maxim Uvarov <muvarov@gmail.com>
with plenty of further shining, polishing, debugging and testing by me.]
Signed-off-by: NMaxim Uvarov <muvarov@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: kexec@lists.infradead.org
Cc: horms@verge.net.au
Patchwork: https://patchwork.linux-mips.org/patch/1026/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

[ralf@linux-mips.org: Original patch by Maxim Uvarov <muvarov@gmail.com>
with plenty of further shining, polishing, debugging and testing by me.]
Signed-off-by: NMaxim Uvarov <muvarov@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: kexec@lists.infradead.org
Cc: horms@verge.net.au
Patchwork: https://patchwork.linux-mips.org/patch/1025/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The actual bug is a missing else statement - but really this should be
expressed using a switch() statement.

Found by Al Viro who writes "the funny thing is, it *does* work only
because r2 is syscall number and syscall number around 512 => return
value being ENOSYS and not one of ERESTART...  so we really can't hit
the first if and emerge from it with ERESTART_RESTARTBLOCK.  still
wrong to write it that way..."
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

2957c9e6 (kernel.org) rsp.
b934da913f236bca00c41d9e386e980586000461 (lmo) [[MIPS] IRIX: Goodbye and
thanks for all the fish] left two fields in struct thread_struct which
were only being used for the IRIX compat code.  Remove them.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

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

The problem occurs [1] when a kernel-mode task returns from a system
call with a pending signal.

A real-life scenario is a child of 'khelper' returning from a failed
kernel_execve() in ____call_usermodehelper() [ kernel/kmod.c ].
kernel_execve() fails due to a pending SIGKILL, which is the result of
"kill -9 -1" (at least, busybox's init does it upon reboot).

The loop is as follows:

* syscall_exit_work:
 - work_pending:            // start_of_the_loop
 - work_notifysig:
   - do_notify_resume()
     - do_signal()
       - if (!user_mode(regs)) return;
 - resume_userspace         // TIF_SIGPENDING is still set
 - work_pending             // so we call work_pending => goto
                            // start_of_the_loop

More information can be found in another LKML thread:
http://www.serverphorums.com/read.php?12,457826

[1] The problem was also reproduced on !CONFIG_VM86 x86, and the
following fix was accepted.

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=29a2e2836ff9ea65a603c89df217f4198973a74fSigned-off-by: NDmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3571/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Broken since e05ea74fc56f347f872ef9946d27c53e8bf20864 (lmo) rsp.
cea7e2df (kernel.org) [MIPS: Sort out CPU
type to name translation.]  These CPUs are no longer very popular to say
the least ...
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Reported-by: NMurphy McCauley <murphy.mccauley@gmail.com>

This needs to use the compat entry point or it's going to fail on big
endian systems.

Noticed by Al Viro.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

By using the native syscall entry point the kernel was also expecting
64-bit iovec structures.

This is broken since ddd9e91b [preadv/
pwritev: MIPS: Add preadv(2) and pwritev(2) syscalls.] which originally
added these two syscalls.  I walked through piles of code, including
libc and couldn't find anything that would have worked around the issue
so this change the API to what it should always have been.

Noticed and patch suggested by Al Viro.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

Without this, we may end up with something like this in /proc/iomem:

01100000-014fffff : System RAM
  01100000-013bf48f : Kernel code
  013bf490-0149e01f : Kernel data
01500000-0c0fffff : System RAM

but the two System RAM ranges should be one single range.  This particular
case will result in kexec failure on Octeon systems if the kernel being
loaded by kexec is bigger than the already running kernel.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The kbuild test robot <fengguang.wu@intel.com> report the following error
when building mips with user namespace support enabled.

All error/warnings:
arch/mips/kernel/mips-mt-fpaff.c: In function 'check_same_owner':
arch/mips/kernel/mips-mt-fpaff.c:53:22: error: invalid operands to binary == (have 'kuid_t' and 'kuid_t')
arch/mips/kernel/mips-mt-fpaff.c:54:15: error: invalid operands to binary == (have 'kuid_t' and 'kuid_t')

Replace "a == b" with uid_eq(a, b) removes this error and allows the
code to work with user namespaces enabled.

Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Add support for XLP performance counters register in perf. Update
mips/Kconfig so that perf events can be selected for XLP.
Signed-off-by: NZi Shen Lim <zlim@netlogicmicro.com>
Signed-off-by: NJayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4457Signed-off-by: NJohn Crispin <blogic@openwrt.org>

The CPUNum Field in EBase register is 10bit wide, so after 1 bit right
shift, the mask value should be 0x1ff.
Signed-off-by: Njerin jacob <jerinjacobk@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4420/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Acked-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This version contains a few updates by David Daney, in particular it's
now using __builtin_frame_address() instead of asm() which depending
on personal taste, is slightly more appealing.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

getname() is intended to copy pathname strings from userspace into a
kernel buffer. The result is just a string in kernel space. It would
however be quite helpful to be able to attach some ancillary info to
the string.

For instance, we could attach some audit-related info to reduce the
amount of audit-related processing needed. When auditing is enabled,
we could also call getname() on the string more than once and not
need to recopy it from userspace.

This patchset converts the getname()/putname() interfaces to return
a struct instead of a string. For now, the struct just tracks the
string in kernel space and the original userland pointer for it.

Later, we'll add other information to the struct as it becomes
convenient.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This fault was detected using the kgdb test suite on boot and it
crashes recursively due to the fact that CONFIG_KPROBES on mips adds
an extra die notifier in the page fault handler.  The crash signature
looks like this:

kgdbts:RUN bad memory access test
KGDB: re-enter exception: ALL breakpoints killed
Call Trace:
[<807b7548>] dump_stack+0x20/0x54
[<807b7548>] dump_stack+0x20/0x54

The fix for now is to have kgdb return immediately if the fault type
is DIE_PAGE_FAULT and allow the kprobe code to decide what is supposed
to happen.

Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>

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