linux.git/arch/mips/include/asm/cpu-features.h, branch v3.11

MIPS: oprofile: Fix BUG due to smp_processor_id() in preemptible code.

2013-08-05T11:34:22+00:00

current_cpu_type() is not preemption-safe.
If CONFIG_PREEMPT is enabled then mipsxx_reg_setup() can be called from preemptible state.
Added get_cpu()/put_cpu() pair to make it preemption-safe.

This was found while testing oprofile with CONFIG_DEBUG_PREEMPT enable.

/usr/zntestsuite # opcontrol --init
/usr/zntestsuite # opcontrol --setup --event=L2_CACHE_ACCESSES:500 --event=L2_CACHE_MISSES:500 --no-vmlinux
/usr/zntestsuite # opcontrol --start
Using 2.6+ OProfile kernel interface.
BUG: using smp_processor_id() in preemptible [00000000] code: oprofiled/1362
caller is mipsxx_reg_setup+0x11c/0x164
CPU: 0 PID: 1362 Comm: oprofiled Not tainted 3.10.4 #18
Stack : 00000006 70757465 00000000 00000000 00000000 00000000 80b173f6 00000037
          80b10000 00000000 80b21614 88f5a220 00000000 00000000 00000000 00000000
          00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
          00000000 00000000 00000000 89c49c00 89c49c2c 80721254 807b7927 8012c1d0
          80b10000 80721254 00000000 00000552 88f5a220 80b1335c 807b78e6 89c49ba8
          ...
Call Trace:
[<801099a4>] show_stack+0x64/0x7c
[<80665520>] dump_stack+0x20/0x2c
[<803a2250>] debug_smp_processor_id+0xe0/0xf0
[<8052df24>] mipsxx_reg_setup+0x11c/0x164
[<8052cd70>] op_mips_setup+0x24/0x4c
[<80529cfc>] oprofile_setup+0x5c/0x12c
[<8052b9f8>] event_buffer_open+0x78/0xf8
[<801c3150>] do_dentry_open.isra.15+0x2b8/0x3b0
[<801c3270>] finish_open+0x28/0x4c
[<801d49b8>] do_last.isra.41+0x2cc/0xd00
[<801d54a0>] path_openat+0xb4/0x4c4
[<801d5c44>] do_filp_open+0x3c/0xac
[<801c4744>] do_sys_open+0x110/0x1f4
[<8010f47c>] stack_done+0x20/0x44

Bug reported and original patch by Jerin Jacob .

Signed-off-by: Ralf Baechle 
Acked-by: Jerin Jacob

MIPS: Cleanup indentation and whitespace

2013-07-01T13:10:57+00:00

Signed-off-by: Tony Wu 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5536/
Signed-off-by: Ralf Baechle

MIPS: Only set cpu_has_mmips if SYS_SUPPORTS_MICROMIPS

2013-07-01T13:10:57+00:00

As Jonas Gorske said in his patch:

   Disable cpu_has_mmips for everything but SEAD3 and MALTA. Most of
   these platforms are from before the micromips introduction, so they
   are very unlikely to implement it.

   Reduces an -Os compiled, uncompressed kernel image by 8KiB for
   BCM63XX.

This patch taks a different approach than his, we gate the runtime
test for microMIPS by the config symbol SYS_SUPPORTS_MICROMIPS.

Signed-off-by: David Daney 
Cc: Jonas Gorski 
Cc: Steven J. Hill 
Acked-by: Steven J. Hill 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5327/
Signed-off-by: Ralf Baechle

MIPS: Get rid of MIPS I flag and test macros.

2013-07-01T13:10:56+00:00

MIPS I is the ancestor of all MIPS ISA and architecture variants.  Anything
ever build in the MIPS empire is either MIPS I or at least contains MIPS I.
If it's running Linux, that is.

So there is little point in having cpu_has_mips_1 because it will always
evaluate as true - though usually only at runtime.  Thus there is no
point in having the MIPS_CPU_ISA_I ISA flag, so get rid of it.

Little complication: traps.c was using a test for a pure MIPS I ISA as
a test for an R3000-style cp0.  To deal with that, use a check for
cpu_has_3kex or cpu_has_4kex instead.

cpu_has_3kex is a new macro.  At the moment its default implementation is
!cpu_has_4kex but this may eventually change if Linux is ever going to
support the oddball MIPS processors R6000 and R8000 so users of either
of these macros should not make any assumptions.

Signed-off-by: Ralf Baechle 
Patchwork: https://patchwork.linux-mips.org/patch/5551/

MIPS: Build uasm-generated code only once to avoid CPU Hotplug problem

2013-05-07T23:19:06+00:00

This and the next patch resolve memory corruption problems while CPU
hotplug. Without these patches, memory corruption can triggered easily
as below:

On a quad-core MIPS platform, use "spawn" of UnixBench-5.1.3 (http://
code.google.com/p/byte-unixbench/) and a CPU hotplug script like this
(hotplug.sh):
while true; do
echo 0 >/sys/devices/system/cpu/cpu1/online
echo 0 >/sys/devices/system/cpu/cpu2/online
echo 0 >/sys/devices/system/cpu/cpu3/online
sleep 1
echo 1 >/sys/devices/system/cpu/cpu1/online
echo 1 >/sys/devices/system/cpu/cpu2/online
echo 1 >/sys/devices/system/cpu/cpu3/online
sleep 1
done

Run "hotplug.sh" and then run "spawn 10000", spawn will get segfault
after a few minutes.

This patch:
Currently, clear_page()/copy_page() are generated by Micro-assembler
dynamically. But they are unavailable until uasm_resolve_relocs() has
finished because jump labels are illegal before that. Since these
functions are shared by every CPU, we only call build_clear_page()/
build_copy_page() only once at boot time. Without this patch, programs
will get random memory corruption (segmentation fault, bus error, etc.)
while CPU Hotplug (e.g. one CPU is using clear_page() while another is
generating it in cpu_cache_init()).

For similar reasons we modify build_tlb_refill_handler()'s invocation.

V2:
1, Rework the code to make CPU#0 can be online/offline.
2, Introduce cpu_has_local_ebase feature since some types of MIPS CPU
   need a per-CPU tlb_refill_handler().

Signed-off-by: Huacai Chen 
Signed-off-by: Hongbing Hu 
Acked-by: David Daney 
Patchwork: http://patchwork.linux-mips.org/patch/4994/
Acked-by: John Crispin

Merge branch 'mips-next-3.9' of git://git.linux-mips.org/pub/scm/john/linux-john into mips-for-linux-next

2013-02-21T11:51:33+00:00

MIPS: Probe for and report hardware virtualization support.

2013-02-19T08:36:36+00:00

The presence of the MIPS Virtualization Application-Specific Extension
is indicated by CP0_Config3[23].  Probe for this and report it in
/proc/cpuinfo.

Signed-off-by: David Daney 
Patchwork: http://patchwork.linux-mips.org/patch/4904/
Signed-off-by: John Crispin

MIPS: Add support for the M14KEc core.

2013-02-16T23:15:23+00:00

Signed-off-by: Steven J. Hill 
Patchwork: http://patchwork.linux-mips.org/patch/4682/
Signed-off-by: John Crispin

MIPS: Add printing of ISA version in cpuinfo.

2013-02-15T22:07:38+00:00

Display the MIPS ISA version release in the /proc/cpuinfo file.

[ralf@linux-mips.org: Add support for MIPS I ... IV legacy architecture
revisions.  Also differenciate between MIPS32 and MIPS64 versions instead
of lumping them together as just r1 and r2.

Note to application programmers: this indicates the CPU's ISA level
It does not imply the current execution environment does support it.  For
example an O32 application seeing "mips64r2" would still be restricted by
by the execution environment to 32-bit - but the kernel could run mips64r2
code.  The same for a 32-bit kernel running on a 64-bit processor.  This
field doesn't include ASEs or optional architecture modules nor other
detailed flags such as the availability of an FPU.]

Signed-off-by: Steven J. Hill 
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/4714/
Signed-off-by: Ralf Baechle

MIPS: Whitespace cleanup.

2013-02-01T09:00:22+00:00

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