Commit Graph

26 Commits

Author SHA1 Message Date
Maneesh Soni d8d4e3ae0b MIPS Kprobes: Refactor branch emulation
This patch refactors MIPS branch emulation code so as to allow skipping
delay slot instruction in case of branch likely instructions when branch is
not taken. This is useful for keeping the code common for use cases like
kprobes where one would like to handle the branch instructions keeping the
delay slot instuction also in picture for branch likely instructions. Also
allow emulation when instruction to be decoded is not at pt_regs->cp0_epc
as in case of kprobes where pt_regs->cp0_epc points to the breakpoint
instruction.

The patch also exports the function for modules.

Signed-off-by: Maneesh Soni <manesoni@cisco.com>
Signed-off-by: Victor Kamensky <kamensky@cisco.com>
Cc: David Daney <david.daney@cavium.com>
Cc: ananth@in.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2913/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-12-07 22:04:03 +00:00
Peter Zijlstra a8b0ca17b8 perf: Remove the nmi parameter from the swevent and overflow interface
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.

For the various event classes:

  - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
  - tracepoint: nmi=0; since tracepoint could be from NMI context.
  - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-01 11:06:35 +02:00
David Daney 515b029d00 MIPS: Send proper signal and siginfo on FP emulator faults.
We were unconditionally sending SIGBUS with an empty siginfo on FP
emulator faults.  This differs from what happens when real floating
point hardware would get a fault.

For most faults we need to send SIGSEGV with the faulting address
filled in in the struct siginfo.

Reported-by: Camm Maguire <camm@maguirefamily.org>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Cc: Camm Maguire <camm@maguirefamily.org>
Patchwork: https://patchwork.linux-mips.org/patch/1727/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-12-16 18:10:57 +00:00
Deng-Cheng Zhu 7f788d2d53 MIPS: add support for software performance events
Software events are required as part of the measurable stuff by the
Linux performance counter subsystem. Here is the list of events added by
this patch:
PERF_COUNT_SW_PAGE_FAULTS
PERF_COUNT_SW_PAGE_FAULTS_MIN
PERF_COUNT_SW_PAGE_FAULTS_MAJ
PERF_COUNT_SW_ALIGNMENT_FAULTS
PERF_COUNT_SW_EMULATION_FAULTS

Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: linux-mips@linux-mips.org
Cc: a.p.zijlstra@chello.nl
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: jamie.iles@picochip.com
Acked-by: David Daney <ddaney@caviumnetworks.com>
Reviewed-by: Matt Fleming <matt@console-pimps.org>
Patchwork: https://patchwork.linux-mips.org/patch/1686/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-10-29 19:08:48 +01:00
Justin P. Mattock 50a23e6eec Update broken web addresses in arch directory.
The patch below updates broken web addresses in the arch directory.

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Reviewed-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-10-18 11:03:21 +02:00
Shane McDonald 3f13553044 MIPS: Coding style cleanups of access of FCSR rounding mode bits
Replaces references to the magic number 0x3 with constants and macros
indicating the real purpose of those bits.  They are the rounding mode
bits of the FCSR register.

Signed-off-by: Shane McDonald <mcdonald.shane@gmail.com>
To: anemo@mba.ocn.ne.jp
To: kevink@paralogos.com
To: linux-mips@linux-mips.org
To: sshtylyov@mvista.com
Patchwork: http://patchwork.linux-mips.org/patch/1206/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-05-21 21:31:17 +01:00
Shane McDonald 95e8f634d7 MIPS FPU emulator: allow Cause bits of FCSR to be writeable by ctc1
In the FPU emulator code of the MIPS, the Cause bits of the FCSR register
    are not currently writeable by the ctc1 instruction.  In odd corner cases,
    this can cause problems.  For example, a case existed where a divide-by-zero
    exception was generated by the FPU, and the signal handler attempted to
    restore the FPU registers to their state before the exception occurred.  In
    this particular setup, writing the old value to the FCSR register would
    cause another divide-by-zero exception to occur immediately.  The solution
    is to change the ctc1 instruction emulator code to allow the Cause bits of
    the FCSR register to be writeable.  This is the behaviour of the hardware
    that the code is emulating.
    
    This problem was found by Shane McDonald, but the credit for the fix goes
    to Kevin Kissell.  In Kevin's words:
    
    I submit that the bug is indeed in that ctc_op:  case of the emulator.  The
    Cause bits (17:12) are supposed to be writable by that instruction, but the
    CTC1 emulation won't let them be updated by the instruction.  I think that
    actually if you just completely removed lines 387-388 [...] things would
    work a good deal better.  At least, it would be a more accurate emulation of
    the architecturally defined FPU.  If I wanted to be really, really pedantic
    (which I sometimes do), I'd also protect the reserved bits that aren't
    necessarily writable.
    
    Signed-off-by: Shane McDonald <mcdonald.shane@gmail.com>
    To: anemo@mba.ocn.ne.jp
    To: kevink@paralogos.com
    To: sshtylyov@mvista.com
    Patchwork: http://patchwork.linux-mips.org/patch/1205/
    Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

---
2010-05-15 21:59:53 +01:00
David Daney b6ee75ed4f MIPS: Collect FPU emulator statistics per-CPU.
On SMP systems, the collection of statistics can cause cache line
bouncing in the lines associated with the counters.  Also there are
races incrementing the counters on multiple CPUs.

To fix both problems, we collect the statistics in per-CPU variables,
and add them up in the debugfs read operation.

As a test I ran the LTP float_bessel test on a 12 CPU Octeon system.

Without CONFIG_DEBUG_FS :             2602 seconds.
With CONFIG_DEBUG_FS:                 2640 seconds.
With non-cpu-local atomic statistics: 14569 seconds.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-12-17 01:57:08 +00:00
David Daney da0bac3341 MIPS: Fix emulation of 64-bit FPU on FPU-less 64-bit CPUs.
Running a 64-bit kernel on a 64-bit CPU without an FPU would cause the
emulator to run in 32-bit mode.  The c0_Status.FR bit is wired to zero
on systems without an FPU, so using that bit to decide how the emulator
behaves doesn't allow for proper emulation on 64-bit FPU-less
processors.

Instead, we need to select the emulator mode based on the user-space
ABI.  Since the thread flag TIF_32BIT_REGS is used to set c0_Status.FR,
we can just use it to decide if the emulator should be in 32-bit or
64-bit mode.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-11-13 18:10:37 +01:00
Ralf Baechle ba3049ed40 MIPS: Switch FPU emulator trap to BREAK instruction.
Arguably using the address error handler has always been ugly.  But with
processors that handle unaligned loads and stores in hardware the
current mechanism ceases to work so switch it to a BREAK instruction and
allocate break code 514 to the FPU emulator.

Yoichi Yuasa provided a build fix for CONFIG_BUG=n.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
2008-10-30 14:44:34 +00:00
Zhaolei ecab1f4479 MIPS: Fix debugfs_create_*'s error checking method for arch/mips/math-emu/
debugfs_create_*() returns NULL on error.  Make its caller debugfs_fpuemu
return -ENODEV on error.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-10-27 16:18:25 +00:00
Ralf Baechle 21a151d8ca [MIPS] checkfiles: Fix "need space after that ','" errors.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-11 23:46:15 +01:00
Ralf Baechle 49a89efbbb [MIPS] Fix "no space between function name and open parenthesis" warnings.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-11 23:46:15 +01:00
Atsushi Nemoto e70dfc10b9 [MIPS] math-emu minor cleanup
Declaring emulpc and contpc as "unsigned long" can get rid of some casts.
This also get rid of some sparse warnings.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-07-13 17:40:00 +01:00
Atsushi Nemoto 83fd38cabc [MIPS] Add debugfs files to show fpuemu statistics
Export contents of struct mips_fpu_emulator_stats via debugfs.

There is no way to read these statistics for now but they (at least
the "emulated" count) might be sometimes useful for performance tuning
on FPU-less CPUs.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-07-10 17:33:04 +01:00
Atsushi Nemoto e04582b7bc [MIPS] Make sure cpu_has_fpu is used only in atomic context
Make sure cpu_has_fpu (which uses smp_processor_id()) is used only in
atomic context.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-09 23:20:48 +01:00
Atsushi Nemoto eae89076e6 [MIPS] Unify mips_fpu_soft_struct and mips_fpu_hard_structs.
The struct mips_fpu_soft_struct and mips_fpu_hard_struct are
completely same now and the kernel fpu emulator assumes that.  This
patch unifies them to mips_fpu_struct and get rid of mips_fpu_union.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-06-19 17:39:18 +01:00
Ralf Baechle 4b724efdde Get rid of SINGLE_ONLY_FPU. Linux does not support half FPU other than
by emulation of a full FPU.
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:32:52 +01:00
Ralf Baechle 3fccc0150e Fix all the get_user / put_user related sparse warnings.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:32:52 +01:00
Ralf Baechle 12616ed202 FPU emulator garbage collection.
First argument of fpu_emulator_cop1Handler() was unused.
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:32:43 +01:00
Ralf Baechle 587cb98f36 GCC bulletproofing: __mips64 is only defined when compiling for 64-bit
processors.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:32:22 +01:00
Ralf Baechle 4a99d1e25b Now that a struct is the only member left in struct
mips_fpu_emulator_stats cleanup that unnecessary nesting of structs.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:31:14 +01:00
Ralf Baechle cd21dfcfbb Fix preemption and SMP problems in the FP emulator code.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:31:12 +01:00
Ralf Baechle 333d1f6794 Gross macro abuse. Get rid of gpreg_t, vaddr_t, REG_TO_VA and
VA_TO_REG.  Who ever wrote this apparently did enjoy the C Puzzle Book.
ISBN 0201604612, a little old but still fun reading for the next
blackout ;)

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:30:46 +01:00
Yoichi Yuasa 766160c29f [PATCH] mips: fix build warnings
This patch has fixed the following warnings.

arch/mips/kernel/genex.S:250:5: warning: "CONFIG_64BIT" is not defined
arch/mips/math-emu/cp1emu.c:1128:5: warning: "__mips64" is not defined
arch/mips/math-emu/cp1emu.c:1206:5: warning: "__mips64" is not defined
arch/mips/math-emu/cp1emu.c:1270:5: warning: "__mips64" is not defined
arch/mips/math-emu/cp1emu.c:323:5: warning: "__mips64" is not defined
arch/mips/math-emu/cp1emu.c:808:5: warning: "__mips64" is not defined
arch/mips/math-emu/cp1emu.c:953:5: warning: "__mips64" is not defined
arch/mips/mm/tlbex.c:519:5: warning: "CONFIG_64BIT" is not defined
include/asm/reg.h:73:5: warning: "CONFIG_64BIT" is not defined

Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:08 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00