Commit Graph

17 Commits

Author SHA1 Message Date
Paul Burton 0fa24340f7 MIPS: Fix octeon FP context switch handling
Commit 1a3d59579b ("MIPS: Tidy up FPU context switching") removed FP
context saving from the asm-written resume function in favour of reusing
existing code to perform the same task. However it only removed the FP
context saving code from the r4k_switch.S implementation of resume.
Octeon uses its own implementation in octeon_switch.S, so remove FP
context saving there too in order to prevent attempting to save context
twice. That formerly led to an exception from the second save as follows
because the FPU had already been disabled by the first save:

    do_cpu invoked from kernel context![#1]:
    CPU: 0 PID: 2 Comm: kthreadd Not tainted 4.3.0-rc2-dirty #2
    task: 800000041f84a008 ti: 800000041f864000 task.ti: 800000041f864000
    $ 0   : 0000000000000000 0000000010008ce1 0000000000100000 ffffffffbfffffff
    $ 4   : 800000041f84a008 800000041f84ac08 800000041f84c000 0000000000000004
    $ 8   : 0000000000000001 0000000000000000 0000000000000000 0000000000000001
    $12   : 0000000010008ce3 0000000000119c60 0000000000000036 800000041f864000
    $16   : 800000041f84ac08 800000000792ce80 800000041f84a008 ffffffff81758b00
    $20   : 0000000000000000 ffffffff8175ae50 0000000000000000 ffffffff8176c740
    $24   : 0000000000000006 ffffffff81170300
    $28   : 800000041f864000 800000041f867d90 0000000000000000 ffffffff815f3fa0
    Hi    : 0000000000fa8257
    Lo    : ffffffffe15cfc00
    epc   : ffffffff8112821c resume+0x9c/0x200
    ra    : ffffffff815f3fa0 __schedule+0x3f0/0x7d8
    Status: 10008ce2        KX SX UX KERNEL EXL
    Cause : 1080002c (ExcCode 0b)
    PrId  : 000d0601 (Cavium Octeon+)
    Modules linked in:
    Process kthreadd (pid: 2, threadinfo=800000041f864000, task=800000041f84a008, tls=0000000000000000)
    Stack : ffffffff81604218 ffffffff815f7e08 800000041f84a008 ffffffff811681b0
              800000041f84a008 ffffffff817e9878 0000000000000000 ffffffff81770000
              ffffffff81768340 ffffffff81161398 0000000000000001 0000000000000000
              0000000000000000 ffffffff815f4424 0000000000000000 ffffffff81161d68
              ffffffff81161be8 0000000000000000 0000000000000000 0000000000000000
              0000000000000000 0000000000000000 0000000000000000 ffffffff8111e16c
              0000000000000000 0000000000000000 0000000000000000 0000000000000000
              0000000000000000 0000000000000000 0000000000000000 0000000000000000
              0000000000000000 0000000000000000 0000000000000000 0000000000000000
              0000000000000000 0000000000000000 0000000000000000 0000000000000000
              ...
    Call Trace:
    [<ffffffff8112821c>] resume+0x9c/0x200
    [<ffffffff815f3fa0>] __schedule+0x3f0/0x7d8
    [<ffffffff815f4424>] schedule+0x34/0x98
    [<ffffffff81161d68>] kthreadd+0x180/0x198
    [<ffffffff8111e16c>] ret_from_kernel_thread+0x14/0x1c

Tested using cavium_octeon_defconfig on an EdgeRouter Lite.

Fixes: 1a3d59579b ("MIPS: Tidy up FPU context switching")
Reported-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-kernel@vger.kernel.org
Cc: Chandrakala Chavva <cchavva@caviumnetworks.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Leonid Rosenboim <lrosenboim@caviumnetworks.com>
Patchwork: https://patchwork.linux-mips.org/patch/11166/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-10-02 19:16:06 +02:00
Aleksey Makarov 69f7cd4724 MIPS: OCTEON: Delete unused COP2 saving code
Commit 2c952e06e4 ("MIPS: Move cop2 save/restore to switch_to()")
removes assembler code to store COP2 registers.  Commit
a36d8225bc ("MIPS: OCTEON: Enable use of FPU") mistakenly
restores it

Fixes: a36d8225bc ("MIPS: OCTEON: Enable use of FPU")
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/8937/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 15:30:23 +01:00
Chandrakala Chavva 2d98cae6e3 MIPS: OCTEON: Use correct instruction to read 64-bit COP0 register
Use dmfc0/dmtc0 instructions for reading CvmMemCtl COP0 register,
its a 64-bit wide.

Signed-off-by: Chandrakala Chavva <cchavva@caviumnetworks.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/8936/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 15:29:36 +01:00
David Daney 6b3a287e63 MIPS: OCTEON: Save and restore CP2 SHA3 state
Allocate new save space, and then save/restore the registers if
OCTEON III.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8935/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 15:29:08 +01:00
David Daney d6e41525e3 MIPS: OCTEON: Fix FP context save.
It wasn't being saved on task switch.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8934/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 15:28:51 +01:00
David Daney ac655fb762 MIPS: OCTEON: Save/Restore wider multiply registers in OCTEON III CPUs
The wide multiplier is twice as wide, so we need to save twice as much
state.  Detect the multiplier type (CPU type) at start up and install
model specific handlers.

[aleksey.makarov@auriga.com:
	conflict resolution,
	support for old compilers]

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Leonid Rosenboim <lrosenboim@caviumnetworks.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8933/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 15:28:29 +01:00
David Daney a36d8225bc MIPS: OCTEON: Enable use of FPU
Some versions of the assembler will not assemble CFC1 for OCTEON, so
override the ISA for these.

Add r4k_fpu.o to handle low level FPU initialization.

Modify octeon_switch.S to save the FPU registers.  And include
r4k_switch.S to pick up more FPU support.

Get rid of "#define cpu_has_fpu		0"

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7006/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-30 21:01:09 +02:00
James Hogan 8b3c569a39 MIPS: stack protector: Fix per-task canary switch
Commit 1400eb6 (MIPS: r4k,octeon,r2300: stack protector: change canary
per task) was merged in v3.11 and introduced assembly in the MIPS resume
functions to update the value of the current canary in
__stack_chk_guard. However it used PTR_L resulting in a load of the
canary value, instead of PTR_LA to construct its address. The value is
intended to be random but is then treated as an address in the
subsequent LONG_S (store).

This was observed to cause a fault and panic:

CPU 0 Unable to handle kernel paging request at virtual address 139fea20, epc == 8000cc0c, ra == 8034f2a4
Oops[#1]:
...
$24   : 139fea20 1e1f7cb6
...
Call Trace:
[<8000cc0c>] resume+0xac/0x118
[<8034f2a4>] __schedule+0x5f8/0x78c
[<8034f4e0>] schedule_preempt_disabled+0x20/0x2c
[<80348eec>] rest_init+0x74/0x84
[<804dc990>] start_kernel+0x43c/0x454
Code: 3c18804b  8f184030  8cb901f8 <af190000> 00c0e021  8cb002f0 8cb102f4  8cb202f8  8cb302fc

This can also be forced by modifying
arch/mips/include/asm/stackprotector.h so that the default
__stack_chk_guard value is more likely to be a bad (or unaligned)
pointer.

Fix it to use PTR_LA instead, to load the address of the canary value,
which the LONG_S can then use to write into it.

Reported-by: bobjones (via #mipslinux on IRC)
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gregory Fong <gregory.0xf0@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/6026/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-10-07 15:31:04 +02:00
Gregory Fong 1400eb6567 MIPS: r4k,octeon,r2300: stack protector: change canary per task
For non-SMP, uses the new random canary value that is stored in the
task struct whenever a new task is forked.  Based on ARM version in
df0698be14 and subject to the same
limitations: the variable GCC expects, __stack_chk_guard, is global,
so this will not work on SMP.

Quoting Nicolas Pitre <nico@fluxnic.net>: "One way to overcome this
GCC limitation would be to locate the __stack_chk_guard variable into
a memory page of its own for each CPU, and then use TLB locking to
have each CPU see its own page at the same virtual address for each of
them."

Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5488/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-07-01 15:10:52 +02:00
Jayachandran C 2c952e06e4 MIPS: Move cop2 save/restore to switch_to()
Move the common code for saving and restoring platform specific COP2
registers to switch_to(). This will make supporting new platforms (like
Netlogic XLP) easier.

The platform specific COP2 definitions are to be specified in
asm/processor.h and in asm/cop2.h.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Cc: ddaney.cavm@gmail.com
Patchwork: https://patchwork.linux-mips.org/patch/5411/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-06-13 17:46:41 +02:00
Ralf Baechle 7034228792 MIPS: Whitespace cleanup.
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>
2013-02-01 10:00:22 +01:00
Ralf Baechle 348dd600c3 MIPS: Don't include <asm/page.h> unnecessarily.
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>
2012-12-28 17:04:04 +01:00
Leonid Yegoshin 2dd17030c9 MIPS: Fix race condition with FPU thread task flag during context switch.
[ralf@linux-mips.org: Cosmetic changes; also fixed up r2300_switch.S and
octeon_switch.S which needed similar modifications.]

Signed-off-by: Leonid Yegoshin <yegoshin@mips.com>
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3784/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-07-19 11:23:43 +02:00
Justin P. Mattock 79add62773 update David Miller's old email address
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-04-06 06:19:38 -07:00
Ralf Baechle e0e53dee69 MIPS: Nuke trailing blank lines
Recent git versions now warn about those and they've always been a bit of
an annoyance.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-02-27 12:53:14 +01:00
Ralf Baechle f4c6b6bc5a MIPS: Consolidate all CONFIG_CPU_HAS_LLSC use in a single C file.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-09-17 20:07:49 +02:00
David Daney 5b3b16880f MIPS: Add Cavium OCTEON processor support files to arch/mips/cavium-octeon.
These are the rest of the new files needed to add OCTEON processor
support to the Linux kernel.  Other than Makefile and Kconfig which
should be obvious, we have:

csrc-octeon.c   -- Clock source driver for OCTEON.
dma-octeon.c    -- Helper functions for mapping DMA memory.
flash_setup.c   -- Register on-board flash with the MTD subsystem.
octeon-irq.c    -- OCTEON interrupt controller managment.
octeon-memcpy.S -- Optimized memcpy() implementation.
serial.c        -- Register 8250 platform driver and early console.
setup.c         -- Early architecture initialization.
smp.c           -- OCTEON SMP support.
octeon_switch.S -- Scheduler context switch for OCTEON.
c-octeon.c      -- OCTEON cache controller support.
cex-oct.S       -- OCTEON cache exception handler.

asm/mach-cavium-octeon/*.h -- Architecture include files.

Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

 create mode 100644 arch/mips/cavium-octeon/Kconfig
 create mode 100644 arch/mips/cavium-octeon/Makefile
 create mode 100644 arch/mips/cavium-octeon/csrc-octeon.c
 create mode 100644 arch/mips/cavium-octeon/dma-octeon.c
 create mode 100644 arch/mips/cavium-octeon/flash_setup.c
 create mode 100644 arch/mips/cavium-octeon/octeon-irq.c
 create mode 100644 arch/mips/cavium-octeon/octeon-memcpy.S
 create mode 100644 arch/mips/cavium-octeon/serial.c
 create mode 100644 arch/mips/cavium-octeon/setup.c
 create mode 100644 arch/mips/cavium-octeon/smp.c
 create mode 100644 arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h
 create mode 100644 arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
 create mode 100644 arch/mips/include/asm/mach-cavium-octeon/irq.h
 create mode 100644 arch/mips/include/asm/mach-cavium-octeon/kernel-entry-init.h
 create mode 100644 arch/mips/include/asm/mach-cavium-octeon/war.h
 create mode 100644 arch/mips/include/asm/octeon/octeon.h
 create mode 100644 arch/mips/kernel/octeon_switch.S
 create mode 100644 arch/mips/mm/c-octeon.c
 create mode 100644 arch/mips/mm/cex-oct.S
2009-01-11 09:57:21 +00:00