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2014-01-13MIPS: Support for 64-bit FP with O32 binariesPaul Burton1-2/+43
CPUs implementing MIPS32 R2 may include a 64-bit FPU, just as MIPS64 CPUs do. In order to preserve backwards compatibility a 64-bit FPU will act like a 32-bit FPU (by accessing doubles from the least significant 32 bits of an even-odd pair of FP registers) when the Status.FR bit is zero, again just like a mips64 CPU. The standard O32 ABI is defined expecting a 32-bit FPU, however recent toolchains support use of a 64-bit FPU from an O32 MIPS32 executable. When an ELF executable is built to use a 64-bit FPU a new flag (EF_MIPS_FP64) is set in the ELF header. With this patch the kernel will check the EF_MIPS_FP64 flag when executing an O32 binary, and set Status.FR accordingly. The addition of O32 64-bit FP support lessens the opportunity for optimisation in the FPU emulator, so a CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option is introduced to allow this support to be disabled for those that don't require it. Inspired by an earlier patch by Leonid Yegoshin, but implemented more cleanly & correctly. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Paul Burton <paul.burton@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/6154/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-10-07MIPS: stack protector: Fix per-task canary switchJames Hogan1-1/+1
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>
2013-07-01MIPS: r4k,octeon,r2300: stack protector: change canary per taskGregory Fong1-0/+6
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 df0698be14c6683606d5df2d83e3ae40f85ed0d9 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>
2013-02-01MIPS: Whitespace cleanup.Ralf Baechle1-2/+2
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>
2012-12-28MIPS: Don't include <asm/page.h> unnecessarily.Ralf Baechle1-1/+0
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>
2012-07-19MIPS: Fix race condition with FPU thread task flag during context switch.Leonid Yegoshin1-9/+3
[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>
2011-04-06update David Miller's old email addressJustin P. Mattock1-1/+1
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>
2009-09-17MIPS: Consolidate all CONFIG_CPU_HAS_LLSC use in a single C file.Ralf Baechle1-3/+0
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-07-12[MIPS] Fix resume for 64K page size on R4000 class processors.Ralf Baechle1-6/+1
Problem reported by Peter Watkins <pwatkins@sicortex.com> but this is a different fix. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-06-06[MIPS] Remove duplicate fpu enable hazard code.Chris Dearman1-1/+1
Use common code from hazards.h instead. Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-04-20[MIPS] Disallow CpU exception in kernel again.Atsushi Nemoto1-6/+4
The commit 4d40bff7110e9e1a97ff8c01bdd6350e9867cc10 ("Allow CpU exception in kernel partially") was broken. The commit was to fix theoretical problem but broke usual case. Revert it for now. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-03-17[MIPS] FPU ownership management & preemption fixesAtsushi Nemoto1-4/+6
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-01[MIPS] 16K & 64K page size fixesRalf Baechle1-0/+5
Derived from Peter Watkins <treestem@gmail.com>'s work. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel1-1/+0
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-29[MIPS] Fix use of ehb instruction for non-R2 configurations.Ralf Baechle1-3/+3
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-06-19[MIPS] Fix fpu_save_double on 64-bit.Atsushi Nemoto1-5/+8
> Without this fix, _save_fp() in 64-bit kernel is seriously broken. > > ffffffff8010bec0 <_save_fp>: > ffffffff8010bec0: 400d6000 mfc0 t1,c0_status > ffffffff8010bec4: 000c7140 sll t2,t0,0x5 > ffffffff8010bec8: 05c10011 bgez t2,ffffffff8010bf10 <_save_fp+0x50> > ffffffff8010becc: 00000000 nop > ffffffff8010bed0: f4810328 sdc1 $f1,808(a0) > ... Fix register usage in fpu_save_double() and make fpu_restore_double() more symmetric with fpu_save_double(). Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-04-19[MIPS] MT: Improved multithreading support.Ralf Baechle1-1/+33
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-09-09kbuild: mips use generic asm-offsets.h supportSam Ravnborg1-1/+1
Removed obsolete stuff from arch makefile. mips had a special rule for generating asm-offsets.h so preserved it using an architecture specific hook in top-level Kbuild file. Renamed .h file to asm-offsets.h Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-09-05[PATCH] mips: nuke trailing whitespaceRalf Baechle1-2/+2
Signed-off-by: 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[PATCH] mips: clean up 32/64-bit configurationRalf Baechle1-2/+2
Start cleaning 32-bit vs. 64-bit configuration. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds1-0/+221
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!
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