talos-obmc-linux/arch/mips/kernel, branch v2.6.33-rc5

MIPS: Cleanup random differences beween lmo and Linus' kernel.

2009-12-17T01:57:36+00:00

Signed-off-by: Ralf Baechle

MIPS: Fix and enhance built-in kernel command line

2009-12-17T01:57:35+00:00

Currently, MIPS kernels silently overwrite kernel command-line parameters hardcoded in CONFIG_CMDLINE by the ones received from firmware. Therefore, using firmware remains the only reliable method to transfer the command-line parameters, which is not always desirable or convenient, and the CONFIG_CMDLINE option is thereby effectively rendered useless. This patch fixes the problem described above and introduces a more flexible scheme of handling the kernel command line, in a manner identical to what is currently used for x86. The default behavior, i.e. when CONFIG_CMDLINE_BOOL is not defined, retains the existing semantics, and firmware command-line arguments override the hardcoded ones. [Ralf: I fixed up all the defconfig files so the stay unaffected by this change.] Signed-off-by: Dmitri Vorobiev Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/689/ Signed-off-by: Ralf Baechle

MIPS: Cleanup signal code initialization

2009-12-17T01:57:32+00:00

Signed-off-by: Ralf Baechle Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/709/

MIPS: Modularize COP2 handling

2009-12-17T01:57:30+00:00

Away with the daemons of ifdef; get ready for future COP2 users. Signed-off-by: Ralf Baechle Patchwork: http://patchwork.linux-mips.org/patch/708/

MIPS: Tracing: Make function graph tracer work with -mmcount-ra-address

2009-12-17T01:57:27+00:00

That thread "MIPS: Add option to pass return address location to _mcount" from "David Daney " have added a new option -mmcount-ra-address to gcc(4.5) for MIPS to transfer the location of the return address to _mcount. Benefit from this new feature, function graph tracer on MIPS will be easier and safer to hijack the return address of the kernel function, which will save some overhead and make the whole thing more reliable. In this patch, at first, try to enable the option -mmcount-ra-address in arch/mips/Makefile with cc-option, if gcc support it, it will be enabled, otherwise, no side effect. and then, we need to support this new option of gcc 4.5 and also support the old gcc versions. with _mcount in the old gcc versions, it's not easy to get the location of return address(tracing: add function graph tracer support for MIPS), so, we do it in a C function: ftrace_get_parent_addr(ftrace.c), but with -mmcount-ra-address, only several instructions need to get what we want, so, I put into asm(mcount.S). and also, as the $12(t0) is used by -mmcount-ra-address for transferring the localtion of return address to _mcount, we need to save it into the stack and restore it when enabled dynamic function tracer, 'Cause we have called "ftrace_call" before "ftrace_graph_caller", which may destroy $12(t0). (Thanks to David for providing that -mcount-ra-address and giving the idea of KBUILD_MCOUNT_RA_ADDRESS, both of them have made the whole thing more beautiful!) Signed-off-by: Wu Zhangjin Cc: Steven Rostedt Cc: Nicholas Mc Guire Cc: zhangfx@lemote.com Cc: Wu Zhangjin Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Frederic Weisbecker Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/681/ Signed-off-by: Ralf Baechle

MIPS: Tracing: Reserve $12(t0) for mcount-ra-address of gcc 4.5

2009-12-17T01:57:26+00:00

A new option -mmcount-ra-address for gcc 4.5 have been sent by David Daney in the thread "MIPS: Add option to pass return address location to _mcount", which help to record the location of the return address(ra) for the function graph tracer of MIPS to hijack the return address easier and safer. that option used the $12(t0) register by default, so, we reserve it for it, and use t1,t2,t3 instead of t0,t1,t2. Signed-off-by: Wu Zhangjin Cc: Steven Rostedt Cc: Nicholas Mc Guire Cc: zhangfx@lemote.com Cc: Wu Zhangjin Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Frederic Weisbecker Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/680/ Signed-off-by: Ralf Baechle

MIPS: Tracing: Make ftrace for MIPS work without -fno-omit-frame-pointer

2009-12-17T01:57:25+00:00

When remove the -fno-omit-frame-pointer, gcc will not save the frame pointer for us, we need to save one ourselves. Signed-off-by: Wu Zhangjin Cc: Steven Rostedt Cc: Nicholas Mc Guire Cc: zhangfx@lemote.com Cc: Wu Zhangjin Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Frederic Weisbecker Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/679/ Signed-off-by: Ralf Baechle

MIPS: Tracing: Add dynamic function graph tracer for MIPS

2009-12-17T01:57:25+00:00

This patch make function graph tracer work with dynamic function tracer. To share the source code of dynamic function tracer(MCOUNT_SAVE_REGS), and avoid restoring the whole saved registers, we need to restore the ra register from the stack. (NOTE: This not work with 32bit! need to ensure why!) Signed-off-by: Wu Zhangjin Cc: Steven Rostedt Cc: Nicholas Mc Guire Cc: zhangfx@lemote.com Cc: Wu Zhangjin Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Frederic Weisbecker Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/678/ Signed-off-by: Ralf Baechle

MIPS: Tracing: Add function graph tracer support for MIPS

2009-12-17T01:57:25+00:00

The implementation of function graph tracer for MIPS is a little different from X86. in MIPS, gcc(with -pg) only transfer the caller's return address(at) and the _mcount's return address(ra) to us. For the kernel part without -mlong-calls: move at, ra jal _mcount For the module part with -mlong-calls: lui v1, hi16bit_of_mcount addiu v1, v1, low16bit_of_mcount move at, ra jal _mcount Without -mlong-calls, if the function is a leaf, it will not save the return address(ra): ffffffff80101298 : ffffffff80101298: 67bdfff0 daddiu sp,sp,-16 ffffffff8010129c: ffbe0008 sd s8,8(sp) ffffffff801012a0: 03a0f02d move s8,sp ffffffff801012a4: 03e0082d move at,ra ffffffff801012a8: 0c042930 jal ffffffff8010a4c0 <_mcount> ffffffff801012ac: 00020021 nop so, we can hijack it directly in _mcount, but if the function is non-leaf, the return address is saved in the stack. ffffffff80133030 : ffffffff80133030: 67bdff50 daddiu sp,sp,-176 ffffffff80133034: ffbe00a0 sd s8,160(sp) ffffffff80133038: 03a0f02d move s8,sp ffffffff8013303c: ffbf00a8 sd ra,168(sp) ffffffff80133040: ffb70098 sd s7,152(sp) ffffffff80133044: ffb60090 sd s6,144(sp) ffffffff80133048: ffb50088 sd s5,136(sp) ffffffff8013304c: ffb40080 sd s4,128(sp) ffffffff80133050: ffb30078 sd s3,120(sp) ffffffff80133054: ffb20070 sd s2,112(sp) ffffffff80133058: ffb10068 sd s1,104(sp) ffffffff8013305c: ffb00060 sd s0,96(sp) ffffffff80133060: 03e0082d move at,ra ffffffff80133064: 0c042930 jal ffffffff8010a4c0 <_mcount> ffffffff80133068: 00020021 nop but we can not get the exact stack address(which saved ra) directly in _mcount, we need to search the content of at register in the stack space or search the "s{d,w} ra, offset(sp)" instruction in the text. 'Cause we can not prove there is only a match in the stack space, so, we search the text instead. as we can see, if the first instruction above "move at, ra" is not a store instruction, there should be a leaf function, so we hijack the at register directly via putting &return_to_handler into it, otherwise, we search the "s{d,w} ra, offset(sp)" instruction to get the stack offset, and then the stack address. we use the above copy_process() as an example, we at last find "ffbf00a8", 0xa8 is the stack offset, we plus it with s8(fp), that is the stack address, we hijack the content via writing the &return_to_handler in. If with -mlong-calls, since there are two more instructions above "move at, ra", so, we can move the pointer to the position above "lui v1, hi16bit_of_mcount". Signed-off-by: Wu Zhangjin Cc: Steven Rostedt Cc: Nicholas Mc Guire Cc: zhangfx@lemote.com Cc: Wu Zhangjin Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Frederic Weisbecker Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/677/ Signed-off-by: Ralf Baechle

MIPS: Tracing: Add IRQENTRY_EXIT section for MIPS

2009-12-17T01:57:24+00:00

This patch add a new section for MIPS to record the block of the hardirq handling for function graph tracer(print_graph_irq) via adding the __irq_entry annotation to the the entrypoints of the hardirqs(the block with irq_enter()...irq_exit()). Thanks goes to Steven & Frederic Weisbecker for their feedbacks. Signed-off-by: Wu Zhangjin Cc: Steven Rostedt Cc: Nicholas Mc Guire Cc: zhangfx@lemote.com Cc: Wu Zhangjin Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Frederic Weisbecker Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Reviewed-by: Frederic Weisbecker Patchwork: http://patchwork.linux-mips.org/patch/676/ Signed-off-by: Ralf Baechle