user/sven/linux.git/arch/mips/Kconfig.debug, branch v4.8.5

MIPS: Remove compact branch policy Kconfig entries

2016-09-13T12:14:50Z

Commit c1a0e9bc885d ("MIPS: Allow compact branch policy to be changed") added Kconfig entries allowing for the compact branch policy used by the compiler for MIPSr6 kernels to be specified. This can be useful for debugging, particularly in systems where compact branches have recently been introduced. Unfortunately mainline gcc 5.x supports MIPSr6 but not the -mcompact-branches compiler flag, leading to MIPSr6 kernels failing to build with gcc 5.x with errors such as: mipsel-linux-gnu-gcc: error: unrecognized command line option '-mcompact-branches=optimal' make[2]: *** [kernel/bounds.s] Error 1 Fixing this by hiding the Kconfig entry behind another seems to be more hassle than it's worth, as MIPSr6 & compact branches have been around for a while now and if policy does need to be set for debug it can be done easily enough with KCFLAGS. Therefore remove the compact branch policy Kconfig entries & their handling in the Makefile. This reverts commit c1a0e9bc885d ("MIPS: Allow compact branch policy to be changed"). Signed-off-by: Paul Burton Reported-by: kbuild test robot Fixes: c1a0e9bc885d ("MIPS: Allow compact branch policy to be changed") Cc: stable # v4.4+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14241/ Signed-off-by: Ralf Baechle

MIPS: CPS: Early debug using an ns16550-compatible UART

2015-11-11T07:34:25Z

Provide support for outputting early debug information, in the form of various register values should an exception occur, during the early bringup of secondary cores. This code requires an ns16550-compatible UART accessible from the secondary core, and is written in assembly due to the environment in which such early exceptions occur where way may not have a stack, be coherent or even have initialised caches. [ralf@linux-mips.org: Fix merge conflict.] Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: Steven J. Hill Cc: Andrew Bresticker Cc: Leonid Yegoshin Cc: Maciej W. Rozycki Cc: Jason Cooper Cc: linux-kernel@vger.kernel.org Cc: James Hogan Cc: Markos Chandras Patchwork: https://patchwork.linux-mips.org/patch/11202/ Signed-off-by: Ralf Baechle

MIPS: Allow L2 prefetch to be configured via debugfs

2015-10-26T08:49:42Z

When debugging or examining the performance of a system it can be useful to examine the effect of L2 prefetching. Provide an optional debugfs entry to allow a user to enable or disable L2 prefetching. Signed-off-by: Paul Burton Cc: Maciej W. Rozycki Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11182/ Signed-off-by: Ralf Baechle

MIPS: Allow compact branch policy to be changed

2015-10-26T08:49:40Z

When debugging it can be helpful to change the policy for compiler use of MIPSr6 compact branches, in order to rule out or home in on their involvement in bugs. Allow the GCC -mcompact-branches= flag to be set via Kconfig under the "Kernel hacking" menu. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11178/ Signed-off-by: Ralf Baechle

MIPS: Drop CONFIG_RUNTIME_DEBUG & debug.h

2015-08-26T13:23:36Z

The debug.h header provided some MIPS-specific debug macros, which are no longer used at all. Remove them. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10693/ Signed-off-by: Ralf Baechle

MIPS: kernel: elf: Improve the overall ABI and FPU mode checks

2015-02-17T15:37:39Z

The previous implementation did not cover all possible FPU combinations and it silently allowed ABI incompatible objects to be loaded with the wrong ABI. For example, the previous logic would set the FP_64 ABI as the matching ABI for an FP_XX object combined with an FP_64A object. This was wrong, and the matching ABI should have been FP_64A. The previous logic is now replaced with a new one which determines the appropriate FPU mode to be used rather than the FP ABI. This has the advantage that the entire logic is much simpler since it is the FPU mode we are interested in rather than the FP ABI resulting to code simplifications. This also removes the now obsolete FP32XX_HYBRID_FPRS option. Cc: Matthew Fortune Cc: Paul Burton Signed-off-by: Markos Chandras

MIPS: Kconfig option to better exercise/debug hybrid FPRs

2014-11-24T06:45:08Z

The hybrid FPR scheme exists to allow for compatibility between existing FP32 code and newly compiled FP64A code. Such code should hopefully be rare in the real world, and for the moment is difficult to come across. All code except that built for the FP64 ABI can correctly execute using the hybrid FPR scheme, so debugging the hybrid FPR implementation can be eased by forcing all such code to use it. This is undesirable in general due to the trap & emulate overhead of the hybrid FPR implementation, but is a very useful option to have for debugging. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: Alexander Viro Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7680/ Signed-off-by: Ralf Baechle

MIPS: MT: Remove SMTC support

2014-05-23T22:07:01Z

Nobody is maintaining SMTC anymore and there also seems to be no userbase. Which is a pity - the SMTC technology primarily developed by Kevin D. Kissell is an ingenious demonstration for the MT ASE's power and elegance. Based on Markos Chandras patch https://patchwork.linux-mips.org/patch/6719/ which while very similar did no longer apply cleanly when I tried to merge it plus some additional post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to merge once upon a time. Signed-off-by: Ralf Baechle

MIPS: Fix build error due to multiple prom_putchar() definitions.

2014-03-31T08:16:52Z

This can happen if both the generic 8250 and another early console driver are enable. Fixed by using an auxilliary kconfig symbol to restrict that choice. Signed-off-by: Ralf Baechle

MIPS: Add 8250/16550 serial early printk driver

2013-10-29T20:24:36Z

Signed-off-by: Yoichi Yuasa Cc: linux-mips Patchwork: https://patchwork.linux-mips.org/patch/947/ Signed-off-by: Ralf Baechle