kernel/linux.git/arch/mips/math-emu, branch master

mips: math-emu: replace deprecated strcpy() in me-debugfs

2025-09-12T09:56:06+00:00

use strscpy() instead of deprecated strcpy(). Signed-off-by: Osama Abdelkader Signed-off-by: Thomas Bogendoerfer

mips/math-emu: fix emulation of the prefx instruction

2025-01-11T11:49:05+00:00

Currently, installation of Debian 12.8 for mipsel fails on machines without an FPU [1]. This is caused by the fact that zstd (which is used for initramfs compression) executes the prefx instruction, which is not emulated properly by the kernel. The prefx (Prefetch Indexed) instruction fetches data from memory into the cache without any side effects. Though functionally unrelated, it requires an FPU [2]. Bytecode format of this instruction ends on "001111" binary: (prefx instruction format) & 0x0000003f = 0x0000000f The code in fpux_emu() runs like so: #define MIPSInst(x) x #define MIPSInst_FMA_FFMT(x) (MIPSInst(x) & 0x00000007) #define MIPSInst_FUNC(x) (MIPSInst(x) & 0x0000003f) enum cop1x_func { ..., pfetch_op = 0x0f, ... }; ... switch (MIPSInst_FMA_FFMT(ir)) { ... case 0x3: if (MIPSInst_FUNC(ir) != pfetch_op) return SIGILL; /* ignore prefx operation */ break; default: return SIGILL; } That snippet above contains a logic error and the if (MIPSInst_FUNC(ir) != pfetch_op) comparison always fires. When MIPSInst_FUNC(ir) is equal to pfetch_op, ir must end on 001111 binary. In this case, MIPSInst_FMA_FFMT(ir) must be equal to 0x7, which does not match that case label. This causes emulation failure for the prefx instruction. Fix it. This has been broken by commit 919af8b96c89 ("MIPS: Make definitions of MIPSInst_FMA_{FUNC,FMTM} consistent with MIPS64 manual") which modified the MIPSInst_FMA_FFMT macro without updating the users. Signed-off-by: Mateusz Jończyk Cc: stable@vger.kernel.org # after 3 weeks Cc: Dengcheng Zhu Cc: Thomas Bogendoerfer Cc: Ming Wang Cc: Tiezhu Yang Fixes: 919af8b96c89 ("MIPS: Make definitions of MIPSInst_FMA_{FUNC,FMTM} consistent with MIPS64 manual") [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1091858 [2] MIPS Architecture For Programmers Volume II-A: The MIPS32 Instruction Set Signed-off-by: Thomas Bogendoerfer

MIPS: Fix comment typo

2022-09-12T13:33:24+00:00

The double `it' is duplicated in the comment, remove one. Signed-off-by: Jason Wang Signed-off-by: Thomas Bogendoerfer

MIPS: math-emu: Use the bitmap API to allocate bitmaps

2022-07-11T08:27:50+00:00

Use bitmap_zalloc()/bitmap_free() instead of hand-writing them. It is less verbose and it improves the semantic. Signed-off-by: Christophe JAILLET Signed-off-by: Thomas Bogendoerfer

MIPS: Use fallthrough for arch/mips

2020-05-07T09:55:47+00:00

Convert the various /* fallthrough */ comments to the pseudo-keyword fallthrough; Done via script: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/ Signed-off-by: Liangliang Huang Reviewed-by: Huacai Chen Signed-off-by: Thomas Bogendoerfer

MIPS: Add MAC2008 Support

2020-01-22T23:56:08+00:00

MAC2008 means the processor implemented IEEE754 style Fused MADD instruction. It was introduced in Release3 but removed in Release5. The toolchain support of MAC2008 have never landed except for Loongson processors. This patch aimed to disabled the MAC2008 if it's optional. For MAC2008 only processors, we corrected math-emu behavior to align with actual hardware behavior. Signed-off-by: Jiaxun Yang [paulburton@kernel.org: Fixup MIPSr2-r5 check in cpu_set_fpu_2008.] Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: chenhc@lemote.com Cc: paul.burton@mips.com Cc: linux-kernel@vger.kernel.org

MIPS: math-emu: Reuse name array in debugfs_fpuemu()

2019-11-11T18:56:14+00:00

The FPU_STAT_CREATE_EX() macro used 114 times in debugfs_fpuemu() declares a 32 byte char array to hold the name of a debugfs file. Since each use of the macro declares a new char array out of the scope of all the other uses, we end up with an unnecessarily large stack frame of 3648 bytes (ie. 114*32) plus the size of 2 pointers (fpuemu_debugfs_base_dir & fpuemu_debugfs_inst_dir). This is enough to trigger the frame size warnings from GCC in common configurations. Avoid the unnecessary stack bloat by using a single name char array which each usage of FPU_STAT_CREATE_EX() will reinitialize via the strcpy() in adjust_instruction_counter_name(). Signed-off-by: Paul Burton Reported-by: kbuild test robot URL: https://lore.kernel.org/linux-mips/201911090929.xvXYuHUz%25lkp@intel.com/

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 454

2019-06-19T15:09:09+00:00

Based on 1 normalized pattern(s): this program is free software you can distribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 8 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Enrico Weigelt Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081201.231815901@linutronix.de Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 397

2019-06-05T15:37:12+00:00

Based on 1 normalized pattern(s): this program is free software you can distribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 33 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Reviewed-by: Kate Stewart Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531081038.563233189@linutronix.de Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 309

2019-06-05T15:37:04+00:00

Based on 2 normalized pattern(s): it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 11 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000434.249870634@linutronix.de Signed-off-by: Greg Kroah-Hartman