kernel/arch/mips/include/asm/hazards.h, branch linux-rolling-stable

mips: Replace ASSEMBLY with ASSEMBLER in the mips headers

2025-08-29T20:34:29Z

While the GCC and Clang compilers already define __ASSEMBLER__ automatically when compiling assembler code, __ASSEMBLY__ is a macro that only gets defined by the Makefiles in the kernel. Defining such a macro was necessary in the early days of the kernel, since GCC only started providing __ASSEMBLER__ since version 3.0 in 2000 (see https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=f8f769ea4e69 ). However, having two macros can be very confusing nowadays for the developers when switching between userspace and kernelspace coding, or when dealing with uapi headers that should use __ASSEMBLER__ instead. So let's now standardize on the __ASSEMBLER__ macro that is provided by the compilers. This is almost a completely mechanical patch (done with a simple "sed -i" statement), with just one comment tweaked manually in arch/mips/include/asm/cpu.h (that was missing some underscores). Cc: Thomas Bogendoerfer Cc: linux-mips@vger.kernel.org Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Maciej W. Rozycki Signed-off-by: Thomas Huth Signed-off-by: Thomas Bogendoerfer

MIPS: Remove NETLOGIC support

2021-10-24T15:24:47Z

No (active) developer owns this hardware, so let's remove Linux support. Signed-off-by: Thomas Bogendoerfer

mips: Add MIPS Release 5 support

2020-05-22T07:09:01Z

There are five MIPS32/64 architecture releases currently available: from 1 to 6 except fourth one, which was intentionally skipped. Three of them can be called as major: 1st, 2nd and 6th, that not only have some system level alterations, but also introduced significant core/ISA level updates. The rest of the MIPS architecture releases are minor. Even though they don't have as much ISA/system/core level changes as the major ones with respect to the previous releases, they still provide a set of updates (I'd say they were intended to be the intermediate releases before a major one) that might be useful for the kernel and user-level code, when activated by the kernel or compiler. In particular the following features were introduced or ended up being available at/after MIPS32/64 Release 5 architecture: + the last release of the misaligned memory access instructions, + virtualisation - VZ ASE - is optional component of the arch, + SIMD - MSA ASE - is optional component of the arch, + DSP ASE is optional component of the arch, + CP0.Status.FR=1 for CP1.FIR.F64=1 (pure 64-bit FPU general registers) must be available if FPU is implemented, + CP1.FIR.Has2008 support is required so CP1.FCSR.{ABS2008,NAN2008} bits are available. + UFR/UNFR aliases to access CP0.Status.FR from user-space by means of ctc1/cfc1 instructions (enabled by CP0.Config5.UFR), + CP0.COnfig5.LLB=1 and eretnc instruction are implemented to without accidentally clearing LL-bit when returning from an interrupt, exception, or error trap, + XPA feature together with extended versions of CPx registers is introduced, which needs to have mfhc0/mthc0 instructions available. So due to these changes GNU GCC provides an extended instructions set support for MIPS32/64 Release 5 by default like eretnc/mfhc0/mthc0. Even though the architecture alteration isn't that big, it still worth to be taken into account by the kernel software. Finally we can't deny that some optimization/limitations might be found in future and implemented on some level in kernel or compiler. In this case having even intermediate MIPS architecture releases support would be more than useful. So the most of the changes provided by this commit can be split into either compile- or runtime configs related. The compile-time related changes are caused by adding the new CONFIG_CPU_MIPS32_R5/CONFIG_CPU_MIPSR5 configs and concern the code activating MIPSR2 or MIPSR6 already implemented features (like eretnc/LLbit, mthc0/mfhc0). In addition CPU_HAS_MSA can be now freely enabled for MIPS32/64 release 5 based platforms as this is done for CPU_MIPS32_R6 CPUs. The runtime changes concerns the features which are handled with respect to the MIPS ISA revision detected at run-time by means of CP0.Config.{AT,AR} bits. Alas these fields can be used to detect either r1 or r2 or r6 releases. But since we know which CPUs in fact support the R5 arch, we can manually set MIPS_CPU_ISA_M32R5/MIPS_CPU_ISA_M64R5 bit of c->isa_level and then use cpu_has_mips32r5/cpu_has_mips64r5 where it's appropriate. Since XPA/EVA provide too complex alterationss and to have them used with MIPS32 Release 2 charged kernels (for compatibility with current platform configs) they are left to be setup as a separate kernel configs. Co-developed-by: Alexey Malahov Signed-off-by: Alexey Malahov Signed-off-by: Serge Semin Cc: Thomas Bogendoerfer Cc: Paul Burton Cc: Ralf Baechle Cc: Arnd Bergmann Cc: Rob Herring Cc: devicetree@vger.kernel.org Signed-off-by: Thomas Bogendoerfer

MIPS: Loongson64: Bump ISA level to MIPSR2

2020-01-23T18:26:48Z

Despite early sample of Loongson-3A1000, the whole Loongson64 family have implemented all the features required by MIPS64 Release2. Thus we decide to bump the ISA option to R2. Signed-off-by: Jiaxun Yang 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: Loongson: Unify LOONGSON3/LOONGSON64 Kconfig usage

2019-11-11T18:43:54Z

There are mixed LOONGSON3/LOONGSON64 usages in recently changes, let's establish some rules: 1, In Kconfig symbols, we only use CPU_LOONGSON64, MACH_LOONGSON64 and SYS_HAS_CPU_LOONGSON64, all other derived symbols use "LOONGSON3" since they all not widely-used symbols and sometimes not suitable for all 64-bit Loongson processors. E.g., we use symbols LOONGSON3_ENHANCEMENT, CPU_LOONGSON3_WORKAROUNDS, etc. 2, Hide GSx64/GSx64E in Kconfig title since it is not useful for general users. However, in the full description we use a more detailed manner. E.g., GS264/GS464/GS464E/GS464V. All Kconfig titles and descriptions of Loongson processors and machines have also been updated in this patch for consistency. Signed-off-by: Huacai Chen Signed-off-by: Paul Burton Cc: Ralf Baechle Cc: James Hogan Cc: Paul Burton Cc: linux-mips@linux-mips.org Cc: linux-mips@vger.kernel.org Cc: Fuxin Zhang Cc: Zhangjin Wu Cc: Huacai Chen

MIPS: Loongson64: Rename CPU TYPES

2019-10-31T22:03:10Z

CPU_LOONGSON2 -> CPU_LOONGSON2EF CPU_LOONGSON3 -> CPU_LOONGSON64 As newer loongson-2 products (2G/2H/2K1000) can share kernel implementation with loongson-3 while 2E/2F are less similar with other LOONGSON64 products. Signed-off-by: Jiaxun Yang Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: chenhc@lemote.com Cc: paul.burton@mips.com

MIPS: Avoid using .set mips0 to restore ISA

2018-11-09T18:23:19Z

We currently have 2 commonly used methods for switching ISA within assembly code, then restoring the original ISA. 1) Using a pair of .set push & .set pop directives. For example: .set push .set mips32r2 .set pop 2) Using .set mips0 to restore the ISA originally specified on the command line. For example: .set mips32r2 .set mips0 Unfortunately method 2 does not work with nanoMIPS toolchains, where the assembler rejects the .set mips0 directive like so: Error: cannot change ISA from nanoMIPS to mips0 In preparation for supporting nanoMIPS builds, switch all instances of method 2 in generic non-platform-specific code to use push & pop as in method 1 instead. The .set push & .set pop is arguably cleaner anyway, and if nothing else it's good to consistently use one method. Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/21037/ Cc: linux-mips@linux-mips.org

MIPS: hazards.h: Fix typo

2016-05-28T10:35:06Z

Signed-off-by: Andrea Gelmini Cc: chenhc@lemote.com Cc: james.hogan@imgtec.com Cc: linux-mips@linux-mips.org Cc: trivial@kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13317/ Signed-off-by: Ralf Baechle

MIPS: Loongson-3: Introduce CONFIG_LOONGSON3_ENHANCEMENT

2016-05-13T12:02:15Z

New Loongson 3 CPU (since Loongson-3A R2, as opposed to Loongson-3A R1, Loongson-3B R1 and Loongson-3B R2) has many enhancements, such as FTLB, L1-VCache, EI/DI/Wait/Prefetch instruction, DSP/DSPv2 ASE, User Local register, Read-Inhibit/Execute-Inhibit, SFB (Store Fill Buffer), Fast TLB refill support, etc. This patch introduce a config option, CONFIG_LOONGSON3_ENHANCEMENT, to enable those enhancements which are not probed at run time. If you want a generic kernel to run on all Loongson 3 machines, please say 'N' here. If you want a high-performance kernel to run on new Loongson 3 machines only, please say 'Y' here. Some additional explanations: 1) SFB locates between core and L1 cache, it causes memory access out of order, so writel/outl (and other similar functions) need a I/O reorder barrier. 2) Loongson 3 has a bug that di instruction can not save the irqflag, so arch_local_irq_save() is modified. Since CPU_MIPSR2 is selected by CONFIG_LOONGSON3_ENHANCEMENT, generic kernel doesn't use ei/di at all. 3) CPU_HAS_PREFETCH is selected by CONFIG_LOONGSON3_ENHANCEMENT, so MIPS_CPU_PREFETCH (used by uasm) probing is also put in this patch. Signed-off-by: Huacai Chen Cc: Aurelien Jarno Cc: Steven J . Hill Cc: Fuxin Zhang Cc: Zhangjin Wu Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12755/ Signed-off-by: Ralf Baechle

MIPS: hazards: Add hazard macros for tlb read

2015-06-21T19:52:28Z

Add hazard macros to for the following hazards around tlbr (TLB read) instructions, which are used in TLB dumping code and some KVM TLB management code: - mtc0_tlbr_hazard Between mtc0 (Index) and tlbr. This is copied from mtc0_tlbw_hazard in all cases on the assumption that tlbr always has similar data user timings to tlbw. - tlb_read_hazard Between tlbr and mfc0 (various TLB registers). This is copied from tlbw_use_hazard in all cases on the assumption that tlbr has similar data writer characteristics to tlbw, and mfc0 has similar data user characteristics to loads and stores. Signed-off-by: James Hogan Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10078/ Signed-off-by: Ralf Baechle