kernel/linux.git/arch/mips/include/asm/cpu-features.h, branch v6.12.80

MIPS: cpu-features: Use boot_cpu_type for CPU type based features

2023-06-09T07:56:22+00:00

Some CPU feature macros were using current_cpu_type to mark feature availability. However current_cpu_type will use smp_processor_id, which is prohibited under preemptable context. Since those features are all uniform on all CPUs in a SMP system, use boot_cpu_type instead of current_cpu_type to fix preemptable kernel. Cc: stable@vger.kernel.org Signed-off-by: Jiaxun Yang Signed-off-by: Thomas Bogendoerfer

MIPS: cpu-features: Enable octeon_cache by cpu_type

2023-04-05T07:45:09+00:00

cpu_has_octeon_cache was tied to 0 for generic cpu-features, whith this generic kernel built for octeon CPU won't boot. Just enable this flag by cpu_type. It won't hurt orther platforms because compiler will eliminate the code path on other processors. Signed-off-by: Jiaxun Yang Signed-off-by: Thomas Bogendoerfer

MIPS: Octeon: Opt-out 4k_cache feature

2023-04-05T07:45:09+00:00

Octeon has a different cache interface with traditional R4K one, just opt-out this flag for octeon to avoid run R4K cache initialization code accidentally. Also remove ISA level assumption for 4k cache. Signed-off-by: Jiaxun Yang Signed-off-by: Thomas Bogendoerfer

MIPS: adding a safety check for cpu_has_fpu

2022-05-04T20:26:02+00:00

There is a chance 'cpu_has_fpu' would still be overridden when the CONFIG_MIPS_FP_SUPPORT configuration option has been disabled. So add a safety check for 'cpu_has_fpu'. Suggested-by: Maciej W. Rozycki Signed-off-by: Shida Zhang Signed-off-by: Thomas Bogendoerfer

MIPS: Remove TX39XX support

2022-03-01T09:07:22+00:00

No (active) developer owns this hardware, so let's remove Linux support. Signed-off-by: Thomas Bogendoerfer Acked-by: Guenter Roeck Reviewed-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Acked-by: Atsushi Nemoto

MIPS: MT extensions are not available on MIPS32r1

2021-06-29T08:14:58+00:00

MIPS MT extensions were added with the MIPS 34K processor, which was based on the MIPS32r2 ISA. This fixes a build error when building a generic kernel for a MIPS32r1 CPU. Fixes: c434b9f80b09 ("MIPS: Kconfig: add MIPS_GENERIC_KERNEL symbol") Cc: stable@vger.kernel.org # v5.9 Signed-off-by: Paul Cercueil Signed-off-by: Thomas Bogendoerfer

MIPS: Remove cpu_has_6k_cache and cpu_has_8k_cache in cpu_cache_init()

2020-11-19T12:28:58+00:00

Since commit 02cf2119684e ("Cleanup the mess in cpu_cache_init."), cpu_has_6k_cache and cpu_has_8k_cache have no user, r6k_cache_init() and r8k_cache_init() are not defined for over 15 years, just remove them. Signed-off-by: Tiezhu Yang Signed-off-by: Thomas Bogendoerfer

MIPS: cpu-probe: remove MIPS_CPU_BP_GHIST option bit

2020-10-12T10:05:40+00:00

MIPS_CPU_BP_GHIST is only set two times and more or less immediately used in cpu-probe.c itself. Remove this option to make room in options word. Signed-off-by: Thomas Bogendoerfer

MIPS: handle Loongson-specific GSExc exception

2020-07-31T15:52:47+00:00

Newer Loongson cores (Loongson-3A R2 and newer) use the implementation-dependent ExcCode 16 to signal Loongson-specific exceptions. The extended cause is put in the non-standard CP0.Diag1 register which is CP0 Register 22 Select 1, called GSCause in Loongson manuals. Inside is an exception code bitfield called GSExcCode, only codes 0 to 6 inclusive are documented (so far, in the Loongson 3A3000 User Manual, Volume 2). During experiments, it was found that some undocumented unprivileged instructions can trigger the also-undocumented GSExcCode 8 on Loongson 3A4000. Processor state is not corrupted, but we cannot continue without further knowledge, and Loongson is not providing that information as of this writing. So we send SIGILL on seeing this exception code to thwart easy local DoS attacks. Other exception codes are made fatal, partly because of insufficient knowledge, also partly because they are not as easily reproduced. None of them are encountered in the wild with upstream kernels and userspace so far. Some older cores (Loongson-3A1000 and Loongson-3B1500) have ExcCode 16 too, but the semantic is equivalent to GSExcCode 0. Because the respective manuals did not mention the CP0.Diag1 register or its read behavior, these cores are not covered in this patch, as MFC0 from non-existent CP0 registers is UNDEFINED according to the MIPS architecture spec. Reviewed-by: Huacai Chen Signed-off-by: WANG Xuerui Cc: Huacai Chen Cc: Jiaxun Yang Cc: Tiezhu Yang Signed-off-by: Thomas Bogendoerfer

MIPS: only register FTLBPar exception handler for supported models

2020-07-31T15:52:10+00:00

Previously ExcCode 16 is unconditionally treated as the FTLB parity exception (FTLBPar), but in fact its semantic is implementation- dependent. Looking at various manuals it seems the FTLBPar exception is only present on some recent MIPS Technologies cores, so only register the handler on these. Fixes: 75b5b5e0a262790f ("MIPS: Add support for FTLBs") Reviewed-by: Huacai Chen Signed-off-by: WANG Xuerui Cc: Paul Burton Signed-off-by: Thomas Bogendoerfer