linux-toradex.git/arch/mips/kernel/cpu-probe.c, branch v5.11-rc5

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: cpu-probe: move fpu probing/handling into its own file

2020-10-12T10:04:50+00:00

cpu-probe.c has grown when supporting more and more CPUs and there
are use cases where probing for all the CPUs isn't useful like
running on a R3k system. But still the fpu handling is nearly
the same. For sharing put the fpu code into it's own file.

Signed-off-by: Thomas Bogendoerfer

MIPS: cpu-probe: ingenic: Fix broken BUG_ON

2020-09-18T14:27:32+00:00

The previous code was doing:
BUG_ON(!__builtin_constant_p(cpu_has_counter) || cpu_has_counter);

This only worked as the "cpu_has_counter" macro was overridden in
. The default "cpu_has_counter" macro is
non-constant, which triggered the BUG_ON() independently of the value
returned by the macro.

What we want to check here, is that *if* the macro was overridden to a
compile-time constant, then must be defined to zero, otherwise it's a
bug.

So the correct check is:
BUG_ON(__builtin_constant_p(cpu_has_counter) && cpu_has_counter);

Signed-off-by: Paul Cercueil 
Signed-off-by: Thomas Bogendoerfer

MIPS: cpu-probe: Mark XBurst CPU as having vtagged caches

2020-09-18T14:27:00+00:00

XBurst CPUs present in Ingenic SoCs have virtually tagged caches,
according to the  header.

Add that information to cpu_probe_ingenic().

Signed-off-by: Paul Cercueil 
Signed-off-by: Thomas Bogendoerfer

MIPS: cpu-probe: Set Ingenic's writecombine to _CACHE_CACHABLE_WA

2020-09-18T14:26:36+00:00

Previously, in cpu_probe_ingenic(), c->writecombine was set to
_CACHE_UNCACHED_ACCELERATED, but this macro was defined differently when
CONFIG_MACH_INGENIC was set. This made it impossible to support multiple
CPUs.

Address this issue by setting c->writecombine to _CACHE_CACHABLE_WA
directly and removing the dependency on CONFIG_MACH_INGENIC.

Signed-off-by: Paul Cercueil 
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

MIPS: X2000: Add X2000 system type.

2020-07-24T09:13:57+00:00

1.Add "PRID_COMP_INGENIC_13" and "PRID_IMP_XBURST2" for X2000.
2.Add X2000 system type for cat /proc/cpuinfo to give out X2000.

Signed-off-by: 周琰杰 (Zhou Yanjie) 
Signed-off-by: Thomas Bogendoerfer

MIPS: Unify naming style of vendor CP0.Config6 bits

2020-07-08T09:15:53+00:00

Other vendor-defined registers use the vendor name as a prefix, not an
infix, so unify the naming style of CP0.Config6 bits.

Suggested-by: Maciej W. Rozycki" 
Signed-off-by: Huacai Chen 
Reviewed-by: Maciej W. Rozycki 
Signed-off-by: Thomas Bogendoerfer

KVM: MIPS: Enable KVM support for Loongson-3

2020-06-04T17:51:53+00:00

This patch enable KVM support for Loongson-3 by selecting HAVE_KVM, but
only enable KVM/VZ on Loongson-3A R4+ (because VZ of early processors
are incomplete). Besides, Loongson-3 support SMP guests, so we clear the
linked load bit of LLAddr in kvm_vz_vcpu_load() if the guest has more
than one VCPUs.

Acked-by: Thomas Bogendoerfer 
Reviewed-by: Aleksandar Markovic 
Signed-off-by: Huacai Chen 
Co-developed-by: Jiaxun Yang 
Message-Id: <1590220602-3547-15-git-send-email-chenhc@lemote.com>
Signed-off-by: Paolo Bonzini