linux.git/arch/riscv/kernel, branch v5.4.158

drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()

2021-09-26T12:07:10+00:00

[ Upstream commit 4b92d4add5f6dcf21275185c997d6ecb800054cd ]

DEFINE_SMP_CALL_CACHE_FUNCTION() was usefel before the CPU hotplug rework
to ensure that the cache related functions are called on the upcoming CPU
because the notifier itself could run on any online CPU.

The hotplug state machine guarantees that the callbacks are invoked on the
upcoming CPU. So there is no need to have this SMP function call
obfuscation. That indirection was missed when the hotplug notifiers were
converted.

This also solves the problem of ARM64 init_cache_level() invoking ACPI
functions which take a semaphore in that context. That's invalid as SMP
function calls run with interrupts disabled. Running it just from the
callback in context of the CPU hotplug thread solves this.

Fixes: 8571890e1513 ("arm64: Add support for ACPI based firmware tables")
Reported-by: Guenter Roeck 
Signed-off-by: Thomas Gleixner 
Tested-by: Guenter Roeck 
Acked-by: Will Deacon 
Acked-by: Peter Zijlstra 
Link: https://lore.kernel.org/r/871r69ersb.ffs@tglx
Signed-off-by: Sasha Levin

riscv: Workaround mcount name prior to clang-13

2021-05-22T09:38:29+00:00

[ Upstream commit 7ce04771503074a7de7f539cc43f5e1b385cb99b ]

Prior to clang 13.0.0, the RISC-V name for the mcount symbol was
"mcount", which differs from the GCC version of "_mcount", which results
in the following errors:

riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_level':
main.c:(.text+0xe): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_start':
main.c:(.text+0x4e): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_finish':
main.c:(.text+0x92): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `.LBB32_28':
main.c:(.text+0x30c): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `free_initmem':
main.c:(.text+0x54c): undefined reference to `mcount'

This has been corrected in https://reviews.llvm.org/D98881 but the
minimum supported clang version is 10.0.1. To avoid build errors and to
gain a working function tracer, adjust the name of the mcount symbol for
older versions of clang in mount.S and recordmcount.pl.

Link: https://github.com/ClangBuiltLinux/linux/issues/1331
Signed-off-by: Nathan Chancellor 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

RISC-V: Fix error code returned by riscv_hartid_to_cpuid()

2021-05-19T08:08:26+00:00

[ Upstream commit 533b4f3a789d49574e7ae0f6ececed153f651f97 ]

We should return a negative error code upon failure in
riscv_hartid_to_cpuid() instead of NR_CPUS. This is also
aligned with all uses of riscv_hartid_to_cpuid() which
expect negative error code upon failure.

Fixes: 6825c7a80f18 ("RISC-V: Add logical CPU indexing for RISC-V")
Fixes: f99fb607fb2b ("RISC-V: Use Linux logical CPU number instead of hartid")
Signed-off-by: Anup Patel 
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

riscv,entry: fix misaligned base for excp_vect_table

2021-04-16T09:46:38+00:00

[ Upstream commit ac8d0b901f0033b783156ab2dc1a0e73ec42409b ]

In RV64, the size of each entry in excp_vect_table is 8 bytes. If the
base of the table is not 8-byte aligned, loading an entry in the table
will raise a misaligned exception. Although such exception will be
handled by opensbi/bbl, this still causes performance degradation.

Signed-off-by: Zihao Yu 
Reviewed-by: Anup Patel 
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

riscv: Fix kernel time_init()

2021-01-27T10:47:43+00:00

[ Upstream commit 11f4c2e940e2f317c9d8fb5a79702f2a4a02ff98 ]

If of_clk_init() is not called in time_init(), clock providers defined
in the system device tree are not initialized, resulting in failures for
other devices to initialize due to missing clocks.
Similarly to other architectures and to the default kernel time_init()
implementation, call of_clk_init() before executing timer_probe() in
time_init().

Signed-off-by: Damien Le Moal 
Acked-by: Stephen Boyd 
Reviewed-by: Palmer Dabbelt 
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

riscv: Set text_offset correctly for M-Mode

2020-11-18T18:20:25+00:00

[ Upstream commit 79605f1394261995c2b955c906a5a20fb27cdc84 ]

M-Mode Linux is loaded at the start of RAM, not 2MB later. Perhaps this
should be calculated based on PAGE_OFFSET somehow? Even better would be to
deprecate text_offset and instead introduce something absolute.

Signed-off-by: Sean Anderson 
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

RISC-V: Take text_mutex in ftrace_init_nop()

2020-10-01T11:18:14+00:00

[ Upstream commit 66d18dbda8469a944dfec6c49d26d5946efba218 ]

Without this we get lockdep failures.  They're spurious failures as SMP isn't
up when ftrace_init_nop() is called.  As far as I can tell the easiest fix is
to just take the lock, which also seems like the safest fix.

Signed-off-by: Palmer Dabbelt 
Acked-by: Guo Ren 
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

RISC-V: Don't allow write+exec only page mapping request in mmap

2020-06-30T19:37:06+00:00

[ Upstream commit e0d17c842c0f824fd4df9f4688709fc6907201e1 ]

As per the table 4.4 of version "20190608-Priv-MSU-Ratified" of the
RISC-V instruction set manual[0], the PTE permission bit combination of
"write+exec only" is reserved for future use. Hence, don't allow such
mapping request in mmap call.

An issue is been reported by David Abdurachmanov, that while running
stress-ng with "sysbadaddr" argument, RCU stalls are observed on RISC-V
specific kernel.

This issue arises when the stress-sysbadaddr request for pages with
"write+exec only" permission bits and then passes the address obtain
from this mmap call to various system call. For the riscv kernel, the
mmap call should fail for this particular combination of permission bits
since it's not valid.

[0]: http://dabbelt.com/~palmer/keep/riscv-isa-manual/riscv-privileged-20190608-1.pdf

Signed-off-by: Yash Shah 
Reported-by: David Abdurachmanov 
[Palmer: Refer to the latest ISA specification at the only link I could
find, and update the terminology.]
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

riscv: stacktrace: Fix undefined reference to `walk_stackframe'

2020-06-03T06:21:13+00:00

[ Upstream commit 0502bee37cdef755d63eee60236562e5605e2480 ]

Drop static declaration to fix following build error if FRAME_POINTER disabled,
  riscv64-linux-ld: arch/riscv/kernel/perf_callchain.o: in function `.L0':
  perf_callchain.c:(.text+0x2b8): undefined reference to `walk_stackframe'

Reported-by: Hulk Robot 
Signed-off-by: Kefeng Wang 
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

riscv: fix vdso build with lld

2020-05-20T06:20:13+00:00

[ Upstream commit 3c1918c8f54166598195d938564072664a8275b1 ]

When building with the LLVM linker this error occurrs:
    LD      arch/riscv/kernel/vdso/vdso-syms.o
  ld.lld: error: no input files

This happens because the lld treats -R as an alias to -rpath, as opposed
to ld where -R means --just-symbols.

Use the long option name for compatibility between the two.

Link: https://github.com/ClangBuiltLinux/linux/issues/805
Reported-by: Dmitry Golovin 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Ilie Halip 
Reviewed-by: Fangrui Song 
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin