linux-toradex.git/arch/riscv/include/asm/vdso, branch v6.7

riscv: Using TOOLCHAIN_HAS_ZIHINTPAUSE marco replace zihintpause

2023-11-01T02:15:54+00:00

Actually it is a part of Conor's
commit aae538cd03bc ("riscv: fix detection of toolchain
Zihintpause support").
It is looks like a merge issue. Samuel's
commit 0b1d60d6dd9e ("riscv: Fix build with
CONFIG_CC_OPTIMIZE_FOR_SIZE=y") do not base on Conor's commit and
revert to __riscv_zihintpause. So this patch can fix it.

Signed-off-by: Minda Chen 
Fixes: 3c349eacc559 ("Merge patch "riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y"")
Reviewed-by: Conor Dooley 
Link: https://lore.kernel.org/r/20230802064215.31111-1-minda.chen@starfivetech.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt

RISC-V: Add hwprobe vDSO function and data

2023-04-18T22:48:18+00:00

Add a vDSO function __vdso_riscv_hwprobe, which can sit in front of the
riscv_hwprobe syscall and answer common queries. We stash a copy of
static answers for the "all CPUs" case in the vDSO data page. This data
is private to the vDSO, so we can decide later to change what's stored
there or under what conditions we defer to the syscall. Currently all
data can be discovered at boot, so the vDSO function answers all queries
when the cpumask is set to the "all CPUs" hint.

There's also a boolean in the data that lets the vDSO function know that
all CPUs are the same. In that case, the vDSO will also answer queries
for arbitrary CPU masks in addition to the "all CPUs" hint.

Signed-off-by: Evan Green 
Link: https://lore.kernel.org/r/20230407231103.2622178-7-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt

Merge patch "riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y"

2023-02-01T05:55:43+00:00

This is a single fix, but it conflicts with some recent features.  I'm
merging it on top of the commit it fixes to ease backporting.

* b4-shazam-merge:
  riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y

Link: https://lore.kernel.org/r/20220922060958.44203-1-samuel@sholland.org
Signed-off-by: Palmer Dabbelt

riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y

2023-02-01T05:55:27+00:00

commit 8eb060e10185 ("arch/riscv: add Zihintpause support") broke
building with CONFIG_CC_OPTIMIZE_FOR_SIZE enabled (gcc 11.1.0):

  CC      arch/riscv/kernel/vdso/vgettimeofday.o
In file included from :
./arch/riscv/include/asm/jump_label.h: In function 'cpu_relax':
././include/linux/compiler_types.h:285:33: warning: 'asm' operand 0 probably does not match constraints
  285 | #define asm_volatile_goto(x...) asm goto(x)
      |                                 ^~~
./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro 'asm_volatile_goto'
   41 |         asm_volatile_goto(
      |         ^~~~~~~~~~~~~~~~~
././include/linux/compiler_types.h:285:33: error: impossible constraint in 'asm'
  285 | #define asm_volatile_goto(x...) asm goto(x)
      |                                 ^~~
./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro 'asm_volatile_goto'
   41 |         asm_volatile_goto(
      |         ^~~~~~~~~~~~~~~~~
make[1]: *** [scripts/Makefile.build:249: arch/riscv/kernel/vdso/vgettimeofday.o] Error 1
make: *** [arch/riscv/Makefile:128: vdso_prepare] Error 2

Having a static branch in cpu_relax() is problematic because that
function is widely inlined, including in some quite complex functions
like in the VDSO. A quick measurement shows this static branch is
responsible by itself for around 40% of the jump table.

Drop the static branch, which ends up being the same number of
instructions anyway. If Zihintpause is supported, we trade the nop from
the static branch for a div. If Zihintpause is unsupported, we trade the
jump from the static branch for (what gets interpreted as) a nop.

Fixes: 8eb060e10185 ("arch/riscv: add Zihintpause support")
Signed-off-by: Samuel Holland 
Reviewed-by: Conor Dooley 
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt

riscv: fix detection of toolchain Zihintpause support

2022-10-27T22:13:06+00:00

It is not sufficient to check if a toolchain supports a particular
extension without checking if the linker supports that extension
too. For example, Clang 15 supports Zihintpause but GNU bintutils
2.35.2 does not, leading build errors like so:

riscv64-linux-gnu-ld: -march=rv64i2p0_m2p0_a2p0_c2p0_zihintpause2p0: Invalid or unknown z ISA extension: 'zihintpause'

Add a TOOLCHAIN_HAS_ZIHINTPAUSE which checks if each of the compiler,
assembler and linker support the extension. Replace the ifdef in the
vdso with one depending on this new symbol.

Fixes: 8eb060e10185 ("arch/riscv: add Zihintpause support")
Signed-off-by: Conor Dooley 
Reviewed-by: Heiko Stuebner 
Reviewed-by: Nathan Chancellor 
Link: https://lore.kernel.org/r/20221006173520.1785507-3-conor@kernel.org
Signed-off-by: Palmer Dabbelt

arch/riscv: add Zihintpause support

2022-08-11T15:03:49+00:00

Implement support for the ZiHintPause extension.

The PAUSE instruction is a HINT that indicates the current hart’s rate
of instruction retirement should be temporarily reduced or paused.

Reviewed-by: Heiko Stuebner 
Tested-by: Heiko Stuebner 
Signed-off-by: Dao Lu 
[Palmer: Some minor merge conflicts.]
Link: https://lore.kernel.org/all/20220620201530.3929352-1-daolu@rivosinc.com/
Link: https://lore.kernel.org/all/20220811053356.17375-1-palmer@rivosinc.com/
Signed-off-by: Palmer Dabbelt

riscv/vdso: Add support for time namespaces

2021-10-04T21:16:43+00:00

Implement generic vdso time namespace support which also enables time
namespaces for riscv. This is quite similar to what arm64 does.

selftest/timens test result:
  1..10
  ok 1 Passed for CLOCK_BOOTTIME (syscall)
  ok 2 Passed for CLOCK_BOOTTIME (vdso)
  ok 3 # SKIP CLOCK_BOOTTIME_ALARM isn't supported
  ok 4 # SKIP CLOCK_BOOTTIME_ALARM isn't supported
  ok 5 Passed for CLOCK_MONOTONIC (syscall)
  ok 6 Passed for CLOCK_MONOTONIC (vdso)
  ok 7 Passed for CLOCK_MONOTONIC_COARSE (syscall)
  ok 8 Passed for CLOCK_MONOTONIC_COARSE (vdso)
  ok 9 Passed for CLOCK_MONOTONIC_RAW (syscall)
  ok 10 Passed for CLOCK_MONOTONIC_RAW (vdso)
  # Totals: pass:8 fail:0 xfail:0 xpass:0 skip:2 error:0

Signed-off-by: Tong Tiangen 
Signed-off-by: Palmer Dabbelt

RISC-V: fix barrier() use in

2020-11-25T17:44:27+00:00

riscv's  uses barrier() so it should include


Fixes this build error:
  CC [M]  drivers/net/ethernet/emulex/benet/be_main.o
In file included from ./include/vdso/processor.h:10,
                 from ./arch/riscv/include/asm/processor.h:11,
                 from ./include/linux/prefetch.h:15,
                 from drivers/net/ethernet/emulex/benet/be_main.c:14:
./arch/riscv/include/asm/vdso/processor.h: In function 'cpu_relax':
./arch/riscv/include/asm/vdso/processor.h:14:2: error: implicit declaration of function 'barrier' [-Werror=implicit-function-declaration]
   14 |  barrier();

This happens with a total of 5 networking drivers -- they all use
.

rv64 allmodconfig now builds cleanly after this patch.

Fixes fallout from:
815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive")

Fixes: ad5d1122b82f ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Reported-by: Andreas Schwab 
Signed-off-by: Randy Dunlap 
Acked-by: Arvind Sankar 
Signed-off-by: Palmer Dabbelt 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Palmer Dabbelt

vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter()

2020-08-06T08:57:30+00:00

MIPS already uses and S390 will need the vdso data pointer in
__arch_get_hw_counter().

This works nicely as long as the architecture does not support time
namespaces in the VDSO. With time namespaces enabled the regular
accessor to the vdso data pointer __arch_get_vdso_data() will return the
namespace specific VDSO data page for tasks which are part of a
non-root time namespace. This would cause the architectures which need
the vdso data pointer in __arch_get_hw_counter() to access the wrong
vdso data page.

Add a vdso_data pointer argument to __arch_get_hw_counter() and hand it in
from the call sites in the core code. For architectures which do not need
the data pointer in their counter accessor function the compiler will just
optimize it out.

Fix up all existing architecture implementations and make MIPS utilize the
pointer instead of invoking the accessor function.

No functional change and no change in the resulting object code (except
MIPS).

Signed-off-by: Thomas Gleixner 
Link: https://lkml.kernel.org/r/draft-87wo2ekuzn.fsf@nanos.tec.linutronix.de

asm/rwonce: Don't pull into 'asm-generic/rwonce.h'

2020-07-21T09:50:36+00:00

Now that 'smp_read_barrier_depends()' has gone the way of the Norwegian
Blue, drop the inclusion of  in 'asm-generic/rwonce.h'.

This requires fixups to some architecture vdso headers which were
previously relying on 'asm/barrier.h' coming in via 'linux/compiler.h'.

Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: Will Deacon