lkml.org 
[lkml]   [2018]   [Aug]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v2 01/17] asm: simd context helper API
From
On Fri, 24 Aug 2018 14:38:33 PDT (-0700), Jason@zx2c4.com wrote:
> Sometimes it's useful to amortize calls to XSAVE/XRSTOR and the related
> FPU/SIMD functions over a number of calls, because FPU restoration is
> quite expensive. This adds a simple header for carrying out this pattern:
>
> simd_context_t simd_context = simd_get();
> while ((item = get_item_from_queue()) != NULL) {
> encrypt_item(item, simd_context);
> simd_context = simd_relax(simd_context);
> }
> simd_put(simd_context);
>
> The relaxation step ensures that we don't trample over preemption, and
> the get/put API should be a familiar paradigm in the kernel.
>
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Greg KH <gregkh@linuxfoundation.org>
> Cc: Samuel Neves <sneves@dei.uc.pt>
> Cc: linux-arch@vger.kernel.org
> ---
> arch/alpha/include/asm/Kbuild | 5 ++--
> arch/arc/include/asm/Kbuild | 1 +
> arch/arm/include/asm/simd.h | 42 ++++++++++++++++++++++++++++++
> arch/arm64/include/asm/simd.h | 37 +++++++++++++++++++++-----
> arch/c6x/include/asm/Kbuild | 3 ++-
> arch/h8300/include/asm/Kbuild | 3 ++-
> arch/hexagon/include/asm/Kbuild | 1 +
> arch/ia64/include/asm/Kbuild | 1 +
> arch/m68k/include/asm/Kbuild | 1 +
> arch/microblaze/include/asm/Kbuild | 1 +
> arch/mips/include/asm/Kbuild | 1 +
> arch/nds32/include/asm/Kbuild | 7 ++---
> arch/nios2/include/asm/Kbuild | 1 +
> arch/openrisc/include/asm/Kbuild | 7 ++---
> arch/parisc/include/asm/Kbuild | 1 +
> arch/powerpc/include/asm/Kbuild | 3 ++-
> arch/riscv/include/asm/Kbuild | 3 ++-
> arch/s390/include/asm/Kbuild | 3 ++-
> arch/sh/include/asm/Kbuild | 1 +
> arch/sparc/include/asm/Kbuild | 1 +
> arch/um/include/asm/Kbuild | 3 ++-
> arch/unicore32/include/asm/Kbuild | 1 +
> arch/x86/include/asm/simd.h | 30 ++++++++++++++++++++-
> arch/xtensa/include/asm/Kbuild | 1 +
> include/asm-generic/simd.h | 15 +++++++++++
> include/linux/simd.h | 28 ++++++++++++++++++++
> 26 files changed, 180 insertions(+), 21 deletions(-)
> create mode 100644 arch/arm/include/asm/simd.h
> create mode 100644 include/linux/simd.h

...

> diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
> index 576ffdca06ba..8d3e7aef3234 100644
> --- a/arch/riscv/include/asm/Kbuild
> +++ b/arch/riscv/include/asm/Kbuild
> @@ -4,9 +4,9 @@ generic-y += checksum.h
> generic-y += cputime.h
> generic-y += device.h
> generic-y += div64.h
> -generic-y += dma.h
> generic-y += dma-contiguous.h
> generic-y += dma-mapping.h
> +generic-y += dma.h
> generic-y += emergency-restart.h
> generic-y += errno.h
> generic-y += exec.h

If this is the canonical ordering and doing so makes your life easier then I'm
OK taking this as a separate patch into the RISC-V tree, but if not then feel
free to roll something like this up into your next patch set.

> @@ -45,6 +45,7 @@ generic-y += setup.h
> generic-y += shmbuf.h
> generic-y += shmparam.h
> generic-y += signal.h
> +generic-y += simd.h
> generic-y += socket.h
> generic-y += sockios.h
> generic-y += stat.h

Either way, this looks fine for as far as the RISC-V stuff goes as it's pretty
much a NOP. As long as it stays a NOP then feel free to add a

Reviewed-by: Palmer Dabbelt <palmer@sifive.com>

as far as the RISC-V parts are conceded. It looks like there's a lot of other
issues, though, so it's not much of a review :)

\
 
 \ /
  Last update: 2018-08-27 21:51    [W:0.140 / U:0.212 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site