Thread (44 messages) flat view 44 messages, 10 authors, 2018-09-06

Re: [PATCH v2 01/17] asm: simd context helper API

From: Palmer Dabbelt <hidden>
Date: 2018-08-27 19:50:39
Also in: linux-arch, lkml

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 <redacted>
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
...
quoted hunk ↗ jump to hunk
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.
quoted hunk ↗ jump to hunk
@@ -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 <redacted>

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 :)
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