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* [PATCH v2 0/2] riscv: Optimize bitops with Zbb extension
@ 2023-09-20  7:46 Xiao Wang
  2023-09-20  7:46 ` [PATCH v2 1/2] riscv: Rearrange hwcap.h and cpufeature.h Xiao Wang
  2023-09-20  7:46 ` [PATCH v2 2/2] riscv: Optimize bitops with Zbb extension Xiao Wang
  0 siblings, 2 replies; 6+ messages in thread
From: Xiao Wang @ 2023-09-20  7:46 UTC (permalink / raw)
  To: paul.walmsley, palmer, aou, ardb
  Cc: anup, haicheng.li, ajones, linux-riscv, linux-efi, linux-kernel,
	Xiao Wang

Bitops optimization with specialized instructions is common practice in
popular ISAs, this patch set uses RISC-V Zbb extension to optimize four
bitops: __ffs, __fls, ffs and fls.

The first patch rearranges the content in hwcap.h cpufeature.h, it helps
to avoid a cyclic header including issue for patch 2.

The second patch leverages the alternative mechanism to dynamically apply
this optimization.

The series has following dependency:
https://lore.kernel.org/linux-riscv/20230918131518.56803-8-ajones@ventanamicro.com/

Thanks,
Xiao

v2:
- Remove the "EFI_" prefix from macro name "EFI_NO_ALTERNATIVE" to make it
  generic. (Ard)
- patch-1 is added, it's based on "RISC-V: Enable cbo.zero in usermode". (Andrew)

Xiao Wang (2):
  riscv: Rearrange hwcap.h and cpufeature.h
  riscv: Optimize bitops with Zbb extension

 arch/riscv/include/asm/bitops.h       | 266 +++++++++++++++++++++++++-
 arch/riscv/include/asm/cpufeature.h   |  83 ++++++++
 arch/riscv/include/asm/hwcap.h        |  91 ---------
 arch/riscv/include/asm/pgtable.h      |   1 +
 arch/riscv/include/asm/switch_to.h    |   2 +-
 arch/riscv/include/asm/vector.h       |   2 +-
 drivers/firmware/efi/libstub/Makefile |   2 +-
 7 files changed, 350 insertions(+), 97 deletions(-)

-- 
2.25.1


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^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2023-09-26  8:40 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-09-20  7:46 [PATCH v2 0/2] riscv: Optimize bitops with Zbb extension Xiao Wang
2023-09-20  7:46 ` [PATCH v2 1/2] riscv: Rearrange hwcap.h and cpufeature.h Xiao Wang
2023-09-20  8:29   ` Andrew Jones
2023-09-26  6:18   ` kernel test robot
2023-09-26  8:39     ` Wang, Xiao W
2023-09-20  7:46 ` [PATCH v2 2/2] riscv: Optimize bitops with Zbb extension Xiao Wang

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