On Tue, 07 Aug 2018 20:24:40 PDT (-0700), alan...@andestech.com wrote:
This patchset adds an option, CONFIG_FPU, to enable/disable floating-
point procedures.
Kernel's new behavior will be as follows:
* with CONFIG_FPU=y
All FPU codes are reserved. If no FPU is found during booting, a
global flag will be set, and those functions will be bypassed with
condition check to that flag.
* with CONFIG_FPU=n
No floating-point instructions in kernel and all related settings
are excluded.
Changes in v4:
- Append a new patch to detect existence of FPU and followups.
- Add SPDX header to newly created fpu.S.
- Fix a build error, sorry for that.
- Fix wording, style, etc.
Changes in v3:
- Refactor the whole patch into independent ones.
Changes in v2:
- Various code cleanups and style fixes.
Alan Kao (5):
Extract FPU context operations from entry.S
Refactor FPU code in signal setup/return procedures
Cleanup ISA string setting
Allow to disable FPU support
Auto-detect whether a FPU exists
arch/riscv/Kconfig | 9 +++
arch/riscv/Makefile| 19 +++---
arch/riscv/include/asm/hwcap.h | 3 +
arch/riscv/include/asm/switch_to.h | 21 ++
arch/riscv/kernel/Makefile | 1 +
arch/riscv/kernel/cpufeature.c | 11 +++
arch/riscv/kernel/entry.S | 87 ---
arch/riscv/kernel/fpu.S| 106 +
arch/riscv/kernel/process.c| 4 +-
arch/riscv/kernel/signal.c | 79 +
10 files changed, 214 insertions(+), 126 deletions(-)
create mode 100644 arch/riscv/kernel/fpu.S
Aside from the CFLAGS issue this looks good. I've queued this up in
kernel.org/palmer/linux.git/next-nofpu, but I'm not going to put this on
for-next until after the merge window closes.
Thanks!
