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 v8: - Fix a build fail introduced in v7. Changes in v7: - Remove "fd" attribute from KBUILD_CFLAGS. Changes in v6 (PATCH 0005 only): - Make the flag checking neater. Changes in v5: - Invert the polarity of checking flag from no_fpu to has_fpu. 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/switch_to.h | 12 ++++- arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/cpufeature.c | 8 +++ arch/riscv/kernel/entry.S | 87 ------------------------------ arch/riscv/kernel/fpu.S | 106 +++++++++++++++++++++++++++++++++++++ arch/riscv/kernel/process.c | 6 ++- arch/riscv/kernel/signal.c | 75 ++++++++++++++++---------- 9 files changed, 196 insertions(+), 127 deletions(-) create mode 100644 arch/riscv/kernel/fpu.S -- 2.7.4
