Re: [PATCH 14/19] riscv: hwprobe: Disambiguate vector and xtheadvector in hwprobe

On Thu, Apr 11, 2024 at 09:11:20PM -0700, Charlie Jenkins wrote:

Ensure that hwprobe does not flag "v" when xtheadvector is present.

Signed-off-by: Charlie Jenkins charlie@rivosinc.com

arch/riscv/kernel/sys_hwprobe.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c index 8cae41a502dd..e0a42c851511 100644 --- a/arch/riscv/kernel/sys_hwprobe.c +++ b/arch/riscv/kernel/sys_hwprobe.c @@ -69,7 +69,7 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, if (riscv_isa_extension_available(NULL, c)) pair->value |= RISCV_HWPROBE_IMA_C;

• if (has_vector())

• if (has_vector() && !riscv_has_vendor_extension_unlikely(RISCV_ISA_VENDOR_EXT_XTHEADVECTOR))

Hmm, I think this is "dangerous". has_vector() is used across the kernel now in several places for the in-kernel vector. I don't think that has_vector() should return true for the T-Head stuff given that & has_vector() should represent the ratified spec. I'll have to think about this one and how nasty this makes any of the save/restore code etc.

pair->value |= RISCV_HWPROBE_IMA_V;

/* @@ -112,7 +112,7 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, EXT_KEY(ZACAS); EXT_KEY(ZICOND);

• if (has_vector()) {
  

• if (has_vector() && !riscv_has_vendor_extension_unlikely(RISCV_ISA_VENDOR_EXT_XTHEADVECTOR)) {
  EXT_KEY(ZVBB);
  EXT_KEY(ZVBC);
  EXT_KEY(ZVKB);
  
  

-- 2.44.0