Unverified Commit b75a22e7 authored by Samuel Holland's avatar Samuel Holland Committed by Palmer Dabbelt
Browse files

riscv: cpufeature: Do not drop Linux-internal extensions 



The Linux-internal Xlinuxenvcfg ISA extension is omitted from the
riscv_isa_ext array because it has no DT binding and should not appear
in /proc/cpuinfo. The logic added in commit 625034ab ("riscv: add
ISA extensions validation callback") assumes all extensions are included
in riscv_isa_ext, and so riscv_resolve_isa() wrongly drops Xlinuxenvcfg
from the final ISA string. Instead, accept such Linux-internal ISA
extensions as if they have no validation callback.

Fixes: 625034ab ("riscv: add ISA extensions validation callback")
Signed-off-by: default avatarSamuel Holland <samuel.holland@sifive.com>
Reviewed-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240718213011.2600150-1-samuel.holland@sifive.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 8400291e

arch/riscv/kernel/cpufeature.c

+6 −8
Original line number Diff line number Diff line
@@ -432,28 +432,26 @@ static void __init riscv_resolve_isa(unsigned long *source_isa, 
		bitmap_copy(prev_resolved_isa, resolved_isa, RISCV_ISA_EXT_MAX);

		for_each_set_bit(bit, source_isa, RISCV_ISA_EXT_MAX) {

			ext = riscv_get_isa_ext_data(bit);

			if (!ext)

				continue;



			if (ext->validate) {

			if (ext && ext->validate) {

				ret = ext->validate(ext, resolved_isa);

				if (ret == -EPROBE_DEFER) {

					loop = true;

					continue;

				} else if (ret) {

					/* Disable the extension entirely */

					clear_bit(ext->id, source_isa);

					clear_bit(bit, source_isa);

					continue;

				}

			}



			set_bit(ext->id, resolved_isa);

			set_bit(bit, resolved_isa);

			/* No need to keep it in source isa now that it is enabled */

			clear_bit(ext->id, source_isa);

			clear_bit(bit, source_isa);



			/* Single letter extensions get set in hwcap */

			if (ext->id < RISCV_ISA_EXT_BASE)

				*this_hwcap |= isa2hwcap[ext->id];

			if (bit < RISCV_ISA_EXT_BASE)

				*this_hwcap |= isa2hwcap[bit];

		}

	} while (loop && memcmp(prev_resolved_isa, resolved_isa, sizeof(prev_resolved_isa)));

}