riscv: hwprobe: simplify has_fpu() to check D extension only

The kernel never supports D without F, since D depends on F. The
D-extension flag is cleared during devicetree/ACPI parsing whenever
F is not present, so has_fpu() checking either extension with '||'
never actually produces a different result than checking D alone -
F without D cannot occur in practice, and there is no observable
impact on RISCV_HWPROBE_IMA_FD or userspace.

Simplify has_fpu() to check D only, matching the expectations set
elsewhere in the kernel for this dependency, rather than relying on
a redundant OR condition.

sys_hwprobe.c already calls has_fpu() and needs no changes.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=221874
Suggested-by: Conor Dooley <conor.dooley@microchip.com>
Suggested-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Ivy Lopez <skunkolee@gmail.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20260901013746.19386-1-skunkolee@gmail.com
[pjw@kernel.org: updated to apply]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
This commit is contained in:
Ivy Lopez 2026-08-31 19:37:46 -06:00 committed by Paul Walmsley
parent f643f520c4
commit 93a27367ba

View File

@ -61,8 +61,8 @@ static inline void __switch_to_fpu(struct task_struct *prev,
static __always_inline bool has_fpu(void)
{
return riscv_has_extension_likely(RISCV_ISA_EXT_F) ||
riscv_has_extension_likely(RISCV_ISA_EXT_D);
/* D extension depends on F, so checking D alone is sufficient. */
return riscv_has_extension_likely(RISCV_ISA_EXT_D);
}
#else
static __always_inline bool has_fpu(void) { return false; }