This series returns to my earlier suggestion to make x86 not support kernel-mode FPU when hardirqs are disabled, aligning it with arm64 (https://lore.kernel.org/r/20250220051325.340691-2-ebiggers@xxxxxxxxxx). To make this possible despite the use of the kernel-mode FPU functions by __save_processor_state() (which I mentioned at https://lore.kernel.org/r/20250228035924.GC5588@sol.localdomain), I've changed __save_processor_state() to use a new function instead of (mis)using the kernel-mode FPU functions. This slightly reduces the overhead of kernel-mode FPU (since the result is fewer checks), and it fixes the issue reported at https://lore.kernel.org/r/20250516112217.GBaCcf6Yoc6LkIIryP@fat_crate.local/ where irq_fpu_usable() incorrectly returned false during CPU initialization, causing a crash in the SHA-256 library code. Eric Biggers (3): x86/fpu: Add fpu_save_state() for __save_processor_state() x86/pm: Use fpu_save_state() in __save_processor_state() x86/fpu: Don't support kernel-mode FPU when irqs_disabled() arch/x86/include/asm/fpu/api.h | 1 + arch/x86/kernel/fpu/core.c | 92 ++++++++++++++++++++-------------- arch/x86/power/cpu.c | 18 +++---- 3 files changed, 62 insertions(+), 49 deletions(-) base-commit: 8566fc3b96539e3235909d6bdda198e1282beaed -- 2.49.0
