diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2023-03-16 00:51:42 +0100 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2023-05-17 15:08:14 +0200 |
| commit | 4708fb041346fa9cc6745dafb8c248a3e2f1075b (patch) | |
| tree | f80f1ea6a8b1084b4e1943a33d4d992f7a2839e2 /arch/arm/vfp/entry.S | |
| parent | 4a0548c6681cd25b8d76e897e01bfb62ce93916d (diff) | |
ARM: vfp: Reimplement VFP exception entry in C code
En/disabling softirqs from asm code turned out to be trickier than
expected, so vfp_support_entry now returns by tail calling
__local_enable_bh_ip() and passing the same arguments that a C call to
local_bh_enable() would pass. However, this is slightly hacky, as we
don't want to carry our own implementation of local_bh_enable().
So let's bite the bullet, and get rid of the asm logic in
vfp_support_entry that reasons about whether or not to save and/or
reload the VFP state, and about whether or not an FP exception is
pending, and only keep the VFP loading logic as a function that is
callable from C.
Replicate the removed logic in vfp_entry(), and use the exact same
reasoning as in the asm code. To emphasize the correspondence, retain
some of the asm comments in the C version as well.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'arch/arm/vfp/entry.S')
| -rw-r--r-- | arch/arm/vfp/entry.S | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/arm/vfp/entry.S b/arch/arm/vfp/entry.S index 62206ef25037..547c94c62cd3 100644 --- a/arch/arm/vfp/entry.S +++ b/arch/arm/vfp/entry.S @@ -22,10 +22,10 @@ @ IRQs enabled. @ ENTRY(do_vfp) - mov r1, r10 - str lr, [sp, #-8]! - add r3, sp, #4 - str r9, [r3] - bl vfp_entry - ldr pc, [sp], #8 + mov r1, r0 @ pass trigger opcode via R1 + mov r0, sp @ pass struct pt_regs via R0 + bl vfp_support_entry @ dispatch the VFP exception + cmp r0, #0 @ handled successfully? + reteq r9 @ then use R9 as return address + ret lr @ pass to undef handler ENDPROC(do_vfp) |