diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2023-03-21 12:01:02 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2023-04-11 11:07:08 +0100 |
| commit | dae904d96ad6a5fa79bd9d99a3decf93685d398b (patch) | |
| tree | ad23ef12e2f542d51e76bb4cf489f40b69f90d91 /arch/arm/vfp | |
| parent | 197b6b60ae7bc51dd0814953c562833143b292aa (diff) | |
ARM: 9292/1: vfp: Pass thread_info pointer to vfp_support_entry
Instead of dereferencing thread_info in do_vfp, pass the thread_info
pointer to vfp_support_entry via R1. That way, we only use a single
caller save register, which makes it easier to convert do_vfp to C code
in a subsequent patch.
Note that, unlike the CPU number, which can change due to preemption,
passing the thread_info pointer can safely be done with preemption
enabled.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/vfp')
| -rw-r--r-- | arch/arm/vfp/entry.S | 5 | ||||
| -rw-r--r-- | arch/arm/vfp/vfphw.S | 10 |
2 files changed, 8 insertions, 7 deletions
diff --git a/arch/arm/vfp/entry.S b/arch/arm/vfp/entry.S index 9a89264cdcc0..cfedc2a3dbd6 100644 --- a/arch/arm/vfp/entry.S +++ b/arch/arm/vfp/entry.S @@ -22,15 +22,12 @@ @ IRQs enabled. @ ENTRY(do_vfp) - local_bh_disable r10, r4 + mov r1, r10 ldr r4, .LCvfp - ldr r11, [r10, #TI_CPU] @ CPU number - add r10, r10, #TI_VFPSTATE @ r10 = workspace ldr pc, [r4] @ call VFP entry point ENDPROC(do_vfp) ENTRY(vfp_null_entry) - local_bh_enable_ti r10, r4 ret lr ENDPROC(vfp_null_entry) diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S index 26c4f61ecfa3..6d056d810e48 100644 --- a/arch/arm/vfp/vfphw.S +++ b/arch/arm/vfp/vfphw.S @@ -6,9 +6,9 @@ * Written by Deep Blue Solutions Limited. * * This code is called from the kernel's undefined instruction trap. + * r1 holds the thread_info pointer * r9 holds the return address for successful handling. * lr holds the return address for unrecognised instructions. - * r10 points at the start of the private FP workspace in the thread structure * sp points to a struct pt_regs (as defined in include/asm/proc/ptrace.h) */ #include <linux/init.h> @@ -69,13 +69,17 @@ @ VFP hardware support entry point. @ @ r0 = instruction opcode (32-bit ARM or two 16-bit Thumb) +@ r1 = thread_info pointer @ r2 = PC value to resume execution after successful emulation @ r9 = normal "successful" return address -@ r10 = vfp_state union -@ r11 = CPU number @ lr = unrecognised instruction return address @ IRQs enabled. ENTRY(vfp_support_entry) + local_bh_disable r1, r4 + + ldr r11, [r1, #TI_CPU] @ CPU number + add r10, r1, #TI_VFPSTATE @ r10 = workspace + DBGSTR3 "instr %08x pc %08x state %p", r0, r2, r10 .fpu vfpv2 |