tegrakernel/kernel/kernel-4.9/arch/arm/kvm/hyp/vfp.S

69 lines
1.9 KiB
ArmAsm

/*
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Author: Christoffer Dall <c.dall@virtualopensystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/linkage.h>
#include <asm/vfpmacros.h>
.text
.pushsection .hyp.text, "ax"
/* void __vfp_save_state(struct vfp_hard_struct *vfp); */
ENTRY(__vfp_save_state)
push {r4, r5}
VFPFMRX r1, FPEXC
@ Make sure *really* VFP is enabled so we can touch the registers.
orr r5, r1, #FPEXC_EN
tst r5, #FPEXC_EX @ Check for VFP Subarchitecture
bic r5, r5, #FPEXC_EX @ FPEXC_EX disable
VFPFMXR FPEXC, r5
isb
VFPFMRX r2, FPSCR
beq 1f
@ If FPEXC_EX is 0, then FPINST/FPINST2 reads are upredictable, so
@ we only need to save them if FPEXC_EX is set.
VFPFMRX r3, FPINST
tst r5, #FPEXC_FP2V
VFPFMRX r4, FPINST2, ne @ vmrsne
1:
VFPFSTMIA r0, r5 @ Save VFP registers
stm r0, {r1-r4} @ Save FPEXC, FPSCR, FPINST, FPINST2
pop {r4, r5}
bx lr
ENDPROC(__vfp_save_state)
/* void __vfp_restore_state(struct vfp_hard_struct *vfp);
* Assume FPEXC_EN is on and FPEXC_EX is off */
ENTRY(__vfp_restore_state)
VFPFLDMIA r0, r1 @ Load VFP registers
ldm r0, {r0-r3} @ Load FPEXC, FPSCR, FPINST, FPINST2
VFPFMXR FPSCR, r1
tst r0, #FPEXC_EX @ Check for VFP Subarchitecture
beq 1f
VFPFMXR FPINST, r2
tst r0, #FPEXC_FP2V
VFPFMXR FPINST2, r3, ne
1:
VFPFMXR FPEXC, r0 @ FPEXC (last, in case !EN)
bx lr
ENDPROC(__vfp_restore_state)
.popsection