kernel-fxtec-pro1x/arch/arm64/include/asm/fpsimdmacros.h
Will Deacon 5959e25729 arm64: fpsimd: avoid restoring fpcr if the contents haven't changed
Writing to the FPCR is commonly implemented as a self-synchronising
operation in the CPU, so avoid writing to the register when the saved
value matches that in the hardware already.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-18 10:21:17 +01:00

112 lines
3.1 KiB
C

/*
* FP/SIMD state saving and restoring macros
*
* Copyright (C) 2012 ARM Ltd.
* Author: Catalin Marinas <catalin.marinas@arm.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/>.
*/
.macro fpsimd_save state, tmpnr
stp q0, q1, [\state, #16 * 0]
stp q2, q3, [\state, #16 * 2]
stp q4, q5, [\state, #16 * 4]
stp q6, q7, [\state, #16 * 6]
stp q8, q9, [\state, #16 * 8]
stp q10, q11, [\state, #16 * 10]
stp q12, q13, [\state, #16 * 12]
stp q14, q15, [\state, #16 * 14]
stp q16, q17, [\state, #16 * 16]
stp q18, q19, [\state, #16 * 18]
stp q20, q21, [\state, #16 * 20]
stp q22, q23, [\state, #16 * 22]
stp q24, q25, [\state, #16 * 24]
stp q26, q27, [\state, #16 * 26]
stp q28, q29, [\state, #16 * 28]
stp q30, q31, [\state, #16 * 30]!
mrs x\tmpnr, fpsr
str w\tmpnr, [\state, #16 * 2]
mrs x\tmpnr, fpcr
str w\tmpnr, [\state, #16 * 2 + 4]
.endm
.macro fpsimd_restore_fpcr state, tmp
/*
* Writes to fpcr may be self-synchronising, so avoid restoring
* the register if it hasn't changed.
*/
mrs \tmp, fpcr
cmp \tmp, \state
b.eq 9999f
msr fpcr, \state
9999:
.endm
/* Clobbers \state */
.macro fpsimd_restore state, tmpnr
ldp q0, q1, [\state, #16 * 0]
ldp q2, q3, [\state, #16 * 2]
ldp q4, q5, [\state, #16 * 4]
ldp q6, q7, [\state, #16 * 6]
ldp q8, q9, [\state, #16 * 8]
ldp q10, q11, [\state, #16 * 10]
ldp q12, q13, [\state, #16 * 12]
ldp q14, q15, [\state, #16 * 14]
ldp q16, q17, [\state, #16 * 16]
ldp q18, q19, [\state, #16 * 18]
ldp q20, q21, [\state, #16 * 20]
ldp q22, q23, [\state, #16 * 22]
ldp q24, q25, [\state, #16 * 24]
ldp q26, q27, [\state, #16 * 26]
ldp q28, q29, [\state, #16 * 28]
ldp q30, q31, [\state, #16 * 30]!
ldr w\tmpnr, [\state, #16 * 2]
msr fpsr, x\tmpnr
ldr w\tmpnr, [\state, #16 * 2 + 4]
fpsimd_restore_fpcr x\tmpnr, \state
.endm
.altmacro
.macro fpsimd_save_partial state, numnr, tmpnr1, tmpnr2
mrs x\tmpnr1, fpsr
str w\numnr, [\state, #8]
mrs x\tmpnr2, fpcr
stp w\tmpnr1, w\tmpnr2, [\state]
adr x\tmpnr1, 0f
add \state, \state, x\numnr, lsl #4
sub x\tmpnr1, x\tmpnr1, x\numnr, lsl #1
br x\tmpnr1
.irp qa, 30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0
.irp qb, %(qa + 1)
stp q\qa, q\qb, [\state, # -16 * \qa - 16]
.endr
.endr
0:
.endm
.macro fpsimd_restore_partial state, tmpnr1, tmpnr2
ldp w\tmpnr1, w\tmpnr2, [\state]
msr fpsr, x\tmpnr1
fpsimd_restore_fpcr x\tmpnr2, x\tmpnr1
adr x\tmpnr1, 0f
ldr w\tmpnr2, [\state, #8]
add \state, \state, x\tmpnr2, lsl #4
sub x\tmpnr1, x\tmpnr1, x\tmpnr2, lsl #1
br x\tmpnr1
.irp qa, 30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0
.irp qb, %(qa + 1)
ldp q\qa, q\qb, [\state, # -16 * \qa - 16]
.endr
.endr
0:
.endm