diff options
Diffstat (limited to 'arch/arm64/include/asm/assembler.h')
| -rw-r--r-- | arch/arm64/include/asm/assembler.h | 28 |
1 files changed, 10 insertions, 18 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 039fbd822ec6..e3a15c751b13 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -1,20 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * Based on arch/arm/include/asm/assembler.h, arch/arm/mm/proc-macros.S * * Copyright (C) 1996-2000 Russell King * Copyright (C) 2012 ARM Ltd. - * - * 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/>. */ #ifndef __ASSEMBLY__ #error "Only include this from assembly code" @@ -107,7 +96,11 @@ * RAS Error Synchronization barrier */ .macro esb +#ifdef CONFIG_ARM64_RAS_EXTN hint #16 +#else + nop +#endif .endm /* @@ -718,12 +711,11 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU * the output section, any use of such directives is undefined. * * The yield itself consists of the following: - * - Check whether the preempt count is exactly 1, in which case disabling - * preemption once will make the task preemptible. If this is not the case, - * yielding is pointless. - * - Check whether TIF_NEED_RESCHED is set, and if so, disable and re-enable - * kernel mode NEON (which will trigger a reschedule), and branch to the - * yield fixup code. + * - Check whether the preempt count is exactly 1 and a reschedule is also + * needed. If so, calling of preempt_enable() in kernel_neon_end() will + * trigger a reschedule. If it is not the case, yielding is pointless. + * - Disable and re-enable kernel mode NEON, and branch to the yield fixup + * code. * * This macro sequence may clobber all CPU state that is not guaranteed by the * AAPCS to be preserved across an ordinary function call. |