arch/arm64/include/asm/daifflags.h

   1 /*
   2  * Copyright (C) 2017 ARM Ltd.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16 #ifndef __ASM_DAIFFLAGS_H
  17 #define __ASM_DAIFFLAGS_H
  18
  19 #include <linux/irqflags.h>
  20
  21 #define DAIF_PROCCTX            0
  22 #define DAIF_PROCCTX_NOIRQ      PSR_I_BIT
  23
  24 /* mask/save/unmask/restore all exceptions, including interrupts. */
  25 static inline void local_daif_mask(void)
  26 {
  27         asm volatile(
  28                 "msr    daifset, #0xf           // local_daif_mask\n"
  29                 :
  30                 :
  31                 : "memory");
  32         trace_hardirqs_off();
  33 }
  34
  35 static inline unsigned long local_daif_save(void)
  36 {
  37         unsigned long flags;
  38
  39         asm volatile(
  40                 "mrs    %0, daif                // local_daif_save\n"
  41                 : "=r" (flags)
  42                 :
  43                 : "memory");
  44         local_daif_mask();
  45
  46         return flags;
  47 }
  48
  49 static inline void local_daif_unmask(void)
  50 {
  51         trace_hardirqs_on();
  52         asm volatile(
  53                 "msr    daifclr, #0xf           // local_daif_unmask"
  54                 :
  55                 :
  56                 : "memory");
  57 }
  58
  59 static inline void local_daif_restore(unsigned long flags)
  60 {
  61         if (!arch_irqs_disabled_flags(flags))
  62                 trace_hardirqs_on();
  63         asm volatile(
  64                 "msr    daif, %0                // local_daif_restore"
  65                 :
  66                 : "r" (flags)
  67                 : "memory");
  68         if (arch_irqs_disabled_flags(flags))
  69                 trace_hardirqs_off();
  70 }
  71
  72 #endif