arch/sparc/kernel/jump_label.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/kernel.h>
   3 #include <linux/types.h>
   4 #include <linux/mutex.h>
   5 #include <linux/cpu.h>
   6
   7 #include <linux/jump_label.h>
   8 #include <linux/memory.h>
   9
  10 #include <asm/cacheflush.h>
  11
  12 void arch_jump_label_transform(struct jump_entry *entry,
  13                                enum jump_label_type type)
  14 {
  15         u32 *insn = (u32 *) (unsigned long) entry->code;
  16         u32 val;
  17
  18         if (type == JUMP_LABEL_JMP) {
  19                 s32 off = (s32)entry->target - (s32)entry->code;
  20                 bool use_v9_branch = false;
  21
  22                 BUG_ON(off & 3);
  23
  24 #ifdef CONFIG_SPARC64
  25                 if (off <= 0xfffff && off >= -0x100000)
  26                         use_v9_branch = true;
  27 #endif
  28                 if (use_v9_branch) {
  29                         /* WDISP19 - target is . + immed << 2 */
  30                         /* ba,pt %xcc, . + off */
  31                         val = 0x10680000 | (((u32) off >> 2) & 0x7ffff);
  32                 } else {
  33                         /* WDISP22 - target is . + immed << 2 */
  34                         BUG_ON(off > 0x7fffff);
  35                         BUG_ON(off < -0x800000);
  36                         /* ba . + off */
  37                         val = 0x10800000 | (((u32) off >> 2) & 0x3fffff);
  38                 }
  39         } else {
  40                 val = 0x01000000;
  41         }
  42
  43         mutex_lock(&text_mutex);
  44         *insn = val;
  45         flushi(insn);
  46         mutex_unlock(&text_mutex);
  47 }