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 #ifdef HAVE_JUMP_LABEL
  13
  14 void arch_jump_label_transform(struct jump_entry *entry,
  15                                enum jump_label_type type)
  16 {
  17         u32 *insn = (u32 *) (unsigned long) entry->code;
  18         u32 val;
  19
  20         if (type == JUMP_LABEL_JMP) {
  21                 s32 off = (s32)entry->target - (s32)entry->code;
  22                 bool use_v9_branch = false;
  23
  24                 BUG_ON(off & 3);
  25
  26 #ifdef CONFIG_SPARC64
  27                 if (off <= 0xfffff && off >= -0x100000)
  28                         use_v9_branch = true;
  29 #endif
  30                 if (use_v9_branch) {
  31                         /* WDISP19 - target is . + immed << 2 */
  32                         /* ba,pt %xcc, . + off */
  33                         val = 0x10680000 | (((u32) off >> 2) & 0x7ffff);
  34                 } else {
  35                         /* WDISP22 - target is . + immed << 2 */
  36                         BUG_ON(off > 0x7fffff);
  37                         BUG_ON(off < -0x800000);
  38                         /* ba . + off */
  39                         val = 0x10800000 | (((u32) off >> 2) & 0x3fffff);
  40                 }
  41         } else {
  42                 val = 0x01000000;
  43         }
  44
  45         mutex_lock(&text_mutex);
  46         *insn = val;
  47         flushi(insn);
  48         mutex_unlock(&text_mutex);
  49 }
  50
  51 #endif