arch/arm/include/asm/tls.h

   1 #ifndef __ASMARM_TLS_H
   2 #define __ASMARM_TLS_H
   3
   4 #ifdef __ASSEMBLY__
   5 #include <asm/asm-offsets.h>
   6         .macro switch_tls_none, base, tp, tpuser, tmp1, tmp2
   7         .endm
   8
   9         .macro switch_tls_v6k, base, tp, tpuser, tmp1, tmp2
  10         mrc     p15, 0, \tmp2, c13, c0, 2       @ get the user r/w register
  11         mcr     p15, 0, \tp, c13, c0, 3         @ set TLS register
  12         mcr     p15, 0, \tpuser, c13, c0, 2     @ and the user r/w register
  13         str     \tmp2, [\base, #TI_TP_VALUE + 4] @ save it
  14         .endm
  15
  16         .macro switch_tls_v6, base, tp, tpuser, tmp1, tmp2
  17         ldr     \tmp1, =elf_hwcap
  18         ldr     \tmp1, [\tmp1, #0]
  19         mov     \tmp2, #0xffff0fff
  20         tst     \tmp1, #HWCAP_TLS               @ hardware TLS available?
  21         streq   \tp, [\tmp2, #-15]              @ set TLS value at 0xffff0ff0
  22         mrcne   p15, 0, \tmp2, c13, c0, 2       @ get the user r/w register
  23         mcrne   p15, 0, \tp, c13, c0, 3         @ yes, set TLS register
  24         mcrne   p15, 0, \tpuser, c13, c0, 2     @ set user r/w register
  25         strne   \tmp2, [\base, #TI_TP_VALUE + 4] @ save it
  26         .endm
  27
  28         .macro switch_tls_software, base, tp, tpuser, tmp1, tmp2
  29         mov     \tmp1, #0xffff0fff
  30         str     \tp, [\tmp1, #-15]              @ set TLS value at 0xffff0ff0
  31         .endm
  32 #endif
  33
  34 #ifdef CONFIG_TLS_REG_EMUL
  35 #define tls_emu         1
  36 #define has_tls_reg             1
  37 #define switch_tls      switch_tls_none
  38 #elif defined(CONFIG_CPU_V6)
  39 #define tls_emu         0
  40 #define has_tls_reg             (elf_hwcap & HWCAP_TLS)
  41 #define switch_tls      switch_tls_v6
  42 #elif defined(CONFIG_CPU_32v6K)
  43 #define tls_emu         0
  44 #define has_tls_reg             1
  45 #define switch_tls      switch_tls_v6k
  46 #else
  47 #define tls_emu         0
  48 #define has_tls_reg             0
  49 #define switch_tls      switch_tls_software
  50 #endif
  51
  52 #ifndef __ASSEMBLY__
  53 static inline unsigned long get_tpuser(void)
  54 {
  55         unsigned long reg = 0;
  56
  57         if (has_tls_reg && !tls_emu)
  58                 __asm__("mrc p15, 0, %0, c13, c0, 2" : "=r" (reg));
  59
  60         return reg;
  61 }
  62 #endif
  63 #endif  /* __ASMARM_TLS_H */