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, prev, next, tp, tpuser, tmp1, tmp2
   7         .endm
   8
   9         .macro switch_tls_v6k, prev, next, tp, tpuser, tmp1, tmp2
  10         ldrd    \tp, \tpuser, [\next, #TI_TP_VALUE]     @ get the next TLS and user r/w register
  11         mrc     p15, 0, \tmp2, c13, c0, 2       @ get the user r/w register
  12         mcr     p15, 0, \tp, c13, c0, 3         @ set TLS register
  13         mcr     p15, 0, \tpuser, c13, c0, 2     @ and the user r/w register
  14         str     \tmp2, [\prev, #TI_TP_VALUE + 4] @ save it
  15         .endm
  16
  17         .macro switch_tls_v6, prev, next, tp, tpuser, tmp1, tmp2
  18         ldr     \tmp1, =elf_hwcap
  19         ldr     \tmp1, [\tmp1, #0]
  20         mov     \tmp2, #0xffff0fff
  21         ldr     \tp, [\next, #TI_TP_VALUE]      @ get the next TLS register
  22         tst     \tmp1, #HWCAP_TLS               @ hardware TLS available?
  23         streq   \tp, [\tmp2, #-15]              @ set TLS value at 0xffff0ff0
  24         mrcne   p15, 0, \tmp2, c13, c0, 2       @ get the previous user r/w register
  25         ldrne   \tpuser, [\next, #TI_TP_VALUE + 4]      @ get the next user r/w register
  26         mcrne   p15, 0, \tp, c13, c0, 3         @ yes, set TLS register
  27         mcrne   p15, 0, \tpuser, c13, c0, 2     @ set user r/w register
  28         strne   \tmp2, [\prev, #TI_TP_VALUE + 4] @ save it
  29         .endm
  30
  31         .macro switch_tls_software, prev, next, tp, tpuser, tmp1, tmp2
  32         mov     \tmp1, #0xffff0fff
  33         str     \tp, [\tmp1, #-15]              @ set TLS value at 0xffff0ff0
  34         .endm
  35 #endif
  36
  37 #ifdef CONFIG_TLS_REG_EMUL
  38 #define tls_emu         1
  39 #define has_tls_reg             1
  40 #define switch_tls      switch_tls_none
  41 #elif defined(CONFIG_CPU_V6)
  42 #define tls_emu         0
  43 #define has_tls_reg             (elf_hwcap & HWCAP_TLS)
  44 #define switch_tls      switch_tls_v6
  45 #elif defined(CONFIG_CPU_32v6K)
  46 #define tls_emu         0
  47 #define has_tls_reg             1
  48 #define switch_tls      switch_tls_v6k
  49 #else
  50 #define tls_emu         0
  51 #define has_tls_reg             0
  52 #define switch_tls      switch_tls_software
  53 #endif
  54
  55 #ifndef __ASSEMBLY__
  56 static inline unsigned long get_tpuser(void)
  57 {
  58         unsigned long reg = 0;
  59
  60         if (has_tls_reg && !tls_emu)
  61                 __asm__("mrc p15, 0, %0, c13, c0, 2" : "=r" (reg));
  62
  63         return reg;
  64 }
  65 #endif
  66 #endif  /* __ASMARM_TLS_H */