arch/arm/include/asm/arch_timer.h

   1 #ifndef __ASMARM_ARCH_TIMER_H
   2 #define __ASMARM_ARCH_TIMER_H
   3
   4 #include <asm/barrier.h>
   5 #include <asm/errno.h>
   6 #include <linux/clocksource.h>
   7 #include <linux/init.h>
   8 #include <linux/types.h>
   9
  10 #include <clocksource/arm_arch_timer.h>
  11
  12 #ifdef CONFIG_ARM_ARCH_TIMER
  13 int arch_timer_arch_init(void);
  14
  15 /*
  16  * These register accessors are marked inline so the compiler can
  17  * nicely work out which register we want, and chuck away the rest of
  18  * the code. At least it does so with a recent GCC (4.6.3).
  19  */
  20 static __always_inline
  21 void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u32 val)
  22 {
  23         if (access == ARCH_TIMER_PHYS_ACCESS) {
  24                 switch (reg) {
  25                 case ARCH_TIMER_REG_CTRL:
  26                         asm volatile("mcr p15, 0, %0, c14, c2, 1" : : "r" (val));
  27                         break;
  28                 case ARCH_TIMER_REG_TVAL:
  29                         asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val));
  30                         break;
  31                 }
  32         } else if (access == ARCH_TIMER_VIRT_ACCESS) {
  33                 switch (reg) {
  34                 case ARCH_TIMER_REG_CTRL:
  35                         asm volatile("mcr p15, 0, %0, c14, c3, 1" : : "r" (val));
  36                         break;
  37                 case ARCH_TIMER_REG_TVAL:
  38                         asm volatile("mcr p15, 0, %0, c14, c3, 0" : : "r" (val));
  39                         break;
  40                 }
  41         }
  42
  43         isb();
  44 }
  45
  46 static __always_inline
  47 u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg)
  48 {
  49         u32 val = 0;
  50
  51         if (access == ARCH_TIMER_PHYS_ACCESS) {
  52                 switch (reg) {
  53                 case ARCH_TIMER_REG_CTRL:
  54                         asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
  55                         break;
  56                 case ARCH_TIMER_REG_TVAL:
  57                         asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val));
  58                         break;
  59                 }
  60         } else if (access == ARCH_TIMER_VIRT_ACCESS) {
  61                 switch (reg) {
  62                 case ARCH_TIMER_REG_CTRL:
  63                         asm volatile("mrc p15, 0, %0, c14, c3, 1" : "=r" (val));
  64                         break;
  65                 case ARCH_TIMER_REG_TVAL:
  66                         asm volatile("mrc p15, 0, %0, c14, c3, 0" : "=r" (val));
  67                         break;
  68                 }
  69         }
  70
  71         return val;
  72 }
  73
  74 static inline u32 arch_timer_get_cntfrq(void)
  75 {
  76         u32 val;
  77         asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val));
  78         return val;
  79 }
  80
  81 static inline u64 arch_counter_get_cntvct(void)
  82 {
  83         u64 cval;
  84
  85         isb();
  86         asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (cval));
  87         return cval;
  88 }
  89
  90 static inline void arch_counter_set_user_access(void)
  91 {
  92         u32 cntkctl;
  93
  94         asm volatile("mrc p15, 0, %0, c14, c1, 0" : "=r" (cntkctl));
  95
  96         /* disable user access to everything */
  97         cntkctl &= ~((3 << 8) | (7 << 0));
  98
  99         asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl));
 100 }
 101 #endif
 102
 103 #endif