src/include/cpu/x86/lapic.h

   1 #ifndef CPU_X86_LAPIC_H
   2 #define CPU_X86_LAPIC_H
   3
   4 #include <cpu/x86/lapic_def.h>
   5 #include <cpu/x86/msr.h>
   6 #include <arch/hlt.h>
   7
   8 /* See if I need to initialize the local apic */
   9 #if CONFIG_SMP || CONFIG_IOAPIC
  10 #  define NEED_LAPIC 1
  11 #else
  12 #  define NEED_LAPIC 0
  13 #endif
  14
  15 static inline __attribute__((always_inline)) unsigned long lapic_read(unsigned long reg)
  16 {
  17         return *((volatile unsigned long *)(LAPIC_DEFAULT_BASE+reg));
  18 }
  19
  20 static inline __attribute__((always_inline)) void lapic_write(unsigned long reg, unsigned long v)
  21 {
  22         *((volatile unsigned long *)(LAPIC_DEFAULT_BASE+reg)) = v;
  23 }
  24
  25 static inline __attribute__((always_inline)) void lapic_wait_icr_idle(void)
  26 {
  27         do { } while ( lapic_read( LAPIC_ICR ) & LAPIC_ICR_BUSY );
  28 }
  29
  30
  31
  32 static inline void enable_lapic(void)
  33 {
  34
  35         msr_t msr;
  36         msr = rdmsr(LAPIC_BASE_MSR);
  37         msr.hi &= 0xffffff00;
  38         msr.lo &= 0x000007ff;
  39         msr.lo |= LAPIC_DEFAULT_BASE | (1 << 11);
  40         wrmsr(LAPIC_BASE_MSR, msr);
  41 }
  42
  43 static inline void disable_lapic(void)
  44 {
  45         msr_t msr;
  46         msr = rdmsr(LAPIC_BASE_MSR);
  47         msr.lo &= ~(1 << 11);
  48         wrmsr(LAPIC_BASE_MSR, msr);
  49 }
  50
  51 static inline __attribute__((always_inline)) unsigned long lapicid(void)
  52 {
  53         return lapic_read(LAPIC_ID) >> 24;
  54 }
  55
  56
  57 #if CONFIG_AP_IN_SIPI_WAIT != 1
  58 /* If we need to go back to sipi wait, we use the long non-inlined version of
  59  * this function in lapic_cpu_init.c
  60  */
  61 static inline __attribute__((always_inline)) void stop_this_cpu(void)
  62 {
  63         /* Called by an AP when it is ready to halt and wait for a new task */
  64         for(;;) {
  65                 hlt();
  66         }
  67 }
  68 #else
  69 void stop_this_cpu(void);
  70 #endif
  71
  72 #if !defined(__PRE_RAM__)
  73
  74 #define xchg(ptr,v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr))))
  75
  76 struct __xchg_dummy { unsigned long a[100]; };
  77 #define __xg(x) ((struct __xchg_dummy *)(x))
  78
  79 /*
  80  * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
  81  * Note 2: xchg has side effect, so that attribute volatile is necessary,
  82  *        but generally the primitive is invalid, *ptr is output argument. --ANK
  83  */
  84 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
  85 {
  86         switch (size) {
  87                 case 1:
  88                         __asm__ __volatile__("xchgb %b0,%1"
  89                                 :"=q" (x)
  90                                 :"m" (*__xg(ptr)), "0" (x)
  91                                 :"memory");
  92                         break;
  93                 case 2:
  94                         __asm__ __volatile__("xchgw %w0,%1"
  95                                 :"=r" (x)
  96                                 :"m" (*__xg(ptr)), "0" (x)
  97                                 :"memory");
  98                         break;
  99                 case 4:
 100                         __asm__ __volatile__("xchgl %0,%1"
 101                                 :"=r" (x)
 102                                 :"m" (*__xg(ptr)), "0" (x)
 103                                 :"memory");
 104                         break;
 105         }
 106         return x;
 107 }
 108
 109 static inline void lapic_write_atomic(unsigned long reg, unsigned long v)
 110 {
 111         (void)xchg((volatile unsigned long *)(LAPIC_DEFAULT_BASE+reg), v);
 112 }
 113
 114
 115 #ifdef X86_GOOD_APIC
 116 # define FORCE_READ_AROUND_WRITE 0
 117 # define lapic_read_around(x) lapic_read(x)
 118 # define lapic_write_around(x,y) lapic_write((x),(y))
 119 #else
 120 # define FORCE_READ_AROUND_WRITE 1
 121 # define lapic_read_around(x) lapic_read(x)
 122 # define lapic_write_around(x,y) lapic_write_atomic((x),(y))
 123 #endif
 124
 125 static inline int lapic_remote_read(int apicid, int reg, unsigned long *pvalue)
 126 {
 127         int timeout;
 128         unsigned long status;
 129         int result;
 130         lapic_wait_icr_idle();
 131         lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
 132         lapic_write_around(LAPIC_ICR, LAPIC_DM_REMRD | (reg >> 4));
 133         timeout = 0;
 134         do {
 135 #if 0
 136                 udelay(100);
 137 #endif
 138                 status = lapic_read(LAPIC_ICR) & LAPIC_ICR_RR_MASK;
 139         } while (status == LAPIC_ICR_RR_INPROG && timeout++ < 1000);
 140
 141         result = -1;
 142         if (status == LAPIC_ICR_RR_VALID) {
 143                 *pvalue = lapic_read(LAPIC_RRR);
 144                 result = 0;
 145         }
 146         return result;
 147 }
 148
 149
 150 void setup_lapic(void);
 151
 152 #if CONFIG_SMP == 1
 153 struct device;
 154 int start_cpu(struct device *cpu);
 155 #endif /* CONFIG_SMP */
 156
 157 #endif /* !__PRE_RAM__ */
 158
 159 #endif /* CPU_X86_LAPIC_H */