include/asm-parisc/system.h

   1 #ifndef __PARISC_SYSTEM_H
   2 #define __PARISC_SYSTEM_H
   3
   4 #include <asm/psw.h>
   5
   6 /* The program status word as bitfields.  */
   7 struct pa_psw {
   8         unsigned int y:1;
   9         unsigned int z:1;
  10         unsigned int rv:2;
  11         unsigned int w:1;
  12         unsigned int e:1;
  13         unsigned int s:1;
  14         unsigned int t:1;
  15
  16         unsigned int h:1;
  17         unsigned int l:1;
  18         unsigned int n:1;
  19         unsigned int x:1;
  20         unsigned int b:1;
  21         unsigned int c:1;
  22         unsigned int v:1;
  23         unsigned int m:1;
  24
  25         unsigned int cb:8;
  26
  27         unsigned int o:1;
  28         unsigned int g:1;
  29         unsigned int f:1;
  30         unsigned int r:1;
  31         unsigned int q:1;
  32         unsigned int p:1;
  33         unsigned int d:1;
  34         unsigned int i:1;
  35 };
  36
  37 #ifdef CONFIG_64BIT
  38 #define pa_psw(task) ((struct pa_psw *) ((char *) (task) + TASK_PT_PSW + 4))
  39 #else
  40 #define pa_psw(task) ((struct pa_psw *) ((char *) (task) + TASK_PT_PSW))
  41 #endif
  42
  43 struct task_struct;
  44
  45 extern struct task_struct *_switch_to(struct task_struct *, struct task_struct *);
  46
  47 #define switch_to(prev, next, last) do {                        \
  48         (last) = _switch_to(prev, next);                        \
  49 } while(0)
  50
  51 /*
  52  * On SMP systems, when the scheduler does migration-cost autodetection,
  53  * it needs a way to flush as much of the CPU's caches as possible.
  54  *
  55  * TODO: fill this in!
  56  */
  57 static inline void sched_cacheflush(void)
  58 {
  59 }
  60
  61
  62 /* interrupt control */
  63 #define local_save_flags(x)     __asm__ __volatile__("ssm 0, %0" : "=r" (x) : : "memory")
  64 #define local_irq_disable()     __asm__ __volatile__("rsm %0,%%r0\n" : : "i" (PSW_I) : "memory" )
  65 #define local_irq_enable()      __asm__ __volatile__("ssm %0,%%r0\n" : : "i" (PSW_I) : "memory" )
  66
  67 #define local_irq_save(x) \
  68         __asm__ __volatile__("rsm %1,%0" : "=r" (x) :"i" (PSW_I) : "memory" )
  69 #define local_irq_restore(x) \
  70         __asm__ __volatile__("mtsm %0" : : "r" (x) : "memory" )
  71
  72 #define irqs_disabled()                 \
  73 ({                                      \
  74         unsigned long flags;            \
  75         local_save_flags(flags);        \
  76         (flags & PSW_I) == 0;           \
  77 })
  78
  79 #define mfctl(reg)      ({              \
  80         unsigned long cr;               \
  81         __asm__ __volatile__(           \
  82                 "mfctl " #reg ",%0" :   \
  83                  "=r" (cr)              \
  84         );                              \
  85         cr;                             \
  86 })
  87
  88 #define mtctl(gr, cr) \
  89         __asm__ __volatile__("mtctl %0,%1" \
  90                 : /* no outputs */ \
  91                 : "r" (gr), "i" (cr) : "memory")
  92
  93 /* these are here to de-mystefy the calling code, and to provide hooks */
  94 /* which I needed for debugging EIEM problems -PB */
  95 #define get_eiem() mfctl(15)
  96 static inline void set_eiem(unsigned long val)
  97 {
  98         mtctl(val, 15);
  99 }
 100
 101 #define mfsp(reg)       ({              \
 102         unsigned long cr;               \
 103         __asm__ __volatile__(           \
 104                 "mfsp " #reg ",%0" :    \
 105                  "=r" (cr)              \
 106         );                              \
 107         cr;                             \
 108 })
 109
 110 #define mtsp(gr, cr) \
 111         __asm__ __volatile__("mtsp %0,%1" \
 112                 : /* no outputs */ \
 113                 : "r" (gr), "i" (cr) : "memory")
 114
 115
 116 /*
 117 ** This is simply the barrier() macro from linux/kernel.h but when serial.c
 118 ** uses tqueue.h uses smp_mb() defined using barrier(), linux/kernel.h
 119 ** hasn't yet been included yet so it fails, thus repeating the macro here.
 120 **
 121 ** PA-RISC architecture allows for weakly ordered memory accesses although
 122 ** none of the processors use it. There is a strong ordered bit that is
 123 ** set in the O-bit of the page directory entry. Operating systems that
 124 ** can not tolerate out of order accesses should set this bit when mapping
 125 ** pages. The O-bit of the PSW should also be set to 1 (I don't believe any
 126 ** of the processor implemented the PSW O-bit). The PCX-W ERS states that
 127 ** the TLB O-bit is not implemented so the page directory does not need to
 128 ** have the O-bit set when mapping pages (section 3.1). This section also
 129 ** states that the PSW Y, Z, G, and O bits are not implemented.
 130 ** So it looks like nothing needs to be done for parisc-linux (yet).
 131 ** (thanks to chada for the above comment -ggg)
 132 **
 133 ** The __asm__ op below simple prevents gcc/ld from reordering
 134 ** instructions across the mb() "call".
 135 */
 136 #define mb()            __asm__ __volatile__("":::"memory")     /* barrier() */
 137 #define rmb()           mb()
 138 #define wmb()           mb()
 139 #define smp_mb()        mb()
 140 #define smp_rmb()       mb()
 141 #define smp_wmb()       mb()
 142 #define smp_read_barrier_depends()      do { } while(0)
 143 #define read_barrier_depends()          do { } while(0)
 144
 145 #define set_mb(var, value)              do { var = value; mb(); } while (0)
 146
 147 #ifndef CONFIG_PA20
 148 /* Because kmalloc only guarantees 8-byte alignment for kmalloc'd data,
 149    and GCC only guarantees 8-byte alignment for stack locals, we can't
 150    be assured of 16-byte alignment for atomic lock data even if we
 151    specify "__attribute ((aligned(16)))" in the type declaration.  So,
 152    we use a struct containing an array of four ints for the atomic lock
 153    type and dynamically select the 16-byte aligned int from the array
 154    for the semaphore.  */
 155
 156 #define __PA_LDCW_ALIGNMENT     16
 157 #define __ldcw_align(a) ({                                      \
 158         unsigned long __ret = (unsigned long) &(a)->lock[0];    \
 159         __ret = (__ret + __PA_LDCW_ALIGNMENT - 1)               \
 160                 & ~(__PA_LDCW_ALIGNMENT - 1);                   \
 161         (volatile unsigned int *) __ret;                        \
 162 })
 163 #define __LDCW  "ldcw"
 164
 165 #else /*CONFIG_PA20*/
 166 /* From: "Jim Hull" <jim.hull of hp.com>
 167    I've attached a summary of the change, but basically, for PA 2.0, as
 168    long as the ",CO" (coherent operation) completer is specified, then the
 169    16-byte alignment requirement for ldcw and ldcd is relaxed, and instead
 170    they only require "natural" alignment (4-byte for ldcw, 8-byte for
 171    ldcd). */
 172
 173 #define __PA_LDCW_ALIGNMENT     4
 174 #define __ldcw_align(a) ((volatile unsigned int *)a)
 175 #define __LDCW  "ldcw,co"
 176
 177 #endif /*!CONFIG_PA20*/
 178
 179 /* LDCW, the only atomic read-write operation PA-RISC has. *sigh*.  */
 180 #define __ldcw(a) ({                                            \
 181         unsigned __ret;                                         \
 182         __asm__ __volatile__(__LDCW " 0(%1),%0"                 \
 183                 : "=r" (__ret) : "r" (a));                      \
 184         __ret;                                                  \
 185 })
 186
 187 #ifdef CONFIG_SMP
 188 # define __lock_aligned __attribute__((__section__(".data.lock_aligned")))
 189 #endif
 190
 191 #define KERNEL_START (0x10100000 - 0x1000)
 192 #define arch_align_stack(x) (x)
 193
 194 #endif