arch/parisc/include/asm/system.h

   1 #ifndef __PARISC_SYSTEM_H
   2 #define __PARISC_SYSTEM_H
   3
   4 #include <linux/irqflags.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 #define mfctl(reg)      ({              \
  52         unsigned long cr;               \
  53         __asm__ __volatile__(           \
  54                 "mfctl " #reg ",%0" :   \
  55                  "=r" (cr)              \
  56         );                              \
  57         cr;                             \
  58 })
  59
  60 #define mtctl(gr, cr) \
  61         __asm__ __volatile__("mtctl %0,%1" \
  62                 : /* no outputs */ \
  63                 : "r" (gr), "i" (cr) : "memory")
  64
  65 /* these are here to de-mystefy the calling code, and to provide hooks */
  66 /* which I needed for debugging EIEM problems -PB */
  67 #define get_eiem() mfctl(15)
  68 static inline void set_eiem(unsigned long val)
  69 {
  70         mtctl(val, 15);
  71 }
  72
  73 #define mfsp(reg)       ({              \
  74         unsigned long cr;               \
  75         __asm__ __volatile__(           \
  76                 "mfsp " #reg ",%0" :    \
  77                  "=r" (cr)              \
  78         );                              \
  79         cr;                             \
  80 })
  81
  82 #define mtsp(gr, cr) \
  83         __asm__ __volatile__("mtsp %0,%1" \
  84                 : /* no outputs */ \
  85                 : "r" (gr), "i" (cr) : "memory")
  86
  87
  88 /*
  89 ** This is simply the barrier() macro from linux/kernel.h but when serial.c
  90 ** uses tqueue.h uses smp_mb() defined using barrier(), linux/kernel.h
  91 ** hasn't yet been included yet so it fails, thus repeating the macro here.
  92 **
  93 ** PA-RISC architecture allows for weakly ordered memory accesses although
  94 ** none of the processors use it. There is a strong ordered bit that is
  95 ** set in the O-bit of the page directory entry. Operating systems that
  96 ** can not tolerate out of order accesses should set this bit when mapping
  97 ** pages. The O-bit of the PSW should also be set to 1 (I don't believe any
  98 ** of the processor implemented the PSW O-bit). The PCX-W ERS states that
  99 ** the TLB O-bit is not implemented so the page directory does not need to
 100 ** have the O-bit set when mapping pages (section 3.1). This section also
 101 ** states that the PSW Y, Z, G, and O bits are not implemented.
 102 ** So it looks like nothing needs to be done for parisc-linux (yet).
 103 ** (thanks to chada for the above comment -ggg)
 104 **
 105 ** The __asm__ op below simple prevents gcc/ld from reordering
 106 ** instructions across the mb() "call".
 107 */
 108 #define mb()            __asm__ __volatile__("":::"memory")     /* barrier() */
 109 #define rmb()           mb()
 110 #define wmb()           mb()
 111 #define smp_mb()        mb()
 112 #define smp_rmb()       mb()
 113 #define smp_wmb()       mb()
 114 #define smp_read_barrier_depends()      do { } while(0)
 115 #define read_barrier_depends()          do { } while(0)
 116
 117 #define set_mb(var, value)              do { var = value; mb(); } while (0)
 118
 119 #ifndef CONFIG_PA20
 120 /* Because kmalloc only guarantees 8-byte alignment for kmalloc'd data,
 121    and GCC only guarantees 8-byte alignment for stack locals, we can't
 122    be assured of 16-byte alignment for atomic lock data even if we
 123    specify "__attribute ((aligned(16)))" in the type declaration.  So,
 124    we use a struct containing an array of four ints for the atomic lock
 125    type and dynamically select the 16-byte aligned int from the array
 126    for the semaphore.  */
 127
 128 #define __PA_LDCW_ALIGNMENT     16
 129 #define __ldcw_align(a) ({                                      \
 130         unsigned long __ret = (unsigned long) &(a)->lock[0];    \
 131         __ret = (__ret + __PA_LDCW_ALIGNMENT - 1)               \
 132                 & ~(__PA_LDCW_ALIGNMENT - 1);                   \
 133         (volatile unsigned int *) __ret;                        \
 134 })
 135 #define __LDCW  "ldcw"
 136
 137 #else /*CONFIG_PA20*/
 138 /* From: "Jim Hull" <jim.hull of hp.com>
 139    I've attached a summary of the change, but basically, for PA 2.0, as
 140    long as the ",CO" (coherent operation) completer is specified, then the
 141    16-byte alignment requirement for ldcw and ldcd is relaxed, and instead
 142    they only require "natural" alignment (4-byte for ldcw, 8-byte for
 143    ldcd). */
 144
 145 #define __PA_LDCW_ALIGNMENT     4
 146 #define __ldcw_align(a) (&(a)->slock)
 147 #define __LDCW  "ldcw,co"
 148
 149 #endif /*!CONFIG_PA20*/
 150
 151 /* LDCW, the only atomic read-write operation PA-RISC has. *sigh*.  */
 152 #define __ldcw(a) ({                                            \
 153         unsigned __ret;                                         \
 154         __asm__ __volatile__(__LDCW " 0(%2),%0"                 \
 155                 : "=r" (__ret), "+m" (*(a)) : "r" (a));         \
 156         __ret;                                                  \
 157 })
 158
 159 #ifdef CONFIG_SMP
 160 # define __lock_aligned __attribute__((__section__(".data..lock_aligned")))
 161 #endif
 162
 163 #define arch_align_stack(x) (x)
 164
 165 #endif