include/asm-parisc/system.h

   1 #ifndef __PARISC_SYSTEM_H
   2 #define __PARISC_SYSTEM_H
   3
   4 #include <linux/config.h>
   5 #include <asm/psw.h>
   6
   7 /* The program status word as bitfields.  */
   8 struct pa_psw {
   9         unsigned int y:1;
  10         unsigned int z:1;
  11         unsigned int rv:2;
  12         unsigned int w:1;
  13         unsigned int e:1;
  14         unsigned int s:1;
  15         unsigned int t:1;
  16
  17         unsigned int h:1;
  18         unsigned int l:1;
  19         unsigned int n:1;
  20         unsigned int x:1;
  21         unsigned int b:1;
  22         unsigned int c:1;
  23         unsigned int v:1;
  24         unsigned int m:1;
  25
  26         unsigned int cb:8;
  27
  28         unsigned int o:1;
  29         unsigned int g:1;
  30         unsigned int f:1;
  31         unsigned int r:1;
  32         unsigned int q:1;
  33         unsigned int p:1;
  34         unsigned int d:1;
  35         unsigned int i:1;
  36 };
  37
  38 #ifdef __LP64__
  39 #define pa_psw(task) ((struct pa_psw *) ((char *) (task) + TASK_PT_PSW + 4))
  40 #else
  41 #define pa_psw(task) ((struct pa_psw *) ((char *) (task) + TASK_PT_PSW))
  42 #endif
  43
  44 struct task_struct;
  45
  46 extern struct task_struct *_switch_to(struct task_struct *, struct task_struct *);
  47
  48 #define switch_to(prev, next, last) do {                        \
  49         (last) = _switch_to(prev, next);                        \
  50 } while(0)
  51
  52
  53
  54 /* interrupt control */
  55 #define local_save_flags(x)     __asm__ __volatile__("ssm 0, %0" : "=r" (x) : : "memory")
  56 #define local_irq_disable()     __asm__ __volatile__("rsm %0,%%r0\n" : : "i" (PSW_I) : "memory" )
  57 #define local_irq_enable()      __asm__ __volatile__("ssm %0,%%r0\n" : : "i" (PSW_I) : "memory" )
  58
  59 #define local_irq_save(x) \
  60         __asm__ __volatile__("rsm %1,%0" : "=r" (x) :"i" (PSW_I) : "memory" )
  61 #define local_irq_restore(x) \
  62         __asm__ __volatile__("mtsm %0" : : "r" (x) : "memory" )
  63
  64 #define irqs_disabled()                 \
  65 ({                                      \
  66         unsigned long flags;            \
  67         local_save_flags(flags);        \
  68         (flags & PSW_I) == 0;           \
  69 })
  70
  71 #define mfctl(reg)      ({              \
  72         unsigned long cr;               \
  73         __asm__ __volatile__(           \
  74                 "mfctl " #reg ",%0" :   \
  75                  "=r" (cr)              \
  76         );                              \
  77         cr;                             \
  78 })
  79
  80 #define mtctl(gr, cr) \
  81         __asm__ __volatile__("mtctl %0,%1" \
  82                 : /* no outputs */ \
  83                 : "r" (gr), "i" (cr) : "memory")
  84
  85 /* these are here to de-mystefy the calling code, and to provide hooks */
  86 /* which I needed for debugging EIEM problems -PB */
  87 #define get_eiem() mfctl(15)
  88 static inline void set_eiem(unsigned long val)
  89 {
  90         mtctl(val, 15);
  91 }
  92
  93 #define mfsp(reg)       ({              \
  94         unsigned long cr;               \
  95         __asm__ __volatile__(           \
  96                 "mfsp " #reg ",%0" :    \
  97                  "=r" (cr)              \
  98         );                              \
  99         cr;                             \
 100 })
 101
 102 #define mtsp(gr, cr) \
 103         __asm__ __volatile__("mtsp %0,%1" \
 104                 : /* no outputs */ \
 105                 : "r" (gr), "i" (cr) : "memory")
 106
 107
 108 /*
 109 ** This is simply the barrier() macro from linux/kernel.h but when serial.c
 110 ** uses tqueue.h uses smp_mb() defined using barrier(), linux/kernel.h
 111 ** hasn't yet been included yet so it fails, thus repeating the macro here.
 112 **
 113 ** PA-RISC architecture allows for weakly ordered memory accesses although
 114 ** none of the processors use it. There is a strong ordered bit that is
 115 ** set in the O-bit of the page directory entry. Operating systems that
 116 ** can not tolerate out of order accesses should set this bit when mapping
 117 ** pages. The O-bit of the PSW should also be set to 1 (I don't believe any
 118 ** of the processor implemented the PSW O-bit). The PCX-W ERS states that
 119 ** the TLB O-bit is not implemented so the page directory does not need to
 120 ** have the O-bit set when mapping pages (section 3.1). This section also
 121 ** states that the PSW Y, Z, G, and O bits are not implemented.
 122 ** So it looks like nothing needs to be done for parisc-linux (yet).
 123 ** (thanks to chada for the above comment -ggg)
 124 **
 125 ** The __asm__ op below simple prevents gcc/ld from reordering
 126 ** instructions across the mb() "call".
 127 */
 128 #define mb()            __asm__ __volatile__("":::"memory")     /* barrier() */
 129 #define rmb()           mb()
 130 #define wmb()           mb()
 131 #define smp_mb()        mb()
 132 #define smp_rmb()       mb()
 133 #define smp_wmb()       mb()
 134 #define smp_read_barrier_depends()      do { } while(0)
 135 #define read_barrier_depends()          do { } while(0)
 136
 137 #define set_mb(var, value)              do { var = value; mb(); } while (0)
 138 #define set_wmb(var, value)             do { var = value; wmb(); } while (0)
 139
 140
 141 #ifndef CONFIG_PA20
 142 /* Because kmalloc only guarantees 8-byte alignment for kmalloc'd data,
 143    and GCC only guarantees 8-byte alignment for stack locals, we can't
 144    be assured of 16-byte alignment for atomic lock data even if we
 145    specify "__attribute ((aligned(16)))" in the type declaration.  So,
 146    we use a struct containing an array of four ints for the atomic lock
 147    type and dynamically select the 16-byte aligned int from the array
 148    for the semaphore.  */
 149
 150 #define __PA_LDCW_ALIGNMENT 16
 151 #define __ldcw_align(a) ({ \
 152   unsigned long __ret = (unsigned long) &(a)->lock[0];                  \
 153   __ret = (__ret + __PA_LDCW_ALIGNMENT - 1) & ~(__PA_LDCW_ALIGNMENT - 1); \
 154   (volatile unsigned int *) __ret;                                      \
 155 })
 156 #define LDCW    "ldcw"
 157
 158 #else /*CONFIG_PA20*/
 159 /* From: "Jim Hull" <jim.hull of hp.com>
 160    I've attached a summary of the change, but basically, for PA 2.0, as
 161    long as the ",CO" (coherent operation) completer is specified, then the
 162    16-byte alignment requirement for ldcw and ldcd is relaxed, and instead
 163    they only require "natural" alignment (4-byte for ldcw, 8-byte for
 164    ldcd). */
 165
 166 #define __PA_LDCW_ALIGNMENT 4
 167 #define __ldcw_align(a) ((volatile unsigned int *)a)
 168 #define LDCW    "ldcw,co"
 169
 170 #endif /*!CONFIG_PA20*/
 171
 172 /* LDCW, the only atomic read-write operation PA-RISC has. *sigh*.  */
 173 #define __ldcw(a) ({ \
 174         unsigned __ret; \
 175         __asm__ __volatile__(LDCW " 0(%1),%0" : "=r" (__ret) : "r" (a)); \
 176         __ret; \
 177 })
 178
 179 #ifdef CONFIG_SMP
 180 # define __lock_aligned __attribute__((__section__(".data.lock_aligned")))
 181 #endif
 182
 183 #define KERNEL_START (0x10100000 - 0x1000)
 184 #define arch_align_stack(x) (x)
 185
 186 #endif