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