include/asm-sparc/system.h

   1 /* $Id: system.h,v 1.86 2001/10/30 04:57:10 davem Exp $ */
   2
   3 #ifndef __SPARC_SYSTEM_H
   4 #define __SPARC_SYSTEM_H
   5
   6 #include <linux/kernel.h>
   7 #include <linux/threads.h>      /* NR_CPUS */
   8 #include <linux/thread_info.h>
   9
  10 #include <asm/page.h>
  11 #include <asm/psr.h>
  12 #include <asm/ptrace.h>
  13 #include <asm/btfixup.h>
  14
  15 #ifndef __ASSEMBLY__
  16
  17 /*
  18  * Sparc (general) CPU types
  19  */
  20 enum sparc_cpu {
  21   sun4        = 0x00,
  22   sun4c       = 0x01,
  23   sun4m       = 0x02,
  24   sun4d       = 0x03,
  25   sun4e       = 0x04,
  26   sun4u       = 0x05, /* V8 ploos ploos */
  27   sun_unknown = 0x06,
  28   ap1000      = 0x07, /* almost a sun4m */
  29 };
  30
  31 /* Really, userland should not be looking at any of this... */
  32 #ifdef __KERNEL__
  33
  34 extern enum sparc_cpu sparc_cpu_model;
  35
  36 #ifndef CONFIG_SUN4
  37 #define ARCH_SUN4C_SUN4 (sparc_cpu_model==sun4c)
  38 #define ARCH_SUN4 0
  39 #else
  40 #define ARCH_SUN4C_SUN4 1
  41 #define ARCH_SUN4 1
  42 #endif
  43
  44 #define SUN4M_NCPUS            4              /* Architectural limit of sun4m. */
  45
  46 extern struct thread_info *current_set[NR_CPUS];
  47
  48 extern unsigned long empty_bad_page;
  49 extern unsigned long empty_bad_page_table;
  50 extern unsigned long empty_zero_page;
  51
  52 extern void sun_do_break(void);
  53 extern int serial_console;
  54 extern int stop_a_enabled;
  55
  56 static __inline__ int con_is_present(void)
  57 {
  58         return serial_console ? 0 : 1;
  59 }
  60
  61 /* When a context switch happens we must flush all user windows so that
  62  * the windows of the current process are flushed onto its stack. This
  63  * way the windows are all clean for the next process and the stack
  64  * frames are up to date.
  65  */
  66 extern void flush_user_windows(void);
  67 extern void kill_user_windows(void);
  68 extern void synchronize_user_stack(void);
  69 extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
  70                    void *fpqueue, unsigned long *fpqdepth);
  71
  72 #ifdef CONFIG_SMP
  73 #define SWITCH_ENTER(prv) \
  74         do {                    \
  75         if (test_tsk_thread_flag(prv, TIF_USEDFPU)) { \
  76                 put_psr(get_psr() | PSR_EF); \
  77                 fpsave(&(prv)->thread.float_regs[0], &(prv)->thread.fsr, \
  78                        &(prv)->thread.fpqueue[0], &(prv)->thread.fpqdepth); \
  79                 clear_tsk_thread_flag(prv, TIF_USEDFPU); \
  80                 (prv)->thread.kregs->psr &= ~PSR_EF; \
  81         } \
  82         } while(0)
  83
  84 #define SWITCH_DO_LAZY_FPU(next)        /* */
  85 #else
  86 #define SWITCH_ENTER(prv)               /* */
  87 #define SWITCH_DO_LAZY_FPU(nxt) \
  88         do {                    \
  89         if (last_task_used_math != (nxt))               \
  90                 (nxt)->thread.kregs->psr&=~PSR_EF;      \
  91         } while(0)
  92 #endif
  93
  94 /*
  95  * Flush windows so that the VM switch which follows
  96  * would not pull the stack from under us.
  97  *
  98  * SWITCH_ENTER and SWITH_DO_LAZY_FPU do not work yet (e.g. SMP does not work)
  99  * XXX WTF is the above comment? Found in late teen 2.4.x.
 100  */
 101 #define prepare_arch_switch(next) do { \
 102         __asm__ __volatile__( \
 103         ".globl\tflush_patch_switch\nflush_patch_switch:\n\t" \
 104         "save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \
 105         "save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \
 106         "save %sp, -0x40, %sp\n\t" \
 107         "restore; restore; restore; restore; restore; restore; restore"); \
 108 } while(0)
 109
 110         /* Much care has gone into this code, do not touch it.
 111          *
 112          * We need to loadup regs l0/l1 for the newly forked child
 113          * case because the trap return path relies on those registers
 114          * holding certain values, gcc is told that they are clobbered.
 115          * Gcc needs registers for 3 values in and 1 value out, so we
 116          * clobber every non-fixed-usage register besides l2/l3/o4/o5.  -DaveM
 117          *
 118          * Hey Dave, that do not touch sign is too much of an incentive
 119          * - Anton & Pete
 120          */
 121 #define switch_to(prev, next, last) do {                                                \
 122         SWITCH_ENTER(prev);                                                             \
 123         SWITCH_DO_LAZY_FPU(next);                                                       \
 124         cpu_set(smp_processor_id(), next->active_mm->cpu_vm_mask);                      \
 125         __asm__ __volatile__(                                                           \
 126         "sethi  %%hi(here - 0x8), %%o7\n\t"                                             \
 127         "mov    %%g6, %%g3\n\t"                                                         \
 128         "or     %%o7, %%lo(here - 0x8), %%o7\n\t"                                       \
 129         "rd     %%psr, %%g4\n\t"                                                        \
 130         "std    %%sp, [%%g6 + %4]\n\t"                                                  \
 131         "rd     %%wim, %%g5\n\t"                                                        \
 132         "wr     %%g4, 0x20, %%psr\n\t"                                                  \
 133         "nop\n\t"                                                                       \
 134         "std    %%g4, [%%g6 + %3]\n\t"                                                  \
 135         "ldd    [%2 + %3], %%g4\n\t"                                                    \
 136         "mov    %2, %%g6\n\t"                                                           \
 137         ".globl patchme_store_new_current\n"                                            \
 138 "patchme_store_new_current:\n\t"                                                        \
 139         "st     %2, [%1]\n\t"                                                           \
 140         "wr     %%g4, 0x20, %%psr\n\t"                                                  \
 141         "nop\n\t"                                                                       \
 142         "nop\n\t"                                                                       \
 143         "nop\n\t"       /* LEON needs all 3 nops: load to %sp depends on CWP. */                \
 144         "ldd    [%%g6 + %4], %%sp\n\t"                                                  \
 145         "wr     %%g5, 0x0, %%wim\n\t"                                                   \
 146         "ldd    [%%sp + 0x00], %%l0\n\t"                                                \
 147         "ldd    [%%sp + 0x38], %%i6\n\t"                                                \
 148         "wr     %%g4, 0x0, %%psr\n\t"                                                   \
 149         "nop\n\t"                                                                       \
 150         "nop\n\t"                                                                       \
 151         "jmpl   %%o7 + 0x8, %%g0\n\t"                                                   \
 152         " ld    [%%g3 + %5], %0\n\t"                                                    \
 153         "here:\n"                                                                       \
 154         : "=&r" (last)                                                                  \
 155         : "r" (&(current_set[hard_smp_processor_id()])),        \
 156           "r" (task_thread_info(next)),                         \
 157           "i" (TI_KPSR),                                        \
 158           "i" (TI_KSP),                                         \
 159           "i" (TI_TASK)                                         \
 160         :       "g1", "g2", "g3", "g4", "g5",       "g7",       \
 161           "l0", "l1",       "l3", "l4", "l5", "l6", "l7",       \
 162           "i0", "i1", "i2", "i3", "i4", "i5",                   \
 163           "o0", "o1", "o2", "o3",                   "o7");      \
 164         } while(0)
 165
 166 /*
 167  * On SMP systems, when the scheduler does migration-cost autodetection,
 168  * it needs a way to flush as much of the CPU's caches as possible.
 169  *
 170  * TODO: fill this in!
 171  */
 172 static inline void sched_cacheflush(void)
 173 {
 174 }
 175
 176 /*
 177  * Changing the IRQ level on the Sparc.
 178  */
 179 extern void local_irq_restore(unsigned long);
 180 extern unsigned long __local_irq_save(void);
 181 extern void local_irq_enable(void);
 182
 183 static inline unsigned long getipl(void)
 184 {
 185         unsigned long retval;
 186
 187         __asm__ __volatile__("rd        %%psr, %0" : "=r" (retval));
 188         return retval;
 189 }
 190
 191 #define local_save_flags(flags) ((flags) = getipl())
 192 #define local_irq_save(flags)   ((flags) = __local_irq_save())
 193 #define local_irq_disable()     ((void) __local_irq_save())
 194 #define irqs_disabled()         ((getipl() & PSR_PIL) != 0)
 195
 196 /* XXX Change this if we ever use a PSO mode kernel. */
 197 #define mb()    __asm__ __volatile__ ("" : : : "memory")
 198 #define rmb()   mb()
 199 #define wmb()   mb()
 200 #define read_barrier_depends()  do { } while(0)
 201 #define set_mb(__var, __value)  do { __var = __value; mb(); } while(0)
 202 #define smp_mb()        __asm__ __volatile__("":::"memory")
 203 #define smp_rmb()       __asm__ __volatile__("":::"memory")
 204 #define smp_wmb()       __asm__ __volatile__("":::"memory")
 205 #define smp_read_barrier_depends()      do { } while(0)
 206
 207 #define nop() __asm__ __volatile__ ("nop")
 208
 209 /* This has special calling conventions */
 210 #ifndef CONFIG_SMP
 211 BTFIXUPDEF_CALL(void, ___xchg32, void)
 212 #endif
 213
 214 static inline unsigned long xchg_u32(__volatile__ unsigned long *m, unsigned long val)
 215 {
 216 #ifdef CONFIG_SMP
 217         __asm__ __volatile__("swap [%2], %0"
 218                              : "=&r" (val)
 219                              : "0" (val), "r" (m)
 220                              : "memory");
 221         return val;
 222 #else
 223         register unsigned long *ptr asm("g1");
 224         register unsigned long ret asm("g2");
 225
 226         ptr = (unsigned long *) m;
 227         ret = val;
 228
 229         /* Note: this is magic and the nop there is
 230            really needed. */
 231         __asm__ __volatile__(
 232         "mov    %%o7, %%g4\n\t"
 233         "call   ___f____xchg32\n\t"
 234         " nop\n\t"
 235         : "=&r" (ret)
 236         : "0" (ret), "r" (ptr)
 237         : "g3", "g4", "g7", "memory", "cc");
 238
 239         return ret;
 240 #endif
 241 }
 242
 243 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 244 #define tas(ptr) (xchg((ptr),1))
 245
 246 extern void __xchg_called_with_bad_pointer(void);
 247
 248 static __inline__ unsigned long __xchg(unsigned long x, __volatile__ void * ptr, int size)
 249 {
 250         switch (size) {
 251         case 4:
 252                 return xchg_u32(ptr, x);
 253         };
 254         __xchg_called_with_bad_pointer();
 255         return x;
 256 }
 257
 258 extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn));
 259
 260 #endif /* __KERNEL__ */
 261
 262 #endif /* __ASSEMBLY__ */
 263
 264 #define arch_align_stack(x) (x)
 265
 266 #endif /* !(__SPARC_SYSTEM_H) */