1 #ifndef __SPARC64_SYSTEM_H
2 #define __SPARC64_SYSTEM_H
3
4 #include <asm/ptrace.h>
5 #include <asm/processor.h>
6 #include <asm/visasm.h>
7
8 #ifndef __ASSEMBLY__
9
10 #include <linux/irqflags.h>
11 #include <asm-generic/cmpxchg-local.h>
12
13 /*
14 * Sparc (general) CPU types
15 */
16 enum sparc_cpu {
17 sun4 = 0x00,
18 sun4c = 0x01,
19 sun4m = 0x02,
20 sun4d = 0x03,
21 sun4e = 0x04,
22 sun4u = 0x05, /* V8 ploos ploos */
23 sun_unknown = 0x06,
24 ap1000 = 0x07, /* almost a sun4m */
25 };
26
27 #define sparc_cpu_model sun4u
28
29 /* This cannot ever be a sun4c :) That's just history. */
30 #define ARCH_SUN4C 0
31
32 extern char reboot_command[];
33
34 /* These are here in an effort to more fully work around Spitfire Errata
35 * #51. Essentially, if a memory barrier occurs soon after a mispredicted
36 * branch, the chip can stop executing instructions until a trap occurs.
37 * Therefore, if interrupts are disabled, the chip can hang forever.
38 *
39 * It used to be believed that the memory barrier had to be right in the
40 * delay slot, but a case has been traced recently wherein the memory barrier
41 * was one instruction after the branch delay slot and the chip still hung.
42 * The offending sequence was the following in sym_wakeup_done() of the
43 * sym53c8xx_2 driver:
44 *
45 * call sym_ccb_from_dsa, 0
46 * movge %icc, 0, %l0
47 * brz,pn %o0, .LL1303
48 * mov %o0, %l2
49 * membar #LoadLoad
50 *
51 * The branch has to be mispredicted for the bug to occur. Therefore, we put
52 * the memory barrier explicitly into a "branch always, predicted taken"
53 * delay slot to avoid the problem case.
54 */
55 #define membar_safe(type) \
56 do { __asm__ __volatile__("ba,pt %%xcc, 1f\n\t" \
57 " membar " type "\n" \
58 "1:\n" \
59 : : : "memory"); \
60 } while (0)
61
62 /* The kernel always executes in TSO memory model these days,
63 * and furthermore most sparc64 chips implement more stringent
64 * memory ordering than required by the specifications.
65 */
66 #define mb() membar_safe("#StoreLoad")
67 #define rmb() __asm__ __volatile__("":::"memory")
68 #define wmb() __asm__ __volatile__("":::"memory")
69
70 #endif
71
72 #define nop() __asm__ __volatile__ ("nop")
73
74 #define read_barrier_depends() do { } while(0)
75 #define set_mb(__var, __value) \
76 do { __var = __value; membar_safe("#StoreLoad"); } while(0)
77
78 #ifdef CONFIG_SMP
79 #define smp_mb() mb()
80 #define smp_rmb() rmb()
81 #define smp_wmb() wmb()
82 #else
83 #define smp_mb() __asm__ __volatile__("":::"memory")
84 #define smp_rmb() __asm__ __volatile__("":::"memory")
85 #define smp_wmb() __asm__ __volatile__("":::"memory")
86 #endif
87
88 #define smp_read_barrier_depends() do { } while(0)
89
90 #define flushi(addr) __asm__ __volatile__ ("flush %0" : : "r" (addr) : "memory")
91
92 #define flushw_all() __asm__ __volatile__("flushw")
93
94 /* Performance counter register access. */
95 #define read_pcr(__p) __asm__ __volatile__("rd %%pcr, %0" : "=r" (__p))
96 #define write_pcr(__p) __asm__ __volatile__("wr %0, 0x0, %%pcr" : : "r" (__p))
97 #define read_pic(__p) __asm__ __volatile__("rd %%pic, %0" : "=r" (__p))
98
99 /* Blackbird errata workaround. See commentary in
100 * arch/sparc64/kernel/smp.c:smp_percpu_timer_interrupt()
101 * for more information.
102 */
103 #define write_pic(__p) \
104 __asm__ __volatile__("ba,pt %%xcc, 99f\n\t" \
105 " nop\n\t" \
106 ".align 64\n" \
107 "99:wr %0, 0x0, %%pic\n\t" \
108 "rd %%pic, %%g0" : : "r" (__p))
109 #define reset_pic() write_pic(0)
110
111 #ifndef __ASSEMBLY__
112
113 extern void sun_do_break(void);
114 extern int stop_a_enabled;
115 extern int scons_pwroff;
116
117 extern void fault_in_user_windows(void);
118 extern void synchronize_user_stack(void);
119
120 extern void __flushw_user(void);
121 #define flushw_user() __flushw_user()
122
123 #define flush_user_windows flushw_user
124 #define flush_register_windows flushw_all
125
126 /* Don't hold the runqueue lock over context switch */
127 #define __ARCH_WANT_UNLOCKED_CTXSW
128 #define prepare_arch_switch(next) \
129 do { \
130 flushw_all(); \
131 } while (0)
132
133 /* See what happens when you design the chip correctly?
134 *
135 * We tell gcc we clobber all non-fixed-usage registers except
136 * for l0/l1. It will use one for 'next' and the other to hold
137 * the output value of 'last'. 'next' is not referenced again
138 * past the invocation of switch_to in the scheduler, so we need
139 * not preserve it's value. Hairy, but it lets us remove 2 loads
140 * and 2 stores in this critical code path. -DaveM
141 */
142 #define switch_to(prev, next, last) \
143 do { flush_tlb_pending(); \
144 save_and_clear_fpu(); \
145 /* If you are tempted to conditionalize the following */ \
146 /* so that ASI is only written if it changes, think again. */ \
147 __asm__ __volatile__("wr %%g0, %0, %%asi" \
148 : : "r" (__thread_flag_byte_ptr(task_thread_info(next))[TI_FLAG_BYTE_CURRENT_DS]));\
149 trap_block[current_thread_info()->cpu].thread = \
150 task_thread_info(next); \
151 __asm__ __volatile__( \
152 "mov %%g4, %%g7\n\t" \
153 "stx %%i6, [%%sp + 2047 + 0x70]\n\t" \
154 "stx %%i7, [%%sp + 2047 + 0x78]\n\t" \
155 "rdpr %%wstate, %%o5\n\t" \
156 "stx %%o6, [%%g6 + %6]\n\t" \
157 "stb %%o5, [%%g6 + %5]\n\t" \
158 "rdpr %%cwp, %%o5\n\t" \
159 "stb %%o5, [%%g6 + %8]\n\t" \
160 "wrpr %%g0, 15, %%pil\n\t" \
161 "mov %4, %%g6\n\t" \
162 "ldub [%4 + %8], %%g1\n\t" \
163 "wrpr %%g1, %%cwp\n\t" \
164 "ldx [%%g6 + %6], %%o6\n\t" \
165 "ldub [%%g6 + %5], %%o5\n\t" \
166 "ldub [%%g6 + %7], %%o7\n\t" \
167 "wrpr %%o5, 0x0, %%wstate\n\t" \
168 "ldx [%%sp + 2047 + 0x70], %%i6\n\t" \
169 "ldx [%%sp + 2047 + 0x78], %%i7\n\t" \
170 "ldx [%%g6 + %9], %%g4\n\t" \
171 "wrpr %%g0, 14, %%pil\n\t" \
172 "brz,pt %%o7, switch_to_pc\n\t" \
173 " mov %%g7, %0\n\t" \
174 "sethi %%hi(ret_from_syscall), %%g1\n\t" \
175 "jmpl %%g1 + %%lo(ret_from_syscall), %%g0\n\t" \
176 " nop\n\t" \
177 ".globl switch_to_pc\n\t" \
178 "switch_to_pc:\n\t" \
179 : "=&r" (last), "=r" (current), "=r" (current_thread_info_reg), \
180 "=r" (__local_per_cpu_offset) \
181 : "0" (task_thread_info(next)), \
182 "i" (TI_WSTATE), "i" (TI_KSP), "i" (TI_NEW_CHILD), \
183 "i" (TI_CWP), "i" (TI_TASK) \
184 : "cc", \
185 "g1", "g2", "g3", "g7", \
186 "l1", "l2", "l3", "l4", "l5", "l6", "l7", \
187 "i0", "i1", "i2", "i3", "i4", "i5", \
188 "o0", "o1", "o2", "o3", "o4", "o5", "o7"); \
189 } while(0)
190
xchg32(__volatile__ unsigned int * m,unsigned int val)191 static inline unsigned long xchg32(__volatile__ unsigned int *m, unsigned int val)
192 {
193 unsigned long tmp1, tmp2;
194
195 __asm__ __volatile__(
196 " mov %0, %1\n"
197 "1: lduw [%4], %2\n"
198 " cas [%4], %2, %0\n"
199 " cmp %2, %0\n"
200 " bne,a,pn %%icc, 1b\n"
201 " mov %1, %0\n"
202 : "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
203 : "0" (val), "r" (m)
204 : "cc", "memory");
205 return val;
206 }
207
xchg64(__volatile__ unsigned long * m,unsigned long val)208 static inline unsigned long xchg64(__volatile__ unsigned long *m, unsigned long val)
209 {
210 unsigned long tmp1, tmp2;
211
212 __asm__ __volatile__(
213 " mov %0, %1\n"
214 "1: ldx [%4], %2\n"
215 " casx [%4], %2, %0\n"
216 " cmp %2, %0\n"
217 " bne,a,pn %%xcc, 1b\n"
218 " mov %1, %0\n"
219 : "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
220 : "0" (val), "r" (m)
221 : "cc", "memory");
222 return val;
223 }
224
225 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
226
227 extern void __xchg_called_with_bad_pointer(void);
228
__xchg(unsigned long x,__volatile__ void * ptr,int size)229 static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr,
230 int size)
231 {
232 switch (size) {
233 case 4:
234 return xchg32(ptr, x);
235 case 8:
236 return xchg64(ptr, x);
237 }
238 __xchg_called_with_bad_pointer();
239 return x;
240 }
241
242 extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn));
243
244 /*
245 * Atomic compare and exchange. Compare OLD with MEM, if identical,
246 * store NEW in MEM. Return the initial value in MEM. Success is
247 * indicated by comparing RETURN with OLD.
248 */
249
250 #define __HAVE_ARCH_CMPXCHG 1
251
252 static inline unsigned long
__cmpxchg_u32(volatile int * m,int old,int new)253 __cmpxchg_u32(volatile int *m, int old, int new)
254 {
255 __asm__ __volatile__("cas [%2], %3, %0"
256 : "=&r" (new)
257 : "0" (new), "r" (m), "r" (old)
258 : "memory");
259
260 return new;
261 }
262
263 static inline unsigned long
__cmpxchg_u64(volatile long * m,unsigned long old,unsigned long new)264 __cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new)
265 {
266 __asm__ __volatile__("casx [%2], %3, %0"
267 : "=&r" (new)
268 : "0" (new), "r" (m), "r" (old)
269 : "memory");
270
271 return new;
272 }
273
274 /* This function doesn't exist, so you'll get a linker error
275 if something tries to do an invalid cmpxchg(). */
276 extern void __cmpxchg_called_with_bad_pointer(void);
277
278 static inline unsigned long
__cmpxchg(volatile void * ptr,unsigned long old,unsigned long new,int size)279 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
280 {
281 switch (size) {
282 case 4:
283 return __cmpxchg_u32(ptr, old, new);
284 case 8:
285 return __cmpxchg_u64(ptr, old, new);
286 }
287 __cmpxchg_called_with_bad_pointer();
288 return old;
289 }
290
291 #define cmpxchg(ptr,o,n) \
292 ({ \
293 __typeof__(*(ptr)) _o_ = (o); \
294 __typeof__(*(ptr)) _n_ = (n); \
295 (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
296 (unsigned long)_n_, sizeof(*(ptr))); \
297 })
298
299 /*
300 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
301 * them available.
302 */
303
__cmpxchg_local(volatile void * ptr,unsigned long old,unsigned long new,int size)304 static inline unsigned long __cmpxchg_local(volatile void *ptr,
305 unsigned long old,
306 unsigned long new, int size)
307 {
308 switch (size) {
309 case 4:
310 case 8: return __cmpxchg(ptr, old, new, size);
311 default:
312 return __cmpxchg_local_generic(ptr, old, new, size);
313 }
314
315 return old;
316 }
317
318 #define cmpxchg_local(ptr, o, n) \
319 ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
320 (unsigned long)(n), sizeof(*(ptr))))
321 #define cmpxchg64_local(ptr, o, n) \
322 ({ \
323 BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
324 cmpxchg_local((ptr), (o), (n)); \
325 })
326
327 #endif /* !(__ASSEMBLY__) */
328
329 #define arch_align_stack(x) (x)
330
331 #endif /* !(__SPARC64_SYSTEM_H) */
332