1 #ifndef __SPARC_SYSTEM_H
2 #define __SPARC_SYSTEM_H
3 
4 #include <linux/kernel.h>
5 #include <linux/threads.h>	/* NR_CPUS */
6 #include <linux/thread_info.h>
7 
8 #include <asm/page.h>
9 #include <asm/psr.h>
10 #include <asm/ptrace.h>
11 #include <asm/btfixup.h>
12 #include <asm/smp.h>
13 
14 #ifndef __ASSEMBLY__
15 
16 #include <linux/irqflags.h>
17 
probe_irq_mask(unsigned long val)18 static inline unsigned int probe_irq_mask(unsigned long val)
19 {
20 	return 0;
21 }
22 
23 /*
24  * Sparc (general) CPU types
25  */
26 enum sparc_cpu {
27   sun4        = 0x00,
28   sun4c       = 0x01,
29   sun4m       = 0x02,
30   sun4d       = 0x03,
31   sun4e       = 0x04,
32   sun4u       = 0x05, /* V8 ploos ploos */
33   sun_unknown = 0x06,
34   ap1000      = 0x07, /* almost a sun4m */
35   sparc_leon  = 0x08, /* Leon SoC */
36 };
37 
38 /* Really, userland should not be looking at any of this... */
39 #ifdef __KERNEL__
40 
41 extern enum sparc_cpu sparc_cpu_model;
42 
43 #define ARCH_SUN4C (sparc_cpu_model==sun4c)
44 
45 #define SUN4M_NCPUS            4              /* Architectural limit of sun4m. */
46 
47 extern char reboot_command[];
48 
49 extern struct thread_info *current_set[NR_CPUS];
50 
51 extern unsigned long empty_bad_page;
52 extern unsigned long empty_bad_page_table;
53 extern unsigned long empty_zero_page;
54 
55 extern void sun_do_break(void);
56 extern int serial_console;
57 extern int stop_a_enabled;
58 extern int scons_pwroff;
59 
con_is_present(void)60 static inline int con_is_present(void)
61 {
62 	return serial_console ? 0 : 1;
63 }
64 
65 /* When a context switch happens we must flush all user windows so that
66  * the windows of the current process are flushed onto its stack. This
67  * way the windows are all clean for the next process and the stack
68  * frames are up to date.
69  */
70 extern void flush_user_windows(void);
71 extern void kill_user_windows(void);
72 extern void synchronize_user_stack(void);
73 extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
74 		   void *fpqueue, unsigned long *fpqdepth);
75 
76 #ifdef CONFIG_SMP
77 #define SWITCH_ENTER(prv) \
78 	do {			\
79 	if (test_tsk_thread_flag(prv, TIF_USEDFPU)) { \
80 		put_psr(get_psr() | PSR_EF); \
81 		fpsave(&(prv)->thread.float_regs[0], &(prv)->thread.fsr, \
82 		       &(prv)->thread.fpqueue[0], &(prv)->thread.fpqdepth); \
83 		clear_tsk_thread_flag(prv, TIF_USEDFPU); \
84 		(prv)->thread.kregs->psr &= ~PSR_EF; \
85 	} \
86 	} while(0)
87 
88 #define SWITCH_DO_LAZY_FPU(next)	/* */
89 #else
90 #define SWITCH_ENTER(prv)		/* */
91 #define SWITCH_DO_LAZY_FPU(nxt)	\
92 	do {			\
93 	if (last_task_used_math != (nxt))		\
94 		(nxt)->thread.kregs->psr&=~PSR_EF;	\
95 	} while(0)
96 #endif
97 
98 extern void flushw_all(void);
99 
100 /*
101  * Flush windows so that the VM switch which follows
102  * would not pull the stack from under us.
103  *
104  * SWITCH_ENTER and SWITH_DO_LAZY_FPU do not work yet (e.g. SMP does not work)
105  * XXX WTF is the above comment? Found in late teen 2.4.x.
106  */
107 #define prepare_arch_switch(next) do { \
108 	__asm__ __volatile__( \
109 	".globl\tflush_patch_switch\nflush_patch_switch:\n\t" \
110 	"save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \
111 	"save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \
112 	"save %sp, -0x40, %sp\n\t" \
113 	"restore; restore; restore; restore; restore; restore; restore"); \
114 } while(0)
115 
116 	/* Much care has gone into this code, do not touch it.
117 	 *
118 	 * We need to loadup regs l0/l1 for the newly forked child
119 	 * case because the trap return path relies on those registers
120 	 * holding certain values, gcc is told that they are clobbered.
121 	 * Gcc needs registers for 3 values in and 1 value out, so we
122 	 * clobber every non-fixed-usage register besides l2/l3/o4/o5.  -DaveM
123 	 *
124 	 * Hey Dave, that do not touch sign is too much of an incentive
125 	 * - Anton & Pete
126 	 */
127 #define switch_to(prev, next, last) do {						\
128 	SWITCH_ENTER(prev);								\
129 	SWITCH_DO_LAZY_FPU(next);							\
130 	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next->active_mm));		\
131 	__asm__ __volatile__(								\
132 	"sethi	%%hi(here - 0x8), %%o7\n\t"						\
133 	"mov	%%g6, %%g3\n\t"								\
134 	"or	%%o7, %%lo(here - 0x8), %%o7\n\t"					\
135 	"rd	%%psr, %%g4\n\t"							\
136 	"std	%%sp, [%%g6 + %4]\n\t"							\
137 	"rd	%%wim, %%g5\n\t"							\
138 	"wr	%%g4, 0x20, %%psr\n\t"							\
139 	"nop\n\t"									\
140 	"std	%%g4, [%%g6 + %3]\n\t"							\
141 	"ldd	[%2 + %3], %%g4\n\t"							\
142 	"mov	%2, %%g6\n\t"								\
143 	".globl	patchme_store_new_current\n"						\
144 "patchme_store_new_current:\n\t"							\
145 	"st	%2, [%1]\n\t"								\
146 	"wr	%%g4, 0x20, %%psr\n\t"							\
147 	"nop\n\t"									\
148 	"nop\n\t"									\
149 	"nop\n\t"	/* LEON needs all 3 nops: load to %sp depends on CWP. */		\
150 	"ldd	[%%g6 + %4], %%sp\n\t"							\
151 	"wr	%%g5, 0x0, %%wim\n\t"							\
152 	"ldd	[%%sp + 0x00], %%l0\n\t"						\
153 	"ldd	[%%sp + 0x38], %%i6\n\t"						\
154 	"wr	%%g4, 0x0, %%psr\n\t"							\
155 	"nop\n\t"									\
156 	"nop\n\t"									\
157 	"jmpl	%%o7 + 0x8, %%g0\n\t"							\
158 	" ld	[%%g3 + %5], %0\n\t"							\
159 	"here:\n"									\
160         : "=&r" (last)									\
161         : "r" (&(current_set[hard_smp_processor_id()])),	\
162 	  "r" (task_thread_info(next)),				\
163 	  "i" (TI_KPSR),					\
164 	  "i" (TI_KSP),						\
165 	  "i" (TI_TASK)						\
166 	:       "g1", "g2", "g3", "g4", "g5",       "g7",	\
167 	  "l0", "l1",       "l3", "l4", "l5", "l6", "l7",	\
168 	  "i0", "i1", "i2", "i3", "i4", "i5",			\
169 	  "o0", "o1", "o2", "o3",                   "o7");	\
170 	} while(0)
171 
172 /* XXX Change this if we ever use a PSO mode kernel. */
173 #define mb()	__asm__ __volatile__ ("" : : : "memory")
174 #define rmb()	mb()
175 #define wmb()	mb()
176 #define read_barrier_depends()	do { } while(0)
177 #define set_mb(__var, __value)  do { __var = __value; mb(); } while(0)
178 #define smp_mb()	__asm__ __volatile__("":::"memory")
179 #define smp_rmb()	__asm__ __volatile__("":::"memory")
180 #define smp_wmb()	__asm__ __volatile__("":::"memory")
181 #define smp_read_barrier_depends()	do { } while(0)
182 
183 #define nop() __asm__ __volatile__ ("nop")
184 
185 /* This has special calling conventions */
186 #ifndef CONFIG_SMP
BTFIXUPDEF_CALL(void,___xchg32,void)187 BTFIXUPDEF_CALL(void, ___xchg32, void)
188 #endif
189 
190 static inline unsigned long xchg_u32(__volatile__ unsigned long *m, unsigned long val)
191 {
192 #ifdef CONFIG_SMP
193 	__asm__ __volatile__("swap [%2], %0"
194 			     : "=&r" (val)
195 			     : "0" (val), "r" (m)
196 			     : "memory");
197 	return val;
198 #else
199 	register unsigned long *ptr asm("g1");
200 	register unsigned long ret asm("g2");
201 
202 	ptr = (unsigned long *) m;
203 	ret = val;
204 
205 	/* Note: this is magic and the nop there is
206 	   really needed. */
207 	__asm__ __volatile__(
208 	"mov	%%o7, %%g4\n\t"
209 	"call	___f____xchg32\n\t"
210 	" nop\n\t"
211 	: "=&r" (ret)
212 	: "0" (ret), "r" (ptr)
213 	: "g3", "g4", "g7", "memory", "cc");
214 
215 	return ret;
216 #endif
217 }
218 
219 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
220 
221 extern void __xchg_called_with_bad_pointer(void);
222 
__xchg(unsigned long x,__volatile__ void * ptr,int size)223 static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, int size)
224 {
225 	switch (size) {
226 	case 4:
227 		return xchg_u32(ptr, x);
228 	};
229 	__xchg_called_with_bad_pointer();
230 	return x;
231 }
232 
233 /* Emulate cmpxchg() the same way we emulate atomics,
234  * by hashing the object address and indexing into an array
235  * of spinlocks to get a bit of performance...
236  *
237  * See arch/sparc/lib/atomic32.c for implementation.
238  *
239  * Cribbed from <asm-parisc/atomic.h>
240  */
241 #define __HAVE_ARCH_CMPXCHG	1
242 
243 /* bug catcher for when unsupported size is used - won't link */
244 extern void __cmpxchg_called_with_bad_pointer(void);
245 /* we only need to support cmpxchg of a u32 on sparc */
246 extern unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
247 
248 /* don't worry...optimizer will get rid of most of this */
249 static inline unsigned long
__cmpxchg(volatile void * ptr,unsigned long old,unsigned long new_,int size)250 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
251 {
252 	switch (size) {
253 	case 4:
254 		return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_);
255 	default:
256 		__cmpxchg_called_with_bad_pointer();
257 		break;
258 	}
259 	return old;
260 }
261 
262 #define cmpxchg(ptr, o, n)						\
263 ({									\
264 	__typeof__(*(ptr)) _o_ = (o);					\
265 	__typeof__(*(ptr)) _n_ = (n);					\
266 	(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,	\
267 			(unsigned long)_n_, sizeof(*(ptr)));		\
268 })
269 
270 #include <asm-generic/cmpxchg-local.h>
271 
272 /*
273  * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
274  * them available.
275  */
276 #define cmpxchg_local(ptr, o, n)				  	       \
277 	((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
278 			(unsigned long)(n), sizeof(*(ptr))))
279 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
280 
281 extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn));
282 
283 #endif /* __KERNEL__ */
284 
285 #endif /* __ASSEMBLY__ */
286 
287 #define arch_align_stack(x) (x)
288 
289 #endif /* !(__SPARC_SYSTEM_H) */
290