1 /*
2  * include/asm/processor.h
3  *
4  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
5  */
6 
7 #ifndef __ASM_SPARC64_PROCESSOR_H
8 #define __ASM_SPARC64_PROCESSOR_H
9 
10 /*
11  * Sparc64 implementation of macro that returns current
12  * instruction pointer ("program counter").
13  */
14 #define current_text_addr() ({ void *pc; __asm__("rd %%pc, %0" : "=r" (pc)); pc; })
15 
16 #include <asm/asi.h>
17 #include <asm/pstate.h>
18 #include <asm/ptrace.h>
19 #include <asm/page.h>
20 
21 /* Don't hold the runqueue lock over context switch */
22 #define __ARCH_WANT_UNLOCKED_CTXSW
23 
24 /* The sparc has no problems with write protection */
25 #define wp_works_ok 1
26 #define wp_works_ok__is_a_macro /* for versions in ksyms.c */
27 
28 /*
29  * User lives in his very own context, and cannot reference us. Note
30  * that TASK_SIZE is a misnomer, it really gives maximum user virtual
31  * address that the kernel will allocate out.
32  *
33  * XXX No longer using virtual page tables, kill this upper limit...
34  */
35 #define VA_BITS		44
36 #ifndef __ASSEMBLY__
37 #define VPTE_SIZE	(1UL << (VA_BITS - PAGE_SHIFT + 3))
38 #else
39 #define VPTE_SIZE	(1 << (VA_BITS - PAGE_SHIFT + 3))
40 #endif
41 
42 #define TASK_SIZE_OF(tsk) \
43 	(test_tsk_thread_flag(tsk,TIF_32BIT) ? \
44 	 (1UL << 32UL) : ((unsigned long)-VPTE_SIZE))
45 #define TASK_SIZE \
46 	(test_thread_flag(TIF_32BIT) ? \
47 	 (1UL << 32UL) : ((unsigned long)-VPTE_SIZE))
48 #ifdef __KERNEL__
49 
50 #define STACK_TOP32	((1UL << 32UL) - PAGE_SIZE)
51 #define STACK_TOP64	(0x0000080000000000UL - (1UL << 32UL))
52 
53 #define STACK_TOP	(test_thread_flag(TIF_32BIT) ? \
54 			 STACK_TOP32 : STACK_TOP64)
55 
56 #define STACK_TOP_MAX	STACK_TOP64
57 
58 #endif
59 
60 #ifndef __ASSEMBLY__
61 
62 typedef struct {
63 	unsigned char seg;
64 } mm_segment_t;
65 
66 /* The Sparc processor specific thread struct. */
67 /* XXX This should die, everything can go into thread_info now. */
68 struct thread_struct {
69 #ifdef CONFIG_DEBUG_SPINLOCK
70 	/* How many spinlocks held by this thread.
71 	 * Used with spin lock debugging to catch tasks
72 	 * sleeping illegally with locks held.
73 	 */
74 	int smp_lock_count;
75 	unsigned int smp_lock_pc;
76 #else
77 	int dummy; /* f'in gcc bug... */
78 #endif
79 };
80 
81 #endif /* !(__ASSEMBLY__) */
82 
83 #ifndef CONFIG_DEBUG_SPINLOCK
84 #define INIT_THREAD  {			\
85 	0,				\
86 }
87 #else /* CONFIG_DEBUG_SPINLOCK */
88 #define INIT_THREAD  {					\
89 /* smp_lock_count, smp_lock_pc, */			\
90    0,		   0,					\
91 }
92 #endif /* !(CONFIG_DEBUG_SPINLOCK) */
93 
94 #ifndef __ASSEMBLY__
95 
96 #include <linux/types.h>
97 
98 /* Return saved PC of a blocked thread. */
99 struct task_struct;
100 extern unsigned long thread_saved_pc(struct task_struct *);
101 
102 /* On Uniprocessor, even in RMO processes see TSO semantics */
103 #ifdef CONFIG_SMP
104 #define TSTATE_INITIAL_MM	TSTATE_TSO
105 #else
106 #define TSTATE_INITIAL_MM	TSTATE_RMO
107 #endif
108 
109 /* Do necessary setup to start up a newly executed thread. */
110 #define start_thread(regs, pc, sp) \
111 do { \
112 	unsigned long __asi = ASI_PNF; \
113 	regs->tstate = (regs->tstate & (TSTATE_CWP)) | (TSTATE_INITIAL_MM|TSTATE_IE) | (__asi << 24UL); \
114 	regs->tpc = ((pc & (~3)) - 4); \
115 	regs->tnpc = regs->tpc + 4; \
116 	regs->y = 0; \
117 	set_thread_wstate(1 << 3); \
118 	if (current_thread_info()->utraps) { \
119 		if (*(current_thread_info()->utraps) < 2) \
120 			kfree(current_thread_info()->utraps); \
121 		else \
122 			(*(current_thread_info()->utraps))--; \
123 		current_thread_info()->utraps = NULL; \
124 	} \
125 	__asm__ __volatile__( \
126 	"stx		%%g0, [%0 + %2 + 0x00]\n\t" \
127 	"stx		%%g0, [%0 + %2 + 0x08]\n\t" \
128 	"stx		%%g0, [%0 + %2 + 0x10]\n\t" \
129 	"stx		%%g0, [%0 + %2 + 0x18]\n\t" \
130 	"stx		%%g0, [%0 + %2 + 0x20]\n\t" \
131 	"stx		%%g0, [%0 + %2 + 0x28]\n\t" \
132 	"stx		%%g0, [%0 + %2 + 0x30]\n\t" \
133 	"stx		%%g0, [%0 + %2 + 0x38]\n\t" \
134 	"stx		%%g0, [%0 + %2 + 0x40]\n\t" \
135 	"stx		%%g0, [%0 + %2 + 0x48]\n\t" \
136 	"stx		%%g0, [%0 + %2 + 0x50]\n\t" \
137 	"stx		%%g0, [%0 + %2 + 0x58]\n\t" \
138 	"stx		%%g0, [%0 + %2 + 0x60]\n\t" \
139 	"stx		%%g0, [%0 + %2 + 0x68]\n\t" \
140 	"stx		%1,   [%0 + %2 + 0x70]\n\t" \
141 	"stx		%%g0, [%0 + %2 + 0x78]\n\t" \
142 	"wrpr		%%g0, (1 << 3), %%wstate\n\t" \
143 	: \
144 	: "r" (regs), "r" (sp - sizeof(struct reg_window) - STACK_BIAS), \
145 	  "i" ((const unsigned long)(&((struct pt_regs *)0)->u_regs[0]))); \
146 } while (0)
147 
148 #define start_thread32(regs, pc, sp) \
149 do { \
150 	unsigned long __asi = ASI_PNF; \
151 	pc &= 0x00000000ffffffffUL; \
152 	sp &= 0x00000000ffffffffUL; \
153 	regs->tstate = (regs->tstate & (TSTATE_CWP))|(TSTATE_INITIAL_MM|TSTATE_IE|TSTATE_AM) | (__asi << 24UL); \
154 	regs->tpc = ((pc & (~3)) - 4); \
155 	regs->tnpc = regs->tpc + 4; \
156 	regs->y = 0; \
157 	set_thread_wstate(2 << 3); \
158 	if (current_thread_info()->utraps) { \
159 		if (*(current_thread_info()->utraps) < 2) \
160 			kfree(current_thread_info()->utraps); \
161 		else \
162 			(*(current_thread_info()->utraps))--; \
163 		current_thread_info()->utraps = NULL; \
164 	} \
165 	__asm__ __volatile__( \
166 	"stx		%%g0, [%0 + %2 + 0x00]\n\t" \
167 	"stx		%%g0, [%0 + %2 + 0x08]\n\t" \
168 	"stx		%%g0, [%0 + %2 + 0x10]\n\t" \
169 	"stx		%%g0, [%0 + %2 + 0x18]\n\t" \
170 	"stx		%%g0, [%0 + %2 + 0x20]\n\t" \
171 	"stx		%%g0, [%0 + %2 + 0x28]\n\t" \
172 	"stx		%%g0, [%0 + %2 + 0x30]\n\t" \
173 	"stx		%%g0, [%0 + %2 + 0x38]\n\t" \
174 	"stx		%%g0, [%0 + %2 + 0x40]\n\t" \
175 	"stx		%%g0, [%0 + %2 + 0x48]\n\t" \
176 	"stx		%%g0, [%0 + %2 + 0x50]\n\t" \
177 	"stx		%%g0, [%0 + %2 + 0x58]\n\t" \
178 	"stx		%%g0, [%0 + %2 + 0x60]\n\t" \
179 	"stx		%%g0, [%0 + %2 + 0x68]\n\t" \
180 	"stx		%1,   [%0 + %2 + 0x70]\n\t" \
181 	"stx		%%g0, [%0 + %2 + 0x78]\n\t" \
182 	"wrpr		%%g0, (2 << 3), %%wstate\n\t" \
183 	: \
184 	: "r" (regs), "r" (sp - sizeof(struct reg_window32)), \
185 	  "i" ((const unsigned long)(&((struct pt_regs *)0)->u_regs[0]))); \
186 } while (0)
187 
188 /* Free all resources held by a thread. */
189 #define release_thread(tsk)		do { } while (0)
190 
191 extern pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
192 
193 extern unsigned long get_wchan(struct task_struct *task);
194 
195 #define task_pt_regs(tsk) (task_thread_info(tsk)->kregs)
196 #define KSTK_EIP(tsk)  (task_pt_regs(tsk)->tpc)
197 #define KSTK_ESP(tsk)  (task_pt_regs(tsk)->u_regs[UREG_FP])
198 
199 #define cpu_relax()	barrier()
200 
201 /* Prefetch support.  This is tuned for UltraSPARC-III and later.
202  * UltraSPARC-I will treat these as nops, and UltraSPARC-II has
203  * a shallower prefetch queue than later chips.
204  */
205 #define ARCH_HAS_PREFETCH
206 #define ARCH_HAS_PREFETCHW
207 #define ARCH_HAS_SPINLOCK_PREFETCH
208 
209 static inline void prefetch(const void *x)
210 {
211 	/* We do not use the read prefetch mnemonic because that
212 	 * prefetches into the prefetch-cache which only is accessible
213 	 * by floating point operations in UltraSPARC-III and later.
214 	 * By contrast, "#one_write" prefetches into the L2 cache
215 	 * in shared state.
216 	 */
217 	__asm__ __volatile__("prefetch [%0], #one_write"
218 			     : /* no outputs */
219 			     : "r" (x));
220 }
221 
222 static inline void prefetchw(const void *x)
223 {
224 	/* The most optimal prefetch to use for writes is
225 	 * "#n_writes".  This brings the cacheline into the
226 	 * L2 cache in "owned" state.
227 	 */
228 	__asm__ __volatile__("prefetch [%0], #n_writes"
229 			     : /* no outputs */
230 			     : "r" (x));
231 }
232 
233 #define spin_lock_prefetch(x)	prefetchw(x)
234 
235 #define HAVE_ARCH_PICK_MMAP_LAYOUT
236 
237 #endif /* !(__ASSEMBLY__) */
238 
239 #endif /* !(__ASM_SPARC64_PROCESSOR_H) */
240