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