1 /* include/asm/processor.h
2  *
3  * Copyright (C) 1994 David S. Miller (davem@caip.rutgers.edu)
4  */
5 
6 #ifndef __ASM_SPARC_PROCESSOR_H
7 #define __ASM_SPARC_PROCESSOR_H
8 
9 /*
10  * Sparc32 implementation of macro that returns current
11  * instruction pointer ("program counter").
12  */
13 #define current_text_addr() ({ void *pc; __asm__("sethi %%hi(1f), %0; or %0, %%lo(1f), %0;\n1:" : "=r" (pc)); pc; })
14 
15 #include <asm/psr.h>
16 #include <asm/ptrace.h>
17 #include <asm/head.h>
18 #include <asm/signal.h>
19 #include <asm/page.h>
20 
21 /*
22  * The sparc has no problems with write protection
23  */
24 #define wp_works_ok 1
25 #define wp_works_ok__is_a_macro /* for versions in ksyms.c */
26 
27 /* Whee, this is STACK_TOP + PAGE_SIZE and the lowest kernel address too...
28  * That one page is used to protect kernel from intruders, so that
29  * we can make our access_ok test faster
30  */
31 #define TASK_SIZE	PAGE_OFFSET
32 #ifdef __KERNEL__
33 #define STACK_TOP	(PAGE_OFFSET - PAGE_SIZE)
34 #define STACK_TOP_MAX	STACK_TOP
35 #endif /* __KERNEL__ */
36 
37 struct task_struct;
38 
39 #ifdef __KERNEL__
40 struct fpq {
41 	unsigned long *insn_addr;
42 	unsigned long insn;
43 };
44 #endif
45 
46 typedef struct {
47 	int seg;
48 } mm_segment_t;
49 
50 /* The Sparc processor specific thread struct. */
51 struct thread_struct {
52 	struct pt_regs *kregs;
53 	unsigned int _pad1;
54 
55 	/* Special child fork kpsr/kwim values. */
56 	unsigned long fork_kpsr __attribute__ ((aligned (8)));
57 	unsigned long fork_kwim;
58 
59 	/* Floating point regs */
60 	unsigned long   float_regs[32] __attribute__ ((aligned (8)));
61 	unsigned long   fsr;
62 	unsigned long   fpqdepth;
63 	struct fpq	fpqueue[16];
64 	unsigned long flags;
65 	mm_segment_t current_ds;
66 };
67 
68 #define SPARC_FLAG_KTHREAD      0x1    /* task is a kernel thread */
69 #define SPARC_FLAG_UNALIGNED    0x2    /* is allowed to do unaligned accesses */
70 
71 #define INIT_THREAD  { \
72 	.flags = SPARC_FLAG_KTHREAD, \
73 	.current_ds = KERNEL_DS, \
74 }
75 
76 /* Return saved PC of a blocked thread. */
77 extern unsigned long thread_saved_pc(struct task_struct *t);
78 
79 /* Do necessary setup to start up a newly executed thread. */
80 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
81 				    unsigned long sp)
82 {
83 	register unsigned long zero asm("g1");
84 
85 	regs->psr = (regs->psr & (PSR_CWP)) | PSR_S;
86 	regs->pc = ((pc & (~3)) - 4);
87 	regs->npc = regs->pc + 4;
88 	regs->y = 0;
89 	zero = 0;
90 	__asm__ __volatile__("std\t%%g0, [%0 + %3 + 0x00]\n\t"
91 			     "std\t%%g0, [%0 + %3 + 0x08]\n\t"
92 			     "std\t%%g0, [%0 + %3 + 0x10]\n\t"
93 			     "std\t%%g0, [%0 + %3 + 0x18]\n\t"
94 			     "std\t%%g0, [%0 + %3 + 0x20]\n\t"
95 			     "std\t%%g0, [%0 + %3 + 0x28]\n\t"
96 			     "std\t%%g0, [%0 + %3 + 0x30]\n\t"
97 			     "st\t%1, [%0 + %3 + 0x38]\n\t"
98 			     "st\t%%g0, [%0 + %3 + 0x3c]"
99 			     : /* no outputs */
100 			     : "r" (regs),
101 			       "r" (sp - sizeof(struct reg_window32)),
102 			       "r" (zero),
103 			       "i" ((const unsigned long)(&((struct pt_regs *)0)->u_regs[0]))
104 			     : "memory");
105 }
106 
107 /* Free all resources held by a thread. */
108 #define release_thread(tsk)		do { } while(0)
109 
110 extern unsigned long get_wchan(struct task_struct *);
111 
112 #define task_pt_regs(tsk) ((tsk)->thread.kregs)
113 #define KSTK_EIP(tsk)  ((tsk)->thread.kregs->pc)
114 #define KSTK_ESP(tsk)  ((tsk)->thread.kregs->u_regs[UREG_FP])
115 
116 #ifdef __KERNEL__
117 
118 extern struct task_struct *last_task_used_math;
119 
120 #define cpu_relax()	barrier()
121 extern void (*sparc_idle)(void);
122 
123 #endif
124 
125 #endif /* __ASM_SPARC_PROCESSOR_H */
126