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/btfixup.h>
20 #include <asm/page.h>
21 
22 /*
23  * The sparc has no problems with write protection
24  */
25 #define wp_works_ok 1
26 #define wp_works_ok__is_a_macro /* for versions in ksyms.c */
27 
28 /* Whee, this is STACK_TOP + PAGE_SIZE and the lowest kernel address too...
29  * That one page is used to protect kernel from intruders, so that
30  * we can make our access_ok test faster
31  */
32 #define TASK_SIZE	PAGE_OFFSET
33 #ifdef __KERNEL__
34 #define STACK_TOP	(PAGE_OFFSET - PAGE_SIZE)
35 #define STACK_TOP_MAX	STACK_TOP
36 #endif /* __KERNEL__ */
37 
38 struct task_struct;
39 
40 #ifdef __KERNEL__
41 struct fpq {
42 	unsigned long *insn_addr;
43 	unsigned long insn;
44 };
45 #endif
46 
47 typedef struct {
48 	int seg;
49 } mm_segment_t;
50 
51 /* The Sparc processor specific thread struct. */
52 struct thread_struct {
53 	struct pt_regs *kregs;
54 	unsigned int _pad1;
55 
56 	/* Special child fork kpsr/kwim values. */
57 	unsigned long fork_kpsr __attribute__ ((aligned (8)));
58 	unsigned long fork_kwim;
59 
60 	/* Floating point regs */
61 	unsigned long   float_regs[32] __attribute__ ((aligned (8)));
62 	unsigned long   fsr;
63 	unsigned long   fpqdepth;
64 	struct fpq	fpqueue[16];
65 	unsigned long flags;
66 	mm_segment_t current_ds;
67 };
68 
69 #define SPARC_FLAG_KTHREAD      0x1    /* task is a kernel thread */
70 #define SPARC_FLAG_UNALIGNED    0x2    /* is allowed to do unaligned accesses */
71 
72 #define INIT_THREAD  { \
73 	.flags = SPARC_FLAG_KTHREAD, \
74 	.current_ds = KERNEL_DS, \
75 }
76 
77 /* Return saved PC of a blocked thread. */
78 extern unsigned long thread_saved_pc(struct task_struct *t);
79 
80 /* Do necessary setup to start up a newly executed thread. */
81 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
82 				    unsigned long sp)
83 {
84 	register unsigned long zero asm("g1");
85 
86 	regs->psr = (regs->psr & (PSR_CWP)) | PSR_S;
87 	regs->pc = ((pc & (~3)) - 4);
88 	regs->npc = regs->pc + 4;
89 	regs->y = 0;
90 	zero = 0;
91 	__asm__ __volatile__("std\t%%g0, [%0 + %3 + 0x00]\n\t"
92 			     "std\t%%g0, [%0 + %3 + 0x08]\n\t"
93 			     "std\t%%g0, [%0 + %3 + 0x10]\n\t"
94 			     "std\t%%g0, [%0 + %3 + 0x18]\n\t"
95 			     "std\t%%g0, [%0 + %3 + 0x20]\n\t"
96 			     "std\t%%g0, [%0 + %3 + 0x28]\n\t"
97 			     "std\t%%g0, [%0 + %3 + 0x30]\n\t"
98 			     "st\t%1, [%0 + %3 + 0x38]\n\t"
99 			     "st\t%%g0, [%0 + %3 + 0x3c]"
100 			     : /* no outputs */
101 			     : "r" (regs),
102 			       "r" (sp - sizeof(struct reg_window32)),
103 			       "r" (zero),
104 			       "i" ((const unsigned long)(&((struct pt_regs *)0)->u_regs[0]))
105 			     : "memory");
106 }
107 
108 /* Free all resources held by a thread. */
109 #define release_thread(tsk)		do { } while(0)
110 extern pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
111 
112 /* Prepare to copy thread state - unlazy all lazy status */
113 #define prepare_to_copy(tsk)	do { } while (0)
114 
115 extern unsigned long get_wchan(struct task_struct *);
116 
117 #define task_pt_regs(tsk) ((tsk)->thread.kregs)
118 #define KSTK_EIP(tsk)  ((tsk)->thread.kregs->pc)
119 #define KSTK_ESP(tsk)  ((tsk)->thread.kregs->u_regs[UREG_FP])
120 
121 #ifdef __KERNEL__
122 
123 extern struct task_struct *last_task_used_math;
124 
125 #define cpu_relax()	barrier()
126 
127 #endif
128 
129 #endif /* __ASM_SPARC_PROCESSOR_H */
130