1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_IA64_UNWIND_H
3 #define _ASM_IA64_UNWIND_H
4 
5 /*
6  * Copyright (C) 1999-2000, 2003 Hewlett-Packard Co
7  *	David Mosberger-Tang <davidm@hpl.hp.com>
8  *
9  * A simple API for unwinding kernel stacks.  This is used for
10  * debugging and error reporting purposes.  The kernel doesn't need
11  * full-blown stack unwinding with all the bells and whitles, so there
12  * is not much point in implementing the full IA-64 unwind API (though
13  * it would of course be possible to implement the kernel API on top
14  * of it).
15  */
16 
17 struct task_struct;	/* forward declaration */
18 struct switch_stack;	/* forward declaration */
19 
20 enum unw_application_register {
21 	UNW_AR_BSP,
22 	UNW_AR_BSPSTORE,
23 	UNW_AR_PFS,
24 	UNW_AR_RNAT,
25 	UNW_AR_UNAT,
26 	UNW_AR_LC,
27 	UNW_AR_EC,
28 	UNW_AR_FPSR,
29 	UNW_AR_RSC,
30 	UNW_AR_CCV,
31 	UNW_AR_CSD,
32 	UNW_AR_SSD
33 };
34 
35 /*
36  * The following declarations are private to the unwind
37  * implementation:
38  */
39 
40 struct unw_stack {
41 	unsigned long limit;
42 	unsigned long top;
43 };
44 
45 #define UNW_FLAG_INTERRUPT_FRAME	(1UL << 0)
46 
47 /*
48  * No user of this module should every access this structure directly
49  * as it is subject to change.  It is declared here solely so we can
50  * use automatic variables.
51  */
52 struct unw_frame_info {
53 	struct unw_stack regstk;
54 	struct unw_stack memstk;
55 	unsigned int flags;
56 	short hint;
57 	short prev_script;
58 
59 	/* current frame info: */
60 	unsigned long bsp;		/* backing store pointer value */
61 	unsigned long sp;		/* stack pointer value */
62 	unsigned long psp;		/* previous sp value */
63 	unsigned long ip;		/* instruction pointer value */
64 	unsigned long pr;		/* current predicate values */
65 	unsigned long *cfm_loc;		/* cfm save location (or NULL) */
66 	unsigned long pt;		/* struct pt_regs location */
67 
68 	struct task_struct *task;
69 	struct switch_stack *sw;
70 
71 	/* preserved state: */
72 	unsigned long *bsp_loc;		/* previous bsp save location */
73 	unsigned long *bspstore_loc;
74 	unsigned long *pfs_loc;
75 	unsigned long *rnat_loc;
76 	unsigned long *rp_loc;
77 	unsigned long *pri_unat_loc;
78 	unsigned long *unat_loc;
79 	unsigned long *pr_loc;
80 	unsigned long *lc_loc;
81 	unsigned long *fpsr_loc;
82 	struct unw_ireg {
83 		unsigned long *loc;
84 		struct unw_ireg_nat {
85 			unsigned long type : 3;		/* enum unw_nat_type */
86 			signed long off : 61;		/* NaT word is at loc+nat.off */
87 		} nat;
88 	} r4, r5, r6, r7;
89 	unsigned long *b1_loc, *b2_loc, *b3_loc, *b4_loc, *b5_loc;
90 	struct ia64_fpreg *f2_loc, *f3_loc, *f4_loc, *f5_loc, *fr_loc[16];
91 };
92 
93 /*
94  * The official API follows below:
95  */
96 
97 struct unw_table_entry {
98 	u64 start_offset;
99 	u64 end_offset;
100 	u64 info_offset;
101 };
102 
103 /*
104  * Initialize unwind support.
105  */
106 extern void unw_init (void);
107 
108 extern void *unw_add_unwind_table (const char *name, unsigned long segment_base, unsigned long gp,
109 				   const void *table_start, const void *table_end);
110 
111 extern void unw_remove_unwind_table (void *handle);
112 
113 /*
114  * Prepare to unwind blocked task t.
115  */
116 extern void unw_init_from_blocked_task (struct unw_frame_info *info, struct task_struct *t);
117 
118 extern void unw_init_frame_info (struct unw_frame_info *info, struct task_struct *t,
119 				 struct switch_stack *sw);
120 
121 /*
122  * Prepare to unwind the currently running thread.
123  */
124 extern void unw_init_running (void (*callback)(struct unw_frame_info *info, void *arg), void *arg);
125 
126 /*
127  * Unwind to previous to frame.  Returns 0 if successful, negative
128  * number in case of an error.
129  */
130 extern int unw_unwind (struct unw_frame_info *info);
131 
132 /*
133  * Unwind until the return pointer is in user-land (or until an error
134  * occurs).  Returns 0 if successful, negative number in case of
135  * error.
136  */
137 extern int unw_unwind_to_user (struct unw_frame_info *info);
138 
139 #define unw_is_intr_frame(info)	(((info)->flags & UNW_FLAG_INTERRUPT_FRAME) != 0)
140 
141 static inline int
unw_get_ip(struct unw_frame_info * info,unsigned long * valp)142 unw_get_ip (struct unw_frame_info *info, unsigned long *valp)
143 {
144 	*valp = (info)->ip;
145 	return 0;
146 }
147 
148 static inline int
unw_get_sp(struct unw_frame_info * info,unsigned long * valp)149 unw_get_sp (struct unw_frame_info *info, unsigned long *valp)
150 {
151 	*valp = (info)->sp;
152 	return 0;
153 }
154 
155 static inline int
unw_get_psp(struct unw_frame_info * info,unsigned long * valp)156 unw_get_psp (struct unw_frame_info *info, unsigned long *valp)
157 {
158 	*valp = (info)->psp;
159 	return 0;
160 }
161 
162 static inline int
unw_get_bsp(struct unw_frame_info * info,unsigned long * valp)163 unw_get_bsp (struct unw_frame_info *info, unsigned long *valp)
164 {
165 	*valp = (info)->bsp;
166 	return 0;
167 }
168 
169 static inline int
unw_get_cfm(struct unw_frame_info * info,unsigned long * valp)170 unw_get_cfm (struct unw_frame_info *info, unsigned long *valp)
171 {
172 	*valp = *(info)->cfm_loc;
173 	return 0;
174 }
175 
176 static inline int
unw_set_cfm(struct unw_frame_info * info,unsigned long val)177 unw_set_cfm (struct unw_frame_info *info, unsigned long val)
178 {
179 	*(info)->cfm_loc = val;
180 	return 0;
181 }
182 
183 static inline int
unw_get_rp(struct unw_frame_info * info,unsigned long * val)184 unw_get_rp (struct unw_frame_info *info, unsigned long *val)
185 {
186 	if (!info->rp_loc)
187 		return -1;
188 	*val = *info->rp_loc;
189 	return 0;
190 }
191 
192 extern int unw_access_gr (struct unw_frame_info *, int, unsigned long *, char *, int);
193 extern int unw_access_br (struct unw_frame_info *, int, unsigned long *, int);
194 extern int unw_access_fr (struct unw_frame_info *, int, struct ia64_fpreg *, int);
195 extern int unw_access_ar (struct unw_frame_info *, int, unsigned long *, int);
196 extern int unw_access_pr (struct unw_frame_info *, unsigned long *, int);
197 
198 static inline int
unw_set_gr(struct unw_frame_info * i,int n,unsigned long v,char nat)199 unw_set_gr (struct unw_frame_info *i, int n, unsigned long v, char nat)
200 {
201 	return unw_access_gr(i, n, &v, &nat, 1);
202 }
203 
204 static inline int
unw_set_br(struct unw_frame_info * i,int n,unsigned long v)205 unw_set_br (struct unw_frame_info *i, int n, unsigned long v)
206 {
207 	return unw_access_br(i, n, &v, 1);
208 }
209 
210 static inline int
unw_set_fr(struct unw_frame_info * i,int n,struct ia64_fpreg v)211 unw_set_fr (struct unw_frame_info *i, int n, struct ia64_fpreg v)
212 {
213 	return unw_access_fr(i, n, &v, 1);
214 }
215 
216 static inline int
unw_set_ar(struct unw_frame_info * i,int n,unsigned long v)217 unw_set_ar (struct unw_frame_info *i, int n, unsigned long v)
218 {
219 	return unw_access_ar(i, n, &v, 1);
220 }
221 
222 static inline int
unw_set_pr(struct unw_frame_info * i,unsigned long v)223 unw_set_pr (struct unw_frame_info *i, unsigned long v)
224 {
225 	return unw_access_pr(i, &v, 1);
226 }
227 
228 #define unw_get_gr(i,n,v,nat)	unw_access_gr(i,n,v,nat,0)
229 #define unw_get_br(i,n,v)	unw_access_br(i,n,v,0)
230 #define unw_get_fr(i,n,v)	unw_access_fr(i,n,v,0)
231 #define unw_get_ar(i,n,v)	unw_access_ar(i,n,v,0)
232 #define unw_get_pr(i,v)		unw_access_pr(i,v,0)
233 
234 #endif /* _ASM_UNWIND_H */
235