1/*
2 *  Port on Texas Instruments TMS320C6x architecture
3 *
4 *  Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
5 *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
6 *
7 *  Updated for 2.6.34: Mark Salter <msalter@redhat.com>
8 *
9 *  This program is free software; you can redistribute it and/or modify
10 *  it under the terms of the GNU General Public License version 2 as
11 *  published by the Free Software Foundation.
12 */
13#include <linux/ptrace.h>
14#include <linux/tracehook.h>
15#include <linux/regset.h>
16#include <linux/elf.h>
17
18#include <asm/cacheflush.h>
19
20#define PT_REG_SIZE	  (sizeof(struct pt_regs))
21
22/*
23 * Called by kernel/ptrace.c when detaching.
24 */
25void ptrace_disable(struct task_struct *child)
26{
27	/* nothing to do */
28}
29
30/*
31 * Get a register number from live pt_regs for the specified task.
32 */
33static inline long get_reg(struct task_struct *task, int regno)
34{
35	long *addr = (long *)task_pt_regs(task);
36
37	if (regno == PT_TSR || regno == PT_CSR)
38		return 0;
39
40	return addr[regno];
41}
42
43/*
44 * Write contents of register REGNO in task TASK.
45 */
46static inline int put_reg(struct task_struct *task,
47			  int regno,
48			  unsigned long data)
49{
50	unsigned long *addr = (unsigned long *)task_pt_regs(task);
51
52	if (regno != PT_TSR && regno != PT_CSR)
53		addr[regno] = data;
54
55	return 0;
56}
57
58/* regset get/set implementations */
59
60static int gpr_get(struct task_struct *target,
61		   const struct user_regset *regset,
62		   unsigned int pos, unsigned int count,
63		   void *kbuf, void __user *ubuf)
64{
65	struct pt_regs *regs = task_pt_regs(target);
66
67	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
68				   regs,
69				   0, sizeof(*regs));
70}
71
72static int gpr_set(struct task_struct *target,
73		   const struct user_regset *regset,
74		   unsigned int pos, unsigned int count,
75		   const void *kbuf, const void __user *ubuf)
76{
77	int ret;
78	struct pt_regs *regs = task_pt_regs(target);
79
80	/* Don't copyin TSR or CSR */
81	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
82				 &regs,
83				 0, PT_TSR * sizeof(long));
84	if (ret)
85		return ret;
86
87	ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
88					PT_TSR * sizeof(long),
89					(PT_TSR + 1) * sizeof(long));
90	if (ret)
91		return ret;
92
93	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
94				 &regs,
95				 (PT_TSR + 1) * sizeof(long),
96				 PT_CSR * sizeof(long));
97	if (ret)
98		return ret;
99
100	ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
101					PT_CSR * sizeof(long),
102					(PT_CSR + 1) * sizeof(long));
103	if (ret)
104		return ret;
105
106	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
107				 &regs,
108				 (PT_CSR + 1) * sizeof(long), -1);
109	return ret;
110}
111
112enum c6x_regset {
113	REGSET_GPR,
114};
115
116static const struct user_regset c6x_regsets[] = {
117	[REGSET_GPR] = {
118		.core_note_type = NT_PRSTATUS,
119		.n = ELF_NGREG,
120		.size = sizeof(u32),
121		.align = sizeof(u32),
122		.get = gpr_get,
123		.set = gpr_set
124	},
125};
126
127static const struct user_regset_view user_c6x_native_view = {
128	.name		= "tic6x",
129	.e_machine	= EM_TI_C6000,
130	.regsets	= c6x_regsets,
131	.n		= ARRAY_SIZE(c6x_regsets),
132};
133
134const struct user_regset_view *task_user_regset_view(struct task_struct *task)
135{
136	return &user_c6x_native_view;
137}
138
139/*
140 * Perform ptrace request
141 */
142long arch_ptrace(struct task_struct *child, long request,
143		 unsigned long addr, unsigned long data)
144{
145	int ret = 0;
146
147	switch (request) {
148		/*
149		 * write the word at location addr.
150		 */
151	case PTRACE_POKETEXT:
152		ret = generic_ptrace_pokedata(child, addr, data);
153		if (ret == 0 && request == PTRACE_POKETEXT)
154			flush_icache_range(addr, addr + 4);
155		break;
156	default:
157		ret = ptrace_request(child, request, addr, data);
158		break;
159	}
160
161	return ret;
162}
163
164/*
165 * handle tracing of system call entry
166 * - return the revised system call number or ULONG_MAX to cause ENOSYS
167 */
168asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs)
169{
170	if (tracehook_report_syscall_entry(regs))
171		/* tracing decided this syscall should not happen, so
172		 * We'll return a bogus call number to get an ENOSYS
173		 * error, but leave the original number in
174		 * regs->orig_a4
175		 */
176		return ULONG_MAX;
177
178	return regs->b0;
179}
180
181/*
182 * handle tracing of system call exit
183 */
184asmlinkage void syscall_trace_exit(struct pt_regs *regs)
185{
186	tracehook_report_syscall_exit(regs, 0);
187}
188