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4adeefe1 VG |
1 | /* |
2 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * Amit Bhor, Kanika Nema: Codito Technologies 2004 | |
9 | */ | |
10 | ||
11 | #include <linux/errno.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/fs.h> | |
16 | #include <linux/unistd.h> | |
17 | #include <linux/ptrace.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/syscalls.h> | |
20 | #include <linux/elf.h> | |
21 | #include <linux/tick.h> | |
22 | ||
23 | SYSCALL_DEFINE1(arc_settls, void *, user_tls_data_ptr) | |
24 | { | |
25 | task_thread_info(current)->thr_ptr = (unsigned int)user_tls_data_ptr; | |
26 | return 0; | |
27 | } | |
28 | ||
29 | /* | |
30 | * We return the user space TLS data ptr as sys-call return code | |
31 | * Ideally it should be copy to user. | |
32 | * However we can cheat by the fact that some sys-calls do return | |
33 | * absurdly high values | |
34 | * Since the tls dat aptr is not going to be in range of 0xFFFF_xxxx | |
35 | * it won't be considered a sys-call error | |
36 | * and it will be loads better than copy-to-user, which is a definite | |
37 | * D-TLB Miss | |
38 | */ | |
39 | SYSCALL_DEFINE0(arc_gettls) | |
40 | { | |
41 | return task_thread_info(current)->thr_ptr; | |
42 | } | |
bf90e1ea | 43 | |
fa35e42a | 44 | void arch_cpu_idle(void) |
bf90e1ea VG |
45 | { |
46 | /* sleep, but enable all interrupts before committing */ | |
512b5b89 VG |
47 | __asm__ __volatile__( |
48 | "sleep %0 \n" | |
49 | : | |
50 | :"I"(ISA_SLEEP_ARG)); /* can't be "r" has to be embedded const */ | |
bf90e1ea VG |
51 | } |
52 | ||
bf90e1ea VG |
53 | asmlinkage void ret_from_fork(void); |
54 | ||
18e1d1b1 AD |
55 | /* |
56 | * Copy architecture-specific thread state | |
57 | * | |
58 | * Layout of Child kernel mode stack as setup at the end of this function is | |
bf90e1ea VG |
59 | * |
60 | * | ... | | |
61 | * | ... | | |
62 | * | unused | | |
63 | * | | | |
bf90e1ea | 64 | * ------------------ |
16f9afe6 | 65 | * | r25 | <==== top of Stack (thread.ksp) |
bf90e1ea | 66 | * ~ ~ |
09074950 | 67 | * | --to-- | (CALLEE Regs of kernel mode) |
bf90e1ea VG |
68 | * | r13 | |
69 | * ------------------ | |
70 | * | fp | | |
71 | * | blink | @ret_from_fork | |
72 | * ------------------ | |
73 | * | | | |
74 | * ~ ~ | |
75 | * ~ ~ | |
76 | * | | | |
77 | * ------------------ | |
78 | * | r12 | | |
79 | * ~ ~ | |
80 | * | --to-- | (scratch Regs of user mode) | |
81 | * | r0 | | |
3ebedbb2 VG |
82 | * ------------------ |
83 | * | SP | | |
84 | * | orig_r0 | | |
502a0c77 | 85 | * | event/ECR | |
359105bd | 86 | * | user_r25 | |
bf90e1ea VG |
87 | * ------------------ <===== END of PAGE |
88 | */ | |
89 | int copy_thread(unsigned long clone_flags, | |
18e1d1b1 | 90 | unsigned long usp, unsigned long kthread_arg, |
bf90e1ea VG |
91 | struct task_struct *p) |
92 | { | |
93 | struct pt_regs *c_regs; /* child's pt_regs */ | |
94 | unsigned long *childksp; /* to unwind out of __switch_to() */ | |
95 | struct callee_regs *c_callee; /* child's callee regs */ | |
96 | struct callee_regs *parent_callee; /* paren't callee */ | |
97 | struct pt_regs *regs = current_pt_regs(); | |
98 | ||
99 | /* Mark the specific anchors to begin with (see pic above) */ | |
100 | c_regs = task_pt_regs(p); | |
101 | childksp = (unsigned long *)c_regs - 2; /* 2 words for FP/BLINK */ | |
102 | c_callee = ((struct callee_regs *)childksp) - 1; | |
103 | ||
104 | /* | |
105 | * __switch_to() uses thread.ksp to start unwinding stack | |
106 | * For kernel threads we don't need to create callee regs, the | |
107 | * stack layout nevertheless needs to remain the same. | |
108 | * Also, since __switch_to anyways unwinds callee regs, we use | |
109 | * this to populate kernel thread entry-pt/args into callee regs, | |
110 | * so that ret_from_kernel_thread() becomes simpler. | |
111 | */ | |
112 | p->thread.ksp = (unsigned long)c_callee; /* THREAD_KSP */ | |
113 | ||
114 | /* __switch_to expects FP(0), BLINK(return addr) at top */ | |
115 | childksp[0] = 0; /* fp */ | |
116 | childksp[1] = (unsigned long)ret_from_fork; /* blink */ | |
117 | ||
118 | if (unlikely(p->flags & PF_KTHREAD)) { | |
119 | memset(c_regs, 0, sizeof(struct pt_regs)); | |
120 | ||
18e1d1b1 | 121 | c_callee->r13 = kthread_arg; |
bf90e1ea VG |
122 | c_callee->r14 = usp; /* function */ |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
127 | /*--------- User Task Only --------------*/ | |
128 | ||
129 | /* __switch_to expects FP(0), BLINK(return addr) at top of stack */ | |
130 | childksp[0] = 0; /* for POP fp */ | |
131 | childksp[1] = (unsigned long)ret_from_fork; /* for POP blink */ | |
132 | ||
133 | /* Copy parents pt regs on child's kernel mode stack */ | |
134 | *c_regs = *regs; | |
135 | ||
136 | if (usp) | |
137 | c_regs->sp = usp; | |
138 | ||
139 | c_regs->r0 = 0; /* fork returns 0 in child */ | |
140 | ||
141 | parent_callee = ((struct callee_regs *)regs) - 1; | |
142 | *c_callee = *parent_callee; | |
143 | ||
144 | if (unlikely(clone_flags & CLONE_SETTLS)) { | |
145 | /* | |
146 | * set task's userland tls data ptr from 4th arg | |
147 | * clone C-lib call is difft from clone sys-call | |
148 | */ | |
149 | task_thread_info(p)->thr_ptr = regs->r3; | |
150 | } else { | |
151 | /* Normal fork case: set parent's TLS ptr in child */ | |
152 | task_thread_info(p)->thr_ptr = | |
153 | task_thread_info(current)->thr_ptr; | |
154 | } | |
155 | ||
156 | return 0; | |
157 | } | |
158 | ||
2ab402df VG |
159 | /* |
160 | * Do necessary setup to start up a new user task | |
161 | */ | |
162 | void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long usp) | |
163 | { | |
2ab402df VG |
164 | regs->sp = usp; |
165 | regs->ret = pc; | |
166 | ||
167 | /* | |
168 | * [U]ser Mode bit set | |
169 | * [L] ZOL loop inhibited to begin with - cleared by a LP insn | |
170 | * Interrupts enabled | |
171 | */ | |
1f6ccfff | 172 | regs->status32 = STATUS_U_MASK | STATUS_L_MASK | ISA_INIT_STATUS_BITS; |
2ab402df VG |
173 | |
174 | /* bogus seed values for debugging */ | |
175 | regs->lp_start = 0x10; | |
176 | regs->lp_end = 0x80; | |
177 | } | |
178 | ||
bf90e1ea VG |
179 | /* |
180 | * Some archs flush debug and FPU info here | |
181 | */ | |
182 | void flush_thread(void) | |
183 | { | |
184 | } | |
185 | ||
bf90e1ea VG |
186 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) |
187 | { | |
188 | return 0; | |
189 | } | |
190 | ||
bf90e1ea VG |
191 | int elf_check_arch(const struct elf32_hdr *x) |
192 | { | |
193 | unsigned int eflags; | |
194 | ||
1f6ccfff VG |
195 | if (x->e_machine != EM_ARC_INUSE) { |
196 | pr_err("ELF not built for %s ISA\n", | |
197 | is_isa_arcompact() ? "ARCompact":"ARCv2"); | |
bf90e1ea | 198 | return 0; |
1f6ccfff | 199 | } |
bf90e1ea VG |
200 | |
201 | eflags = x->e_flags; | |
840c054f | 202 | if ((eflags & EF_ARC_OSABI_MSK) != EF_ARC_OSABI_CURRENT) { |
bf90e1ea VG |
203 | pr_err("ABI mismatch - you need newer toolchain\n"); |
204 | force_sigsegv(SIGSEGV, current); | |
205 | return 0; | |
206 | } | |
207 | ||
208 | return 1; | |
209 | } | |
210 | EXPORT_SYMBOL(elf_check_arch); |