Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / arch / mips / kernel / syscall.c
blob58c6f634b5506a32858fb9f036c7aff465363fb5
1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
6 * Copyright (C) 1995, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2001 MIPS Technologies, Inc.
9 */
10 #include <linux/capability.h>
11 #include <linux/errno.h>
12 #include <linux/linkage.h>
13 #include <linux/fs.h>
14 #include <linux/smp.h>
15 #include <linux/ptrace.h>
16 #include <linux/string.h>
17 #include <linux/syscalls.h>
18 #include <linux/file.h>
19 #include <linux/utsname.h>
20 #include <linux/unistd.h>
21 #include <linux/sem.h>
22 #include <linux/msg.h>
23 #include <linux/shm.h>
24 #include <linux/compiler.h>
25 #include <linux/ipc.h>
26 #include <linux/uaccess.h>
27 #include <linux/slab.h>
28 #include <linux/elf.h>
29 #include <linux/sched/task_stack.h>
31 #include <asm/asm.h>
32 #include <asm/asm-eva.h>
33 #include <asm/branch.h>
34 #include <asm/cachectl.h>
35 #include <asm/cacheflush.h>
36 #include <asm/asm-offsets.h>
37 #include <asm/signal.h>
38 #include <asm/sim.h>
39 #include <asm/shmparam.h>
40 #include <asm/sysmips.h>
41 #include <asm/switch_to.h>
44 * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
45 * convention. It returns results in registers $v0 / $v1 which means there
46 * is no need for it to do verify the validity of a userspace pointer
47 * argument. Historically that used to be expensive in Linux. These days
48 * the performance advantage is negligible.
50 asmlinkage int sysm_pipe(void)
52 int fd[2];
53 int error = do_pipe_flags(fd, 0);
54 if (error)
55 return error;
56 current_pt_regs()->regs[3] = fd[1];
57 return fd[0];
60 SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
61 unsigned long, prot, unsigned long, flags, unsigned long,
62 fd, off_t, offset)
64 if (offset & ~PAGE_MASK)
65 return -EINVAL;
66 return sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
69 SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
70 unsigned long, prot, unsigned long, flags, unsigned long, fd,
71 unsigned long, pgoff)
73 if (pgoff & (~PAGE_MASK >> 12))
74 return -EINVAL;
76 return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
79 save_static_function(sys_fork);
80 save_static_function(sys_clone);
82 SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
84 struct thread_info *ti = task_thread_info(current);
86 ti->tp_value = addr;
87 if (cpu_has_userlocal)
88 write_c0_userlocal(addr);
90 return 0;
93 static inline int mips_atomic_set(unsigned long addr, unsigned long new)
95 unsigned long old, tmp;
96 struct pt_regs *regs;
97 unsigned int err;
99 if (unlikely(addr & 3))
100 return -EINVAL;
102 if (unlikely(!access_ok(VERIFY_WRITE, (const void __user *)addr, 4)))
103 return -EINVAL;
105 if (cpu_has_llsc && R10000_LLSC_WAR) {
106 __asm__ __volatile__ (
107 " .set arch=r4000 \n"
108 " li %[err], 0 \n"
109 "1: ll %[old], (%[addr]) \n"
110 " move %[tmp], %[new] \n"
111 "2: sc %[tmp], (%[addr]) \n"
112 " beqzl %[tmp], 1b \n"
113 "3: \n"
114 " .insn \n"
115 " .section .fixup,\"ax\" \n"
116 "4: li %[err], %[efault] \n"
117 " j 3b \n"
118 " .previous \n"
119 " .section __ex_table,\"a\" \n"
120 " "STR(PTR)" 1b, 4b \n"
121 " "STR(PTR)" 2b, 4b \n"
122 " .previous \n"
123 " .set mips0 \n"
124 : [old] "=&r" (old),
125 [err] "=&r" (err),
126 [tmp] "=&r" (tmp)
127 : [addr] "r" (addr),
128 [new] "r" (new),
129 [efault] "i" (-EFAULT)
130 : "memory");
131 } else if (cpu_has_llsc) {
132 __asm__ __volatile__ (
133 " .set "MIPS_ISA_ARCH_LEVEL" \n"
134 " li %[err], 0 \n"
135 "1: \n"
136 user_ll("%[old]", "(%[addr])")
137 " move %[tmp], %[new] \n"
138 "2: \n"
139 user_sc("%[tmp]", "(%[addr])")
140 " beqz %[tmp], 1b \n"
141 "3: \n"
142 " .insn \n"
143 " .section .fixup,\"ax\" \n"
144 "5: li %[err], %[efault] \n"
145 " j 3b \n"
146 " .previous \n"
147 " .section __ex_table,\"a\" \n"
148 " "STR(PTR)" 1b, 5b \n"
149 " "STR(PTR)" 2b, 5b \n"
150 " .previous \n"
151 " .set mips0 \n"
152 : [old] "=&r" (old),
153 [err] "=&r" (err),
154 [tmp] "=&r" (tmp)
155 : [addr] "r" (addr),
156 [new] "r" (new),
157 [efault] "i" (-EFAULT)
158 : "memory");
159 } else {
160 do {
161 preempt_disable();
162 ll_bit = 1;
163 ll_task = current;
164 preempt_enable();
166 err = __get_user(old, (unsigned int *) addr);
167 err |= __put_user(new, (unsigned int *) addr);
168 if (err)
169 break;
170 rmb();
171 } while (!ll_bit);
174 if (unlikely(err))
175 return err;
177 regs = current_pt_regs();
178 regs->regs[2] = old;
179 regs->regs[7] = 0; /* No error */
182 * Don't let your children do this ...
184 __asm__ __volatile__(
185 " move $29, %0 \n"
186 " j syscall_exit \n"
187 : /* no outputs */
188 : "r" (regs));
190 /* unreached. Honestly. */
191 unreachable();
195 * mips_atomic_set() normally returns directly via syscall_exit potentially
196 * clobbering static registers, so be sure to preserve them.
198 save_static_function(sys_sysmips);
200 SYSCALL_DEFINE3(sysmips, long, cmd, long, arg1, long, arg2)
202 switch (cmd) {
203 case MIPS_ATOMIC_SET:
204 return mips_atomic_set(arg1, arg2);
206 case MIPS_FIXADE:
207 if (arg1 & ~3)
208 return -EINVAL;
210 if (arg1 & 1)
211 set_thread_flag(TIF_FIXADE);
212 else
213 clear_thread_flag(TIF_FIXADE);
214 if (arg1 & 2)
215 set_thread_flag(TIF_LOGADE);
216 else
217 clear_thread_flag(TIF_LOGADE);
219 return 0;
221 case FLUSH_CACHE:
222 __flush_cache_all();
223 return 0;
226 return -EINVAL;
230 * No implemented yet ...
232 SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
234 return -ENOSYS;
238 * If we ever come here the user sp is bad. Zap the process right away.
239 * Due to the bad stack signaling wouldn't work.
241 asmlinkage void bad_stack(void)
243 do_exit(SIGSEGV);