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1 /*
2  * linux/arch/m32r/kernel/sys_m32r.c
3  *
4  * This file contains various random system calls that
5  * have a non-standard calling sequence on the Linux/M32R platform.
6  *
7  * Taken from i386 version.
8  */
9 
10 #include <linux/errno.h>
11 #include <linux/sched.h>
12 #include <linux/mm.h>
13 #include <linux/fs.h>
14 #include <linux/smp.h>
15 #include <linux/sem.h>
16 #include <linux/msg.h>
17 #include <linux/shm.h>
18 #include <linux/stat.h>
19 #include <linux/syscalls.h>
20 #include <linux/mman.h>
21 #include <linux/file.h>
22 #include <linux/utsname.h>
23 #include <linux/ipc.h>
24 
25 #include <asm/uaccess.h>
26 #include <asm/cachectl.h>
27 #include <asm/cacheflush.h>
28 #include <asm/syscall.h>
29 #include <asm/unistd.h>
30 
31 /*
32  * sys_tas() - test-and-set
33  */
sys_tas(int __user * addr)34 asmlinkage int sys_tas(int __user *addr)
35 {
36 	int oldval;
37 
38 	if (!access_ok(VERIFY_WRITE, addr, sizeof (int)))
39 		return -EFAULT;
40 
41 	/* atomic operation:
42 	 *   oldval = *addr; *addr = 1;
43 	 */
44 	__asm__ __volatile__ (
45 		DCACHE_CLEAR("%0", "r4", "%1")
46 		"	.fillinsn\n"
47 		"1:\n"
48 		"	lock	%0, @%1	    ->	unlock	%2, @%1\n"
49 		"2:\n"
50 		/* NOTE:
51 		 *   The m32r processor can accept interrupts only
52 		 *   at the 32-bit instruction boundary.
53 		 *   So, in the above code, the "unlock" instruction
54 		 *   can be executed continuously after the "lock"
55 		 *   instruction execution without any interruptions.
56 		 */
57 		".section .fixup,\"ax\"\n"
58 		"	.balign 4\n"
59 		"3:	ldi	%0, #%3\n"
60 		"	seth	r14, #high(2b)\n"
61 		"	or3	r14, r14, #low(2b)\n"
62 		"	jmp	r14\n"
63 		".previous\n"
64 		".section __ex_table,\"a\"\n"
65 		"	.balign 4\n"
66 		"	.long 1b,3b\n"
67 		".previous\n"
68 		: "=&r" (oldval)
69 		: "r" (addr), "r" (1), "i"(-EFAULT)
70 		: "r14", "memory"
71 #ifdef CONFIG_CHIP_M32700_TS1
72 		  , "r4"
73 #endif /* CONFIG_CHIP_M32700_TS1 */
74 	);
75 
76 	return oldval;
77 }
78 
sys_cacheflush(void * addr,int bytes,int cache)79 asmlinkage int sys_cacheflush(void *addr, int bytes, int cache)
80 {
81 	/* This should flush more selectively ...  */
82 	_flush_cache_all();
83 	return 0;
84 }
85 
sys_cachectl(char * addr,int nbytes,int op)86 asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
87 {
88 	/* Not implemented yet. */
89 	return -ENOSYS;
90 }
91