90 lines
		
	
	
	
		
			1.9 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			90 lines
		
	
	
	
		
			1.9 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * linux/arch/m32r/kernel/sys_m32r.c
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 *
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 * This file contains various random system calls that
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 * have a non-standard calling sequence on the Linux/M32R platform.
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 *
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 * Taken from i386 version.
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 */
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/smp.h>
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#include <linux/sem.h>
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#include <linux/msg.h>
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#include <linux/shm.h>
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#include <linux/stat.h>
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#include <linux/syscalls.h>
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#include <linux/mman.h>
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#include <linux/file.h>
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#include <linux/utsname.h>
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#include <linux/ipc.h>
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#include <asm/uaccess.h>
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#include <asm/cachectl.h>
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#include <asm/cacheflush.h>
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#include <asm/syscall.h>
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#include <asm/unistd.h>
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/*
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 * sys_tas() - test-and-set
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 */
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asmlinkage int sys_tas(int __user *addr)
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{
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	int oldval;
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	if (!access_ok(VERIFY_WRITE, addr, sizeof (int)))
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		return -EFAULT;
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	/* atomic operation:
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	 *   oldval = *addr; *addr = 1;
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	 */
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	__asm__ __volatile__ (
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		DCACHE_CLEAR("%0", "r4", "%1")
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		"	.fillinsn\n"
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		"1:\n"
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		"	lock	%0, @%1	    ->	unlock	%2, @%1\n"
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		"2:\n"
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		/* NOTE:
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		 *   The m32r processor can accept interrupts only
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		 *   at the 32-bit instruction boundary.
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		 *   So, in the above code, the "unlock" instruction
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		 *   can be executed continuously after the "lock"
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		 *   instruction execution without any interruptions.
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		 */
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		".section .fixup,\"ax\"\n"
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		"	.balign 4\n"
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		"3:	ldi	%0, #%3\n"
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		"	seth	r14, #high(2b)\n"
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		"	or3	r14, r14, #low(2b)\n"
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		"	jmp	r14\n"
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		".previous\n"
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		".section __ex_table,\"a\"\n"
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		"	.balign 4\n"
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		"	.long 1b,3b\n"
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		".previous\n"
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		: "=&r" (oldval)
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		: "r" (addr), "r" (1), "i"(-EFAULT)
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		: "r14", "memory"
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#ifdef CONFIG_CHIP_M32700_TS1
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		  , "r4"
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#endif /* CONFIG_CHIP_M32700_TS1 */
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	);
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	return oldval;
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}
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asmlinkage int sys_cacheflush(void *addr, int bytes, int cache)
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{
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	/* This should flush more selectively ...  */
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	_flush_cache_all();
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	return 0;
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}
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asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
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{
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	/* Not implemented yet. */
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	return -ENOSYS;
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}
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