392 lines
		
	
	
	
		
			9 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			392 lines
		
	
	
	
		
			9 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /*
 | ||
|  |  * csum_partial_copy - do IP checksumming and copy | ||
|  |  * | ||
|  |  * (C) Copyright 1996 Linus Torvalds | ||
|  |  * accellerated versions (and 21264 assembly versions ) contributed by | ||
|  |  *	Rick Gorton	<rick.gorton@alpha-processor.com> | ||
|  |  * | ||
|  |  * Don't look at this too closely - you'll go mad. The things | ||
|  |  * we do for performance.. | ||
|  |  */ | ||
|  | 
 | ||
|  | #include <linux/types.h>
 | ||
|  | #include <linux/string.h>
 | ||
|  | #include <asm/uaccess.h>
 | ||
|  | 
 | ||
|  | 
 | ||
|  | #define ldq_u(x,y) \
 | ||
|  | __asm__ __volatile__("ldq_u %0,%1":"=r" (x):"m" (*(const unsigned long *)(y))) | ||
|  | 
 | ||
|  | #define stq_u(x,y) \
 | ||
|  | __asm__ __volatile__("stq_u %1,%0":"=m" (*(unsigned long *)(y)):"r" (x)) | ||
|  | 
 | ||
|  | #define extql(x,y,z) \
 | ||
|  | __asm__ __volatile__("extql %1,%2,%0":"=r" (z):"r" (x),"r" (y)) | ||
|  | 
 | ||
|  | #define extqh(x,y,z) \
 | ||
|  | __asm__ __volatile__("extqh %1,%2,%0":"=r" (z):"r" (x),"r" (y)) | ||
|  | 
 | ||
|  | #define mskql(x,y,z) \
 | ||
|  | __asm__ __volatile__("mskql %1,%2,%0":"=r" (z):"r" (x),"r" (y)) | ||
|  | 
 | ||
|  | #define mskqh(x,y,z) \
 | ||
|  | __asm__ __volatile__("mskqh %1,%2,%0":"=r" (z):"r" (x),"r" (y)) | ||
|  | 
 | ||
|  | #define insql(x,y,z) \
 | ||
|  | __asm__ __volatile__("insql %1,%2,%0":"=r" (z):"r" (x),"r" (y)) | ||
|  | 
 | ||
|  | #define insqh(x,y,z) \
 | ||
|  | __asm__ __volatile__("insqh %1,%2,%0":"=r" (z):"r" (x),"r" (y)) | ||
|  | 
 | ||
|  | 
 | ||
|  | #define __get_user_u(x,ptr)				\
 | ||
|  | ({							\ | ||
|  | 	long __guu_err;					\ | ||
|  | 	__asm__ __volatile__(				\ | ||
|  | 	"1:	ldq_u %0,%2\n"				\ | ||
|  | 	"2:\n"						\ | ||
|  | 	".section __ex_table,\"a\"\n"			\ | ||
|  | 	"	.long 1b - .\n"				\ | ||
|  | 	"	lda %0,2b-1b(%1)\n"			\ | ||
|  | 	".previous"					\ | ||
|  | 		: "=r"(x), "=r"(__guu_err)		\ | ||
|  | 		: "m"(__m(ptr)), "1"(0));		\ | ||
|  | 	__guu_err;					\ | ||
|  | }) | ||
|  | 
 | ||
|  | #define __put_user_u(x,ptr)				\
 | ||
|  | ({							\ | ||
|  | 	long __puu_err;					\ | ||
|  | 	__asm__ __volatile__(				\ | ||
|  | 	"1:	stq_u %2,%1\n"				\ | ||
|  | 	"2:\n"						\ | ||
|  | 	".section __ex_table,\"a\"\n"			\ | ||
|  | 	"	.long 1b - ."				\ | ||
|  | 	"	lda $31,2b-1b(%0)\n"			\ | ||
|  | 	".previous"					\ | ||
|  | 		: "=r"(__puu_err)			\ | ||
|  | 		: "m"(__m(addr)), "rJ"(x), "0"(0));	\ | ||
|  | 	__puu_err;					\ | ||
|  | }) | ||
|  | 
 | ||
|  | 
 | ||
|  | static inline unsigned short from64to16(unsigned long x) | ||
|  | { | ||
|  | 	/* Using extract instructions is a bit more efficient
 | ||
|  | 	   than the original shift/bitmask version.  */ | ||
|  | 
 | ||
|  | 	union { | ||
|  | 		unsigned long	ul; | ||
|  | 		unsigned int	ui[2]; | ||
|  | 		unsigned short	us[4]; | ||
|  | 	} in_v, tmp_v, out_v; | ||
|  | 
 | ||
|  | 	in_v.ul = x; | ||
|  | 	tmp_v.ul = (unsigned long) in_v.ui[0] + (unsigned long) in_v.ui[1]; | ||
|  | 
 | ||
|  | 	/* Since the bits of tmp_v.sh[3] are going to always be zero,
 | ||
|  | 	   we don't have to bother to add that in.  */ | ||
|  | 	out_v.ul = (unsigned long) tmp_v.us[0] + (unsigned long) tmp_v.us[1] | ||
|  | 			+ (unsigned long) tmp_v.us[2]; | ||
|  | 
 | ||
|  | 	/* Similarly, out_v.us[2] is always zero for the final add.  */ | ||
|  | 	return out_v.us[0] + out_v.us[1]; | ||
|  | } | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * Ok. This isn't fun, but this is the EASY case. | ||
|  |  */ | ||
|  | static inline unsigned long | ||
|  | csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst, | ||
|  | 			 long len, unsigned long checksum, | ||
|  | 			 int *errp) | ||
|  | { | ||
|  | 	unsigned long carry = 0; | ||
|  | 	int err = 0; | ||
|  | 
 | ||
|  | 	while (len >= 0) { | ||
|  | 		unsigned long word; | ||
|  | 		err |= __get_user(word, src); | ||
|  | 		checksum += carry; | ||
|  | 		src++; | ||
|  | 		checksum += word; | ||
|  | 		len -= 8; | ||
|  | 		carry = checksum < word; | ||
|  | 		*dst = word; | ||
|  | 		dst++; | ||
|  | 	} | ||
|  | 	len += 8; | ||
|  | 	checksum += carry; | ||
|  | 	if (len) { | ||
|  | 		unsigned long word, tmp; | ||
|  | 		err |= __get_user(word, src); | ||
|  | 		tmp = *dst; | ||
|  | 		mskql(word, len, word); | ||
|  | 		checksum += word; | ||
|  | 		mskqh(tmp, len, tmp); | ||
|  | 		carry = checksum < word; | ||
|  | 		*dst = word | tmp; | ||
|  | 		checksum += carry; | ||
|  | 	} | ||
|  | 	if (err) *errp = err; | ||
|  | 	return checksum; | ||
|  | } | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * This is even less fun, but this is still reasonably | ||
|  |  * easy. | ||
|  |  */ | ||
|  | static inline unsigned long | ||
|  | csum_partial_cfu_dest_aligned(const unsigned long __user *src, | ||
|  | 			      unsigned long *dst, | ||
|  | 			      unsigned long soff, | ||
|  | 			      long len, unsigned long checksum, | ||
|  | 			      int *errp) | ||
|  | { | ||
|  | 	unsigned long first; | ||
|  | 	unsigned long word, carry; | ||
|  | 	unsigned long lastsrc = 7+len+(unsigned long)src; | ||
|  | 	int err = 0; | ||
|  | 
 | ||
|  | 	err |= __get_user_u(first,src); | ||
|  | 	carry = 0; | ||
|  | 	while (len >= 0) { | ||
|  | 		unsigned long second; | ||
|  | 
 | ||
|  | 		err |= __get_user_u(second, src+1); | ||
|  | 		extql(first, soff, word); | ||
|  | 		len -= 8; | ||
|  | 		src++; | ||
|  | 		extqh(second, soff, first); | ||
|  | 		checksum += carry; | ||
|  | 		word |= first; | ||
|  | 		first = second; | ||
|  | 		checksum += word; | ||
|  | 		*dst = word; | ||
|  | 		dst++; | ||
|  | 		carry = checksum < word; | ||
|  | 	} | ||
|  | 	len += 8; | ||
|  | 	checksum += carry; | ||
|  | 	if (len) { | ||
|  | 		unsigned long tmp; | ||
|  | 		unsigned long second; | ||
|  | 		err |= __get_user_u(second, lastsrc); | ||
|  | 		tmp = *dst; | ||
|  | 		extql(first, soff, word); | ||
|  | 		extqh(second, soff, first); | ||
|  | 		word |= first; | ||
|  | 		mskql(word, len, word); | ||
|  | 		checksum += word; | ||
|  | 		mskqh(tmp, len, tmp); | ||
|  | 		carry = checksum < word; | ||
|  | 		*dst = word | tmp; | ||
|  | 		checksum += carry; | ||
|  | 	} | ||
|  | 	if (err) *errp = err; | ||
|  | 	return checksum; | ||
|  | } | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * This is slightly less fun than the above.. | ||
|  |  */ | ||
|  | static inline unsigned long | ||
|  | csum_partial_cfu_src_aligned(const unsigned long __user *src, | ||
|  | 			     unsigned long *dst, | ||
|  | 			     unsigned long doff, | ||
|  | 			     long len, unsigned long checksum, | ||
|  | 			     unsigned long partial_dest, | ||
|  | 			     int *errp) | ||
|  | { | ||
|  | 	unsigned long carry = 0; | ||
|  | 	unsigned long word; | ||
|  | 	unsigned long second_dest; | ||
|  | 	int err = 0; | ||
|  | 
 | ||
|  | 	mskql(partial_dest, doff, partial_dest); | ||
|  | 	while (len >= 0) { | ||
|  | 		err |= __get_user(word, src); | ||
|  | 		len -= 8; | ||
|  | 		insql(word, doff, second_dest); | ||
|  | 		checksum += carry; | ||
|  | 		stq_u(partial_dest | second_dest, dst); | ||
|  | 		src++; | ||
|  | 		checksum += word; | ||
|  | 		insqh(word, doff, partial_dest); | ||
|  | 		carry = checksum < word; | ||
|  | 		dst++; | ||
|  | 	} | ||
|  | 	len += 8; | ||
|  | 	if (len) { | ||
|  | 		checksum += carry; | ||
|  | 		err |= __get_user(word, src); | ||
|  | 		mskql(word, len, word); | ||
|  | 		len -= 8; | ||
|  | 		checksum += word; | ||
|  | 		insql(word, doff, second_dest); | ||
|  | 		len += doff; | ||
|  | 		carry = checksum < word; | ||
|  | 		partial_dest |= second_dest; | ||
|  | 		if (len >= 0) { | ||
|  | 			stq_u(partial_dest, dst); | ||
|  | 			if (!len) goto out; | ||
|  | 			dst++; | ||
|  | 			insqh(word, doff, partial_dest); | ||
|  | 		} | ||
|  | 		doff = len; | ||
|  | 	} | ||
|  | 	ldq_u(second_dest, dst); | ||
|  | 	mskqh(second_dest, doff, second_dest); | ||
|  | 	stq_u(partial_dest | second_dest, dst); | ||
|  | out: | ||
|  | 	checksum += carry; | ||
|  | 	if (err) *errp = err; | ||
|  | 	return checksum; | ||
|  | } | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * This is so totally un-fun that it's frightening. Don't | ||
|  |  * look at this too closely, you'll go blind. | ||
|  |  */ | ||
|  | static inline unsigned long | ||
|  | csum_partial_cfu_unaligned(const unsigned long __user * src, | ||
|  | 			   unsigned long * dst, | ||
|  | 			   unsigned long soff, unsigned long doff, | ||
|  | 			   long len, unsigned long checksum, | ||
|  | 			   unsigned long partial_dest, | ||
|  | 			   int *errp) | ||
|  | { | ||
|  | 	unsigned long carry = 0; | ||
|  | 	unsigned long first; | ||
|  | 	unsigned long lastsrc; | ||
|  | 	int err = 0; | ||
|  | 
 | ||
|  | 	err |= __get_user_u(first, src); | ||
|  | 	lastsrc = 7+len+(unsigned long)src; | ||
|  | 	mskql(partial_dest, doff, partial_dest); | ||
|  | 	while (len >= 0) { | ||
|  | 		unsigned long second, word; | ||
|  | 		unsigned long second_dest; | ||
|  | 
 | ||
|  | 		err |= __get_user_u(second, src+1); | ||
|  | 		extql(first, soff, word); | ||
|  | 		checksum += carry; | ||
|  | 		len -= 8; | ||
|  | 		extqh(second, soff, first); | ||
|  | 		src++; | ||
|  | 		word |= first; | ||
|  | 		first = second; | ||
|  | 		insql(word, doff, second_dest); | ||
|  | 		checksum += word; | ||
|  | 		stq_u(partial_dest | second_dest, dst); | ||
|  | 		carry = checksum < word; | ||
|  | 		insqh(word, doff, partial_dest); | ||
|  | 		dst++; | ||
|  | 	} | ||
|  | 	len += doff; | ||
|  | 	checksum += carry; | ||
|  | 	if (len >= 0) { | ||
|  | 		unsigned long second, word; | ||
|  | 		unsigned long second_dest; | ||
|  | 
 | ||
|  | 		err |= __get_user_u(second, lastsrc); | ||
|  | 		extql(first, soff, word); | ||
|  | 		extqh(second, soff, first); | ||
|  | 		word |= first; | ||
|  | 		first = second; | ||
|  | 		mskql(word, len-doff, word); | ||
|  | 		checksum += word; | ||
|  | 		insql(word, doff, second_dest); | ||
|  | 		carry = checksum < word; | ||
|  | 		stq_u(partial_dest | second_dest, dst); | ||
|  | 		if (len) { | ||
|  | 			ldq_u(second_dest, dst+1); | ||
|  | 			insqh(word, doff, partial_dest); | ||
|  | 			mskqh(second_dest, len, second_dest); | ||
|  | 			stq_u(partial_dest | second_dest, dst+1); | ||
|  | 		} | ||
|  | 		checksum += carry; | ||
|  | 	} else { | ||
|  | 		unsigned long second, word; | ||
|  | 		unsigned long second_dest; | ||
|  | 
 | ||
|  | 		err |= __get_user_u(second, lastsrc); | ||
|  | 		extql(first, soff, word); | ||
|  | 		extqh(second, soff, first); | ||
|  | 		word |= first; | ||
|  | 		ldq_u(second_dest, dst); | ||
|  | 		mskql(word, len-doff, word); | ||
|  | 		checksum += word; | ||
|  | 		mskqh(second_dest, len, second_dest); | ||
|  | 		carry = checksum < word; | ||
|  | 		insql(word, doff, word); | ||
|  | 		stq_u(partial_dest | word | second_dest, dst); | ||
|  | 		checksum += carry; | ||
|  | 	} | ||
|  | 	if (err) *errp = err; | ||
|  | 	return checksum; | ||
|  | } | ||
|  | 
 | ||
|  | static unsigned int | ||
|  | do_csum_partial_copy_from_user(const char __user *src, char *dst, int len, | ||
|  | 			       unsigned int sum, int *errp) | ||
|  | { | ||
|  | 	unsigned long checksum = (unsigned) sum; | ||
|  | 	unsigned long soff = 7 & (unsigned long) src; | ||
|  | 	unsigned long doff = 7 & (unsigned long) dst; | ||
|  | 
 | ||
|  | 	if (len) { | ||
|  | 		if (!doff) { | ||
|  | 			if (!soff) | ||
|  | 				checksum = csum_partial_cfu_aligned( | ||
|  | 					(const unsigned long __user *) src, | ||
|  | 					(unsigned long *) dst, | ||
|  | 					len-8, checksum, errp); | ||
|  | 			else | ||
|  | 				checksum = csum_partial_cfu_dest_aligned( | ||
|  | 					(const unsigned long __user *) src, | ||
|  | 					(unsigned long *) dst, | ||
|  | 					soff, len-8, checksum, errp); | ||
|  | 		} else { | ||
|  | 			unsigned long partial_dest; | ||
|  | 			ldq_u(partial_dest, dst); | ||
|  | 			if (!soff) | ||
|  | 				checksum = csum_partial_cfu_src_aligned( | ||
|  | 					(const unsigned long __user *) src, | ||
|  | 					(unsigned long *) dst, | ||
|  | 					doff, len-8, checksum, | ||
|  | 					partial_dest, errp); | ||
|  | 			else | ||
|  | 				checksum = csum_partial_cfu_unaligned( | ||
|  | 					(const unsigned long __user *) src, | ||
|  | 					(unsigned long *) dst, | ||
|  | 					soff, doff, len-8, checksum, | ||
|  | 					partial_dest, errp); | ||
|  | 		} | ||
|  | 		checksum = from64to16 (checksum); | ||
|  | 	} | ||
|  | 	return checksum; | ||
|  | } | ||
|  | 
 | ||
|  | unsigned int | ||
|  | csum_partial_copy_from_user(const char __user *src, char *dst, int len, | ||
|  | 			    unsigned int sum, int *errp) | ||
|  | { | ||
|  | 	if (!access_ok(VERIFY_READ, src, len)) { | ||
|  | 		*errp = -EFAULT; | ||
|  | 		memset(dst, 0, len); | ||
|  | 		return sum; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	return do_csum_partial_copy_from_user(src, dst, len, sum, errp); | ||
|  | } | ||
|  | 
 | ||
|  | unsigned int | ||
|  | csum_partial_copy_nocheck(const char __user *src, char *dst, int len, | ||
|  | 			  unsigned int sum) | ||
|  | { | ||
|  | 	return do_csum_partial_copy_from_user(src, dst, len, sum, NULL); | ||
|  | } |