powerpc: Add 64bit csum_and_copy_to_user

This adds the equivalent of csum_and_copy_from_user for the receive side so we
can copy and checksum in one pass. It is modelled on the generic checksum
routine.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Anton Blanchard 2010-08-02 20:11:36 +00:00 committed by Benjamin Herrenschmidt
parent fdd374b62c
commit 8c77391475
2 changed files with 40 additions and 0 deletions

View file

@ -57,6 +57,9 @@ extern __wsum csum_partial_copy_generic(const void *src, void *dst,
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
extern __wsum csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *err_ptr);
#define HAVE_CSUM_COPY_USER
extern __wsum csum_and_copy_to_user(const void *src, void __user *dst,
int len, __wsum sum, int *err_ptr);
#else
/*
* the same as csum_partial, but copies from src to dst while it

View file

@ -63,3 +63,40 @@ __wsum csum_and_copy_from_user(const void __user *src, void *dst,
return (__force __wsum)csum;
}
EXPORT_SYMBOL(csum_and_copy_from_user);
__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
__wsum sum, int *err_ptr)
{
unsigned int csum;
might_sleep();
*err_ptr = 0;
if (!len) {
csum = 0;
goto out;
}
if (unlikely((len < 0) || !access_ok(VERIFY_WRITE, dst, len))) {
*err_ptr = -EFAULT;
csum = -1; /* invalid checksum */
goto out;
}
csum = csum_partial_copy_generic(src, (void __force *)dst,
len, sum, NULL, err_ptr);
if (unlikely(*err_ptr)) {
csum = csum_partial(src, len, sum);
if (copy_to_user(dst, src, len)) {
*err_ptr = -EFAULT;
csum = -1; /* invalid checksum */
}
}
out:
return (__force __wsum)csum;
}
EXPORT_SYMBOL(csum_and_copy_to_user);