summaryrefslogtreecommitdiffstats
path: root/arch/alpha/lib/csum_partial_copy.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/alpha/lib/csum_partial_copy.c')
-rw-r--r--arch/alpha/lib/csum_partial_copy.c385
1 files changed, 385 insertions, 0 deletions
diff --git a/arch/alpha/lib/csum_partial_copy.c b/arch/alpha/lib/csum_partial_copy.c
new file mode 100644
index 000000000..ddb9c2f37
--- /dev/null
+++ b/arch/alpha/lib/csum_partial_copy.c
@@ -0,0 +1,385 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * csum_partial_copy - do IP checksumming and copy
+ *
+ * (C) Copyright 1996 Linus Torvalds
+ * accelerated 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 <linux/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" \
+ EXC(1b,2b,%0,%1) \
+ : "=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" \
+ EXC(1b,2b,$31,%0) \
+ : "=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) *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) *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) *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) *errp = err;
+ return checksum;
+}
+
+__wsum
+csum_partial_copy_from_user(const void __user *src, void *dst, int len,
+ __wsum sum, int *errp)
+{
+ unsigned long checksum = (__force u32) sum;
+ unsigned long soff = 7 & (unsigned long) src;
+ unsigned long doff = 7 & (unsigned long) dst;
+
+ if (len) {
+ if (!access_ok(VERIFY_READ, src, len)) {
+ if (errp) *errp = -EFAULT;
+ memset(dst, 0, len);
+ return sum;
+ }
+ 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 (__force __wsum)checksum;
+}
+EXPORT_SYMBOL(csum_partial_copy_from_user);
+
+__wsum
+csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
+{
+ __wsum checksum;
+ mm_segment_t oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ checksum = csum_partial_copy_from_user((__force const void __user *)src,
+ dst, len, sum, NULL);
+ set_fs(oldfs);
+ return checksum;
+}
+EXPORT_SYMBOL(csum_partial_copy_nocheck);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-27 16:51:16 +0000