[Skiboot] [PATCH 05/15] libc/string: Add memcpy_ci

[Claudio Carvalho]

This adds memcpy_ci, it's a cache inhibited version of memcpy.

We use memcpy_ci to copy the verification code from the secure ROM
to memory. Due to performance issues we opted to run it from memory.

Signed-off-by: Claudio Carvalho <cclaudio at linux.vnet.ibm.com>
---
 libc/include/string.h    |  3 ++-
 libc/string/Makefile.inc |  9 +++++----
 libc/string/memcpy_ci.c  | 50 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 57 insertions(+), 5 deletions(-)
 create mode 100644 libc/string/memcpy_ci.c

diff --git a/libc/include/string.h b/libc/include/string.h
index 890ffc2..a53e4f4 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -1,5 +1,5 @@
 /******************************************************************************
- * Copyright (c) 2004, 2008 IBM Corporation
+ * Copyright (c) 2004, 2016 IBM Corporation
  * All rights reserved.
  * This program and the accompanying materials
  * are made available under the terms of the BSD License
@@ -32,6 +32,7 @@ char *strdup(const char *src);
 void *memset(void *s, int c, size_t n);
 void *memchr(const void *s, int c, size_t n);
 void *memcpy(void *dest, const void *src, size_t n);
+const void *memcpy_ci(const void *destpp, const void *srcpp, size_t len);
 void *memmove(void *dest, const void *src, size_t n);
 int memcmp(const void *s1, const void *s2, size_t n);
 
diff --git a/libc/string/Makefile.inc b/libc/string/Makefile.inc
index 3b7c8ce..5f7fa27 100644
--- a/libc/string/Makefile.inc
+++ b/libc/string/Makefile.inc
@@ -1,5 +1,5 @@
 # *****************************************************************************
-# * Copyright (c) 2004, 2008 IBM Corporation
+# * Copyright (c) 2004, 2016 IBM Corporation
 # * All rights reserved.
 # * This program and the accompanying materials
 # * are made available under the terms of the BSD License
@@ -12,9 +12,10 @@
 
 SUBDIRS += $(LIBCDIR)/string
 
-STRING_OBJS = strcat.o strchr.o strcmp.o strcpy.o strlen.o strncmp.o \
-	      strncpy.o strstr.o memset.o memcpy.o memmove.o memchr.o \
-	      memcmp.o strcasecmp.o strncasecmp.o strtok.o strdup.o
+STRING_OBJS = strcat.o strchr.o strcmp.o strcpy.o strlen.o \
+	      strncmp.o strncpy.o strstr.o memset.o memcpy.o memcpy_ci.o \
+	      memmove.o memchr.o memcmp.o strcasecmp.o strncasecmp.o \
+	      strtok.o strdup.o
 STRING = $(LIBCDIR)/string/built-in.o
 $(STRING): $(STRING_OBJS:%=$(LIBCDIR)/string/%)
 
diff --git a/libc/string/memcpy_ci.c b/libc/string/memcpy_ci.c
new file mode 100644
index 0000000..9af45dc
--- /dev/null
+++ b/libc/string/memcpy_ci.c
@@ -0,0 +1,50 @@
+/* Copyright 2013-2016 IBM Corp
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <string.h>
+#include <io.h>
+
+const void* memcpy_ci(const void *destpp, const void *srcpp, size_t len)
+{
+	size_t i;
+	const size_t block = sizeof(uint32_t);
+
+	unsigned long int destp = (long int) destpp;
+	unsigned long int srcp = (long int) srcpp;
+
+	/* copy just a few bytes to make dst aligned */
+	i = len % block;
+	while (i > 0)
+	{
+		*((uint8_t*) destp) = in_8((uint8_t*)srcp);
+		srcp += 1;
+		destp += 1;
+		i--;
+	}
+
+	len -= len % block;
+
+	/* copy the aligned bytes */
+	while(len > 0)
+	{
+		*((uint32_t*) destp) = in_be32((uint32_t*)srcp);
+		srcp += block;
+		destp += block;
+		len -= block;
+	}
+
+	return destpp;
+}
-- 
1.9.1