From a3169750b5cfcdc950b9e2bdd85cdf65341db307 Mon Sep 17 00:00:00 2001
From: Roy Oursler <roy.j.oursler@intel.com>
Date: Thu, 13 Dec 2018 15:29:05 -0700
Subject: [PATCH] mem: Remove unaligned loads in base function

Change-Id: I8fb0f2e2e372485c864d5c60f816b661a865b707
Signed-off-by: Roy Oursler <roy.j.oursler@intel.com>
---
 include/unaligned.h        |  5 +++++
 mem/mem_zero_detect_base.c | 18 +++++++++---------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/include/unaligned.h b/include/unaligned.h
index d048655..f9437df 100644
--- a/include/unaligned.h
+++ b/include/unaligned.h
@@ -51,5 +51,10 @@ static inline uint64_t load_u64(uint8_t * buf) {
 	return ret;
 }
 
+static inline uintmax_t load_umax(uint8_t * buf) {
+	uintmax_t ret;
+	memcpy(&ret, buf, sizeof(ret));
+	return ret;
+}
 
 #endif
diff --git a/mem/mem_zero_detect_base.c b/mem/mem_zero_detect_base.c
index ae11553..2353016 100644
--- a/mem/mem_zero_detect_base.c
+++ b/mem/mem_zero_detect_base.c
@@ -29,22 +29,22 @@
 
 #include <stdint.h>
 #include <stddef.h>
+#include "unaligned.h"
 
 int mem_zero_detect_base(void *buf, size_t n)
 {
-	unsigned char *c;
-	uintmax_t a = 0, *p = buf;
+	uint8_t *c = buf;
+	uintmax_t a = 0;
 
 	// Check buffer in native machine width comparisons
-	while (n >= sizeof(*p)) {
-		n -= sizeof(*p);
-		if (*p++ != 0)
+	while (n >= sizeof(uintmax_t)) {
+		n -= sizeof(uintmax_t);
+		if (load_umax(c) != 0)
 			return -1;
+		c += sizeof(uintmax_t);
 	}
 
 	// Check remaining bytes
-	c = (unsigned char *)p;
-
 	switch (n) {
 	case 7:
 		a |= *c++;	// fall through to case 6,5,4
@@ -53,12 +53,12 @@ int mem_zero_detect_base(void *buf, size_t n)
 	case 5:
 		a |= *c++;	// fall through to case 4
 	case 4:
-		a |= *((unsigned int *)c);
+		a |= load_u32(c);
 		break;
 	case 3:
 		a |= *c++;	// fall through to case 2
 	case 2:
-		a |= *((unsigned short *)c);
+		a |= load_u16(c);
 		break;
 	case 1:
 		a |= *c;