Any overlap in the reserved memory regions (those specified in the
reserved-memory DT node) is a bug. These bugs might go undetected as
long as the contested region isn't used simultaneously by multiple
software agents, which makes such bugs hard to debug. Fix this by
printing a scary warning during boot if overlap is detected.
Signed-off-by: Mitchel Humpherys <mitchelh@xxxxxxxxxxxxxx>
---
v1..v2:
- Suggestions from Rob Herring (remove superfluous array and
print statement)
---
drivers/of/of_reserved_mem.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 42 insertions(+), 1 deletion(-)
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 726ebe792813..62f467b8ccae 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -1,7 +1,7 @@
/*
* Device tree based initialization code for reserved memory.
*
- * Copyright (c) 2013, The Linux Foundation. All Rights Reserved.
+ * Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved.
* Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
* http://www.samsung.com
* Author: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
@@ -20,6 +20,7 @@
#include <linux/mm.h>
#include <linux/sizes.h>
#include <linux/of_reserved_mem.h>
+#include <linux/sort.h>
#define MAX_RESERVED_REGIONS 16
static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
@@ -197,12 +198,52 @@ static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
return -ENOENT;
}
+static int __init __rmem_cmp(const void *a, const void *b)
+{
+ const struct reserved_mem *ra = a, *rb = b;
+
+ return ra->base - rb->base;
+}
+
+static void __init __rmem_check_for_overlap(void)
+{
+ int i;
+
+ if (reserved_mem_count < 2)
+ return;
+
+ sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
+ __rmem_cmp, NULL);
+ for (i = 0; i < reserved_mem_count - 1; i++) {
+ struct reserved_mem *this, *next;
+
+ this = &reserved_mem[i];
+ next = &reserved_mem[i + 1];
+ if (!(this->base && next->base))
+ continue;
+ if (this->base + this->size > next->base) {
+ phys_addr_t this_end, next_end;
+
+ this_end = this->base + this->size;
+ next_end = next->base + next->size;
+ WARN(1,
+ "Reserved memory: OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
+ this->name, &this->base, &this_end,
+ next->name, &next->base, &next_end);
+ }
+ }
+}
+
/**
* fdt_init_reserved_mem - allocate and init all saved reserved memory regions
*/
void __init fdt_init_reserved_mem(void)
{
int i;
+
+ /* check for overlapping reserved regions */
+ __rmem_check_for_overlap();
+
for (i = 0; i < reserved_mem_count; i++) {
struct reserved_mem *rmem = &reserved_mem[i];
unsigned long node = rmem->fdt_node;
--
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
