ePAR specifies that if the property "ranges" doesn''t exist in
a bus node:
"it is assumed that no mapping exists between children of node and the
parent
address space".
Modify dt_number_of_address to check if the list of ranges are valid. Return
0 (ie there is zero range) if the list is not valid.
This patch has been tested on the Arndale where the bug can occur with the
''/hdmi'' node.
Reported-by: <tsahee@gmx.com>
Signed-off-by: Julien Grall <julien.grall@linaro.org>
---
This patch is a bug fix for Xen 4.4. Without it, Xen can''t boot on the
Arndale
because it''s unable to translate a wrong address.
---
xen/common/device_tree.c | 31 +++++++++++++++++++++++++++----
1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
index 84e709d..9b9a348 100644
--- a/xen/common/device_tree.c
+++ b/xen/common/device_tree.c
@@ -93,7 +93,7 @@ struct dt_bus
{
const char *name;
const char *addresses;
- int (*match)(const struct dt_device_node *parent);
+ bool_t (*match)(const struct dt_device_node *parent);
void (*count_cells)(const struct dt_device_node *child,
int *addrc, int *sizec);
u64 (*map)(__be32 *addr, const __be32 *range, int na, int ns, int pna);
@@ -793,6 +793,18 @@ int dt_n_size_cells(const struct dt_device_node *np)
/*
* Default translator (generic bus)
*/
+static bool_t dt_bus_default_match(const struct dt_device_node *parent)
+{
+ /* Root node doesn''t have "ranges" property */
+ if ( parent->parent == NULL )
+ return 1;
+
+ /* The default bus is only used when the "ranges" property
exists.
+ * Otherwise we can''t translate the address
+ */
+ return (dt_get_property(parent, "ranges", NULL) != NULL);
+}
+
static void dt_bus_default_count_cells(const struct dt_device_node *dev,
int *addrc, int *sizec)
{
@@ -819,7 +831,7 @@ static u64 dt_bus_default_map(__be32 *addr, const __be32
*range,
* If the number of address cells is larger than 2 we assume the
* mapping doesn''t specify a physical address. Rather, the address
* specifies an identifier that must match exactly.
- */
+ */
if ( na > 2 && memcmp(range, addr, na * 4) != 0 )
return DT_BAD_ADDR;
@@ -856,7 +868,7 @@ static const struct dt_bus dt_busses[] {
.name = "default",
.addresses = "reg",
- .match = NULL,
+ .match = dt_bus_default_match,
.count_cells = dt_bus_default_count_cells,
.map = dt_bus_default_map,
.translate = dt_bus_default_translate,
@@ -871,7 +883,6 @@ static const struct dt_bus *dt_match_bus(const struct
dt_device_node *np)
for ( i = 0; i < ARRAY_SIZE(dt_busses); i++ )
if ( !dt_busses[i].match || dt_busses[i].match(np) )
return &dt_busses[i];
- BUG();
return NULL;
}
@@ -890,7 +901,10 @@ static const __be32 *dt_get_address(const struct
dt_device_node *dev,
parent = dt_get_parent(dev);
if ( parent == NULL )
return NULL;
+
bus = dt_match_bus(parent);
+ if ( !bus )
+ return NULL;
bus->count_cells(dev, &na, &ns);
if ( !DT_CHECK_ADDR_COUNT(na) )
@@ -994,6 +1008,8 @@ static u64 __dt_translate_address(const struct
dt_device_node *dev,
if ( parent == NULL )
goto bail;
bus = dt_match_bus(parent);
+ if ( !bus )
+ goto bail;
/* Count address cells & copy address locally */
bus->count_cells(dev, &na, &ns);
@@ -1026,6 +1042,11 @@ static u64 __dt_translate_address(const struct
dt_device_node *dev,
/* Get new parent bus and counts */
pbus = dt_match_bus(parent);
+ if ( pbus == NULL )
+ {
+ dt_printk("DT: %s is not a valid bus\n",
parent->full_name);
+ break;
+ }
pbus->count_cells(dev, &pna, &pns);
if ( !DT_CHECK_COUNTS(pna, pns) )
{
@@ -1164,6 +1185,8 @@ unsigned int dt_number_of_address(const struct
dt_device_node *dev)
return 0;
bus = dt_match_bus(parent);
+ if ( !bus )
+ return 0;
bus->count_cells(dev, &na, &ns);
if ( !DT_CHECK_COUNTS(na, ns) )
--
1.7.10.4