From: Joerg Roedel <jroedel@xxxxxxx>
The main use of MAX_PHANDLE_ARGS is to define the number of
args elements in 'struct of_phandle_args'. This struct is
often declared on the stack and thus it is impractical to
increase MAX_PHANDLE_ARGS again and again.
To handle situations where more than MAX_PHANDLE_ARGS
elements may appear in a device-tree, introduce functions
to allocate/free 'struct of_phandle_args' with more than
MAX_PHANDLE_ARGS elements and provide the new function
of_parse_phandle_with_var_args(), which can handle those
variable-size structs.
This is necessary for the ARM-SMMU driver, where the number
of mmu-masters can be up to 128.
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
drivers/of/base.c | 43 ++++++++++++++++++++++++++++++++++++-------
include/linux/of.h | 7 +++++++
2 files changed, 43 insertions(+), 7 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 8b5a187..2b288db 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -54,6 +54,24 @@ DEFINE_MUTEX(of_mutex);
*/
DEFINE_RAW_SPINLOCK(devtree_lock);
+struct of_phandle_args *of_alloc_phandle_args(int size)
+{
+ struct of_phandle_args *args;
+ int e = max(0, size - MAX_PHANDLE_ARGS);
+
+ args = kzalloc(sizeof(struct of_phandle_args) + e * sizeof(uint32_t),
+ GFP_KERNEL);
+
+ return args;
+}
+EXPORT_SYMBOL(of_alloc_phandle_args);
+
+void of_free_phandle_args(struct of_phandle_args *args)
+{
+ kfree(args);
+}
+EXPORT_SYMBOL(of_free_phandle_args);
+
int of_n_addr_cells(struct device_node *np)
{
const __be32 *ip;
@@ -1446,7 +1464,8 @@ static int __of_parse_phandle_with_args(const struct device_node *np,
const char *list_name,
const char *cells_name,
int cell_count, int index,
- struct of_phandle_args *out_args)
+ struct of_phandle_args *out_args,
+ int elems)
{
const __be32 *list, *list_end;
int rc = 0, size, cur_index = 0;
@@ -1525,8 +1544,8 @@ static int __of_parse_phandle_with_args(const struct device_node *np,
if (out_args) {
int i;
- if (WARN_ON(count > MAX_PHANDLE_ARGS))
- count = MAX_PHANDLE_ARGS;
+ if (WARN_ON(count > elems))
+ count = elems;
out_args->np = node;
out_args->args_count = count;
for (i = 0; i < count; i++)
@@ -1577,7 +1596,7 @@ struct device_node *of_parse_phandle(const struct device_node *np,
return NULL;
if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
- index, &args))
+ index, &args, MAX_PHANDLE_ARGS))
return NULL;
return args.np;
@@ -1623,10 +1642,20 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na
if (index < 0)
return -EINVAL;
return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
- index, out_args);
+ index, out_args, MAX_PHANDLE_ARGS);
}
EXPORT_SYMBOL(of_parse_phandle_with_args);
+int of_parse_phandle_with_var_args(const struct device_node *np, const char *list_name,
+ const char *cells_name, int index,
+ struct of_phandle_args *out_args, int elems)
+{
+ if (index < 0)
+ return -EINVAL;
+ return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
+ index, out_args, elems);
+}
+EXPORT_SYMBOL(of_parse_phandle_with_var_args);
/**
* of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
* @np: pointer to a device tree node containing a list
@@ -1664,7 +1693,7 @@ int of_parse_phandle_with_fixed_args(const struct device_node *np,
if (index < 0)
return -EINVAL;
return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
- index, out_args);
+ index, out_args, MAX_PHANDLE_ARGS);
}
EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
@@ -1687,7 +1716,7 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na
const char *cells_name)
{
return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
- NULL);
+ NULL, MAX_PHANDLE_ARGS);
}
EXPORT_SYMBOL(of_count_phandle_with_args);
diff --git a/include/linux/of.h b/include/linux/of.h
index edc068d..cd9f225 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -75,6 +75,10 @@ struct of_phandle_args {
uint32_t args[MAX_PHANDLE_ARGS];
};
+/* Use these if you need more that MAX_PHANDLE_ARGS */
+extern struct of_phandle_args *of_alloc_phandle_args(int size);
+extern void of_free_phandle_args(struct of_phandle_args *args);
+
struct of_reconfig_data {
struct device_node *dn;
struct property *prop;
@@ -327,6 +331,9 @@ extern struct device_node *of_parse_phandle(const struct device_node *np,
extern int of_parse_phandle_with_args(const struct device_node *np,
const char *list_name, const char *cells_name, int index,
struct of_phandle_args *out_args);
+extern int of_parse_phandle_with_var_args(const struct device_node *np,
+ const char *list_name, const char *cells_name, int index,
+ struct of_phandle_args *out_args, int elems);
extern int of_parse_phandle_with_fixed_args(const struct device_node *np,
const char *list_name, int cells_count, int index,
struct of_phandle_args *out_args);
--
1.9.1
--
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