[PATCH v4 12/14] software node: implement reference properties

Dmitry Torokhov
2019-09-11T05:12:58Z

It is possible to store references to software nodes in the same fashion as
other static properties, so that users do not need to define separate
structures:

static const struct software_node gpio_bank_b_node = {
.name = "B",
};

static const struct property_entry simone_key_enter_props[] = {
PROPERTY_ENTRY_U32("linux,code", KEY_ENTER),
PROPERTY_ENTRY_STRING("label", "enter"),
PROPERTY_ENTRY_REF("gpios", &gpio_bank_b_node, 123, GPIO_ACTIVE_LOW),
{ }
};

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
drivers/base/swnode.c | 48 +++++++++++++++++++++++++++------
include/linux/property.h | 57 +++++++++++++++++++++++++++++-----------
2 files changed, 81 insertions(+), 24 deletions(-)

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 1aa6559993ec..07e1325789d2 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -265,6 +265,12 @@ static int property_entry_copy_data(struct property_entry *dst,
}

dst->pointer = new;
+ } else if (src->type == DEV_PROP_REF) {
+ /*
+ * Reference properties are never stored inline as
+ * they are too big.
+ */
+ return -EINVAL;
} else if (src->type == DEV_PROP_STRING) {
new = kstrdup(src->value.str, GFP_KERNEL);
if (!new && src->value.str)
@@ -460,21 +466,47 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
{
struct swnode *swnode = to_swnode(fwnode);
const struct software_node_reference *ref;
+ const struct software_node_ref_args *ref_array;
+ const struct software_node_ref_args *ref_args;
const struct property_entry *prop;
struct fwnode_handle *refnode;
int i;

- if (!swnode || !swnode->node->references)
+ if (!swnode)
return -ENOENT;

- for (ref = swnode->node->references; ref->name; ref++)
- if (!strcmp(ref->name, propname))
- break;
+ prop = property_entry_get(swnode->node->properties, propname);
+ if (prop) {
+ if (prop->type != DEV_PROP_REF)
+ return -EINVAL;

- if (!ref->name || index > (ref->nrefs - 1))
- return -ENOENT;
+ /*
+ * We expect that references are never stored inline, even
+ * single ones, as they are too big.
+ */
+ if (prop->is_inline)
+ return -EINVAL;
+
+ if (index * sizeof(*ref_args) >= prop->length)
+ return -ENOENT;
+
+ ref_array = prop->pointer;
+ ref_args = &ref_array[index];
+ } else {
+ if (!swnode->node->references)
+ return -ENOENT;
+
+ for (ref = swnode->node->references; ref->name; ref++)
+ if (!strcmp(ref->name, propname))
+ break;
+
+ if (!ref->name || index > (ref->nrefs - 1))
+ return -ENOENT;
+
+ ref_args = &ref->refs[index];
+ }

- refnode = software_node_fwnode(ref->refs[index].node);
+ refnode = software_node_fwnode(ref_args->node);
if (!refnode)
return -ENOENT;

@@ -493,7 +525,7 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
args->nargs = nargs;

for (i = 0; i < nargs; i++)
- args->args[i] = ref->refs[index].args[i];
+ args->args[i] = ref_args->args[i];

return 0;
}
diff --git a/include/linux/property.h b/include/linux/property.h
index ac7823d58cfe..08d3e9d126ef 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -22,6 +22,7 @@ enum dev_prop_type {
DEV_PROP_U32,
DEV_PROP_U64,
DEV_PROP_STRING,
+ DEV_PROP_REF,
};

enum dev_dma_attr {
@@ -218,6 +219,20 @@ static inline int fwnode_property_count_u64(const struct fwnode_handle *fwnode,
return fwnode_property_read_u64_array(fwnode, propname, NULL, 0);
}

+struct software_node;
+
+/**
+ * struct software_node_ref_args - Reference property with additional arguments
+ * @node: Reference to a software node
+ * @nargs: Number of elements in @args array
+ * @args: Integer arguments
+ */
+struct software_node_ref_args {
+ const struct software_node *node;
+ unsigned int nargs;
+ u64 args[NR_FWNODE_REFERENCE_ARGS];
+};
+
/**
* struct property_entry - "Built-in" device property representation.
* @name: Name of the property.
@@ -255,14 +270,20 @@ struct property_entry {
#define __PROPERTY_ENTRY_ELEMENT_SIZE(_elem_) \
sizeof(((struct property_entry *)NULL)->value._elem_)

-#define __PROPERTY_ENTRY_ARRAY_LEN(_name_, _elem_, _Type_, _val_, _len_)\
+#define __PROPERTY_ENTRY_ARRAY_ELSIZE_LEN(_name_, _elsize_, _Type_, \
+ _val_, _len_) \
(struct property_entry) { \
.name = _name_, \
- .length = (_len_) * __PROPERTY_ENTRY_ELEMENT_SIZE(_elem_), \
+ .length = (_len_) * (_elsize_), \
.type = DEV_PROP_##_Type_, \
{ .pointer = _val_ }, \
}

+#define __PROPERTY_ENTRY_ARRAY_LEN(_name_, _elem_, _Type_, _val_, _len_)\
+ __PROPERTY_ENTRY_ARRAY_ELSIZE_LEN(_name_, \
+ __PROPERTY_ENTRY_ELEMENT_SIZE(_elem_), \
+ _Type_, _val_, _len_)
+
#define PROPERTY_ENTRY_U8_ARRAY_LEN(_name_, _val_, _len_) \
__PROPERTY_ENTRY_ARRAY_LEN(_name_, u8_data, U8, _val_, _len_)
#define PROPERTY_ENTRY_U16_ARRAY_LEN(_name_, _val_, _len_) \
@@ -273,6 +294,10 @@ struct property_entry {
__PROPERTY_ENTRY_ARRAY_LEN(_name_, u64_data, U64, _val_, _len_)
#define PROPERTY_ENTRY_STRING_ARRAY_LEN(_name_, _val_, _len_) \
__PROPERTY_ENTRY_ARRAY_LEN(_name_, str, STRING, _val_, _len_)
+#define PROPERTY_ENTRY_REF_ARRAY_LEN(_name_, _val_, _len_) \
+ __PROPERTY_ENTRY_ARRAY_ELSIZE_LEN(_name_, \
+ sizeof(struct software_node_ref_args), \
+ REF, _val_, _len_)

#define PROPERTY_ENTRY_U8_ARRAY(_name_, _val_) \
PROPERTY_ENTRY_U8_ARRAY_LEN(_name_, _val_, ARRAY_SIZE(_val_))
@@ -284,6 +309,8 @@ struct property_entry {
PROPERTY_ENTRY_U64_ARRAY_LEN(_name_, _val_, ARRAY_SIZE(_val_))
#define PROPERTY_ENTRY_STRING_ARRAY(_name_, _val_) \
PROPERTY_ENTRY_STRING_ARRAY_LEN(_name_, _val_, ARRAY_SIZE(_val_))
+#define PROPERTY_ENTRY_REF_ARRAY(_name_, _val_) \
+ PROPERTY_ENTRY_REF_ARRAY_LEN(_name_, _val_, ARRAY_SIZE(_val_))

#define __PROPERTY_ENTRY_ELEMENT(_name_, _elem_, _Type_, _val_) \
(struct property_entry) { \
@@ -310,6 +337,18 @@ struct property_entry {
.name = _name_, \
}

+#define PROPERTY_ENTRY_REF(_name_, _ref_, ...) \
+(struct property_entry) { \
+ .name = _name_, \
+ .length = sizeof(struct software_node_ref_args), \
+ .type = DEV_PROP_REF, \
+ { .pointer = &(const struct software_node_ref_args) { \
+ .node = _ref_, \
+ .nargs = ARRAY_SIZE(((u64[]){ 0, ##__VA_ARGS__ })) - 1, \
+ .args = { __VA_ARGS__ }, \
+ } }, \
+}
+
struct property_entry *
property_entries_dup(const struct property_entry *properties);

@@ -373,20 +412,6 @@ int fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
/* -------------------------------------------------------------------------- */
/* Software fwnode support - when HW description is incomplete or missing */

-struct software_node;
-
-/**
- * struct software_node_ref_args - Reference with additional arguments
- * @node: Reference to a software node
- * @nargs: Number of elements in @args array
- * @args: Integer arguments
- */
-struct software_node_ref_args {
- const struct software_node *node;
- unsigned int nargs;
- u64 args[NR_FWNODE_REFERENCE_ARGS];
-};
-
/**
* struct software_node_reference - Named software node reference property
* @name: Name of the property
--
2.23.0.162.g0b9fbb3734-goog