dm: Use an allocated array for run-time device info

At present we update the driver_info struct with a pointer to the device
that it created (i.e. caused to be bound). This works fine when U-Boot SPL
is stored in read-write memory. But on some platforms, such as Intel
Apollo Lake, it is not possible to update the data memory.

In any case, it is bad form to put this information in a structure that is
in the data region, since it expands the size of the binary.

Create a new driver_rt structure which holds runtime information about
drivers. Update the code to store the device pointer in this instead.
Also update the test check that this works.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/core/device.c

@@ -249,7 +249,7 @@ int device_bind_ofnode(struct udevice *parent, const struct driver *drv,
 }
 
 int device_bind_by_name(struct udevice *parent, bool pre_reloc_only,
-			struct driver_info *info, struct udevice **devp)
+			const struct driver_info *info, struct udevice **devp)
 {
 	struct driver *drv;
 	uint platdata_size = 0;
@@ -269,9 +269,6 @@ int device_bind_by_name(struct udevice *parent, bool pre_reloc_only,
 				 platdata_size, devp);
 	if (ret)
 		return ret;
-#if CONFIG_IS_ENABLED(OF_PLATDATA)
-	info->dev = *devp;
-#endif
 
 	return ret;
 }
@@ -764,9 +761,13 @@ int device_get_global_by_ofnode(ofnode ofnode, struct udevice **devp)
 int device_get_by_driver_info(const struct driver_info *info,
 			      struct udevice **devp)
 {
+	struct driver_info *info_base =
+		ll_entry_start(struct driver_info, driver_info);
+	int idx = info - info_base;
+	struct driver_rt *drt = gd_dm_driver_rt() + idx;
 	struct udevice *dev;
 
-	dev = info->dev;
+	dev = drt->dev;
 	*devp = NULL;
 
 	return device_get_device_tail(dev, dev ? 0 : -ENOENT, devp);

drivers/core/lists.c

@@ -56,14 +56,20 @@ int lists_bind_drivers(struct udevice *parent, bool pre_reloc_only)
 	struct driver_info *info =
 		ll_entry_start(struct driver_info, driver_info);
 	const int n_ents = ll_entry_count(struct driver_info, driver_info);
-	struct driver_info *entry;
-	struct udevice *dev;
 	int result = 0;
-	int ret;
+	uint idx;
+
+	for (idx = 0; idx < n_ents; idx++) {
+		const struct driver_info *entry = info + idx;
+		struct driver_rt *drt = gd_dm_driver_rt() + idx;
+		struct udevice *dev;
+		int ret;
 
-	for (entry = info; entry != info + n_ents; entry++) {
 		ret = device_bind_by_name(parent, pre_reloc_only, entry, &dev);
-		if (ret && ret != -EPERM) {
+		if (!ret) {
+			if (CONFIG_IS_ENABLED(OF_PLATDATA))
+				drt->dev = dev;
+		} else if (ret != -EPERM) {
 			dm_warn("No match for driver '%s'\n", entry->name);
 			if (!result || ret != -ENOENT)
 				result = ret;

drivers/core/root.c

@@ -185,6 +185,17 @@ int dm_scan_platdata(bool pre_reloc_only)
 {
 	int ret;
 
+	if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
+		struct driver_rt *dyn;
+		int n_ents;
+
+		n_ents = ll_entry_count(struct driver_info, driver_info);
+		dyn = calloc(n_ents, sizeof(struct driver_rt));
+		if (!dyn)
+			return -ENOMEM;
+		gd_set_dm_driver_rt(dyn);
+	}
+
 	ret = lists_bind_drivers(DM_ROOT_NON_CONST, pre_reloc_only);
 	if (ret == -ENOENT) {
 		dm_warn("Some drivers were not found\n");

include/asm-generic/global_data.h

@@ -24,6 +24,8 @@
 #include <membuff.h>
 #include <linux/list.h>
 
+struct driver_rt;
+
 typedef struct global_data gd_t;
 
 /**
@@ -192,6 +194,10 @@ struct global_data {
 	 * @uclass_root: head of core tree
 	 */
 	struct list_head uclass_root;
+# if CONFIG_IS_ENABLED(OF_PLATDATA)
+        /** Dynamic info about the driver */
+	struct driver_rt *dm_driver_rt;
+# endif
 #endif
 #ifdef CONFIG_TIMER
 	/**
@@ -438,6 +444,14 @@ struct global_data {
 #define gd_set_of_root(_root)
 #endif
 
+#if CONFIG_IS_ENABLED(OF_PLATDATA)
+#define gd_set_dm_driver_rt(dyn)	gd->dm_driver_rt = dyn
+#define gd_dm_driver_rt()		gd->dm_driver_rt
+#else
+#define gd_set_dm_driver_rt(dyn)
+#define gd_dm_driver_rt()		NULL
+#endif
+
 /**
  * enum gd_flags - global data flags
  *

include/dm/device-internal.h

@@ -81,7 +81,7 @@ int device_bind_with_driver_data(struct udevice *parent,
  * @return 0 if OK, -ve on error
  */
 int device_bind_by_name(struct udevice *parent, bool pre_reloc_only,
-			struct driver_info *info, struct udevice **devp);
+			const struct driver_info *info, struct udevice **devp);
 
 /**
  * device_reparent: reparent the device to a new parent

include/dm/platdata.h

@@ -22,17 +22,27 @@
  * @name:	Driver name
  * @platdata:	Driver-specific platform data
  * @platdata_size: Size of platform data structure
- * @dev:	Device created from this structure data
  */
 struct driver_info {
 	const char *name;
 	const void *platdata;
 #if CONFIG_IS_ENABLED(OF_PLATDATA)
 	uint platdata_size;
-	struct udevice *dev;
 #endif
 };
 
+/**
+ * driver_rt - runtime information set up by U-Boot
+ *
+ * There is one of these for every driver_info in the linker list, indexed by
+ * the driver_info idx value.
+ *
+ * @dev: Device created from this idx
+ */
+struct driver_rt {
+	struct udevice *dev;
+};
+
 /**
  * NOTE: Avoid using these except in extreme circumstances, where device tree
  * is not feasible (e.g. serial driver in SPL where <8KB of SRAM is

test/dm/of_platdata.c

@@ -109,16 +109,16 @@ static int find_driver_info(struct unit_test_state *uts, struct udevice *parent,
 
 	/* If not the root device, find the entry that caused it to be bound */
 	if (parent->parent) {
-		const struct driver_info *info =
-			ll_entry_start(struct driver_info, driver_info);
 		const int n_ents =
 			ll_entry_count(struct driver_info, driver_info);
-		const struct driver_info *entry;
 		int idx = -1;
+		int i;
 
-		for (entry = info; entry != info + n_ents; entry++) {
-			if (entry->dev == parent) {
-				idx = entry - info;
+		for (i = 0; i < n_ents; i++) {
+			const struct driver_rt *drt = gd_dm_driver_rt() + i;
+
+			if (drt->dev == parent) {
+				idx = i;
 				found[idx] = true;
 				break;
 			}
@@ -153,16 +153,17 @@ static int dm_test_of_platdata_dev(struct unit_test_state *uts)
 
 	/* Make sure that the driver entries without devices have no ->dev */
 	for (i = 0; i < n_ents; i++) {
+		const struct driver_rt *drt = gd_dm_driver_rt() + i;
 		const struct driver_info *entry = info + i;
 		struct udevice *dev;
 
 		if (found[i]) {
 			/* Make sure we can find it */
-			ut_assertnonnull(entry->dev);
+			ut_assertnonnull(drt->dev);
 			ut_assertok(device_get_by_driver_info(entry, &dev));
-			ut_asserteq_ptr(dev, entry->dev);
+			ut_asserteq_ptr(dev, drt->dev);
 		} else {
-			ut_assertnull(entry->dev);
+			ut_assertnull(drt->dev);
 			ut_asserteq(-ENOENT,
 				    device_get_by_driver_info(entry, &dev));
 		}