[U-Boot] [PATCH v2 14/14] devres: compile Devres iif CONFIG_DM_DEVICE_REMOVE is enabled

[Masahiro Yamada]

Currently, Devres requires additional 16 byte for each allocation,
which is not so insignificant for SPL in some cases.

If CONFIG_DM_DEVICE_REMOVE is disabled, we never remove devices,
so we do not have to manage resources in the first place.
In this case, devres_alloc() can fall back to the simple kzalloc(),
and likewise, devm_*() to non-managed variants.

Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>
Suggested-by: Simon Glass <sjg at chromium.org>
---

Changes in v2: None

 drivers/core/Makefile        |  4 +--
 include/dm/device-internal.h | 13 +++++++
 include/dm/device.h          | 84 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 99 insertions(+), 2 deletions(-)

diff --git a/drivers/core/Makefile b/drivers/core/Makefile
index 5f019e8..37d64c6 100644
--- a/drivers/core/Makefile
+++ b/drivers/core/Makefile
@@ -4,8 +4,8 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-obj-y += device.o lists.o root.o uclass.o util.o devres.o
+obj-y += device.o lists.o root.o uclass.o util.o
 ifndef CONFIG_SPL_BUILD
 obj-$(CONFIG_OF_CONTROL) += simple-bus.o
 endif
-obj-$(CONFIG_DM_DEVICE_REMOVE)	+= device-remove.o
+obj-$(CONFIG_DM_DEVICE_REMOVE)	+= device-remove.o devres.o
diff --git a/include/dm/device-internal.h b/include/dm/device-internal.h
index 409c687..2c8446e 100644
--- a/include/dm/device-internal.h
+++ b/include/dm/device-internal.h
@@ -118,6 +118,8 @@ static inline void device_free(struct udevice *dev) {}
 #define DM_UCLASS_ROOT_NON_CONST	(((gd_t *)gd)->uclass_root)
 
 /* device resource management */
+#ifdef CONFIG_DM_DEVICE_REMOVE
+
 /**
  * devres_release_probe - Release managed resources allocated after probing
  * @dev: Device to release resources for
@@ -136,4 +138,15 @@ void devres_release_probe(struct udevice *dev);
  */
 void devres_release_all(struct udevice *dev);
 
+#else /* !CONFIG_DM_DEVICE_REMOVE */
+
+static inline void devres_release_probe(struct udevice *dev)
+{
+}
+
+static inline void devres_release_all(struct udevice *dev)
+{
+}
+
+#endif /* CONFIG_DM_DEVICE_REMOVE */
 #endif
diff --git a/include/dm/device.h b/include/dm/device.h
index 1a832a7..33dc470 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -447,6 +447,8 @@ bool device_is_last_sibling(struct udevice *dev);
 typedef void (*dr_release_t)(struct udevice *dev, void *res);
 typedef int (*dr_match_t)(struct udevice *dev, void *res, void *match_data);
 
+#ifdef CONFIG_DM_DEVICE_REMOVE
+
 #ifdef CONFIG_DEBUG_DEVRES
 void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
 		     const char *name);
@@ -623,5 +625,87 @@ static inline void *devm_kcalloc(struct udevice *dev,
  */
 void devm_kfree(struct udevice *dev, void *p);
 
+#else /* !CONFIG_DM_DEVICE_REMOVE */
+
+/*
+ * If CONFIG_DM_DEVICE_REMOVE is not defined, we need not manage resources.
+ * The devres functions fall back to normal allocators.
+ */
+static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
+{
+	return kzalloc(size, gfp);
+}
+
+static inline void devres_free(void *res)
+{
+	kfree(res);
+}
+
+static inline void devres_add(struct udevice *dev, void *res)
+{
+}
+
+static inline void *devres_find(struct udevice *dev, dr_release_t release,
+				dr_match_t match, void *match_data)
+{
+	return NULL;
+}
+
+static inline void *devres_get(struct udevice *dev, void *new_res,
+			       dr_match_t match, void *match_data)
+{
+	return NULL;
+}
+
+static inline void *devres_remove(struct udevice *dev, dr_release_t release,
+				  dr_match_t match, void *match_data)
+{
+	return NULL;
+}
+
+static inline int devres_destroy(struct udevice *dev, dr_release_t release,
+				 dr_match_t match, void *match_data)
+{
+	return 0;
+}
+
+static inline int devres_release(struct udevice *dev, dr_release_t release,
+				 dr_match_t match, void *match_data)
+{
+	return 0;
+}
+
+static inline void *devm_kmalloc(struct udevice *dev, size_t size, gfp_t gfp)
+{
+	return kmalloc(size, gfp);
+}
+
+static inline void *devm_kzalloc(struct udevice *dev, size_t size, gfp_t gfp)
+{
+	return kzalloc(size, gfp);
+}
+
+static inline void *devm_kmaloc_array(struct udevice *dev,
+				      size_t n, size_t size, gfp_t flags)
+{
+	/* TODO: add kmalloc_array() to linux/compat.h */
+	if (size != 0 && n > SIZE_MAX / size)
+		return NULL;
+	return kmalloc(n * size, flags);
+}
+
+static inline void *devm_kcalloc(struct udevice *dev,
+				 size_t n, size_t size, gfp_t flags)
+{
+	/* TODO: add kcalloc() to linux/compat.h */
+	return kmalloc(n * size, flags | __GFP_ZERO);
+}
+
+static inline void devm_kfree(struct udevice *dev, void *p)
+{
+	kfree(p);
+}
+
+#endif /* CONFIG_DM_DEVICE_REMOVE */
 
 #endif
-- 
1.9.1