[PATCH v3 3/7] blk: blkmap: add ramdisk creation utility function

[Masahisa Kojima]

User needs to call several functions to create the ramdisk
with blkmap.
This adds the utility function to create blkmap device and
mount the ramdisk.

Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
Reviewed-by: Simon Glass <sjg at chromium.org>
---
 drivers/block/Makefile        |  1 +
 drivers/block/blkmap.c        | 15 ----------
 drivers/block/blkmap_helper.c | 53 +++++++++++++++++++++++++++++++++++
 include/blkmap.h              | 29 +++++++++++++++++++
 4 files changed, 83 insertions(+), 15 deletions(-)
 create mode 100644 drivers/block/blkmap_helper.c

diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index a161d145fd..c3ccfc03e5 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -15,6 +15,7 @@ endif
 obj-$(CONFIG_SANDBOX) += sandbox.o host-uclass.o host_dev.o
 obj-$(CONFIG_$(SPL_TPL_)BLOCK_CACHE) += blkcache.o
 obj-$(CONFIG_BLKMAP) += blkmap.o
+obj-$(CONFIG_BLKMAP) += blkmap_helper.o
 
 obj-$(CONFIG_EFI_MEDIA) += efi-media-uclass.o
 obj-$(CONFIG_EFI_MEDIA_SANDBOX) += sb_efi_media.o
diff --git a/drivers/block/blkmap.c b/drivers/block/blkmap.c
index 2bb0acc20f..4e95997f61 100644
--- a/drivers/block/blkmap.c
+++ b/drivers/block/blkmap.c
@@ -66,21 +66,6 @@ struct blkmap_slice {
 	void (*destroy)(struct blkmap *bm, struct blkmap_slice *bms);
 };
 
-/**
- * struct blkmap - Block map
- *
- * Data associated with a blkmap.
- *
- * @label: Human readable name of this blkmap
- * @blk: Underlying block device
- * @slices: List of slices associated with this blkmap
- */
-struct blkmap {
-	char *label;
-	struct udevice *blk;
-	struct list_head slices;
-};
-
 static bool blkmap_slice_contains(struct blkmap_slice *bms, lbaint_t blknr)
 {
 	return (blknr >= bms->blknr) && (blknr < (bms->blknr + bms->blkcnt));
diff --git a/drivers/block/blkmap_helper.c b/drivers/block/blkmap_helper.c
new file mode 100644
index 0000000000..0f80035f57
--- /dev/null
+++ b/drivers/block/blkmap_helper.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * blkmap helper function
+ *
+ * Copyright (c) 2023, Linaro Limited
+ */
+
+#include <blk.h>
+#include <blkmap.h>
+#include <dm/device.h>
+#include <dm/device-internal.h>
+
+int blkmap_create_ramdisk(const char *label, ulong image_addr, int image_size,
+			  struct udevice **devp)
+{
+	int ret;
+	lbaint_t blknum;
+	struct blkmap *bm;
+	struct blk_desc *desc;
+	struct udevice *bm_dev;
+
+	ret = blkmap_create(label, &bm_dev);
+	if (ret) {
+		log_err("failed to create blkmap\n");
+		return ret;
+	}
+
+	bm = dev_get_plat(bm_dev);
+	desc = dev_get_uclass_plat(bm->blk);
+	blknum = image_size >> desc->log2blksz;
+	ret = blkmap_map_pmem(bm_dev, 0, blknum, image_addr);
+	if (ret) {
+		log_err("Unable to map %#llx at block %d : %d\n",
+			(unsigned long long)image_addr, 0, ret);
+		goto err;
+	}
+	log_info("Block %d+0x" LBAF " mapped to %#llx\n", 0, blknum,
+		 (unsigned long long)image_addr);
+
+	ret = device_probe(bm->blk);
+	if (ret)
+		goto err;
+
+	if (devp)
+		*devp = bm_dev;
+
+	return 0;
+
+err:
+	blkmap_destroy(bm_dev);
+
+	return ret;
+}
diff --git a/include/blkmap.h b/include/blkmap.h
index af54583c7d..0d87e6db6b 100644
--- a/include/blkmap.h
+++ b/include/blkmap.h
@@ -7,6 +7,23 @@
 #ifndef _BLKMAP_H
 #define _BLKMAP_H
 
+#include <dm/lists.h>
+
+/**
+ * struct blkmap - Block map
+ *
+ * Data associated with a blkmap.
+ *
+ * @label: Human readable name of this blkmap
+ * @blk: Underlying block device
+ * @slices: List of slices associated with this blkmap
+ */
+struct blkmap {
+	char *label;
+	struct udevice *blk;
+	struct list_head slices;
+};
+
 /**
  * blkmap_map_linear() - Map region of other block device
  *
@@ -74,4 +91,16 @@ int blkmap_create(const char *label, struct udevice **devp);
  */
 int blkmap_destroy(struct udevice *dev);
 
+/**
+ * blkmap_create_ramdisk() - Create new ramdisk with blkmap
+ *
+ * @label: Label of the new blkmap
+ * @image_addr: Target memory start address of this mapping
+ * @image_size: Target memory size of this mapping
+ * @devp: Updated with the address of the created blkmap device
+ * Returns: 0 on success, negative error code on failure
+ */
+int blkmap_create_ramdisk(const char *label, ulong image_addr, int image_size,
+			  struct udevice **devp);
+
 #endif	/* _BLKMAP_H */
-- 
2.34.1