[PATCH v2 2/6] ramdisk: add ramdisk uclass and driver
Masahisa Kojima
masahisa.kojima at linaro.org
Fri Jul 14 07:44:02 CEST 2023
This introcudes the ramdisk uclass and driver.
Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
---
Newly introcuded in v2
disk/part.c | 3 +
drivers/block/Kconfig | 7 +-
drivers/block/Makefile | 2 +
drivers/block/blk-uclass.c | 1 +
drivers/block/blk_ramdisk.c | 187 +++++++++++++++++++++++++++++++
drivers/block/ramdisk-uclass.c | 14 +++
include/dm/uclass-id.h | 1 +
include/ramdisk.h | 32 ++++++
lib/efi_loader/efi_device_path.c | 25 +++++
9 files changed, 271 insertions(+), 1 deletion(-)
create mode 100644 drivers/block/blk_ramdisk.c
create mode 100644 drivers/block/ramdisk-uclass.c
create mode 100644 include/ramdisk.h
diff --git a/disk/part.c b/disk/part.c
index 35300df590..d0cee3cc03 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -152,6 +152,9 @@ void dev_print(struct blk_desc *dev_desc)
case UCLASS_EFI_MEDIA:
printf("EFI media Block Device %d\n", dev_desc->devnum);
break;
+ case UCLASS_RAM_DISK:
+ printf("RAM Disk Block Device %d\n", dev_desc->devnum);
+ break;
case UCLASS_INVALID:
puts("device type unknown\n");
return;
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 5a1aeb3d2b..ab56ef3406 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -2,7 +2,7 @@ config BLK
bool # "Support block devices"
depends on DM
default y if MMC || USB || SCSI || NVME || IDE || AHCI || SATA
- default y if EFI_MEDIA || VIRTIO_BLK || PVBLOCK
+ default y if EFI_MEDIA || VIRTIO_BLK || PVBLOCK || RAM_DISK
help
Enable support for block devices, such as SCSI, MMC and USB
flash sticks. These provide a block-level interface which permits
@@ -255,3 +255,8 @@ config SYS_64BIT_LBA
help
Make the block subsystem use 64bit sector addresses, rather than the
default of 32bit.
+
+config RAM_DISK
+ bool "Enable RAM disk"
+ help
+ This option enables to mount the RAM disk.
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index a161d145fd..e867c7a126 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -19,3 +19,5 @@ obj-$(CONFIG_BLKMAP) += blkmap.o
obj-$(CONFIG_EFI_MEDIA) += efi-media-uclass.o
obj-$(CONFIG_EFI_MEDIA_SANDBOX) += sb_efi_media.o
obj-$(CONFIG_EFI_MEDIA_BLK) += efi_blk.o
+obj-$(CONFIG_RAM_DISK) += blk_ramdisk.o
+obj-$(CONFIG_RAM_DISK) += ramdisk-uclass.o
diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
index 614b975e25..ea411fe674 100644
--- a/drivers/block/blk-uclass.c
+++ b/drivers/block/blk-uclass.c
@@ -34,6 +34,7 @@ static struct {
{ UCLASS_VIRTIO, "virtio" },
{ UCLASS_PVBLOCK, "pvblock" },
{ UCLASS_BLKMAP, "blkmap" },
+ { UCLASS_RAM_DISK, "ramdisk" },
};
static enum uclass_id uclass_name_to_iftype(const char *uclass_idname)
diff --git a/drivers/block/blk_ramdisk.c b/drivers/block/blk_ramdisk.c
new file mode 100644
index 0000000000..8016837a80
--- /dev/null
+++ b/drivers/block/blk_ramdisk.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RAM Disk block device driver
+ *
+ * Copyright (c) 2023, Linaro Limited
+ */
+
+#include <blk.h>
+#include <common.h>
+#include <dm.h>
+#include <log.h>
+#include <part.h>
+#include <ramdisk.h>
+#include <dm/device-internal.h>
+#include <dm/root.h>
+
+#if (IS_ENABLED(CONFIG_EFI_LOADER))
+#include <efi_loader.h>
+#endif
+
+#define MEM_BLOCK_SIZE_SHIFT 9 /* 512 bytes */
+
+/**
+ * ramdisk_read() - read from block device
+ *
+ * @dev: device
+ * @blknr: first block to be read
+ * @blkcnt: number of blocks to read
+ * @buffer: output buffer
+ * Return: number of blocks transferred
+ */
+static ulong ramdisk_read(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt,
+ void *buffer)
+{
+ u8 *start;
+ struct ramdisk_blk_plat *plat = dev_get_plat(dev);
+
+ log_debug("read buf=%p, block=%lx, count=%lx: ", buffer, (ulong)blknr,
+ (ulong)blkcnt);
+
+ if (!buffer)
+ return 0;
+
+ if (blknr + blkcnt > (plat->size >> MEM_BLOCK_SIZE_SHIFT))
+ return 0;
+
+ start = plat->start + (blknr << MEM_BLOCK_SIZE_SHIFT);
+ memmove(buffer, start, blkcnt << MEM_BLOCK_SIZE_SHIFT);
+
+ return blkcnt;
+}
+
+/**
+ * ramdisk_write() - write to block device
+ *
+ * @dev: device
+ * @blknr: first block to be write
+ * @blkcnt: number of blocks to write
+ * @buffer: input buffer
+ * Return: number of blocks transferred
+ */
+static ulong ramdisk_write(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt,
+ const void *buffer)
+{
+ u8 *start;
+ struct ramdisk_blk_plat *plat = dev_get_plat(dev);
+
+ log_debug("write buf=%p, block=%lx, count=%lx: ", buffer, (ulong)blknr,
+ (ulong)blkcnt);
+
+ if (!buffer)
+ return 0;
+
+ if (blknr + blkcnt > (plat->size >> MEM_BLOCK_SIZE_SHIFT))
+ return 0;
+
+ start = plat->start + (blknr << MEM_BLOCK_SIZE_SHIFT);
+ memmove(start, buffer, blkcnt << MEM_BLOCK_SIZE_SHIFT);
+
+ return blkcnt;
+}
+
+static const struct blk_ops ramdisk_blk_ops = {
+ .read = ramdisk_read,
+ .write = ramdisk_write,
+};
+
+U_BOOT_DRIVER(ramdisk_blk) = {
+ .name = "ramdisk_blk",
+ .id = UCLASS_BLK,
+ .ops = &ramdisk_blk_ops,
+ .plat_auto = sizeof(struct ramdisk_blk_plat),
+};
+
+/*
+ * ramdisk_mount - mount ramdisk
+ *
+ * @start_address: The base address of registered RAM disk
+ * @size: The size of registered RAM disk
+ * @guid: The type of registered RAM disk
+ * Return: Pointer to the udevice strucure, return NULL if failed
+ */
+struct udevice *ramdisk_mount(u64 start_address, u64 size, void *guid)
+{
+ int ret;
+ char name[20];
+ struct udevice *parent, *bdev;
+ static struct ramdisk_blk_plat *plat;
+
+ if (!start_address || !size)
+ return NULL;
+
+ ret = device_bind(dm_root(), DM_DRIVER_GET(ramdisk), "ramdisk", NULL,
+ ofnode_null(), &parent);
+ if (ret) {
+ log_err("bind ramdisk error\n");
+ return NULL;
+ }
+ snprintf(name, sizeof(name), "ramdisk%d", dev_seq(parent));
+ device_set_name(parent, name);
+
+ ret = blk_create_device(parent, "ramdisk_blk", "ramdisk_blk",
+ UCLASS_RAM_DISK, dev_seq(parent),
+ 1 << MEM_BLOCK_SIZE_SHIFT,
+ (size >> MEM_BLOCK_SIZE_SHIFT) - 1, &bdev);
+ if (ret) {
+ log_err("ramdisk create block device failed\n");
+ goto err;
+ }
+ snprintf(name, sizeof(name), "ramdisk_blk#%d", dev_seq(parent));
+ device_set_name(bdev, name);
+
+ plat = dev_get_plat(bdev);
+ plat->start = (u8 *)start_address;
+ plat->size = size;
+#if (IS_ENABLED(CONFIG_EFI_LOADER))
+ if (guid)
+ guidcpy(&plat->disk_type_guid, guid);
+#endif
+ ret = blk_probe_or_unbind(bdev);
+ if (ret) {
+ log_err("ramdisk probe error\n");
+ goto err;
+ }
+
+ return bdev;
+
+err:
+ if (parent) {
+ ret = device_remove(parent, DM_REMOVE_NORMAL);
+ if (ret)
+ return NULL;
+
+ ret = device_unbind(parent);
+ }
+
+ return NULL;
+}
+
+/*
+ * ramdisk_unmount - unmount ramdisk
+ *
+ * @dev: The device to be unmounted
+ * Return: 0 if success, negative value if error
+ */
+int ramdisk_unmount(struct udevice *dev)
+{
+ int ret;
+ struct udevice *parent;
+
+ if (!dev)
+ return -EINVAL;
+
+ parent = dev->parent;
+ ret = device_remove(parent, DM_REMOVE_NORMAL);
+ if (ret)
+ return ret;
+
+ ret = device_unbind(parent);
+
+ return ret;
+}
+
+U_BOOT_DRIVER(ramdisk) = {
+ .name = "ramdisk",
+ .id = UCLASS_RAM_DISK,
+};
diff --git a/drivers/block/ramdisk-uclass.c b/drivers/block/ramdisk-uclass.c
new file mode 100644
index 0000000000..f1bf68f635
--- /dev/null
+++ b/drivers/block/ramdisk-uclass.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RAM Disk block device driver
+ *
+ * Copyright (c) 2023, Linaro Limited
+ */
+
+#include <common.h>
+#include <dm.h>
+
+UCLASS_DRIVER(ramdisk) = {
+ .name = "ramdisk",
+ .id = UCLASS_RAM_DISK,
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 307ad6931c..42b4907b1f 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -109,6 +109,7 @@ enum uclass_id {
UCLASS_PWRSEQ, /* Power sequence device */
UCLASS_QFW, /* QEMU firmware config device */
UCLASS_RAM, /* RAM controller */
+ UCLASS_RAM_DISK, /* RAM disk device */
UCLASS_REBOOT_MODE, /* Reboot mode */
UCLASS_REGULATOR, /* Regulator device */
UCLASS_REMOTEPROC, /* Remote Processor device */
diff --git a/include/ramdisk.h b/include/ramdisk.h
new file mode 100644
index 0000000000..71383be5b8
--- /dev/null
+++ b/include/ramdisk.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * ramdisk support
+ *
+ * Copyright (c) 2023, Linaro Limited
+ */
+
+#ifndef _RAMDISK_H
+#define _RAMDISK_H
+
+#ifdef CONFIG_EFI_LOADER
+#include <efi.h>
+#endif
+
+/**
+ * struct ramdisk_blk_plat - attributes of a block device
+ *
+ * @handle: handle of the controller on which this driver is installed
+ * @io: block io protocol proxied by this driver
+ */
+struct ramdisk_blk_plat {
+ u8 *start;
+ u64 size;
+#if (IS_ENABLED(CONFIG_EFI_LOADER))
+ efi_guid_t disk_type_guid;
+#endif
+};
+
+struct udevice *ramdisk_mount(u64 start_address, u64 size, void *guid);
+int ramdisk_unmount(struct udevice *dev);
+
+#endif
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index 04ebb449ca..1f16bda6ac 100644
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -17,6 +17,7 @@
#include <nvme.h>
#include <efi_loader.h>
#include <part.h>
+#include <ramdisk.h>
#include <uuid.h>
#include <asm-generic/unaligned.h>
#include <linux/compat.h> /* U16_MAX */
@@ -568,6 +569,11 @@ __maybe_unused static unsigned int dp_size(struct udevice *dev)
*/
return dp_size(dev->parent)
+ sizeof(struct efi_device_path_vendor) + 1;
+#endif
+#ifdef CONFIG_RAM_DISK
+ case UCLASS_RAM_DISK:
+ return dp_size(dev->parent)
+ + sizeof(struct efi_device_path_ram_disk_path) + 1;
#endif
default:
return dp_size(dev->parent);
@@ -766,6 +772,25 @@ __maybe_unused static void *dp_fill(void *buf, struct udevice *dev)
dp->controller_number = desc->lun;
return &dp[1];
}
+#endif
+#if defined(CONFIG_RAM_DISK)
+ case UCLASS_RAM_DISK: {
+ struct ramdisk_blk_plat *plat = dev_get_plat(dev);
+ struct efi_device_path_ram_disk_path *dp =
+ dp_fill(buf, dev->parent);
+
+ dp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
+ dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_RAM_DISK_PATH;
+ dp->dp.length =
+ sizeof(struct efi_device_path_ram_disk_path);
+ put_unaligned_le64((u64)plat->start,
+ &dp->starting_address);
+ put_unaligned_le64((u64)(plat->start + plat->size - 1),
+ &dp->ending_address);
+ guidcpy(&dp->disk_type_guid, &plat->disk_type_guid);
+ dp->disk_instance = 0;
+ return &dp[1];
+ }
#endif
default:
debug("%s(%u) %s: unhandled parent class: %s (%u)\n",
--
2.34.1
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