[PATCH v2 2/6] ramdisk: add ramdisk uclass and driver
Heinrich Schuchardt
xypron.glpk at gmx.de
Wed Jul 19 17:10:51 CEST 2023
On 14.07.23 07:44, Masahisa Kojima wrote:
> 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:
What is the difference to UCLASS_BLKMAP?
[PATCH v2 0/9] blk: blkmap: Composable virtual block devices
https://lore.kernel.org/u-boot/20230216153355.448302-1-tobias@waldekranz.com/
Best regards
Heinrich
> + 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",
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