u-boot/drivers/block/efi_blk.c
Simon Glass d8063dc373 efi: Add a media/block driver for EFI block devices
Add a block driver which handles read/write for EFI block devices. This
driver actually already exists ('efi_block') but is not really suitable
for use as a real U-Boot driver:

- The operations do not provide a udevice
- The code is designed for running as part of EFI loader, so uses
    EFI_PRINT() and EFI_CALL().
- The bind method probes the device, which is not permitted
- It uses 'EFI' as its parent device

The new driver is more 'normal', just requiring its platform data be set
up in advance.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2021-12-09 11:43:25 -08:00

115 lines
2.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Block driver for EFI devices
* This supports a media driver of UCLASS_EFI with a child UCLASS_BLK
* It allows block-level access to EFI devices made available via EFI boot
* services
*
* Copyright 2021 Google LLC
*/
#include <common.h>
#include <blk.h>
#include <dm.h>
#include <efi.h>
#include <efi_api.h>
struct efi_block_plat {
struct efi_block_io *blkio;
};
/**
* 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 efi_bl_read(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt,
void *buffer)
{
struct efi_block_plat *plat = dev_get_plat(dev);
struct efi_block_io *io = plat->blkio;
efi_status_t ret;
log_debug("read buf=%p, block=%lx, count=%lx: ", buffer, (ulong)blknr,
(ulong)blkcnt);
ret = io->read_blocks(io, io->media->media_id, blknr,
blkcnt * io->media->block_size, buffer);
log_debug("ret=%lx (dec %ld)\n", ret & ~EFI_ERROR_MASK,
ret & ~EFI_ERROR_MASK);
if (ret)
return 0;
return blkcnt;
}
/**
* 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 efi_bl_write(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt,
const void *buffer)
{
struct efi_block_plat *plat = dev_get_plat(dev);
struct efi_block_io *io = plat->blkio;
efi_status_t ret;
log_debug("write buf=%p, block=%lx, count=%lx: ", buffer, (ulong)blknr,
(ulong)blkcnt);
ret = io->write_blocks(io, io->media->media_id, blknr,
blkcnt * io->media->block_size, (void *)buffer);
log_debug("ret=%lx (dec %ld)\n", ret & ~EFI_ERROR_MASK,
ret & ~EFI_ERROR_MASK);
if (ret)
return 0;
return blkcnt;
}
/* Block device driver operators */
static const struct blk_ops efi_blk_ops = {
.read = efi_bl_read,
.write = efi_bl_write,
};
U_BOOT_DRIVER(efi_block) = {
.name = "efi_block",
.id = UCLASS_BLK,
.ops = &efi_blk_ops,
.plat_auto = sizeof(struct efi_block_plat),
};
static int efi_media_bind(struct udevice *dev)
{
struct efi_media_plat *plat = dev_get_plat(dev);
struct efi_block_plat *blk_plat;
struct udevice *blk;
int ret;
ret = blk_create_devicef(dev, "efi_block", "blk", IF_TYPE_EFI_MEDIA,
dev_seq(dev), plat->blkio->media->block_size,
plat->blkio->media->last_block, &blk);
if (ret) {
debug("Cannot create block device\n");
return ret;
}
blk_plat = dev_get_plat(blk);
blk_plat->blkio = plat->blkio;
return 0;
}
U_BOOT_DRIVER(efi_media) = {
.name = "efi_media",
.id = UCLASS_EFI_MEDIA,
.bind = efi_media_bind,
.plat_auto = sizeof(struct efi_media_plat),
};