Re: [RFC v2 15/20] efi_loader: disk: a helper function to create efi_disk objects from udevice

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

On Sun, Jan 02, 2022 at 10:18:18AM +0100, Heinrich Schuchardt wrote:
> On 12/10/21 07:49, AKASHI Takahiro wrote:
> > Add efi_disk_probe() function.
> > This function creates an efi_disk object for a raw disk device (UCLASS_BLK)
> > and additional objects for related partitions (UCLASS_PARTITION).
> > 
> > So this function is expected to be called through driver model's "probe"
> > interface every time one raw disk device is detected and activated.
> > We assume that partition devices (UCLASS_PARTITION) have been created
> > when this function is invoked.
> > 
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > ---
> >   include/efi_loader.h       |   4 +-
> >   lib/efi_loader/Kconfig     |   2 +
> >   lib/efi_loader/efi_disk.c  | 206 ++++++++++++++++++++++++-------------
> >   lib/efi_loader/efi_setup.c |  11 +-
> >   4 files changed, 142 insertions(+), 81 deletions(-)
> > 
> > diff --git a/include/efi_loader.h b/include/efi_loader.h
> > index d52e399841ba..a51095930efa 100644
> > --- a/include/efi_loader.h
> > +++ b/include/efi_loader.h
> > @@ -519,8 +519,8 @@ efi_status_t EFIAPI efi_convert_pointer(efi_uintn_t debug_disposition,
> >   void efi_carve_out_dt_rsv(void *fdt);
> >   /* Called by bootefi to make console interface available */
> >   efi_status_t efi_console_register(void);
> > -/* Called by bootefi to make all disk storage accessible as EFI objects */
> > -efi_status_t efi_disk_register(void);
> > +/* Called by efi_init_obj_list() to initialize efi_disks */
> > +efi_status_t efi_disk_init(void);
> >   /* Called by efi_init_obj_list() to install EFI_RNG_PROTOCOL */
> >   efi_status_t efi_rng_register(void);
> >   /* Called by efi_init_obj_list() to install EFI_TCG2_PROTOCOL */
> > diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> > index 700dc838ddb9..108c00343fce 100644
> > --- a/lib/efi_loader/Kconfig
> > +++ b/lib/efi_loader/Kconfig
> > @@ -11,6 +11,7 @@ config EFI_LOADER
> >   	# We need EFI_STUB_32BIT to be set on x86_32 with EFI_STUB
> >   	depends on !EFI_STUB || !X86 || X86_64 || EFI_STUB_32BIT
> >   	depends on BLK
> > +	depends on EVENT
> >   	depends on DM_ETH || !NET
> >   	depends on !EFI_APP
> >   	default y if !ARM || SYS_CPU = armv7 || SYS_CPU = armv8
> > @@ -41,6 +42,7 @@ config CMD_BOOTEFI_BOOTMGR
> > 
> >   config EFI_SETUP_EARLY
> >   	bool
> > +	default y
> > 
> >   choice
> >   	prompt "Store for non-volatile UEFI variables"
> > diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
> > index 45127d176869..2941b0c3db47 100644
> > --- a/lib/efi_loader/efi_disk.c
> > +++ b/lib/efi_loader/efi_disk.c
> > @@ -10,6 +10,9 @@
> >   #include <common.h>
> >   #include <blk.h>
> >   #include <dm.h>
> > +#include <dm/device-internal.h>
> > +#include <dm/tag.h>
> > +#include <event.h>
> >   #include <efi_loader.h>
> >   #include <fs.h>
> >   #include <log.h>
> > @@ -487,103 +490,158 @@ error:
> >   	return ret;
> >   }
> > 
> > -/**
> > - * efi_disk_create_partitions() - create handles and protocols for partitions
> > +/*
> > + * Create a handle for a whole raw disk
> >    *
> > - * Create handles and protocols for the partitions of a block device.
> > + * @dev		uclass device (UCLASS_BLK)
> >    *
> > - * @parent:		handle of the parent disk
> > - * @desc:		block device
> > - * @if_typename:	interface type
> > - * @diskid:		device number
> > - * @pdevname:		device name
> > - * Return:		number of partitions created
> > + * Create an efi_disk object which is associated with @dev.
> > + * The type of @dev must be UCLASS_BLK.
> > + *
> > + * @return	0 on success, -1 otherwise
> >    */
> > -int efi_disk_create_partitions(efi_handle_t parent, struct blk_desc *desc,
> > -			       const char *if_typename, int diskid,
> > -			       const char *pdevname)
> > +static int efi_disk_create_raw(struct udevice *dev)
> >   {
> > -	int disks = 0;
> > -	char devname[32] = { 0 }; /* dp->str is u16[32] long */
> > -	int part;
> > -	struct efi_device_path *dp = NULL;
> > +	struct efi_disk_obj *disk;
> > +	struct blk_desc *desc;
> > +	const char *if_typename;
> > +	int diskid;
> >   	efi_status_t ret;
> > -	struct efi_handler *handler;
> > 
> > -	/* Get the device path of the parent */
> > -	ret = efi_search_protocol(parent, &efi_guid_device_path, &handler);
> > -	if (ret == EFI_SUCCESS)
> > -		dp = handler->protocol_interface;
> > -
> > -	/* Add devices for each partition */
> > -	for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
> > -		struct disk_partition info;
> > -
> > -		if (part_get_info(desc, part, &info))
> > -			continue;
> > -		snprintf(devname, sizeof(devname), "%s:%x", pdevname,
> > -			 part);
> > -		ret = efi_disk_add_dev(parent, dp, if_typename, desc, diskid,
> > -				       &info, part, NULL);
> > -		if (ret != EFI_SUCCESS) {
> > -			log_err("Adding partition %s failed\n", pdevname);
> > -			continue;
> > -		}
> > -		disks++;
> > +	desc = dev_get_uclass_plat(dev);
> > +	if_typename = blk_get_if_type_name(desc->if_type);
> > +	diskid = desc->devnum;
> > +
> > +	ret = efi_disk_add_dev(NULL, NULL, if_typename, desc,
> > +			       diskid, NULL, 0, &disk);
> > +	if (ret != EFI_SUCCESS) {
> > +		if (ret == EFI_NOT_READY)
> > +			log_notice("Disk %s not ready\n", dev->name);
> > +		else
> > +			log_err("Adding disk for %s failed\n", dev->name);
> > +
> > +		return -1;
> > +	}
> > +	disk->dev = dev;
> > +	if (dev_tag_set_ptr(dev, DM_TAG_EFI, &disk->header)) {
> > +		efi_free_pool(disk->dp);
> > +		efi_delete_handle(&disk->header);
> > +
> > +		return -1;
> >   	}
> > 
> > -	return disks;
> > +	return 0;
> >   }
> > 
> > -/**
> > - * efi_disk_register() - register block devices
> > - *
> > - * U-Boot doesn't have a list of all online disk devices. So when running our
> > - * EFI payload, we scan through all of the potentially available ones and
> > - * store them in our object pool.
> > +/*
> > + * Create a handle for a disk partition
> >    *
> > - * This function is called in efi_init_obj_list().
> > + * @dev		uclass device (UCLASS_PARTITION)
> >    *
> > - * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
> > - * Consider converting the code to look up devices as needed. The EFI device
> > - * could be a child of the UCLASS_BLK block device, perhaps.
> > + * Create an efi_disk object which is associated with @dev.
> > + * The type of @dev must be UCLASS_PARTITION.
> >    *
> > - * Return:	status code
> > + * @return	0 on success, -1 otherwise
> >    */
> > -efi_status_t efi_disk_register(void)
> > +static int efi_disk_create_part(struct udevice *dev)
> >   {
> > +	efi_handle_t parent;
> > +	struct blk_desc *desc;
> > +	const char *if_typename;
> > +	struct disk_part *part_data;
> > +	struct disk_partition *info;
> > +	unsigned int part;
> > +	int diskid;
> > +	struct efi_handler *handler;
> > +	struct efi_device_path *dp_parent;
> >   	struct efi_disk_obj *disk;
> > -	int disks = 0;
> >   	efi_status_t ret;
> > +
> > +	if (dev_tag_get_ptr(dev_get_parent(dev), DM_TAG_EFI, (void **)&parent))
> > +		return -1;
> > +
> > +	desc = dev_get_uclass_plat(dev_get_parent(dev));
> > +	if_typename = blk_get_if_type_name(desc->if_type);
> > +	diskid = desc->devnum;
> > +
> > +	part_data = dev_get_uclass_plat(dev);
> > +	part = part_data->partnum;
> > +	info = &part_data->gpt_part_info;
> > +
> > +	ret = efi_search_protocol(parent, &efi_guid_device_path, &handler);
> > +	if (ret != EFI_SUCCESS)
> > +		return -1;
> > +	dp_parent = (struct efi_device_path *)handler->protocol_interface;
> > +
> > +	ret = efi_disk_add_dev(parent, dp_parent, if_typename, desc, diskid,
> > +			       info, part, &disk);
> > +	if (ret != EFI_SUCCESS) {
> > +		log_err("Adding partition for %s failed\n", dev->name);
> > +		return -1;
> > +	}
> > +	disk->dev = dev;
> > +	if (dev_tag_set_ptr(dev, DM_TAG_EFI, &disk->header)) {
> > +		efi_free_pool(disk->dp);
> > +		efi_delete_handle(&disk->header);
> > +
> > +		return -1;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> > + * Create efi_disk objects for a block device
> > + *
> > + * @dev		uclass device (UCLASS_BLK)
> > + *
> > + * Create efi_disk objects for partitions as well as a raw disk
> > + * which is associated with @dev.
> > + * The type of @dev must be UCLASS_BLK.
> > + * This function is expected to be called at EV_PM_POST_PROBE.
> > + *
> > + * @return	0 on success, -1 otherwise
> > + */
> > +static int efi_disk_probe(void *ctx, struct event *event)
> > +{
> >   	struct udevice *dev;
> > +	enum uclass_id id;
> > +	struct udevice *child;
> > +	int ret;
> > 
> > -	for (uclass_first_device_check(UCLASS_BLK, &dev); dev;
> > -	     uclass_next_device_check(&dev)) {
> > -		struct blk_desc *desc = dev_get_uclass_plat(dev);
> > -		const char *if_typename = blk_get_if_type_name(desc->if_type);
> > +	dev = event->data.dm.dev;
> > +	id = device_get_uclass_id(dev);
> > 
> > -		/* Add block device for the full device */
> > -		log_info("Scanning disk %s...\n", dev->name);
> > -		ret = efi_disk_add_dev(NULL, NULL, if_typename,
> > -					desc, desc->devnum, NULL, 0, &disk);
> > -		if (ret == EFI_NOT_READY) {
> > -			log_notice("Disk %s not ready\n", dev->name);
> > -			continue;
> > -		}
> > -		if (ret) {
> > -			log_err("ERROR: failure to add disk device %s, r = %lu\n",
> > -				dev->name, ret & ~EFI_ERROR_MASK);
> > -			continue;
> > -		}
> > -		disks++;
> > +	/* TODO: We won't support partitions in a partition */
> > +	if (id != UCLASS_BLK) {
> > +		if (id != UCLASS_PARTITION)
> > +			log_info("Not a block device: %s\n", dev->name);
> 
> I get the following messages on the sandbox:
> 
> Not a block device: pinmux_i2c0_pins
> Not a block device: i2c@0
> Not a block device: rtc@61
> Not a block device: bootcount@0
> Not a block device: emul
> Not a block device: emull
> 
> Why do you create these?

They are debug messages as I intended to make sure that a 'probe' hook
was always called in vain even if a given udevice was not a block device.
(In this sense, event API has room for improvement.)

On the other hand, this behavior is useful when we want to add a nested
partition, that is, partitions in a partition.

Will drop the message for now.

-Takahiro Akashi


> Best regards
> 
> Heinrich
> 
> > +		return 0;
> > +	}
> > +
> > +	ret = efi_disk_create_raw(dev);
> > +	if (ret)
> > +		return -1;
> > 
> > -		/* Partitions show up as block devices in EFI */
> > -		disks += efi_disk_create_partitions(
> > -					&disk->header, desc, if_typename,
> > -					desc->devnum, dev->name);
> > +	device_foreach_child(child, dev) {
> > +		ret = efi_disk_create_part(child);
> > +		if (ret)
> > +			return -1;
> >   	}
> > 
> > -	log_info("Found %d disks\n", disks);
> > +	return 0;
> > +}
> > +
> > +efi_status_t efi_disk_init(void)
> > +{
> > +	int ret;
> > +
> > +	ret = event_register("efi_disk add", EVT_DM_POST_PROBE,
> > +			     efi_disk_probe, NULL);
> > +	if (ret) {
> > +		log_err("Event registration for efi_disk add failed\n");
> > +		return EFI_OUT_OF_RESOURCES;
> > +	}
> > 
> >   	return EFI_SUCCESS;
> >   }
> > diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
> > index 1aba71cd9624..1c912b0157aa 100644
> > --- a/lib/efi_loader/efi_setup.c
> > +++ b/lib/efi_loader/efi_setup.c
> > @@ -200,11 +200,12 @@ efi_status_t efi_init_obj_list(void)
> >   	if (ret != EFI_SUCCESS)
> >   		goto out;
> > 
> > -#ifdef CONFIG_PARTITIONS
> > -	ret = efi_disk_register();
> > -	if (ret != EFI_SUCCESS)
> > -		goto out;
> > -#endif
> > +	if (IS_ENABLED(CONFIG_BLK)) {
> > +		ret = efi_disk_init();
> > +		if (ret != EFI_SUCCESS)
> > +			goto out;
> > +	}
> > +
> >   	if (IS_ENABLED(CONFIG_EFI_RNG_PROTOCOL)) {
> >   		ret = efi_rng_register();
> >   		if (ret != EFI_SUCCESS)
>