[RESEND v9 1/9] efi_loader: move udevice pointer into struct efi_object

[Heinrich Schuchardt]

On 7/20/22 01:56, Takahiro Akashi wrote:
> On Sun, Jul 17, 2022 at 10:09:42AM +0200, Heinrich Schuchardt wrote:
>> On 7/15/22 16:47, Masahisa Kojima wrote:
>>> This is a preparation patch to provide the unified method
>>> to access udevice pointer associated with the block io device.
>>> The EFI handles of both EFI block io driver implemented in
>>> lib/efi_loader/efi_disk.c and EFI block io driver implemented
>>> as EFI payload can posess the udevice pointer in the struct efi_object.
>>>
>>> We can use this udevice pointer to get the U-Boot friendly
>>> block device name(e.g. mmc 0:1, nvme 0:1) through efi_handle_t.
>>>
>>> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
>>> ---
>>> Newly created in v9
>>>
>>>    include/efi_loader.h      |  8 ++++++++
>>>    lib/efi_loader/efi_disk.c | 20 +++++++++++++-------
>>>    2 files changed, 21 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/include/efi_loader.h b/include/efi_loader.h
>>> index 3a63a1f75f..bba5ffd482 100644
>>> --- a/include/efi_loader.h
>>> +++ b/include/efi_loader.h
>>> @@ -226,6 +226,12 @@ const char *__efi_nesting_dec(void);
>>>    #define EFI_CACHELINE_SIZE 128
>>>    #endif
>>>
>>> +/**
>>> + * efi_handle_to_udev - accessor to the DM device associated to the EFI handle
>>> + * @handle:	pointer to the EFI handle
>>> + */
>>> +#define efi_handle_to_udev(handle) (((struct efi_object *)handle)->dev)
>>
>> This conversion will hide errors if handle is not of type efi_handle_t.
>> We should avoid the conversion and see build time errors instead.
>> Please, remove the macro.
>
> I don't think we should remove the macro itself, but only the type casting.
>
> I think it is a good practice to hide an implementation how the relationship
> between udev and efi_object is maintained *behind* accessor macros.
>
>> For every handle of type efi_handle_t you can access the field
>> handle->dev directly.
>>
>> For struct efi_disk_obj we can use disk->header.dev.
>
> This is a good example for hiding the implementation from the rest of code.

Such a macro is pure code obfuscation.

I won't take such a patch.

Best regards

Heinrich

>
>>> +
>>>    /* Key identifying current memory map */
>>>    extern efi_uintn_t efi_memory_map_key;
>>>
>>> @@ -375,6 +381,7 @@ enum efi_object_type {
>>>     * @protocols:	linked list with the protocol interfaces installed on this
>>>     *		handle
>>>     * @type:	image type if the handle relates to an image
>>> + * @dev:	pointer to the DM device which is associated with this EFI handle
>>>     *
>>>     * UEFI offers a flexible and expandable object model. The objects in the UEFI
>>>     * API are devices, drivers, and loaded images. struct efi_object is our storage
>>> @@ -392,6 +399,7 @@ struct efi_object {
>>>    	/* The list of protocols */
>>>    	struct list_head protocols;
>>>    	enum efi_object_type type;
>>> +	struct udevice *dev;
>>>    };
>>>
>>>    enum efi_image_auth_status {
>>> diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
>>> index 1d700b2a6b..a8e8521e3e 100644
>>> --- a/lib/efi_loader/efi_disk.c
>>> +++ b/lib/efi_loader/efi_disk.c
>>> @@ -46,7 +46,6 @@ struct efi_disk_obj {
>>>    	struct efi_device_path *dp;
>>>    	unsigned int part;
>>>    	struct efi_simple_file_system_protocol *volume;
>>> -	struct udevice *dev; /* TODO: move it to efi_object */
>>
>> ok
>>
>>>    };
>>>
>>>    /**
>>> @@ -124,16 +123,16 @@ static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
>>>    		return EFI_BAD_BUFFER_SIZE;
>>>
>>>    	if (CONFIG_IS_ENABLED(PARTITIONS) &&
>>> -	    device_get_uclass_id(diskobj->dev) == UCLASS_PARTITION) {
>>> +	    device_get_uclass_id(efi_handle_to_udev(diskobj)) == UCLASS_PARTITION) {
>>
>> device_get_uclass_id(diskobj->header.hdev)) == UCLASS_PARTITION) {
>>
>>>    		if (direction == EFI_DISK_READ)
>>> -			n = dev_read(diskobj->dev, lba, blocks, buffer);
>>> +			n = dev_read(efi_handle_to_udev(diskobj), lba, blocks, buffer);
>>
>> dev_read(diskobj->header.hdev)
>>
>>>    		else
>>> -			n = dev_write(diskobj->dev, lba, blocks, buffer);
>>> +			n = dev_write(efi_handle_to_udev(diskobj), lba, blocks, buffer);
>>
>> dev_write(diskobj->header.hdev)
>>
>>>    	} else {
>>>    		/* dev is a block device (UCLASS_BLK) */
>>>    		struct blk_desc *desc;
>>>
>>> -		desc = dev_get_uclass_plat(diskobj->dev);
>>> +		desc = dev_get_uclass_plat(efi_handle_to_udev(diskobj));
>>
>> dev_get_uclass(diskobj->header.hdev)
>>
>>
>>>    		if (direction == EFI_DISK_READ)
>>>    			n = blk_dread(desc, lba, blocks, buffer);
>>>    		else
>>> @@ -552,7 +551,7 @@ static int efi_disk_create_raw(struct udevice *dev)
>>>
>>>    		return -1;
>>>    	}
>>> -	disk->dev = dev;
>>> +	efi_handle_to_udev(disk) = dev;
>>>    	if (dev_tag_set_ptr(dev, DM_TAG_EFI, &disk->header)) {
>>>    		efi_free_pool(disk->dp);
>>>    		efi_delete_handle(&disk->header);
>>> @@ -609,7 +608,7 @@ static int efi_disk_create_part(struct udevice *dev)
>>>    		log_err("Adding partition for %s failed\n", dev->name);
>>>    		return -1;
>>>    	}
>>> -	disk->dev = dev;
>>> +	efi_handle_to_udev(disk) = dev;
>>
>> disk->header.dev = dev;
>
> It's my preference, but I would suggest another accessor:
>         efi_set_udev(handle, dev);
> to hide an implementation.
>
> -Takahiro Akashi
>
>>
>>>    	if (dev_tag_set_ptr(dev, DM_TAG_EFI, &disk->header)) {
>>>    		efi_free_pool(disk->dp);
>>>    		efi_delete_handle(&disk->header);
>>> @@ -656,6 +655,13 @@ static int efi_disk_probe(void *ctx, struct event *event)
>>>    		ret = efi_disk_create_raw(dev);
>>>    		if (ret)
>>>    			return -1;
>>> +	} else {
>>> +		efi_handle_t handle;
>>> +
>>> +		if (dev_tag_get_ptr(dev, DM_TAG_EFI, (void **)&handle))
>>> +			return -1;
>>> +
>>> +		efi_handle_to_udev(handle) = dev;
>>
>> handle->dev = dev;
>>
>> Best regards
>>
>> Heinrich
>>
>>>    	}
>>>
>>>    	device_foreach_child(child, dev) {
>>