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

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

On Sun, Jul 17, 2022 at 01:23:41PM +0200, Heinrich Schuchardt wrote:
> On 7/17/22 10:09, 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@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.
> > 
> > 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.
> > 
> > > +
> > >   /* 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;
> > 
> > >       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))
> 
> Setting handle->dev can be done more easily in efi_bl_bind():

I don't think so.
"dev" field should be maintained in *one* place, i.e. efi_disk_probe(),
which is uniquely called from probe event (even for efi_block_dev case).

To make this clear, we'd better put the code in efi_disk_create_raw():
  efi_disk_create_raw()
      if (desc->if_type == IF_TYPE_EFI_LOADER) { 
          /* handle should exist now */
          dev_tag_get_ptr(dev, DM_TAG_EFI, (void **)&handle));
          efi_set_udev(handle, dev);
          return 0;
      }

      /* normal block devices */
      ...
      efi_set_udev(&disk->header, dev);
      ...


-Takahiro Akashi

> handle->dev = bdev;
> 
> We can further remove the field handle from struct blk_create_device as
> it is now available in handle->dev.
> 
> Best regards
> 
> Heinrich
> 
> > > +            return -1;
> > > +
> > > +        efi_handle_to_udev(handle) = dev;
> > 
> > handle->dev = dev;
> > 
> > Best regards
> > 
> > Heinrich
> > 
> > >       }
> > > 
> > >       device_foreach_child(child, dev) {
> > 
>