Re: [RFC 07/22] dm: blk: add UCLASS_PARTITION

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

Simon,

On Sun, Oct 10, 2021 at 08:14:34AM -0600, Simon Glass wrote:
> Hi Takahiro,
> 
> On Thu, 30 Sept 2021 at 23:03, AKASHI Takahiro
> <takahiro.akashi@linaro.org> wrote:
> >
> > UCLASS_PARTITION device will be created as a child node of
> > UCLASS_BLK device.
> >
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > ---
> >  drivers/block/blk-uclass.c | 111 +++++++++++++++++++++++++++++++++++++
> >  include/blk.h              |   9 +++
> >  include/dm/uclass-id.h     |   1 +
> >  3 files changed, 121 insertions(+)
> >
> > diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
> > index 83682dcc181a..dd7f3c0fe31e 100644
> > --- a/drivers/block/blk-uclass.c
> > +++ b/drivers/block/blk-uclass.c
> > @@ -12,6 +12,7 @@
> >  #include <log.h>
> >  #include <malloc.h>
> >  #include <part.h>
> > +#include <string.h>
> >  #include <dm/device-internal.h>
> >  #include <dm/lists.h>
> >  #include <dm/uclass-internal.h>
> > @@ -695,6 +696,44 @@ int blk_unbind_all(int if_type)
> >         return 0;
> >  }
> >
> > +int blk_create_partitions(struct udevice *parent)
> > +{
> > +       int part, count;
> > +       struct blk_desc *desc = dev_get_uclass_plat(parent);
> > +       struct disk_partition info;
> > +       struct disk_part *part_data;
> > +       char devname[32];
> > +       struct udevice *dev;
> > +       int ret;
> > +
> > +       if (!CONFIG_IS_ENABLED(PARTITIONS) ||
> > +           !CONFIG_IS_ENABLED(HAVE_BLOCK_DEVICE))
> > +               return 0;
> > +
> > +       /* Add devices for each partition */
> > +       for (count = 0, part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
> > +               if (part_get_info(desc, part, &info))
> > +                       continue;
> > +               snprintf(devname, sizeof(devname), "%s:%d", parent->name,
> > +                        part);
> > +
> > +               ret = device_bind_driver(parent, "blk_partition",
> > +                                        strdup(devname), &dev);
> > +               if (ret)
> > +                       return ret;
> > +
> > +               part_data = dev_get_uclass_plat(dev);
> > +               part_data->partnum = part;
> > +               part_data->gpt_part_info = info;
> > +               count++;
> > +
> > +               device_probe(dev);
> > +       }
> > +       debug("%s: %d partitions found in %s\n", __func__, count, parent->name);
> 
> log_debug() and drop __func__

OK.

> > +
> > +       return 0;
> > +}
> > +
> >  static int blk_post_probe(struct udevice *dev)
> >  {
> >         if (IS_ENABLED(CONFIG_PARTITIONS) &&
> > @@ -713,3 +752,75 @@ UCLASS_DRIVER(blk) = {
> >         .post_probe     = blk_post_probe,
> >         .per_device_plat_auto   = sizeof(struct blk_desc),
> >  };
> > +
> > +static ulong blk_part_read(struct udevice *dev, lbaint_t start,
> > +                          lbaint_t blkcnt, void *buffer)
> > +{
> 
> part_blk_read() so that it is clear that this takes a UCLASS_PARTITION
> device, not a UCLASS_BLK

OK.

> > +       struct udevice *parent;
> > +       struct disk_part *part;
> > +       const struct blk_ops *ops;
> > +
> > +       parent = dev_get_parent(dev);
> > +       ops = blk_get_ops(parent);
> > +       if (!ops->read)
> > +               return -ENOSYS;
> > +
> > +       part = dev_get_uclass_plat(dev);
> > +       start += part->gpt_part_info.start;
> > +
> > +       return ops->read(parent, start, blkcnt, buffer);
> > +}
> > +
> > +static ulong blk_part_write(struct udevice *dev, lbaint_t start,
> > +                           lbaint_t blkcnt, const void *buffer)
> > +{
> > +       struct udevice *parent;
> > +       struct disk_part *part;
> > +       const struct blk_ops *ops;
> > +
> > +       parent = dev_get_parent(dev);
> > +       ops = blk_get_ops(parent);
> > +       if (!ops->write)
> > +               return -ENOSYS;
> > +
> > +       part = dev_get_uclass_plat(dev);
> > +       start += part->gpt_part_info.start;
> > +
> > +       return ops->write(parent, start, blkcnt, buffer);
> > +}
> > +
> > +static ulong blk_part_erase(struct udevice *dev, lbaint_t start,
> > +                           lbaint_t blkcnt)
> > +{
> > +       struct udevice *parent;
> > +       struct disk_part *part;
> > +       const struct blk_ops *ops;
> > +
> > +       parent = dev_get_parent(dev);
> > +       ops = blk_get_ops(parent);
> > +       if (!ops->erase)
> > +               return -ENOSYS;
> > +
> > +       part = dev_get_uclass_plat(dev);
> > +       start += part->gpt_part_info.start;
> > +
> > +       return ops->erase(parent, start, blkcnt);
> > +}
> > +
> > +static const struct blk_ops blk_part_ops = {
> > +       .read   = blk_part_read,
> > +       .write  = blk_part_write,
> > +       .erase  = blk_part_erase,
> > +};
> > +
> > +U_BOOT_DRIVER(blk_partition) = {
> > +       .name           = "blk_partition",
> > +       .id             = UCLASS_PARTITION,
> > +       .ops            = &blk_part_ops,
> > +};
> 
> Can you put this all in a separate part-uclass.c file? This too:

OK.
Then put the file under disk/,  driver/block or driver/partition?

> > +
> > +UCLASS_DRIVER(partition) = {
> > +       .id             = UCLASS_PARTITION,
> > +       .per_device_plat_auto   = sizeof(struct disk_part),
> > +       .name           = "partition",
> > +};
> > diff --git a/include/blk.h b/include/blk.h
> > index 19bab081c2cd..3d883eb1db64 100644
> > --- a/include/blk.h
> > +++ b/include/blk.h
> > @@ -366,6 +366,15 @@ int blk_create_devicef(struct udevice *parent, const char *drv_name,
> >                        const char *name, int if_type, int devnum, int blksz,
> >                        lbaint_t lba, struct udevice **devp);
> >
> > +/**
> > + * blk_create_partitions - Create block devices for disk partitions
> > + *
> > + * Create UCLASS_PARTITION udevices for each of disk partitions in @parent
> > + *
> > + * @parent:    Whole disk device
> 
> UCLASS_BLK?
> 
> It is good to document the device types to avoid people getting confused later.

OK.

> > + */
> > +int blk_create_partitions(struct udevice *parent);
> > +
> >  /**
> >   * blk_unbind_all() - Unbind all device of the given interface type
> >   *
> > diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> > index e7edd409f307..30892d01ce13 100644
> > --- a/include/dm/uclass-id.h
> > +++ b/include/dm/uclass-id.h
> > @@ -80,6 +80,7 @@ enum uclass_id {
> >         UCLASS_P2SB,            /* (x86) Primary-to-Sideband Bus */
> >         UCLASS_PANEL,           /* Display panel, such as an LCD */
> >         UCLASS_PANEL_BACKLIGHT, /* Backlight controller for panel */
> > +       UCLASS_PARTITION,       /* Logical disk partition device */
> >         UCLASS_PCH,             /* x86 platform controller hub */
> >         UCLASS_PCI,             /* PCI bus */
> >         UCLASS_PCI_EP,          /* PCI endpoint device */
> > --
> > 2.33.0
> >
> 
> This is a new uclass so needs a sandbox test.

Yes, I intend to do so with pytest once we have some consensus
on interfaces.

-Takahiro Akashi


> Regards,
> Simon