[PATCH 03/10] block: allow block devices to implement the cdev erase operation

[Sascha Hauer]

On Tue, Jul 30, 2024 at 01:10:05PM +0200, Ahmad Fatoum wrote:
> On 30.07.24 10:55, Sascha Hauer wrote:
> > On Tue, Jul 30, 2024 at 09:19:22AM +0200, Ahmad Fatoum wrote:
> >> We mainly implement cdev erase for raw flashes. Many block devices, like
> >> NVMe, SSD or SD/MMC are also flash-based and expose a mechanism or
> >> multiple to trigger an erase on hardware or flash translation layer
> >> level without an accompanied write.
> >>
> >> To make it possible to use this functionality elsewhere in barebox,
> >> let's have the common block device layer pass through the erase
> >> operation, so it may be implemented in a device-specific manner.
> >>
> >> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> >> ---
> >>  common/block.c  | 43 +++++++++++++++++++++++++++++++++++++++++++
> >>  include/block.h |  1 +
> >>  2 files changed, 44 insertions(+)
> >>
> >> diff --git a/common/block.c b/common/block.c
> >> index f55da775a797..b43fcbe6927b 100644
> >> --- a/common/block.c
> >> +++ b/common/block.c
> >> @@ -380,10 +380,45 @@ static int block_op_discard_range(struct cdev *cdev, loff_t count, loff_t offset
> >>  	return 0;
> >>  }
> >>  
> >> +static bool region_overlap(loff_t starta, loff_t lena,
> >> +                           loff_t startb, loff_t lenb)
> >> +{
> >> +        if (starta + lena <= startb)
> >> +                return 0;
> >> +        if (startb + lenb <= starta)
> >> +                return 0;
> >> +        return 1;
> >> +}
> > 
> > We already have this function in fs/devfs-core.c. Time to export it?
> 
> This used to be exported, but the export was removed in commit
> 04e2aa516ed5 ("common.h: move and rename lregion_overlap()").
> 
> I can add it back if you prefer.

I think now that we have two users it makes sense to add it back.

Sascha

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |