Re: [PATCH v3 06/27] ocxl: Tally up the LPC memory on a link & allow it to be mapped

From: Alastair D'Silva
Date: Mon Feb 24 2020 - 00:37:05 EST


On Mon, 2020-02-24 at 16:25 +1100, Andrew Donnellan wrote:
> On 21/2/20 2:26 pm, Alastair D'Silva wrote:
> > From: Alastair D'Silva <alastair@xxxxxxxxxxx>
> >
> > Tally up the LPC memory on an OpenCAPI link & allow it to be mapped
> >
> > Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
>
> This commit message is a bit short and could do with some further
> explanation.
>
> In particular - it's worth explaining why the tracking of available
> LPC
> memory needs to be done at a link level, because a single OpenCAPI
> card
> can have multiple PCI functions, each with multiple AFUs which define
> an
> amount of LPC memory they have, even if the common case is expected
> to
> be a single function with a single AFU and thus one LPC area per
> link.

Ok

>
> Snowpatch has a few checkpatch issues to report:
>
> https://openpower.xyz/job/snowpatch/job/snowpatch-linux-checkpatch/11800//artifact/linux/checkpatch.log
>

Gah, I could have sworn I ran checkpatch against this :/

> The code generally looks okay to me.
>
> > diff --git a/drivers/misc/ocxl/ocxl_internal.h
> > b/drivers/misc/ocxl/ocxl_internal.h
> > index 198e4e4bc51d..d0c8c4838f42 100644
> > --- a/drivers/misc/ocxl/ocxl_internal.h
> > +++ b/drivers/misc/ocxl/ocxl_internal.h
> > @@ -142,4 +142,37 @@ int ocxl_irq_offset_to_id(struct ocxl_context
> > *ctx, u64 offset);
> > u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id);
> > void ocxl_afu_irq_free_all(struct ocxl_context *ctx);
> >
> > +/**
> > + * ocxl_link_add_lpc_mem() - Increment the amount of memory
> > required by an OpenCAPI link
> > + *
> > + * @link_handle: The OpenCAPI link handle
> > + * @offset: The offset of the memory to add
> > + * @size: The amount of memory to increment by
> > + *
> > + * Returns 0 on success, negative on overflow
> > + */
>
> I think "amount of memory required" isn't the best way to express
> this.
>
> Might as well explicitly say -EINVAL on overflow.
>

Ok

--
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819