From: David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>
To: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Thierry Reding
<thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Lucas Stach <l.stach-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>,
devicetree-compiler-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH] checks: Handle #dma-address-cells and #dma-size-cells
Date: Sun, 13 Nov 2022 16:07:11 +1100 [thread overview]
Message-ID: <Y3B7f+IsJniHFtBY@yekko> (raw)
In-Reply-To: <CAL_JsqLV2ZHLJ=14zf9zNfq+S+Rs09EYmZrNHsvdhbmvvehj6g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
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On Fri, Nov 11, 2022 at 11:01:58AM -0600, Rob Herring wrote:
> On Fri, Nov 11, 2022 at 5:47 AM Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> >
> > From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> >
> > The #dma-address-cells and #dma-size-cells properties can be used to
> > override their non-DMA counterparts (#address-cells and #size-cells)
> > for cases where the control bus (defined by the "reg" and "ranges"
> > properties) has different addressing requirements from the DMA bus.
> >
> > The "dma-ranges" property needs to be sized depending on these DMA
> > bus properties rather than the control bus properties, so adjust the
> > check accordingly.
>
> I assume I'll be seeing a spec and schema addition too.
>
> I imagine David is wondering where this is coming from given these are
> new properties, not existing ones that the checks just didn't handle.
Right. In addition, kind of the whole point of dma-ranges is that
it's describing address translations going "up" the tree (reverse of
"ranges"). I'm having trouble seeing how that would make any sense
if the cell numbers are different for the two cases.
> >
> > Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> > ---
> > checks.c | 48 +++++++++++++++++++++++++++++++++++++-----------
> > dtc.h | 1 +
> > 2 files changed, 38 insertions(+), 11 deletions(-)
> >
> > diff --git a/checks.c b/checks.c
> > index 9f31d2607182..ee13dce03483 100644
> > --- a/checks.c
> > +++ b/checks.c
> > @@ -743,6 +743,17 @@ static void fixup_addr_size_cells(struct check *c, struct dt_info *dti,
> > prop = get_property(node, "#size-cells");
> > if (prop)
> > node->size_cells = propval_cell(prop);
> > +
> > + node->dma_addr_cells = -1;
> > + node->dma_size_cells = -1;
> > +
> > + prop = get_property(node, "#dma-address-cells");
> > + if (prop)
> > + node->dma_addr_cells = propval_cell(prop);
>
> else
> node->dma_addr_cells = node->addr_cells;
>
> > +
> > + prop = get_property(node, "#dma-size-cells");
> > + if (prop)
> > + node->dma_size_cells = propval_cell(prop);
> > }
> > WARNING(addr_size_cells, fixup_addr_size_cells, NULL,
> > &address_cells_is_cell, &size_cells_is_cell);
> > @@ -751,6 +762,10 @@ WARNING(addr_size_cells, fixup_addr_size_cells, NULL,
> > (((n)->addr_cells == -1) ? 2 : (n)->addr_cells)
> > #define node_size_cells(n) \
> > (((n)->size_cells == -1) ? 1 : (n)->size_cells)
> > +#define node_dma_addr_cells(n) \
> > + (((n)->dma_addr_cells == -1) ? node_addr_cells(n) : (n)->dma_addr_cells)
> > +#define node_dma_size_cells(n) \
> > + (((n)->dma_size_cells == -1) ? node_size_cells(n) : (n)->dma_size_cells)
>
> Then these can be just "(n)->dma_size_cells".
>
> But wait, what about the default sizes? Those have been a dtc warning
> since longer than I've run dtc. The defaults don't even agree with
> Linux depending on the architecture. Certainly anyone using these new
> properties must not be relying on defaults.
>
> >
> > static void check_reg_format(struct check *c, struct dt_info *dti,
> > struct node *node)
> > @@ -787,6 +802,7 @@ static void check_ranges_format(struct check *c, struct dt_info *dti,
> > struct property *prop;
> > int c_addr_cells, p_addr_cells, c_size_cells, p_size_cells, entrylen;
> > const char *ranges = c->data;
> > + const char *prefix;
> >
> > prop = get_property(node, ranges);
> > if (!prop)
> > @@ -798,28 +814,38 @@ static void check_ranges_format(struct check *c, struct dt_info *dti,
> > return;
> > }
> >
> > - p_addr_cells = node_addr_cells(node->parent);
> > - p_size_cells = node_size_cells(node->parent);
> > - c_addr_cells = node_addr_cells(node);
> > - c_size_cells = node_size_cells(node);
> > + if (strcmp(ranges, "dma-ranges") == 0) {
> > + p_addr_cells = node_dma_addr_cells(node->parent);
> > + p_size_cells = node_dma_size_cells(node->parent);
> > + c_addr_cells = node_dma_addr_cells(node);
> > + c_size_cells = node_dma_size_cells(node);
> > + prefix = "dma-";
> > + } else {
> > + p_addr_cells = node_addr_cells(node->parent);
> > + p_size_cells = node_size_cells(node->parent);
> > + c_addr_cells = node_addr_cells(node);
> > + c_size_cells = node_size_cells(node);
> > + prefix = "";
> > + }
> > +
> > entrylen = (p_addr_cells + c_addr_cells + c_size_cells) * sizeof(cell_t);
> >
> > if (prop->val.len == 0) {
> > if (p_addr_cells != c_addr_cells)
> > FAIL_PROP(c, dti, node, prop, "empty \"%s\" property but its "
> > - "#address-cells (%d) differs from %s (%d)",
> > - ranges, c_addr_cells, node->parent->fullpath,
> > + "#%saddress-cells (%d) differs from %s (%d)",
> > + ranges, prefix, c_addr_cells, node->parent->fullpath,
>
> This is going to misleadingly print '#dma-address-cells' in cases that
> actually have '#address-cells'. It's probably easiest if you say 'DMA?
> address cells' rather than using the property name.
>
> > p_addr_cells);
> > if (p_size_cells != c_size_cells)
> > FAIL_PROP(c, dti, node, prop, "empty \"%s\" property but its "
> > - "#size-cells (%d) differs from %s (%d)",
> > - ranges, c_size_cells, node->parent->fullpath,
> > + "#%ssize-cells (%d) differs from %s (%d)",
> > + ranges, prefix, c_size_cells, node->parent->fullpath,
> > p_size_cells);
> > } else if (!is_multiple_of(prop->val.len, entrylen)) {
> > FAIL_PROP(c, dti, node, prop, "\"%s\" property has invalid length (%d bytes) "
> > - "(parent #address-cells == %d, child #address-cells == %d, "
> > - "#size-cells == %d)", ranges, prop->val.len,
> > - p_addr_cells, c_addr_cells, c_size_cells);
> > + "(parent #%saddress-cells == %d, child #%saddress-cells == %d, "
> > + "#size-cells == %d)", ranges, prop->val.len, prefix,
> > + p_addr_cells, prefix, c_addr_cells, c_size_cells);
> > }
> > }
> > WARNING(ranges_format, check_ranges_format, "ranges", &addr_size_cells);
> > diff --git a/dtc.h b/dtc.h
> > index 0a1f54991026..3d2ef7f3616f 100644
> > --- a/dtc.h
> > +++ b/dtc.h
> > @@ -228,6 +228,7 @@ struct node {
> >
> > cell_t phandle;
> > int addr_cells, size_cells;
> > + int dma_addr_cells, dma_size_cells;
> >
> > struct label *labels;
> > const struct bus_type *bus;
> >
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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next prev parent reply other threads:[~2022-11-13 5:07 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-11 11:47 [PATCH] checks: Handle #dma-address-cells and #dma-size-cells Thierry Reding
[not found] ` <20221111114728.462767-1-thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2022-11-11 17:01 ` Rob Herring
[not found] ` <CAL_JsqLV2ZHLJ=14zf9zNfq+S+Rs09EYmZrNHsvdhbmvvehj6g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2022-11-13 5:07 ` David Gibson [this message]
2022-11-14 10:34 ` Thierry Reding
2022-11-14 14:27 ` Thierry Reding
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