Some of the PCI controllers (such as generic PCI host controller)
use "interrupt-map" DT property to describe the mapping between
PCI endpoints and PCI interrupt pins.
Currently, there is no fw_devlink created based on "interrupt-map"
DT property so interrupt controller is not guaranteed to be probed
before PCI host controller. This mainly affects RISC-V platforms
where both PCI host controller and interrupt controllers are probed
as regular platform devices.
This creates fw_devlink between consumers (PCI host controller) and
supplier (interrupt controller) based on "interrupt-map" DT property.
Signed-off-by: Anup Patel <[email protected]>
---
drivers/of/property.c | 53 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)
diff --git a/drivers/of/property.c b/drivers/of/property.c
index a6358ee99b74..ccbbb651a89a 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1311,6 +1311,58 @@ static struct device_node *parse_interrupts(struct device_node *np,
return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
}
+static struct device_node *parse_interrupt_map(struct device_node *np,
+ const char *prop_name, int index)
+{
+ struct device_node *tn, *ipar, *supnp = NULL;
+ u32 addrcells, intcells, cells;
+ const __be32 *imap, *imap_end;
+ int i, imaplen;
+
+ if (!IS_ENABLED(CONFIG_OF_IRQ))
+ return NULL;
+
+ if (strcmp(prop_name, "interrupt-map"))
+ return NULL;
+
+ ipar = of_node_get(np);
+ do {
+ if (!of_property_read_u32(ipar, "#interrupt-cells", &intcells))
+ break;
+ tn = ipar;
+ ipar = of_irq_find_parent(ipar);
+ of_node_put(tn);
+ } while (ipar);
+ if (!ipar)
+ return NULL;
+ addrcells = of_bus_n_addr_cells(ipar);
+ of_node_put(ipar);
+
+ imap = of_get_property(np, "interrupt-map", &imaplen);
+ if (!imap || imaplen <= (addrcells + intcells))
+ return NULL;
+ imap_end = imap + imaplen;
+
+ for (i = 0; i <= index && imap < imap_end; i++) {
+ if (supnp)
+ of_node_put(supnp);
+
+ imap += addrcells;
+ imap += intcells;
+
+ supnp = of_find_node_by_phandle(be32_to_cpu(imap[0]));
+ if (!supnp)
+ return NULL;
+ imap += 1;
+
+ if (of_property_read_u32(supnp, "#interrupt-cells", &cells))
+ return NULL;
+ imap += cells;
+ }
+
+ return supnp;
+}
+
static struct device_node *parse_remote_endpoint(struct device_node *np,
const char *prop_name,
int index)
@@ -1359,6 +1411,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
{ .parse_prop = parse_msi_parent, },
{ .parse_prop = parse_gpio_compat, },
{ .parse_prop = parse_interrupts, },
+ { .parse_prop = parse_interrupt_map, },
{ .parse_prop = parse_regulators, },
{ .parse_prop = parse_gpio, },
{ .parse_prop = parse_gpios, },
--
2.34.1
On Fri, Apr 12, 2024 at 6:29 AM Anup Patel <[email protected]> wrote:
>
> Some of the PCI controllers (such as generic PCI host controller)
> use "interrupt-map" DT property to describe the mapping between
> PCI endpoints and PCI interrupt pins.
I would go as far as saying that's the only case as that's the only
case where the interrupts are not described in DT.
> Currently, there is no fw_devlink created based on "interrupt-map"
> DT property so interrupt controller is not guaranteed to be probed
> before PCI host controller. This mainly affects RISC-V platforms
> where both PCI host controller and interrupt controllers are probed
> as regular platform devices.
That's *every* system with PCI really.
> This creates fw_devlink between consumers (PCI host controller) and
> supplier (interrupt controller) based on "interrupt-map" DT property.
>
> Signed-off-by: Anup Patel <[email protected]>
> ---
> drivers/of/property.c | 53 +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 53 insertions(+)
>
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index a6358ee99b74..ccbbb651a89a 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1311,6 +1311,58 @@ static struct device_node *parse_interrupts(struct device_node *np,
> return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
> }
>
> +static struct device_node *parse_interrupt_map(struct device_node *np,
> + const char *prop_name, int index)
> +{
> + struct device_node *tn, *ipar, *supnp = NULL;
> + u32 addrcells, intcells, cells;
> + const __be32 *imap, *imap_end;
> + int i, imaplen;
> +
> + if (!IS_ENABLED(CONFIG_OF_IRQ))
> + return NULL;
> +
> + if (strcmp(prop_name, "interrupt-map"))
> + return NULL;
> +
> + ipar = of_node_get(np);
> + do {
> + if (!of_property_read_u32(ipar, "#interrupt-cells", &intcells))
> + break;
> + tn = ipar;
> + ipar = of_irq_find_parent(ipar);
> + of_node_put(tn);
> + } while (ipar);
> + if (!ipar)
> + return NULL;
> + addrcells = of_bus_n_addr_cells(ipar);
> + of_node_put(ipar);
> +
> + imap = of_get_property(np, "interrupt-map", &imaplen);
> + if (!imap || imaplen <= (addrcells + intcells))
> + return NULL;
> + imap_end = imap + imaplen;
> +
> + for (i = 0; i <= index && imap < imap_end; i++) {
> + if (supnp)
> + of_node_put(supnp);
> +
> + imap += addrcells;
> + imap += intcells;
> +
> + supnp = of_find_node_by_phandle(be32_to_cpu(imap[0]));
> + if (!supnp)
> + return NULL;
> + imap += 1;
> +
> + if (of_property_read_u32(supnp, "#interrupt-cells", &cells))
> + return NULL;
> + imap += cells;
This is wrong. Technically, you can have #address-cells too.
The bigger problem I have is this creates 2 sets of 'interrupt-map'
parsing code. Your version skips a lot of things like whether the
interrupt controller is available and there's the list of
'interrupt-map' abusers to think about.
Rob
On Fri, Apr 12, 2024 at 6:07 PM Rob Herring <[email protected]> wrote:
>
> On Fri, Apr 12, 2024 at 6:29 AM Anup Patel <[email protected]> wrote:
> >
> > Some of the PCI controllers (such as generic PCI host controller)
> > use "interrupt-map" DT property to describe the mapping between
> > PCI endpoints and PCI interrupt pins.
>
> I would go as far as saying that's the only case as that's the only
> case where the interrupts are not described in DT.
Sure, I will update the text.
>
> > Currently, there is no fw_devlink created based on "interrupt-map"
> > DT property so interrupt controller is not guaranteed to be probed
> > before PCI host controller. This mainly affects RISC-V platforms
> > where both PCI host controller and interrupt controllers are probed
> > as regular platform devices.
>
> That's *every* system with PCI really.
Okay, I will re-word.
>
> > This creates fw_devlink between consumers (PCI host controller) and
> > supplier (interrupt controller) based on "interrupt-map" DT property.
> >
> > Signed-off-by: Anup Patel <[email protected]>
> > ---
> > drivers/of/property.c | 53 +++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 53 insertions(+)
> >
> > diff --git a/drivers/of/property.c b/drivers/of/property.c
> > index a6358ee99b74..ccbbb651a89a 100644
> > --- a/drivers/of/property.c
> > +++ b/drivers/of/property.c
> > @@ -1311,6 +1311,58 @@ static struct device_node *parse_interrupts(struct device_node *np,
> > return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_argsnp;
> > }
> >
> > +static struct device_node *parse_interrupt_map(struct device_node *np,
> > + const char *prop_name, int index)
> > +{
> > + struct device_node *tn, *ipar, *supnp = NULL;
> > + u32 addrcells, intcells, cells;
> > + const __be32 *imap, *imap_end;
> > + int i, imaplen;
> > +
> > + if (!IS_ENABLED(CONFIG_OF_IRQ))
> > + return NULL;
> > +
> > + if (strcmp(prop_name, "interrupt-map"))
> > + return NULL;
> > +
> > + ipar = of_node_get(np);
> > + do {
> > + if (!of_property_read_u32(ipar, "#interrupt-cells", &intcells))
> > + break;
> > + tn = ipar;
> > + ipar = of_irq_find_parent(ipar);
> > + of_node_put(tn);
> > + } while (ipar);
> > + if (!ipar)
> > + return NULL;
> > + addrcells = of_bus_n_addr_cells(ipar);
> > + of_node_put(ipar);
> > +
> > + imap = of_get_property(np, "interrupt-map", &imaplen);
> > + if (!imap || imaplen <= (addrcells + intcells))
> > + return NULL;
> > + imap_end = imap + imaplen;
> > +
> > + for (i = 0; i <= index && imap < imap_end; i++) {
> > + if (supnp)
> > + of_node_put(supnp);
> > +
> > + imap += addrcells;
> > + imap += intcells;
> > +
> > + supnp = of_find_node_by_phandle(be32_to_cpu(imap[0]));
> > + if (!supnp)
> > + return NULL;
> > + imap += 1;
> > +
> > + if (of_property_read_u32(supnp, "#interrupt-cells", &cells))
> > + return NULL;
> > + imap += cells;
>
> This is wrong. Technically, you can have #address-cells too.
>
> The bigger problem I have is this creates 2 sets of 'interrupt-map'
> parsing code. Your version skips a lot of things like whether the
> interrupt controller is available and there's the list of
> 'interrupt-map' abusers to think about.
>
In my first attempt, I was trying to keep it simple but I guess I
over-simplified it.
I have an alternate approach to use of_irq_parse_raw() over
here (similar to of_irq_parse_pci() in drivers/pci/of.c). Are you
okay with this approach ?
Regards,
Anup