On Sat, Apr 13, 2024 at 02:49:42PM +0530, Anup Patel 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. This 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 affects every platform 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 <apatel@xxxxxxxxxxxxxxxx>
> ---
> Changes since v1:
> - Updated commit description based on Rob's suggestion
> - Use of_irq_parse_raw() for parsing interrupt-map DT property
> ---
> drivers/of/property.c | 58 +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 58 insertions(+)
>
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index a6358ee99b74..67be66384dac 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1311,6 +1311,63 @@ 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)
> +{
> + const __be32 *imap, *imap_end, *addr;
> + struct of_phandle_args sup_args;
> + struct device_node *tn, *ipar;
> + u32 addrcells, intcells;
> + int i, j, 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);
No need for this loop. We've only gotten here if 'interrupt-map' is
present in the node and '#interrupt-cells' is required if
'interrupt-map' is present.
> + 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;
> +
> + sup_args.np = NULL;
> + for (i = 0; i <= index && imap < imap_end; i++) {
> + if (sup_args.np) {
> + of_node_put(sup_args.np);
> + sup_args.np = NULL;
> + }
> +
> + addr = imap;
> + imap += addrcells;
> +
> + sup_args.np = np;
> + sup_args.args_count = intcells;
> + for (j = 0; j < intcells; j++)
> + sup_args.args[j] = be32_to_cpu(imap[j]);
> + imap += intcells;
> +
> + if (of_irq_parse_raw(addr, &sup_args))
> + return NULL;
> + imap += sup_args.args_count + 1;
> + }
Doesn't this leak a ref on the last time the function is invoked? For
example, if we have 2 entries and index is 2. We'll get index=1, but
then exit because imap==imap_end. We need a put on index==1 node.
Look at my next branch where I've converted things to use __free()
cleanups. I don't see it helping here as-is, but maybe when it is
correct.
Rob
