On Wed, Apr 17, 2024 at 6:34 AM Saravana Kannan <saravanak@xxxxxxxxxx> wrote: > > On Tue, Apr 16, 2024 at 7:11 AM Rob Herring <robh@xxxxxxxxxx> wrote: > > > > 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 > > parse_interrupts() calls of_irq_parse_one() that in turn calls > of_irq_parse_one() that does the "interrupts-map" handling. In fact > of_irq_parse_pci() also calls of_irq_parse_one() if the PCI device has > a DT node. So I don't think any new functionality needs to be added. > If I'm not mistaken we just need parse_interrupts to not ignore > interrupts-map? A one line change? > > Why do we need all of this code you wrote below? The of_irq_parse_one() calls of_irq_parse_raw() only if the DT node has "interrupts" or "interrupts-extended" DT property. This means for most PCI host controller DT nodes, the of_irq_parse_one() will not return any interrupts. Here's an example PCI host DT node from the RISC-V world (but this also applies to other architectures): pci@30000000 { compatible = "pci-host-ecam-generic"; device_type = "pci"; #address-cells = <0x03>; #size-cells = <0x02>; #interrupt-cells = <0x01>; interrupt-map-mask = <0x0 0x00 0x00 0x07>; interrupt-map = <0x00 0x00 0x00 0x01 &aplic_slevel 28 0x04>, <0x00 0x00 0x00 0x02 &aplic_slevel 29 0x04>, <0x00 0x00 0x00 0x03 &aplic_slevel 30 0x04>, <0x00 0x00 0x00 0x04 &aplic_slevel 31 0x04>; reg = <0x0 0x30000000 0x0 0x10000000>; ranges = <0x01000000 0x0 0x0 0x0 0x1fff0000 0x00000000 0x10000>, <0x02000000 0x0 0x40000000 0x0 0x40000000 0x0 0x40000000>, <0x03000000 0x100 0x0 0x100 0x0 0x4 0x0>; interrupt-parent = <&aplic_slevel>; msi-parent = <&imsic_slevel>; bus-range = <0x00 0xff>; linux,pci-domain = <0x00>; }; In the above example, the "interrupt-map" DT property maps a set of PCIe endpoints to APLIC interrupt sources but this only applies if the corresponding PCIe endpoints are actually present. Also, which entry of "interrupt-map" DT property is used for a PCIe endpoint also depends on the PCI requester ID (bus-device-func) assigned to the PCIe endpoint. Regards, Anup > > -Saravana > > > > 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