[PATCH] arm64: dts: rockchip: rk3588: add msi-parent for pcie3x4_ep

[PATCH] arm64: dts: rockchip: rk3588: add msi-parent for pcie3x4_ep

[Niklas Cassel]

Add msi-parent for the pcie3x4_ep PCI endpoint node.

The pcie3x4_ep node should use the same msi-parent as the pcie3x4 node
(which represents the PCIe controller running in Root Complex mode).

The GIC ITS can be used to trigger an IRQ on the endpoint when any of
the endpoint's PCI BARs are written to by the host[1].

[1] https://lore.kernel.org/linux-pci/20241116-ep-msi-v8-0-6f1f68ffd1bb@nxp.com/

Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
Hello Heiko, this patch depends on:
https://lore.kernel.org/linux-rockchip/20241107123732.1160063-2-cassel@kernel.org/

 arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi b/arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi
index 4a950907ea6f..ead151941e84 100644
--- a/arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi
@@ -213,6 +213,7 @@ pcie3x4_ep: pcie-ep@fe150000 {
 		interrupt-names = "sys", "pmc", "msg", "legacy", "err",
 				  "dma0", "dma1", "dma2", "dma3";
 		max-link-speed = <3>;
+		msi-parent = <&its1 0x0000>;
 		iommus = <&mmu600_pcie 0x0000>;
 		num-lanes = <4>;
 		phys = <&pcie30phy>;
-- 
2.47.0

Re: [PATCH] arm64: dts: rockchip: rk3588: add msi-parent for pcie3x4_ep

[Heiko Stuebner]

On Wed, 20 Nov 2024 18:10:49 +0100, Niklas Cassel wrote:
> Add msi-parent for the pcie3x4_ep PCI endpoint node.
> 
> The pcie3x4_ep node should use the same msi-parent as the pcie3x4 node
> (which represents the PCIe controller running in Root Complex mode).
> 
> The GIC ITS can be used to trigger an IRQ on the endpoint when any of
> the endpoint's PCI BARs are written to by the host[1].
> 
> [...]

Applied, thanks!

[1/1] arm64: dts: rockchip: rk3588: add msi-parent for pcie3x4_ep
      commit: b6f09f497b07008aa65c31341138cecafa78222c

Best regards,
-- 
Heiko Stuebner <heiko@sntech.de>

Re: [PATCH] arm64: dts: rockchip: rk3588: add msi-parent for pcie3x4_ep

[Niklas Cassel]

On Tue, Dec 03, 2024 at 12:29:16AM +0100, Heiko Stuebner wrote:
> 
> On Wed, 20 Nov 2024 18:10:49 +0100, Niklas Cassel wrote:
> > Add msi-parent for the pcie3x4_ep PCI endpoint node.
> > 
> > The pcie3x4_ep node should use the same msi-parent as the pcie3x4 node
> > (which represents the PCIe controller running in Root Complex mode).
> > 
> > The GIC ITS can be used to trigger an IRQ on the endpoint when any of
> > the endpoint's PCI BARs are written to by the host[1].
> > 
> > [...]
> 
> Applied, thanks!
> 
> [1/1] arm64: dts: rockchip: rk3588: add msi-parent for pcie3x4_ep
>       commit: b6f09f497b07008aa65c31341138cecafa78222c
> 

Hello Heiko,

When I sent this patch, I had tested it against Frank's v8 series which adds
support for a PCIe endpoint triggering an interrupt (using GIC ITS) when the
host side writes to the PCI BAR that the endpoint has configured as doorbell:
https://lore.kernel.org/linux-pci/20241116-ep-msi-v8-0-6f1f68ffd1bb@nxp.com/


However, it seems that in v10 of his series, he has changed it so that the
PCIe endpoint node now requires 'msi-map' instead of 'msi-parent'
(just like how it is done in the PCIe root complex node):

See:
https://lore.kernel.org/linux-pci/20241204-ep-msi-v10-0-87c378dbcd6d@nxp.com/

"""
Changes in v10:

[...]

- Use "msi-map" in pci ep controler node, instead of of msi-parent. first
argument is
	(func_no << 8 | vfunc_no)
"""


I didn't realize that DT property required for this feature could change so
drastically, since DT is supposed to describe hardware, and msi-parent made
perfect sense, since this property is usually the one used for devices
connected to a bus.
(msi-map is usually only used on the host bus adapter / root complex.)

Knowing what I now know, I should have waited until this feature had landed
before submitting this patch. I apologize for this.

Could you please drop this patch from your v6.14-armsoc/dts64 branch?

Or should I send a revert?

Once Frank's series has landed, I can resubmit a patch that adds whichever
DT property he finally ends up using.


Kind regards,
Niklas

Re: [PATCH] arm64: dts: rockchip: rk3588: add msi-parent for pcie3x4_ep

[Heiko Stübner]

Hey Niklas,

Am Freitag, 20. Dezember 2024, 09:03:36 CET schrieb Niklas Cassel:
> On Tue, Dec 03, 2024 at 12:29:16AM +0100, Heiko Stuebner wrote:
> > 
> > On Wed, 20 Nov 2024 18:10:49 +0100, Niklas Cassel wrote:
> > > Add msi-parent for the pcie3x4_ep PCI endpoint node.
> > > 
> > > The pcie3x4_ep node should use the same msi-parent as the pcie3x4 node
> > > (which represents the PCIe controller running in Root Complex mode).
> > > 
> > > The GIC ITS can be used to trigger an IRQ on the endpoint when any of
> > > the endpoint's PCI BARs are written to by the host[1].
> > > 
> > > [...]
> > 
> > Applied, thanks!
> > 
> > [1/1] arm64: dts: rockchip: rk3588: add msi-parent for pcie3x4_ep
> >       commit: b6f09f497b07008aa65c31341138cecafa78222c
> > 

> Could you please drop this patch from your v6.14-armsoc/dts64 branch?

happy new year :-) .

I've now dropped the patch from my queue


Heiko