Hi Rob, On 4/1/2020 8:38 AM, Kishon Vijay Abraham I wrote: > Hi Rob, > > On 3/31/2020 10:15 PM, Rob Herring wrote: >> On Tue, Mar 31, 2020 at 09:08:12AM +0530, Kishon Vijay Abraham I wrote: >>> Hi Rob, >>> >>> On 3/30/2020 9:31 PM, Rob Herring wrote: >>>> On Fri, Mar 27, 2020 at 04:17:25PM +0530, Kishon Vijay Abraham I wrote: >>>>> Deprecate cdns,max-outbound-regions and cdns,no-bar-match-nbits for >>>>> host mode as both these could be derived from "ranges" and "dma-ranges" >>>>> property. "cdns,max-outbound-regions" property would still be required >>>>> for EP mode. >>>>> >>>>> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx> >>>>> --- >>>>> .../bindings/pci/cdns,cdns-pcie-ep.yaml | 2 +- >>>>> .../bindings/pci/cdns,cdns-pcie-host.yaml | 3 +-- >>>>> .../devicetree/bindings/pci/cdns-pcie-ep.yaml | 25 +++++++++++++++++++ >>>>> .../bindings/pci/cdns-pcie-host.yaml | 10 ++++++++ >>>>> .../devicetree/bindings/pci/cdns-pcie.yaml | 8 ------ >>>>> 5 files changed, 37 insertions(+), 11 deletions(-) >>>>> create mode 100644 Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml >>>>> index 2996f8d4777c..50ce5d79d2c7 100644 >>>>> --- a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml >>>>> +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml >>>>> @@ -10,7 +10,7 @@ maintainers: >>>>> - Tom Joseph <tjoseph@xxxxxxxxxxx> >>>>> >>>>> allOf: >>>>> - - $ref: "cdns-pcie.yaml#" >>>>> + - $ref: "cdns-pcie-ep.yaml#" >>>>> - $ref: "pci-ep.yaml#" >>>>> >>>>> properties: >>>>> diff --git a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >>>>> index cabbe46ff578..84a8f095d031 100644 >>>>> --- a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >>>>> +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >>>>> @@ -45,8 +45,6 @@ examples: >>>>> #size-cells = <2>; >>>>> bus-range = <0x0 0xff>; >>>>> linux,pci-domain = <0>; >>>>> - cdns,max-outbound-regions = <16>; >>>>> - cdns,no-bar-match-nbits = <32>; >>>>> vendor-id = <0x17cd>; >>>>> device-id = <0x0200>; >>>>> >>>>> @@ -57,6 +55,7 @@ examples: >>>>> >>>>> ranges = <0x02000000 0x0 0x42000000 0x0 0x42000000 0x0 0x1000000>, >>>>> <0x01000000 0x0 0x43000000 0x0 0x43000000 0x0 0x0010000>; >>>>> + dma-ranges = <0x02000000 0x0 0x0 0x0 0x0 0x1 0x00000000>; >>>>> >>>>> #interrupt-cells = <0x1>; >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml >>>>> new file mode 100644 >>>>> index 000000000000..6150a7a7bdbf >>>>> --- /dev/null >>>>> +++ b/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml >>>>> @@ -0,0 +1,25 @@ >>>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>>>> +%YAML 1.2 >>>>> +--- >>>>> +$id: "http://devicetree.org/schemas/pci/cdns-pcie-ep.yaml#"; >>>>> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"; >>>>> + >>>>> +title: Cadence PCIe Device >>>>> + >>>>> +maintainers: >>>>> + - Tom Joseph <tjoseph@xxxxxxxxxxx> >>>>> + >>>>> +allOf: >>>>> + - $ref: "cdns-pcie.yaml#" >>>>> + >>>>> +properties: >>>>> + cdns,max-outbound-regions: >>>>> + description: maximum number of outbound regions >>>>> + allOf: >>>>> + - $ref: /schemas/types.yaml#/definitions/uint32 >>>>> + minimum: 1 >>>>> + maximum: 32 >>>>> + default: 32 >>>> >>>> I have a feeling that as the PCI endpoint binding evolves this won't be >>>> necessary. I can see a common need to define the number of BARs for an >>>> endpoint and then this will again just be error checking. >>> >>> For every buffer given by the host, we have to create a new outbound >>> translation. If there are no outbound regions, we have to report the error to >>> the endpoint function driver. At-least for reporting the error, we'd need to >>> have this binding no? >> >> But isn't the endpoint defined to have some number of BARs? The PCI host >> doesn't decide that. > > cdns,max-outbound-regions defined here doesn't configure the BARs. BARs provide > an interface for the host to access the endpoints memory. IOW for BARs we > configure the inbound address translation unit. > > cdns,max-outbound-regions is used while configuring the outbound address > translation unit. Outbound regions are used while the endpoint access host > memory and in that path endpoint BARs doesn't come. >> >>>> >>>> What's the result if you write to a non-existent region in register >>>> CDNS_PCIE_AT_OB_REGION_PCI_ADDR0/1? If the register is non-existent and >>>> doesn't abort, you could detect this instead. >>> >>> I'm not sure if we should ever try to write to a non-existent register though >>> the behavior could be different in different platforms. IMHO maximum number of >>> outbound regions is a HW property and is best described in device tree. >> >> AIUI, PCI defines non-existent (config space) registers to return all >> 1s. Not sure if this register is in PCI config space or the host SoC bus >> (e.g. AXI). It seems PCI bridges get done both ways from what I've seen. > > All of that is correct for the Host or RC. However here > cdns,max-outbound-regions is an endpoint specific property (defined only in > cdns-pcie-ep.yaml) and is useful while configuring OB address translation unit > for the endpoint to access host memory. Do you still have concerns regarding this? If you don't have any further comments on this, can you give your Acked-by please? Thanks Kishon
