[v6,2/7] dt-bindings: PCI: ti,am65: Extend for use with PVU

Commit Message

Jan Kiszka Sept. 9, 2024, 5:03 p.m. UTC

From: Jan Kiszka <[e-mail]>

The PVU on the AM65 SoC is capable of restricting DMA from PCIe devices
to specific regions of host memory. Add the optional property
"memory-regions" to point to such regions of memory when PVU is used.

Since the PVU deals with system physical addresses, utilizing the PVU
with PCIe devices also requires setting up the VMAP registers to map the
Requester ID of the PCIe device to the CBA Virtual ID, which in turn is
mapped to the system physical address. Hence, describe the VMAP
registers which are optional unless the PVU shall be used for PCIe.

Signed-off-by: Jan Kiszka <[e-mail]>
---
CC: Lorenzo Pieralisi <[e-mail]>
CC: "Krzysztof Wilczyński" <[e-mail]>
CC: Bjorn Helgaas <[e-mail]>
CC: [e-mail]
---
 .../bindings/pci/ti,am65-pci-host.yaml        | 28 +++++++++++++++++--
 1 file changed, 25 insertions(+), 3 deletions(-)

Comments

Krzysztof Kozlowski Sept. 18, 2024, 9:11 a.m. UTC | #1

On Mon, Sep 09, 2024 at 07:03:55PM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <[e-mail]>
> 
> The PVU on the AM65 SoC is capable of restricting DMA from PCIe devices
> to specific regions of host memory. Add the optional property
> "memory-regions" to point to such regions of memory when PVU is used.
> 
> Since the PVU deals with system physical addresses, utilizing the PVU
> with PCIe devices also requires setting up the VMAP registers to map the
> Requester ID of the PCIe device to the CBA Virtual ID, which in turn is
> mapped to the system physical address. Hence, describe the VMAP
> registers which are optional unless the PVU shall be used for PCIe.
 
> +  memory-region:
> +    maxItems: 1
> +    description: |
> +      phandle to a restricted DMA pool to be used for all devices behind
> +      this controller. The regions should be defined according to
> +      reserved-memory/shared-dma-pool.yaml.
> +      Note that enforcement via the PVU will only be available to
> +      ti,am654-pcie-rc devices.
> +
>  required:
>    - compatible
>    - reg
> @@ -89,6 +102,13 @@ then:
>      - power-domains
>      - msi-map
>      - num-viewport

You could add here schema expressing dependency, e.g.
if:
  properties:
    required:
      - memory-region
then:
  properties:
    reg:
      minItems: 6
    reg-names:
      minItems: 6

If I got your commit msg correctly.

Anyway, it's fine as is.

Reviewed-by: Krzysztof Kozlowski <[e-mail]>

Best regards,
Krzysztof

Patch

diff --git a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
index 0a9d10532cc8..98f6c7f1b1a6 100644
--- a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
+++ b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
@@ -20,14 +20,18 @@  properties:
       - ti,keystone-pcie
 
   reg:
-    maxItems: 4
+    minItems: 4
+    maxItems: 6
 
   reg-names:
+    minItems: 4
     items:
       - const: app
       - const: dbics
       - const: config
       - const: atu
+      - const: vmap_lp
+      - const: vmap_hp
 
   interrupts:
     maxItems: 1
@@ -69,6 +73,15 @@  properties:
     items:
       pattern: '^pcie-phy[0-1]$'
 
+  memory-region:
+    maxItems: 1
+    description: |
+      phandle to a restricted DMA pool to be used for all devices behind
+      this controller. The regions should be defined according to
+      reserved-memory/shared-dma-pool.yaml.
+      Note that enforcement via the PVU will only be available to
+      ti,am654-pcie-rc devices.
+
 required:
   - compatible
   - reg
@@ -89,6 +102,13 @@  then:
     - power-domains
     - msi-map
     - num-viewport
+else:
+  properties:
+    reg:
+      maxItems: 4
+
+    reg-names:
+      maxItems: 4
 
 unevaluatedProperties: false
 
@@ -104,8 +124,10 @@  examples:
         reg =  <0x5500000 0x1000>,
                <0x5501000 0x1000>,
                <0x10000000 0x2000>,
-               <0x5506000 0x1000>;
-        reg-names = "app", "dbics", "config", "atu";
+               <0x5506000 0x1000>,
+               <0x2900000 0x1000>,
+               <0x2908000 0x1000>;
+        reg-names = "app", "dbics", "config", "atu", "vmap_lp", "vmap_hp";
         power-domains = <&k3_pds 120 TI_SCI_PD_EXCLUSIVE>;
         #address-cells = <3>;
         #size-cells = <2>;