Re: [edk2-platforms][PATCH v2 6/7] Platform/RPi4: Add XHCI ACPI table

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

Hi Pete,

On Thu, 19 Dec 2019 at 14:14, Pete Batard <pete@akeo.ie> wrote:
>
> From: Andrei Warkentin <andrey.warkentin@gmail.com>
>
> Since the RPi4 PCIe host bridge is not ECAM compliant, we can
> not expose it as a host bridge to the OS via ACPI. However,
> given the hardwired nature of this platform, we can expose the
> xHCI controller that is guaranteed to live at the base of the
> MMIO32 BAR window as a platform device directly.
>
> It should be noted that the xHCI table is not finalized at this
> stage, as Windows xHCI support is still a major question mark.
>
> Signed-off-by: Pete Batard <pete@akeo.ie>
> ---
>  Platform/RaspberryPi/RPi4/AcpiTables/AcpiTables.inf |   3 +
>  Platform/RaspberryPi/RPi4/AcpiTables/Dsdt.asl       |   1 +
>  Platform/RaspberryPi/RPi4/AcpiTables/Xhci.asl       | 137 ++++++++++++++++++++
>  3 files changed, 141 insertions(+)
>
...
> diff --git a/Platform/RaspberryPi/RPi4/AcpiTables/Xhci.asl b/Platform/RaspberryPi/RPi4/AcpiTables/Xhci.asl
> new file mode 100644
> index 000000000000..e1fd501ab895
> --- /dev/null
> +++ b/Platform/RaspberryPi/RPi4/AcpiTables/Xhci.asl
> @@ -0,0 +1,137 @@
> +/** @file
> + *
> + *  Copyright (c) 2019 Linaro, Limited. All rights reserved.
> + *  Copyright (c) 2019 Andrei Warkentin <andrey.warkentin@gmail.com>
> + *
> + *  SPDX-License-Identifier: BSD-2-Clause-Patent
> + *
> + **/
> +
> +#include <IndustryStandard/Bcm2711.h>
> +
> +/*
> + * The following can be used to remove parenthesis from
> + * defined macros that the compiler complains about.
> + */
> +#define ISOLATE_ARGS(...)               __VA_ARGS__
> +#define REMOVE_PARENTHESES(x)           ISOLATE_ARGS x
> +
> +#define SANITIZED_PCIE_CPU_MMIO_WINDOW  REMOVE_PARENTHESES(PCIE_CPU_MMIO_WINDOW)
> +#define SANITIZED_PCIE_REG_BASE         REMOVE_PARENTHESES(PCIE_REG_BASE)
> +
> +/*
> + * According to UEFI boot log for the VLI device on Pi 4.
> + */
> +#define XHCI_REG_LENGTH                 0x1000
> +
> +Device (SCB0) {
> +    Name (_HID, "ACPI0004")
> +    Name (_UID, 0x0)
> +    Name (_CCA, 0x0)
> +
> +    Method (_CRS, 0, Serialized) { // _CRS: Current Resource Settings
> +        /*
> +         * Container devices with _DMA must have _CRS, meaning SCB0
> +         * to provide all resources that XHC0 consumes (except
> +         * interrupts).
> +         */
> +        Name (RBUF, ResourceTemplate () {
> +            QWordMemory (ResourceProducer,
> +                ,
> +                MinFixed,
> +                MaxFixed,
> +                NonCacheable,
> +                ReadWrite,
> +                0x0,
> +                SANITIZED_PCIE_CPU_MMIO_WINDOW, // MIN
> +                SANITIZED_PCIE_CPU_MMIO_WINDOW, // MAX
> +                0x0,
> +                0x1,                            // LEN
> +                ,
> +                ,
> +                MMIO
> +                )
> +        })
> +        CreateQwordField (RBUF, MMIO._MAX, MMBE)
> +        CreateQwordField (RBUF, MMIO._LEN, MMLE)
> +        Add (MMBE, XHCI_REG_LENGTH - 1, MMBE)
> +        Add (MMLE, XHCI_REG_LENGTH - 1, MMLE)
> +        Return (RBUF)
> +    }
> +
> +    Name (_DMA, ResourceTemplate() {
> +        /*
> +         * XHC0 is limited to DMA to first 3GB. Note this
> +         * only applies to PCIe, not GENET or other devices
> +         * next to the A72.
> +         */
> +        QWordMemory (ResourceConsumer,
> +            ,
> +            MinFixed,
> +            MaxFixed,
> +            NonCacheable,
> +            ReadWrite,
> +            0x0,
> +            0x0,        // MIN
> +            0xbfffffff, // MAX
> +            0x0,        // TRA
> +            0xc0000000, // LEN
> +            ,
> +            ,
> +            )
> +    })
> +
> +    Device (XHC0)
> +    {
> +        Name (_HID, "11063483")     // _HID: Hardware ID

I failed to spot this detail before. Even if MS appears to do so, I
don't think it is OK to string random digits together to create
hardware identifiers (and yes, I am aware it's the vendor and device
IDs concatenated)

What's wrong with using the below as the _HID?

> +        Name (_CID, "PNP0D10")      // _CID: Hardware ID
> +        Name (_UID, 0x0)            // _UID: Unique ID
> +        Name (_CCA, 0x0)            // _CCA: Cache Coherency Attribute
> +
> +        Method (_CRS, 0, Serialized) { // _CRS: Current Resource Settings
> +            Name (RBUF, ResourceTemplate () {
> +                QWordMemory (ResourceConsumer,
> +                    ,
> +                    MinFixed,
> +                    MaxFixed,
> +                    NonCacheable,
> +                    ReadWrite,
> +                    0x0,
> +                    SANITIZED_PCIE_CPU_MMIO_WINDOW, // MIN
> +                    SANITIZED_PCIE_CPU_MMIO_WINDOW, // MAX
> +                    0x0,
> +                    0x1,                            // LEN
> +                    ,
> +                    ,
> +                    MMIO
> +                    )
> +                Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive, ,, ) {
> +                    175
> +                }
> +            })
> +            CreateQwordField (RBUF, MMIO._MAX, MMBE)
> +            CreateQwordField (RBUF, MMIO._LEN, MMLE)
> +            Add (MMBE, XHCI_REG_LENGTH - 1, MMBE)
> +            Add (MMLE, XHCI_REG_LENGTH - 1, MMLE)
> +            Return (RBUF)
> +        }
> +
> +        Method (_INI, 0, Serialized) {
> +            OperationRegion (PCFG, SystemMemory, SANITIZED_PCIE_REG_BASE + PCIE_EXT_CFG_DATA, 0x1000)
> +            Field (PCFG, AnyAcc, NoLock, Preserve) {
> +                Offset (0),
> +                VNID, 16, // Vendor ID
> +                DVID, 16, // Device ID
> +                CMND, 16, // Command register
> +                STAT, 16, // Status register
> +            }
> +
> +            // Set command register to:
> +            // 1) decode MMIO (set bit 1)
> +            // 2) enable DMA (set bit 2)
> +            // 3) enable interrupts (clear bit 10)
> +            Debug = "xHCI enable"
> +            Store (0x6, CMND)
> +        }
> +    }
> +}
> --
> 2.21.0.windows.1
>