[edk2-devel] [PATCH 2/3] Platform/RaspberryPi/Acpitables: Add eMMC2 device and tweak Arasan

Mon Jan 11 05:59:52 UTC 2021

Hi,

On 1/9/21 8:09 AM, Mark Kettenis via groups.io wrote:
> On Fri, Jan 8, 2021 at 05:27 PM, Jeremy Linton wrote:
> 
>>
>> Hi,
>>
>> On 1/8/21 2:28 AM, Ard Biesheuvel wrote:
>>
>>> On 1/8/21 7:16 AM, Jeremy Linton wrote:
>>>
>>>> The primarly problem with the rpi Arasan controller working
>>>> with a default SDHCI driver is the lack of a meaningful
>>>> capabilities register. As such if we add a _DSD entry
>>>> to provide that information, we can then bind it to
>>>> the linux sdhci_iproc driver which already
>>>> hardcodes the remaining controller bugs.
>>>>
>>>> Further we have gotten BRCME88C approved as the HID
>>>> for the newer eMMC2 controller. So lets define an
>>>> ACPI object to describe it.
>>>>
>>>> Of course both devices are sharing an interrupt so
>>>> we should also indicate that in the table as well.
>>>>
>>>> Signed-off-by: Jeremy Linton <jeremy.linton at arm.com>
>>>> ---
>>>> Platform/RaspberryPi/AcpiTables/Dsdt.asl | 2 +
>>>> Platform/RaspberryPi/AcpiTables/Sdhc.asl | 86
>>>> +++++++++++++++++++++++++++++++-
>>>> 2 files changed, 86 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/Platform/RaspberryPi/AcpiTables/Dsdt.asl
>>>> b/Platform/RaspberryPi/AcpiTables/Dsdt.asl
>>>> index d116f965e1..cca08c0539 100644
>>>> --- a/Platform/RaspberryPi/AcpiTables/Dsdt.asl
>>>> +++ b/Platform/RaspberryPi/AcpiTables/Dsdt.asl
>>>> @@ -150,6 +150,7 @@ DefinitionBlock ("Dsdt.aml", "DSDT", 5, "RPIFDN",
>>>> "RPI", 2)
>>>> QWORDMEMORYBUF(23)
>>>> QWORDMEMORYBUF(24)
>>>> QWORDMEMORYBUF(25)
>>>> + QWORDMEMORYBUF(26)
>>>> })
>>>>
>>>> // USB
>>>> @@ -196,6 +197,7 @@ DefinitionBlock ("Dsdt.aml", "DSDT", 5, "RPIFDN",
>>>> "RPI", 2)
>>>> // SDC
>>>> QWORDMEMORYSET(24, MMCHS1_OFFSET, MMCHS1_LENGTH)
>>>> QWORDMEMORYSET(25, SDHOST_OFFSET, SDHOST_LENGTH)
>>>> + QWORDMEMORYSET(26, MMCHS2_OFFSET, MMCHS2_LENGTH)
>>>>
>>>> Return (RBUF)
>>>> }
>>>> diff --git a/Platform/RaspberryPi/AcpiTables/Sdhc.asl
>>>> b/Platform/RaspberryPi/AcpiTables/Sdhc.asl
>>>> index 0ab1ba27f2..a7ac831066 100644
>>>> --- a/Platform/RaspberryPi/AcpiTables/Sdhc.asl
>>>> +++ b/Platform/RaspberryPi/AcpiTables/Sdhc.asl
>>>> @@ -19,7 +19,7 @@
>>>> // Note: UEFI can use either SDHost or Arasan. We expose both to the OS.
>>>> //
>>>>
>>>> -// ArasanSD 3.0 SD Host Controller.
>>>> +// ArasanSD 3.0 SD Host Controller. (brcm,bcm2835-sdhci)
>>>> Device (SDC1)
>>>> {
>>>> Name (_HID, "BCM2847")
>>>> @@ -37,7 +37,7 @@ Device (SDC1)
>>>> Name (RBUF, ResourceTemplate ()
>>>> {
>>>> MEMORY32FIXED (ReadWrite, 0, MMCHS1_LENGTH, RMEM)
>>>> - Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive) {
>>>> BCM2836_MMCHS1_INTERRUPT }
>>>> + Interrupt (ResourceConsumer, Level, ActiveHigh, Shared) {
>>>> BCM2836_MMCHS1_INTERRUPT }
>>>> })
>>>> Method (_CRS, 0x0, Serialized)
>>>> {
>>>> @@ -45,6 +45,86 @@ Device (SDC1)
>>>> Return (^RBUF)
>>>> }
>>>>
>>>> + // The standard CAPs registers on this controller
>>>> + // appear to be 0, lets set some minimal defaults
>>>> + // Since this cap doesn't indicate DMA capability
>>>> + // we don't need a _DMA()
>>>> + Name (_DSD, Package () {
>>>> + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>>>> + Package () {
>>>> + Package () { "sdhci-caps", 0x0100fa81 },
>>>> + }
>>>> + })
>>>> +
>>>> +
>>>> + //
>>>> + // A child device that represents the
>>>> + // sd card, which is marked as non-removable.
>>>> + //
>>>> + Device (SDMM)
>>>> + {
>>>> + Method (_ADR)
>>>> + {
>>>> + Return (0)
>>>> + }
>>>> + Method (_RMV) // Is removable
>>>> + {
>>>> + Return (0) // 0 - fixed
>>>> + }
>>>> + }
>>>> +}
>>>> +
>>>> +#if (RPI_MODEL == 4)
>>>> +// emmc2 Host Controller. (brcm,bcm2711-emmc2)
>>>> +Device (SDC3)
>>>> +{
>>>> + Name (_HID, "BRCME88C")
>>>> + Name (_UID, 0x1)
>>>> + Name (_CCA, 0x0)
>>>> + Name (_S1D, 0x1)
>>>> + Name (_S2D, 0x1)
>>>> + Name (_S3D, 0x1)
>>>> + Name (_S4D, 0x1)
>>>> + Method (_STA)
>>>> + {
>>>> + Return(0xf)
>>>> + }
>>>> + Name (RBUF, ResourceTemplate ()
>>>> + {
>>>> + MEMORY32FIXED (ReadWrite, 0, MMCHS2_LENGTH, RMEM)
>>>> + Interrupt (ResourceConsumer, Level, ActiveHigh, Shared) {
>>>> BCM2836_MMCHS1_INTERRUPT }
>>>> + })
>>>> + Method (_CRS, 0x0, Serialized)
>>>> + {
>>>> + MEMORY32SETBASE (RBUF, RMEM, RBAS, MMCHS2_OFFSET)
>>>> + Return (^RBUF)
>>>> + }
>>>> +
>>>> + // forceably limit to 1G
>>>> + Name (_DMA, ResourceTemplate() {
>>>> + QWordMemory (ResourceConsumer,
>>>> + ,
>>>> + MinFixed,
>>>> + MaxFixed,
>>>> + NonCacheable,
>>>> + ReadWrite,
>>>> + 0x0,
>>>> + 0x0, // MIN
>>>> + 0x3fffffff, // MAX
>>>> + 0x0, // TRA
>>>> + 0x40000000, // LEN
>>>> + ,
>>>> + ,
>>>> + )
>>>> + })
>>>> +
>>>
>>> Shouldn't the _DMA method be on a container object instead of on the
>>> device object itself?
>>
>> Pained cough... There is a _DMA on the gpu devs container of which this
>> device belongs. That doesn't make the DMA work. The spec says that _DMA
>> is to exist on the bus device, and I think what is happening here is
>> that the "device" is the SDMM (which isn't directly visible because of
>> the way diff broke this patch up) contained in the "SDC3 mmc bus".
> 
> The Linux device tree has the following comment:
> 
> /*
> * emmc2 has different DMA constraints based on SoC revisions. It was
> * moved into its own bus, so as for RPi4's firmware to update them.
> * The firmware will find whether the emmc2bus alias is defined, and if
> * so, it'll edit the dma-ranges property below accordingly.
> *
> 
> And the dma-ranges property it references is:
> 
> dma-ranges = <0x0 0xc0000000  0x0 0x00000000  0x40000000>;
> 
> Not sure how the firmware will adjust this, but it does imply that there is actual translation
> going on here and it doesn't match the _DMA property you added.

Just to add to this, its quite possible this shouldn't be a gpudev, as 
I mentioned above. I need to test a couple of the rpi4's i've got to see 
what the variation they mention above is.

AKA, the DT you feed into the videocore isn't always the DT you get out 
of it, so you can't depend on reading the raw DT. That is what is 
happening with the PCIe now, the firmware is modifying the mappings 
based on SOC revision.

> 
>>
>> Frankly, I could be wrong, but what I do know is that without that bit
>> of ugliness DMA doesn't work in linux on this controller. I just
>> stripped it out again to verify the failure with 4.11. It does the same
>> thing, the controller itself seems to be working but the block device
>> associated with it can't be read. There are few other possibilities
>> (like maybe this controller shouldn't be a gpudevs child) and i'm fixing
>> a bug I created..I had kernel instrumentation in 5.9 tracking the dma
>> mask propagation, and I was fairly confident in this a couple months
>> ago, less so now.
>>
> 
> One question I have is whether _DMA methods should be applied recursively or
> not. If you have a bus that provides a translating _DMA method that is behind a
> bus that also has a _DMA method, should the translation specified in that first _DMA
> method be applied or not? The text in the ACPI spec is far for clear her...
> 
> If I read the Linux code in drivers/acpi/scan.c correctly, Linux would not apply
> the translation in this case. Since the _DMA method you add does not specify any
> translation, I think that means the required address translation isn't happening
> which means that DMA transactions would fail. I suspect the block device behind
> the controller would still be detected, but any actual I/O would fail since the right
> memory isn't addressed.
> 
> So I think the best thing to do would be to have a separate ACPI0004 container
> with a translating _DMA method and but the emmc2 device below that.
> 
>>
>>
>>>
>>>> + Name (_DSD, Package () {
>>>> + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>>>> + Package () {
>>>> + Package () { "sdhci-caps-mask", 0x0000000000080000 },
>>>> + }
>>>> + })
>>>> +
>>>> //
>>>> // A child device that represents the
>>>> // sd card, which is marked as non-removable.
>>>> @@ -62,6 +142,7 @@ Device (SDC1)
>>>> }
>>>> }
>>>>
>>>> +#else // !RPI4
>>>>
>>>> // Broadcom SDHost 2.0 SD Host Controller
>>>> Device (SDC2)
>>>> @@ -105,3 +186,4 @@ Device (SDC2)
>>>> }
>>>> }
>>>> }
>>>> +#endif // !RPI4
>>>
>>>
>>
>>
> 
> 
> 
> 
> 
> 

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