Reviewed-by: Andrei Warkentin <awarkentin@vmware.com>

From: Pete Batard <pete@akeo.ie>
Sent: Monday, February 8, 2021 11:08 AM
To: Jeremy Linton <jeremy.linton@arm.com>; devel@edk2.groups.io <devel@edk2.groups.io>
Cc: Andrei Warkentin <awarkentin@vmware.com>; samer.el-haj-mahmoud@arm.com <samer.el-haj-mahmoud@arm.com>; leif@nuviainc.com <leif@nuviainc.com>; ardb+tianocore@kernel.org <ardb+tianocore@kernel.org>
Subject: Re: [PATCH v2 3/4] Platform/RaspberryPi: User control of eMMC2 DMA
 
On 2021.02.01 22:53, Jeremy Linton wrote:
> DMA translation on the eMMC2 vary based on SOC, and
> this is made worse by the poor _DMA support in linux.
>
> For now the "safe" option is to simply run the eMMC2
> controller in PIO mode. More advanced users or !linux
> operating systems may choose to enable this to gain
> a perf boost.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> ---
>   Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c      | 16 +++++++++++++++-
>   Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.inf    |  1 +
>   Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxeHii.uni |  5 +++++
>   Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxeHii.vfr | 17 +++++++++++++++++
>   Platform/RaspberryPi/Include/ConfigVars.h               |  8 ++++++++
>   Platform/RaspberryPi/RPi3/RPi3.dsc                      |  1 +
>   Platform/RaspberryPi/RPi4/RPi4.dsc                      |  1 +
>   Platform/RaspberryPi/RaspberryPi.dec                    |  1 +
>   8 files changed, 49 insertions(+), 1 deletion(-)
>
> diff --git a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
> index 7f26f7b4be..1b8b360ddc 100644
> --- a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
> +++ b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
> @@ -346,6 +346,15 @@ SetupVariables (
>     }
>
>  
>
>     Size = sizeof (UINT32);
>
> +  Status = gRT->GetVariable (L"MmcEnableDma",
>
> +                  &gConfigDxeFormSetGuid,
>
> +                  NULL, &Size, &Var32);
>
> +  if (EFI_ERROR (Status)) {
>
> +    Status = PcdSet32S (PcdMmcEnableDma, PcdGet32 (PcdMmcEnableDma));
>
> +    ASSERT_EFI_ERROR (Status);
>
> +  }
>
> +
>
> +  Size = sizeof (UINT32);
>
>     Status = gRT->GetVariable (L"DebugEnableJTAG",
>
>                     &gConfigDxeFormSetGuid,
>
>                     NULL, &Size, &Var32);
>
> @@ -730,6 +739,11 @@ STATIC CONST AML_NAME_OP_REPLACE SsdtNameOpReplace[] = {
>     { }
>
>   };
>
>  
>
> +STATIC CONST AML_NAME_OP_REPLACE SsdtEmmcNameOpReplace[] = {
>
> +  { "SDMA", PcdToken (PcdMmcEnableDma) },
>
> +  { }
>
> +};
>
> +
>
>   STATIC CONST NAMESPACE_TABLES SdtTables[] = {
>
>     {
>
>       SIGNATURE_64 ('R', 'P', 'I', 'T', 'H', 'F', 'A', 'N'),
>
> @@ -741,7 +755,7 @@ STATIC CONST NAMESPACE_TABLES SdtTables[] = {
>       SIGNATURE_64 ('R', 'P', 'I', '4', 'E', 'M', 'M', 'C'),
>
>       0,
>
>       PcdToken(PcdSdIsArasan),
>
> -    NULL
>
> +    SsdtEmmcNameOpReplace
>
>     },
>
>     {
>
>       SIGNATURE_64 ('R', 'P', 'I', 0, 0, 0, 0, 0),
>
> diff --git a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.inf b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.inf
> index 544e3b3e10..d51e54e010 100644
> --- a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.inf
> +++ b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.inf
> @@ -84,6 +84,7 @@
>     gRaspberryPiTokenSpaceGuid.PcdMmcSdDefaultSpeedMHz
>
>     gRaspberryPiTokenSpaceGuid.PcdMmcSdHighSpeedMHz
>
>     gRaspberryPiTokenSpaceGuid.PcdMmcDisableMulti
>
> +  gRaspberryPiTokenSpaceGuid.PcdMmcEnableDma
>
>     gRaspberryPiTokenSpaceGuid.PcdDebugEnableJTAG
>
>     gRaspberryPiTokenSpaceGuid.PcdDisplayEnableScaledVModes
>
>     gRaspberryPiTokenSpaceGuid.PcdDisplayEnableSShot
>
> diff --git a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxeHii.uni b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxeHii.uni
> index 2afe8f32ae..6abccc1fdb 100644
> --- a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxeHii.uni
> +++ b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxeHii.uni
> @@ -94,6 +94,11 @@
>   #string STR_MMC_SD_HS_PROMPT     #language en-US "SD High Speed (MHz)"
>
>   #string STR_MMC_SD_HS_HELP       #language en-US "Override default 50Mhz"
>
>  
>
> +#string STR_MMC_EMMC_PROMPT      #language en-US "Enable eMMC DMA modes"
>
> +#string STR_MMC_EMMC_PIO         #language en-US "PIO"
>
> +#string STR_MMC_EMMC_DMA         #language en-US "SDMA/ADMA2"
>
> +#string STR_MMC_EMMC_HELP        #language en-US "Enable eMMC DMA modes for OS's that support ACPI _DMA() translations"

For consistency, since that's what we already use for other UI strings,
the plural of OS should be "OSes" rather than "OS's"

>
> +

(very minor) Extra line added here.

>
>  
>
>   /*
>
>    * Display settings.
>
> diff --git a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxeHii.vfr b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxeHii.vfr
> index de5e43471a..cc7a09cfb7 100644
> --- a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxeHii.vfr
> +++ b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxeHii.vfr
> @@ -96,6 +96,11 @@ formset
>         name  = MmcSdHighSpeedMHz,
>
>         guid  = CONFIGDXE_FORM_SET_GUID;
>
>  
>
> +    efivarstore MMC_EMMC_DMA_VARSTORE_DATA,
>
> +      attribute = EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_NON_VOLATILE,
>
> +      name  = MmcEnableDma,
>
> +      guid  = CONFIGDXE_FORM_SET_GUID;
>
> +
>
>       efivarstore DEBUG_ENABLE_JTAG_VARSTORE_DATA,
>
>         attribute = EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_NON_VOLATILE,
>
>         name  = DebugEnableJTAG,
>
> @@ -275,6 +280,18 @@ formset
>                maximum = 100,
>
>                default = 50,
>
>           endnumeric;
>
> +#if (RPI_MODEL == 4)
>
> +        grayoutif ideqval SdIsArasan.Routing == 1;
>
> +        oneof varid = MmcEnableDma.EnableDma,
>
> +            prompt      = STRING_TOKEN(STR_MMC_EMMC_PROMPT),
>
> +            help        = STRING_TOKEN(STR_MMC_EMMC_HELP),
>
> +            flags       = NUMERIC_SIZE_4 | INTERACTIVE | RESET_REQUIRED,
>
> +            option text = STRING_TOKEN(STR_MMC_EMMC_PIO), value = 0, flags = DEFAULT;
>
> +            option text = STRING_TOKEN(STR_MMC_EMMC_DMA), value = 1, flags = 0;
>
> +        endoneof;
>
> +        endif;
>
> +#endif
>
> +
>
>       endform;
>
>  
>
>       form formid = 0x1004,
>
> diff --git a/Platform/RaspberryPi/Include/ConfigVars.h b/Platform/RaspberryPi/Include/ConfigVars.h
> index c185bfe28b..142317985a 100644
> --- a/Platform/RaspberryPi/Include/ConfigVars.h
> +++ b/Platform/RaspberryPi/Include/ConfigVars.h
> @@ -135,4 +135,12 @@ typedef struct {
>     UINT32 MHz;
>
>   } MMC_SD_HS_MHZ_VARSTORE_DATA;
>
>  
>
> +typedef struct {
>
> +  /*
>
> +   * 0 - eMMC PIO mode
>
> +   * 1 - eMMC DMA mode
>
> +   */
>
> +  UINT32 EnableDma;
>
> +} MMC_EMMC_DMA_VARSTORE_DATA;
>
> +
>
>   #endif /* CONFIG_VARS_H */
>
> diff --git a/Platform/RaspberryPi/RPi3/RPi3.dsc b/Platform/RaspberryPi/RPi3/RPi3.dsc
> index 530b42796a..107cbda297 100644
> --- a/Platform/RaspberryPi/RPi3/RPi3.dsc
> +++ b/Platform/RaspberryPi/RPi3/RPi3.dsc
> @@ -470,6 +470,7 @@
>     gRaspberryPiTokenSpaceGuid.PcdMmcSdDefaultSpeedMHz|L"MmcSdDefaultSpeedMHz"|gConfigDxeFormSetGuid|0x0|25
>
>     gRaspberryPiTokenSpaceGuid.PcdMmcSdHighSpeedMHz|L"MmcSdHighSpeedMHz"|gConfigDxeFormSetGuid|0x0|50
>
>     gRaspberryPiTokenSpaceGuid.PcdMmcDisableMulti|L"MmcDisableMulti"|gConfigDxeFormSetGuid|0x0|0
>
> +  gRaspberryPiTokenSpaceGuid.PcdMmcEnableDma|L"MmcEnableDma"|gConfigDxeFormSetGuid|0x0|0
>
>  
>
>     #
>
>     # Debug-related.
>
> diff --git a/Platform/RaspberryPi/RPi4/RPi4.dsc b/Platform/RaspberryPi/RPi4/RPi4.dsc
> index 5f8452aa0b..9962df0076 100644
> --- a/Platform/RaspberryPi/RPi4/RPi4.dsc
> +++ b/Platform/RaspberryPi/RPi4/RPi4.dsc
> @@ -481,6 +481,7 @@
>     gRaspberryPiTokenSpaceGuid.PcdMmcSdDefaultSpeedMHz|L"MmcSdDefaultSpeedMHz"|gConfigDxeFormSetGuid|0x0|25
>
>     gRaspberryPiTokenSpaceGuid.PcdMmcSdHighSpeedMHz|L"MmcSdHighSpeedMHz"|gConfigDxeFormSetGuid|0x0|50
>
>     gRaspberryPiTokenSpaceGuid.PcdMmcDisableMulti|L"MmcDisableMulti"|gConfigDxeFormSetGuid|0x0|0
>
> +  gRaspberryPiTokenSpaceGuid.PcdMmcEnableDma|L"MmcEnableDma"|gConfigDxeFormSetGuid|0x0|0
>
>  
>
>     #
>
>     # Debug-related.
>
> diff --git a/Platform/RaspberryPi/RaspberryPi.dec b/Platform/RaspberryPi/RaspberryPi.dec
> index 10723036aa..08135717ed 100644
> --- a/Platform/RaspberryPi/RaspberryPi.dec
> +++ b/Platform/RaspberryPi/RaspberryPi.dec
> @@ -69,3 +69,4 @@
>     gRaspberryPiTokenSpaceGuid.PcdFanOnGpio|0|UINT32|0x0000001C
>
>     gRaspberryPiTokenSpaceGuid.PcdFanTemp|0|UINT32|0x0000001D
>
>     gRaspberryPiTokenSpaceGuid.PcdPlatformResetDelay|0|UINT32|0x0000001E
>
> +  gRaspberryPiTokenSpaceGuid.PcdMmcEnableDma|0|UINT32|0x0000001F
>

Reviewed-by: Pete Batard <pete@akeo.ie>