Re: [PATCH] MdeModulePkg SataControllerDxe: Calculate ChannelCount based on PI value

["Wu, Hao A" <hao.a.wu@intel.com>]

Reviewed-by: Hao Wu <hao.a.wu@intel.com>

Best Regards,
Hao Wu


> -----Original Message-----
> From: Zeng, Star
> Sent: Thursday, June 28, 2018 6:14 PM
> To: edk2-devel@lists.01.org
> Cc: Zeng, Star; Chan, Amy; Hsueh, Hong-chihX; Yao, Jiewen; Sami Mujawar; Ni,
> Ruiyu; Wu, Hao A
> Subject: [PATCH] MdeModulePkg SataControllerDxe: Calculate ChannelCount
> based on PI value
> 
> Current code calculates ChannelCount based on CAP(NP) value.
> It only works when the ports implemented number are <= CAP(NP),
> for example, platform has CAP(NP) = 5 (means 6 ports) and ports
> implemented are 0, 1, 2, 3, 4 and 5.
> 
> But we have some platform that has CAP(NP) = 1 (means 2 ports) and
> ports implemented are 1 and 2, and has no port 0 implemented, then
> current code does not work.
> 
> This patch updates the code to calculate ChannelCount based on PI value.
> 
> Cc: Amy Chan <amy.chan@intel.com>
> Cc: Hong-chihX Hsueh <hong-chihx.hsueh@intel.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Sami Mujawar <sami.mujawar@arm.com>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Hao Wu <hao.a.wu@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Star Zeng <star.zeng@intel.com>
> ---
>  .../Bus/Pci/SataControllerDxe/SataController.c     | 28 ++++++++++++++++++---
> -
>  .../Bus/Pci/SataControllerDxe/SataController.h     |  1 +
>  2 files changed, 25 insertions(+), 4 deletions(-)
> 
> diff --git a/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.c
> b/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.c
> index 7dc40f82e819..d47e918f5757 100644
> --- a/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.c
> +++ b/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.c
> @@ -366,6 +366,7 @@ SataControllerStart (
>    UINT32                            Data32;
>    UINTN                             TotalCount;
>    UINT64                            Supports;
> +  UINT8                             MaxPortNumber;
> 
>    DEBUG ((EFI_D_INFO, "SataControllerStart start\n"));
> 
> @@ -472,12 +473,31 @@ SataControllerStart (
>      Private->DeviceCount          = IDE_MAX_DEVICES;
>    } else if (IS_PCI_SATADPA (&PciData)) {
>      //
> -    // Read Host Capability Register(CAP) to get Number of Ports(NPS) and
> Supports Port Multiplier(SPM)
> -    //   NPS is 0's based value indicating the maximum number of ports
> supported by the HBA silicon.
> -    //   A maximum of 32 ports can be supported. A value of '0h', indicating one
> port, is the minimum requirement.
> +    // Read Ports Implemented(PI) to calculate max port number (0 based).
> +    //
> +    Data32 = AhciReadReg (PciIo, R_AHCI_PI);
> +    DEBUG ((DEBUG_INFO, "Ports Implemented(PI) = 0x%x\n", Data32));
> +    if (Data32 == 0) {
> +      Status = EFI_UNSUPPORTED;
> +      goto Done;
> +    }
> +    MaxPortNumber = 31;
> +    while (MaxPortNumber > 0) {
> +      if (Data32 & (1 << MaxPortNumber)) {
> +        break;
> +      }
> +      MaxPortNumber--;
> +    }
> +    //
> +    // Make the ChannelCount equal to the max port number (0 based) plus 1.
> +    //
> +    Private->IdeInit.ChannelCount = MaxPortNumber + 1;
> +
> +    //
> +    // Read HBA Capabilities(CAP) to get Supports Port Multiplier(SPM).
>      //
>      Data32 = AhciReadReg (PciIo, R_AHCI_CAP);
> -    Private->IdeInit.ChannelCount = (UINT8) ((Data32 & B_AHCI_CAP_NPS) + 1);
> +    DEBUG ((DEBUG_INFO, "HBA Capabilities(CAP) = 0x%x\n", Data32));
>      Private->DeviceCount          = AHCI_MAX_DEVICES;
>      if ((Data32 & B_AHCI_CAP_SPM) == B_AHCI_CAP_SPM) {
>        Private->DeviceCount = AHCI_MULTI_MAX_DEVICES;
> diff --git a/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.h
> b/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.h
> index 436eff2dc673..7ffd3e218a61 100644
> --- a/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.h
> +++ b/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.h
> @@ -44,6 +44,7 @@ extern EFI_COMPONENT_NAME2_PROTOCOL
> gSataControllerComponentName2;
>  #define R_AHCI_CAP 0x0
>  #define   B_AHCI_CAP_NPS (BIT4 | BIT3 | BIT2 | BIT1 | BIT0) // Number of
> Ports
>  #define   B_AHCI_CAP_SPM BIT17                              // Supports Port Multiplier
> +#define R_AHCI_PI  0xC
> 
>  ///
>  /// AHCI each channel can have up to 1 device
> --
> 2.7.0.windows.1