Re: [PATCH 1/4] MdeModulePkg: Add definitions for EDKII PEI NVME host controller PPI

["Ni, Ruiyu" <ruiyu.ni@intel.com>]

Thanks/Ray

> -----Original Message-----
> From: Wu, Hao A
> Sent: Friday, June 15, 2018 3:04 PM
> To: edk2-devel@lists.01.org
> Cc: Wu, Hao A <hao.a.wu@intel.com>; Zeng, Star <star.zeng@intel.com>;
> Dong, Eric <eric.dong@intel.com>; Ni, Ruiyu <ruiyu.ni@intel.com>; Yao,
> Jiewen <jiewen.yao@intel.com>
> Subject: [PATCH 1/4] MdeModulePkg: Add definitions for EDKII PEI NVME
> host controller PPI
> 
> Introduces the below PPI:
> 
> struct EDKII_NVM_EXPRESS_HOST_CONTROLLER_PPI {
>   EDKII_NVM_EXPRESS_HC_GET_MMIO_BAR       GetNvmeHcMmioBar;
>   EDKII_NVM_EXPRESS_HC_GET_DEVICE_PATH    GetNvmeHcDevicePath;
> };
> 
> The GetNvmeHcMmioBar service will provide the caller with the MMIO BAR
> address of each NVMe HC within the system;
> 
> The GetNvmeHcDevicePath service will provide the caller with the device
> path information of each NVMe HC.
> 
> Cc: Star Zeng <star.zeng@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Hao Wu <hao.a.wu@intel.com>
> ---
>  MdeModulePkg/Include/Ppi/NvmExpressHostController.h | 97
> ++++++++++++++++++++
>  MdeModulePkg/MdeModulePkg.dec                       |  3 +
>  2 files changed, 100 insertions(+)
> 
> diff --git a/MdeModulePkg/Include/Ppi/NvmExpressHostController.h
> b/MdeModulePkg/Include/Ppi/NvmExpressHostController.h
> new file mode 100644
> index 0000000000..de9ae4a59c
> --- /dev/null
> +++ b/MdeModulePkg/Include/Ppi/NvmExpressHostController.h
> @@ -0,0 +1,97 @@
> +/** @file
> +
> +  Copyright (c) 2018, Intel Corporation. All rights reserved.<BR>  This
> + program and the accompanying materials  are licensed and made
> + available under the terms and conditions of the BSD License  which
> + accompanies this distribution.  The full text of the license may be
> + found at  http://opensource.org/licenses/bsd-license.php
> +
> +  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
> BASIS,
> + WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
> EXPRESS OR IMPLIED.
> +
> +**/
> +
> +#ifndef _EDKII_NVM_EXPRESS_HOST_CONTROLLER_PPI_H_
> +#define _EDKII_NVM_EXPRESS_HOST_CONTROLLER_PPI_H_
> +
> +#include <Protocol/DevicePath.h>
> +
> +///
> +/// Global ID for the EDKII_NVM_EXPRESS_HOST_CONTROLLER_PPI.
> +///
> +#define EDKII_NVME_EXPRESS_HOST_CONTROLLER_PPI_GUID \
> +  { \
> +    0xcae3aa63, 0x676f, 0x4da3, { 0xbd, 0x50, 0x6c, 0xc5, 0xed, 0xde,
> +0x9a, 0xad } \
> +  }
> +
> +//
> +// Forward declaration for the
> EDKII_NVM_EXPRESS_HOST_CONTROLLER_PPI.
> +//
> +typedef struct _EDKII_NVM_EXPRESS_HOST_CONTROLLER_PPI
> +EDKII_NVM_EXPRESS_HOST_CONTROLLER_PPI;
> +
> +/**
> +  Get the MMIO base address of NVM Express host controller.
> +
> +  @param[in]  PeiServices          Describes the list of possible PEI Services.
> +  @param[in]  This                 The PPI instance pointer.
> +  @param[in]  ControllerId         The ID of the NVM Express host controller.
> +  @param[out] MmioBar              The MMIO base address of the controller.
> +
> +  @retval EFI_SUCCESS              The operation succeeds.
> +  @retval EFI_INVALID_PARAMETER    The parameters are invalid.
> +  @retval EFI_NOT_FOUND            The specified NVM Express host controller
> not
> +                                   found.
> +
> +**/
> +typedef
> +EFI_STATUS
> +(EFIAPI *EDKII_NVM_EXPRESS_HC_GET_MMIO_BAR) (
> +  IN  EFI_PEI_SERVICES                         **PeiServices,

1. PeiServices is not needed.

> +  IN  EDKII_NVM_EXPRESS_HOST_CONTROLLER_PPI    *This,
> +  IN  UINT8                                    ControllerId,
> +  OUT UINTN                                    *MmioBar
> +  );
> +
> +/**
> +  Get the device path of NVM Express host controller.
> +
> +  @param[in]  PeiServices          Describes the list of possible PEI Services.
> +  @param[in]  This                 The PPI instance pointer.
> +  @param[in]  ControllerId         The ID of the NVM Express host controller.
> +  @param[out] DevicePathLenth      The length of the device path in bytes
> specified
> +                                   by DevicePath.
> +  @param[out] DevicePath           The device path of NVM Express host
> controller.
> +                                   The caller is responsible for freeing it.
> +                                   This field re-uses EFI Device Path Protocol as
> +                                   defined by Section 10.2 EFI Device Path Protocol
> +                                   of UEFI 2.7 Specification.
> +
> +  @retval EFI_SUCCESS              The operation succeeds.
> +  @retval EFI_INVALID_PARAMETER    The parameters are invalid.
> +  @retval EFI_NOT_FOUND            The specified NVM Express host controller
> not
> +                                   found.
> +  @retval EFI_OUT_OF_RESOURCES     The operation fails due to lack of
> resources.
> +
> +**/
> +typedef
> +EFI_STATUS
> +(EFIAPI *EDKII_NVM_EXPRESS_HC_GET_DEVICE_PATH) (
> +  IN  EFI_PEI_SERVICES                         **PeiServices,
> +  IN  EDKII_NVM_EXPRESS_HOST_CONTROLLER_PPI    *This,
> +  IN  UINT8                                    ControllerId,
> +  OUT UINTN                                    *DevicePathLenth,
> +  OUT EFI_DEVICE_PATH_PROTOCOL                 **DevicePath

2. Firstly, FreePool() is not supported in PEI phase so requiring caller to free is
confusing.
Secondly, can the device path be determined at build time? If yes, then a
pointer to global variable can be returned so no need for caller to free.

> +  );
> +
> +//
> +// This PPI contains a set of services to interact with the NVM Express
> +host // controller.
> +//
> +struct _EDKII_NVM_EXPRESS_HOST_CONTROLLER_PPI {
> +  EDKII_NVM_EXPRESS_HC_GET_MMIO_BAR       GetNvmeHcMmioBar;
> +  EDKII_NVM_EXPRESS_HC_GET_DEVICE_PATH    GetNvmeHcDevicePath;
> +};
> +
> +extern EFI_GUID gEdkiiPeiNvmExpressHostControllerPpiGuid;
> +
> +#endif
> diff --git a/MdeModulePkg/MdeModulePkg.dec
> b/MdeModulePkg/MdeModulePkg.dec index 3802b6e0b8..8d7c97ee91
> 100644
> --- a/MdeModulePkg/MdeModulePkg.dec
> +++ b/MdeModulePkg/MdeModulePkg.dec
> @@ -471,6 +471,9 @@
>    ## Include/Ppi/PlatformSpecificResetHandler.h
>    gEdkiiPlatformSpecificResetHandlerPpiGuid = { 0x75cf14ae, 0x3441, 0x49dc,
> { 0xaa, 0x10, 0xbb, 0x35, 0xa7, 0xba, 0x8b, 0xab } }
> 
> +  ## Include/Ppi/NvmExpressHostController.h
> +  gEdkiiPeiNvmExpressHostControllerPpiGuid  = { 0xcae3aa63, 0x676f,
> + 0x4da3, { 0xbd, 0x50, 0x6c, 0xc5, 0xed, 0xde, 0x9a, 0xad } }
> +
>  [Protocols]
>    ## Load File protocol provides capability to load and unload EFI image into
> memory and execute it.
>    #  Include/Protocol/LoadPe32Image.h
> --
> 2.12.0.windows.1