[platforms: PATCH v3 1/8] Marvell/Armada: Implement EFI_RNG_PROTOCOL driver for EIP76 TRNG

[Marcin Wojtas <mw@semihalf.com>]

From: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Add an implementation of EFI_RNG_PROTOCOL so that the OS loader has
access to entropy for KASLR and other purposes (i.e., seeding the OS's
entropy pool very early on).

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
---
 Platform/Marvell/Armada/Armada.dsc.inc                                |   4 +
 Platform/Marvell/Armada/Armada70x0.fdf                                |   1 +
 Platform/Marvell/Armada/Drivers/Armada70x0RngDxe/Armada70x0RngDxe.c   | 255 ++++++++++++++++++++
 Platform/Marvell/Armada/Drivers/Armada70x0RngDxe/Armada70x0RngDxe.inf |  47 ++++
 Platform/Marvell/Marvell.dec                                          |   3 +
 5 files changed, 310 insertions(+)

diff --git a/Platform/Marvell/Armada/Armada.dsc.inc b/Platform/Marvell/Armada/Armada.dsc.inc
index 1aa485c..ec24d76 100644
--- a/Platform/Marvell/Armada/Armada.dsc.inc
+++ b/Platform/Marvell/Armada/Armada.dsc.inc
@@ -364,6 +364,9 @@
   gArmTokenSpaceGuid.PcdSystemMemorySize|0x40000000
   gArmTokenSpaceGuid.PcdArmScr|0x531
 
+  # TRNG
+  gMarvellTokenSpaceGuid.PcdEip76TrngBaseAddress|0xF2760000
+
 ################################################################################
 #
 # Components Section - list of all EDK II Modules needed by this Platform
@@ -400,6 +403,7 @@
   Platform/Marvell/Drivers/I2c/Devices/MvEeprom/MvEeprom.inf
   Platform/Marvell/Drivers/Spi/MvSpiDxe.inf
   Platform/Marvell/Drivers/Spi/Devices/MvSpiFlash.inf
+  Platform/Marvell/Armada/Drivers/Armada70x0RngDxe/Armada70x0RngDxe.inf
 
   # Network support
   MdeModulePkg/Universal/Network/SnpDxe/SnpDxe.inf
diff --git a/Platform/Marvell/Armada/Armada70x0.fdf b/Platform/Marvell/Armada/Armada70x0.fdf
index 933c3ed..a94a9ff 100644
--- a/Platform/Marvell/Armada/Armada70x0.fdf
+++ b/Platform/Marvell/Armada/Armada70x0.fdf
@@ -113,6 +113,7 @@ FvNameGuid         = 5eda4200-2c5f-43cb-9da3-0baf74b1b30c
   INF Platform/Marvell/Drivers/I2c/Devices/MvEeprom/MvEeprom.inf
   INF Platform/Marvell/Drivers/Spi/MvSpiDxe.inf
   INF Platform/Marvell/Drivers/Spi/Devices/MvSpiFlash.inf
+  INF Platform/Marvell/Armada/Drivers/Armada70x0RngDxe/Armada70x0RngDxe.inf
 
   # Network support
   INF MdeModulePkg/Universal/Network/SnpDxe/SnpDxe.inf
diff --git a/Platform/Marvell/Armada/Drivers/Armada70x0RngDxe/Armada70x0RngDxe.c b/Platform/Marvell/Armada/Drivers/Armada70x0RngDxe/Armada70x0RngDxe.c
new file mode 100644
index 0000000..014443d
--- /dev/null
+++ b/Platform/Marvell/Armada/Drivers/Armada70x0RngDxe/Armada70x0RngDxe.c
@@ -0,0 +1,255 @@
+/** @file
+
+  This driver produces an EFI_RNG_PROTOCOL instance for the Armada 70x0 TRNG
+
+  Copyright (C) 2017, Linaro Ltd. 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.
+
+**/
+
+#include <Library/BaseMemoryLib.h>
+#include <Library/IoLib.h>
+#include <Library/PcdLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+
+#include <Protocol/Rng.h>
+
+#define TRNG_OUTPUT_REG                         mTrngBaseAddress
+#define TRNG_OUTPUT_SIZE                        0x10
+
+#define TRNG_STATUS_REG                         (mTrngBaseAddress + 0x10)
+#define TRNG_STATUS_READY                       BIT0
+
+#define TRNG_INTACK_REG                         (mTrngBaseAddress + 0x10)
+#define TRNG_INTACK_READY                       BIT0
+
+#define TRNG_CONTROL_REG                        (mTrngBaseAddress + 0x14)
+#define TRNG_CONTROL_REG_ENABLE                 BIT10
+
+#define TRNG_CONFIG_REG                         (mTrngBaseAddress + 0x18)
+#define __MIN_REFILL_SHIFT                      0
+#define __MAX_REFILL_SHIFT                      16
+#define TRNG_CONFIG_MIN_REFILL_CYCLES           (0x05 << __MIN_REFILL_SHIFT)
+#define TRNG_CONFIG_MAX_REFILL_CYCLES           (0x22 << __MAX_REFILL_SHIFT)
+
+#define TRNG_FRODETUNE_REG                      (mTrngBaseAddress + 0x24)
+#define TRNG_FRODETUNE_MASK                     0x0
+
+#define TRNG_FROENABLE_REG                      (mTrngBaseAddress + 0x20)
+#define TRNG_FROENABLE_MASK                     0xffffff
+
+#define TRNG_MAX_RETRIES                        20
+
+STATIC EFI_PHYSICAL_ADDRESS                     mTrngBaseAddress;
+
+/**
+  Returns information about the random number generation implementation.
+
+  @param[in]     This                 A pointer to the EFI_RNG_PROTOCOL
+                                      instance.
+  @param[in,out] RNGAlgorithmListSize On input, the size in bytes of
+                                      RNGAlgorithmList.
+                                      On output with a return code of
+                                      EFI_SUCCESS, the size in bytes of the
+                                      data returned in RNGAlgorithmList. On
+                                      output with a return code of
+                                      EFI_BUFFER_TOO_SMALL, the size of
+                                      RNGAlgorithmList required to obtain the
+                                      list.
+  @param[out] RNGAlgorithmList        A caller-allocated memory buffer filled
+                                      by the driver with one EFI_RNG_ALGORITHM
+                                      element for each supported RNG algorithm.
+                                      The list must not change across multiple
+                                      calls to the same driver. The first
+                                      algorithm in the list is the default
+                                      algorithm for the driver.
+
+  @retval EFI_SUCCESS                 The RNG algorithm list was returned
+                                      successfully.
+  @retval EFI_UNSUPPORTED             The services is not supported by this
+                                      driver.
+  @retval EFI_DEVICE_ERROR            The list of algorithms could not be
+                                      retrieved due to a hardware or firmware
+                                      error.
+  @retval EFI_INVALID_PARAMETER       One or more of the parameters are
+                                      incorrect.
+  @retval EFI_BUFFER_TOO_SMALL        The buffer RNGAlgorithmList is too small
+                                      to hold the result.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+Armada70x0RngGetInfo (
+  IN      EFI_RNG_PROTOCOL        *This,
+  IN OUT  UINTN                   *RNGAlgorithmListSize,
+  OUT     EFI_RNG_ALGORITHM       *RNGAlgorithmList
+  )
+{
+  if (This == NULL || RNGAlgorithmListSize == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (*RNGAlgorithmListSize < sizeof (EFI_RNG_ALGORITHM)) {
+    *RNGAlgorithmListSize = sizeof (EFI_RNG_ALGORITHM);
+    return EFI_BUFFER_TOO_SMALL;
+  }
+
+  if (RNGAlgorithmList == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  *RNGAlgorithmListSize = sizeof (EFI_RNG_ALGORITHM);
+  CopyGuid (RNGAlgorithmList, &gEfiRngAlgorithmRaw);
+
+  return EFI_SUCCESS;
+}
+
+STATIC
+EFI_STATUS
+GetTrngData (
+  IN    UINTN   Length,
+  OUT   UINT8   *Bits
+  )
+{
+  UINTN   Tries;
+  UINT32  Buf[TRNG_OUTPUT_SIZE / sizeof (UINT32)];
+  UINTN   Index;
+
+  for (Tries = 0; Tries < TRNG_MAX_RETRIES; Tries++) {
+    if (MmioRead32 (TRNG_STATUS_REG) & TRNG_STATUS_READY) {
+      for (Index = 0; Index < ARRAY_SIZE (Buf); Index++) {
+        Buf[Index] = MmioRead32 (TRNG_OUTPUT_REG + Index * sizeof (UINT32));
+      }
+      CopyMem (Bits, Buf, Length);
+      MmioWrite32 (TRNG_INTACK_REG, TRNG_INTACK_READY);
+
+      return EFI_SUCCESS;
+    }
+    // Wait for more TRNG data to arrive
+    gBS->Stall (10);
+  }
+  return EFI_DEVICE_ERROR;
+}
+
+/**
+  Produces and returns an RNG value using either the default or specified RNG
+  algorithm.
+
+  @param[in]  This                    A pointer to the EFI_RNG_PROTOCOL
+                                      instance.
+  @param[in]  RNGAlgorithm            A pointer to the EFI_RNG_ALGORITHM that
+                                      identifies the RNG algorithm to use. May
+                                      be NULL in which case the function will
+                                      use its default RNG algorithm.
+  @param[in]  RNGValueLength          The length in bytes of the memory buffer
+                                      pointed to by RNGValue. The driver shall
+                                      return exactly this numbers of bytes.
+  @param[out] RNGValue                A caller-allocated memory buffer filled
+                                      by the driver with the resulting RNG
+                                      value.
+
+  @retval EFI_SUCCESS                 The RNG value was returned successfully.
+  @retval EFI_UNSUPPORTED             The algorithm specified by RNGAlgorithm
+                                      is not supported by this driver.
+  @retval EFI_DEVICE_ERROR            An RNG value could not be retrieved due
+                                      to a hardware or firmware error.
+  @retval EFI_NOT_READY               There is not enough random data available
+                                      to satisfy the length requested by
+                                      RNGValueLength.
+  @retval EFI_INVALID_PARAMETER       RNGValue is NULL or RNGValueLength is
+                                      zero.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+Armada70x0RngGetRNG (
+  IN EFI_RNG_PROTOCOL            *This,
+  IN EFI_RNG_ALGORITHM           *RNGAlgorithm, OPTIONAL
+  IN UINTN                       RNGValueLength,
+  OUT UINT8                      *RNGValue
+  )
+{
+  UINTN         Length;
+  EFI_STATUS    Status;
+
+  if (This == NULL || RNGValueLength == 0 || RNGValue == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // We only support the raw algorithm, so reject requests for anything else
+  //
+  if (RNGAlgorithm != NULL &&
+      !CompareGuid (RNGAlgorithm, &gEfiRngAlgorithmRaw)) {
+    return EFI_UNSUPPORTED;
+  }
+
+  do {
+    Length = MIN (RNGValueLength, TRNG_OUTPUT_SIZE);
+    Status = GetTrngData (Length, RNGValue);
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+
+    RNGValue += Length;
+    RNGValueLength -= Length;
+  } while (RNGValueLength > 0);
+
+  return EFI_SUCCESS;
+}
+
+STATIC EFI_RNG_PROTOCOL mArmada70x0RngProtocol = {
+  Armada70x0RngGetInfo,
+  Armada70x0RngGetRNG
+};
+
+//
+// Entry point of this driver.
+//
+EFI_STATUS
+EFIAPI
+Armada70x0RngDxeEntryPoint (
+  IN EFI_HANDLE       ImageHandle,
+  IN EFI_SYSTEM_TABLE *SystemTable
+  )
+{
+  mTrngBaseAddress = PcdGet64 (PcdEip76TrngBaseAddress);
+
+  //
+  // Disable the TRNG before updating its configuration
+  //
+  MmioAnd32 (TRNG_CONTROL_REG, ~TRNG_CONTROL_REG_ENABLE);
+
+  //
+  // Configure the internal conditioning parameters of the TRNG
+  //
+  MmioWrite32 (TRNG_CONFIG_REG, TRNG_CONFIG_MIN_REFILL_CYCLES |
+                                TRNG_CONFIG_MAX_REFILL_CYCLES);
+
+  //
+  // Configure the FROs
+  //
+  MmioWrite32 (TRNG_FRODETUNE_REG, TRNG_FRODETUNE_MASK);
+  MmioWrite32 (TRNG_FROENABLE_REG, TRNG_FROENABLE_MASK);
+
+  //
+  // Enable the TRNG
+  //
+  MmioOr32 (TRNG_CONTROL_REG, TRNG_CONTROL_REG_ENABLE);
+
+  return SystemTable->BootServices->InstallMultipleProtocolInterfaces (
+                                      &ImageHandle,
+                                      &gEfiRngProtocolGuid,
+                                      &mArmada70x0RngProtocol,
+                                      NULL
+                                      );
+}
diff --git a/Platform/Marvell/Armada/Drivers/Armada70x0RngDxe/Armada70x0RngDxe.inf b/Platform/Marvell/Armada/Drivers/Armada70x0RngDxe/Armada70x0RngDxe.inf
new file mode 100644
index 0000000..189ffc5
--- /dev/null
+++ b/Platform/Marvell/Armada/Drivers/Armada70x0RngDxe/Armada70x0RngDxe.inf
@@ -0,0 +1,47 @@
+## @file
+# This driver produces an EFI_RNG_PROTOCOL instance for the Armada 70x0 TRNG
+#
+# Copyright (C) 2017, Linaro Ltd. 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.
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010019
+  BASE_NAME                      = Armada70x0RngDxe
+  FILE_GUID                      = dd87096a-cae5-4328-bec1-2ddb755f2e08
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = Armada70x0RngDxeEntryPoint
+
+[Sources]
+  Armada70x0RngDxe.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  Platform/Marvell/Marvell.dec
+
+[LibraryClasses]
+  BaseMemoryLib
+  IoLib
+  PcdLib
+  UefiDriverEntryPoint
+
+[Pcd]
+  gMarvellTokenSpaceGuid.PcdEip76TrngBaseAddress
+
+[Protocols]
+  gEfiRngProtocolGuid              ## PRODUCES
+
+[Guids]
+  gEfiRngAlgorithmRaw
+
+[Depex]
+  TRUE
diff --git a/Platform/Marvell/Marvell.dec b/Platform/Marvell/Marvell.dec
index e7d7c2c..78f5e53 100644
--- a/Platform/Marvell/Marvell.dec
+++ b/Platform/Marvell/Marvell.dec
@@ -195,6 +195,9 @@
 #RTC
   gMarvellTokenSpaceGuid.PcdRtcEnabled|{ 0x0 }|VOID*|0x40000052
 
+#TRNG
+  gMarvellTokenSpaceGuid.PcdEip76TrngBaseAddress|0x0|UINT64|0x50000053
+
 [Protocols]
   gMarvellEepromProtocolGuid               = { 0x71954bda, 0x60d3, 0x4ef8, { 0x8e, 0x3c, 0x0e, 0x33, 0x9f, 0x3b, 0xc2, 0x2b }}
   gMarvellMdioProtocolGuid                 = { 0x40010b03, 0x5f08, 0x496a, { 0xa2, 0x64, 0x10, 0x5e, 0x72, 0xd3, 0x71, 0xaa }}
-- 
2.7.4