Silicon/SynQuacer: disregard DRAM below 4 GB

Force the use of 64-bit DMA for PCI by removing the first DRAM region,
which is the only 32-bit addressable chunk of memory available on this
platform. This forces drivers for PCIe devices to enable 64-bit DMA
addressing, which many don't bother to do since it is not usually
necessary on a x86/PC platform.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

3 files changed, 18 insertions, 2 deletions

diff --git a/Silicon/Socionext/SynQuacer/Library/SynQuacerMemoryInitPeiLib/SynQuacerMemoryInitPeiLib.c b/Silicon/Socionext/SynQuacer/Library/SynQuacerMemoryInitPeiLib/SynQuacerMemoryInitPeiLib.c
index 1ec0be0f..fb1eb484 100644
--- a/Silicon/Socionext/SynQuacer/Library/SynQuacerMemoryInitPeiLib/SynQuacerMemoryInitPeiLib.c
+++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerMemoryInitPeiLib/SynQuacerMemoryInitPeiLib.c
@@ -163,6 +163,13 @@ DeclareDram (
     Status = DramInfo->GetRegion (Idx, &Base, &Size);

     ASSERT_EFI_ERROR (Status);

 

+    if (Base < PcdGet64 (PcdSystemMemoryBase)) {

+      DEBUG ((DEBUG_WARN,

+        "%a: ignoring system memory below PcdSystemMemoryBase\n",

+        __FUNCTION__));

+      continue;

+    }

+

     BuildResourceDescriptorHob (EFI_RESOURCE_SYSTEM_MEMORY,

       mDramResourceAttributes, Base, Size);

 

@@ -174,6 +181,7 @@ DeclareDram (
     DramDescriptor->VirtualBase  = Base;

     DramDescriptor->Length       = MIN (Size, MAX_ALLOC_ADDRESS - Base + 1);

     DramDescriptor->Attributes   = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;

+

     DramDescriptor++;

   }

 

diff --git a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c
index 7c529a22..af8dfd12 100644
--- a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c
+++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c
@@ -163,14 +163,21 @@ PlatformPeim (
     ASSERT_EFI_ERROR (Status);

   }

 

+  Value = 0;

+  Status = ReadGpioInput (Gpio, FixedPcdGet8 (PcdIgnoreFirstMemRegionGpioPin),

+             &Value);

+  if (!EFI_ERROR (Status) && Value != 0) {

+    DEBUG ((DEBUG_WARN, "%a: ignoring 32-bit addressable DRAM\n", __FUNCTION__));

+  }

+

   //

   // Record the first region into PcdSystemMemoryBase and PcdSystemMemorySize.

   // This is the region we will use for UEFI itself.

   //

-  Status = PcdSet64S (PcdSystemMemoryBase, mDramInfo->Entry[0].Base);

+  Status = PcdSet64S (PcdSystemMemoryBase, mDramInfo->Entry[Value].Base);

   ASSERT_EFI_ERROR (Status);

 

-  Status = PcdSet64S (PcdSystemMemorySize, mDramInfo->Entry[0].Size);

+  Status = PcdSet64S (PcdSystemMemorySize, mDramInfo->Entry[Value].Size);

   ASSERT_EFI_ERROR (Status);

 

   BuildFvHob (FixedPcdGet64 (PcdFvBaseAddress), FixedPcdGet32 (PcdFvSize));

diff --git a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf
index eb6a5bf9..c4e53767 100644
--- a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf
+++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf
@@ -44,6 +44,7 @@
   gSynQuacerTokenSpaceGuid.PcdClearSettingsGpioPin

   gSynQuacerTokenSpaceGuid.PcdDramInfoBase

   gSynQuacerTokenSpaceGuid.PcdPcie0PresenceDetectGpioPin

+  gSynQuacerTokenSpaceGuid.PcdIgnoreFirstMemRegionGpioPin

 

 [Ppis]

   gEdkiiEmbeddedGpioPpiGuid             ## CONSUMES