OvmfPkg/PciHotPlugInitDxe: generalize RESOURCE_PADDING composition

PciHotPlugInitDxe has a static variable called "mPadding" (of type
RESOURCE_PADDING), which describes two constant resource reservations:

- MmioPadding: 2MB of non-prefetchable (hence 32-bit) MMIO space,

- IoPadding: 512B of IO space.

In the GetResourcePadding() member function of
EFI_PCI_HOT_PLUG_INIT_PROTOCOL, the driver outputs a dynamically allocated
verbatim copy of "mPadding", for PciBusDxe to consume in its
ApplyResourcePadding() function.

In a later patch, we're going to compose the set of resource reservations
dynamically, based on QEMU hints. Generalize the RESOURCE_PADDING
structure so that we may generate (or not generate) each resource type
individually:

- Replace the named "MmioPadding" and "IoPadding" fields in
  RESOURCE_PADDING with an array of descriptors,

- remove "mPadding",

- in GetResourcePadding(), request the same (default) reservations as
  before, as if we attempted and failed to fetch the QEMU hints.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

2 files changed, 98 insertions, 64 deletions

diff --git a/OvmfPkg/PciHotPlugInitDxe/PciHotPlugInit.c b/OvmfPkg/PciHotPlugInitDxe/PciHotPlugInit.c
index 5c98f806de..b1b2c5cd8d 100644
--- a/OvmfPkg/PciHotPlugInitDxe/PciHotPlugInit.c
+++ b/OvmfPkg/PciHotPlugInitDxe/PciHotPlugInit.c
@@ -15,6 +15,7 @@
 

 #include <IndustryStandard/Acpi10.h>

 

+#include <Library/BaseMemoryLib.h>

 #include <Library/DebugLib.h>

 #include <Library/DevicePathLib.h>

 #include <Library/MemoryAllocationLib.h>

@@ -42,81 +43,59 @@ STATIC EFI_PCI_HOT_PLUG_INIT_PROTOCOL mPciHotPlugInit;
 // This structure is interpreted by the ApplyResourcePadding() function in the

 // edk2 PCI Bus UEFI_DRIVER.

 //

+// We can request padding for at most four resource types, each of which is

+// optional, independently of the others:

+// (a) bus numbers,

+// (b) IO space,

+// (c) non-prefetchable MMIO space (32-bit only),

+// (d) prefetchable MMIO space (either 32-bit or 64-bit, never both).

+//

 #pragma pack (1)

 typedef struct {

-  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR MmioPadding;

-  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR IoPadding;

+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR Padding[4];

   EFI_ACPI_END_TAG_DESCRIPTOR       EndDesc;

 } RESOURCE_PADDING;

 #pragma pack ()

 

-STATIC CONST RESOURCE_PADDING mPadding = {

-  //

-  // MmioPadding

-  //

-  {

-    ACPI_ADDRESS_SPACE_DESCRIPTOR,                 // Desc

-    (UINT16)(                                      // Len

-      sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) -

-      OFFSET_OF (

-        EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR,

-        ResType

-        )

-      ),

-    ACPI_ADDRESS_SPACE_TYPE_MEM, // ResType

-    0,                           // GenFlag:

-                                 //   ignored

-    0,                           // SpecificFlag:

-                                 //   non-prefetchable

-    32,                          // AddrSpaceGranularity:

-                                 //   reserve 32-bit aperture

-    0,                           // AddrRangeMin:

-                                 //   ignored

-    SIZE_2MB - 1,                // AddrRangeMax:

-                                 //   align at 2MB

-    0,                           // AddrTranslationOffset:

-                                 //   ignored

-    SIZE_2MB                     // AddrLen:

-                                 //   2MB padding

-  },

+

+/**

+  Initialize a RESOURCE_PADDING object.

+

+  @param[out] ResourcePadding  The caller-allocated RESOURCE_PADDING object to

+                               initialize.

+**/

+STATIC

+VOID

+InitializeResourcePadding (

+  OUT RESOURCE_PADDING *ResourcePadding

+  )

+{

+  UINTN Index;

+

+  ZeroMem (ResourcePadding, sizeof *ResourcePadding);

 

   //

-  // IoPadding

+  // Fill in the Padding fields that don't vary across resource types.

   //

-  {

-    ACPI_ADDRESS_SPACE_DESCRIPTOR,                 // Desc

-    (UINT16)(                                      // Len

-      sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) -

-      OFFSET_OF (

-        EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR,

-        ResType

-        )

-      ),

-    ACPI_ADDRESS_SPACE_TYPE_IO,// ResType

-    0,                          // GenFlag:

-                                //   ignored

-    0,                          // SpecificFlag:

-                                //   ignored

-    0,                          // AddrSpaceGranularity:

-                                //   ignored

-    0,                          // AddrRangeMin:

-                                //   ignored

-    512 - 1,                    // AddrRangeMax:

-                                //   align at 512 IO ports

-    0,                          // AddrTranslationOffset:

-                                //   ignored

-    512                         // AddrLen:

-                                //   512 IO ports

-  },

+  for (Index = 0; Index < ARRAY_SIZE (ResourcePadding->Padding); ++Index) {

+    EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *Descriptor;

+

+    Descriptor       = ResourcePadding->Padding + Index;

+    Descriptor->Desc = ACPI_ADDRESS_SPACE_DESCRIPTOR;

+    Descriptor->Len  = (UINT16)(

+                         sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) -

+                         OFFSET_OF (

+                           EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR,

+                           ResType

+                           )

+                         );

+  }

 

   //

-  // EndDesc

+  // Fill in the End Tag.

   //

-  {

-    ACPI_END_TAG_DESCRIPTOR, // Desc

-    0                        // Checksum: to be ignored

-  }

-};

+  ResourcePadding->EndDesc.Desc = ACPI_END_TAG_DESCRIPTOR;

+}

 

 

 /**

@@ -275,6 +254,11 @@ GetResourcePadding (
   OUT EFI_HPC_PADDING_ATTRIBUTES     *Attributes

   )

 {

+  BOOLEAN                                         DefaultIo;

+  BOOLEAN                                         DefaultMmio;

+  RESOURCE_PADDING                                ReservationRequest;

+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR               *FirstResource;

+

   DEBUG_CODE (

     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS *Address;

     CHAR16                                      *DevicePathString;

@@ -295,7 +279,56 @@ GetResourcePadding (
     return EFI_INVALID_PARAMETER;

   }

 

-  *Padding = AllocateCopyPool (sizeof mPadding, &mPadding);

+  DefaultIo = TRUE;

+  DefaultMmio = TRUE;

+

+  //

+  // Init ReservationRequest, and point FirstResource one past the last

+  // descriptor entry. We're going to build the entries backwards from

+  // ReservationRequest.EndDesc.

+  //

+  InitializeResourcePadding (&ReservationRequest);

+  FirstResource = ReservationRequest.Padding +

+                  ARRAY_SIZE (ReservationRequest.Padding);

+

+  //

+  // (b) Reserve IO space.

+  //

+  if (DefaultIo) {

+    //

+    // Request defaults.

+    //

+    --FirstResource;

+    FirstResource->ResType      = ACPI_ADDRESS_SPACE_TYPE_IO;

+    FirstResource->AddrRangeMax = 512 - 1; // align at 512 IO ports

+    FirstResource->AddrLen      = 512;     // 512 IO ports

+  }

+

+  //

+  // (c) Reserve non-prefetchable MMIO space (32-bit only).

+  //

+  if (DefaultMmio) {

+    //

+    // Request defaults.

+    //

+    --FirstResource;

+    FirstResource->ResType              = ACPI_ADDRESS_SPACE_TYPE_MEM;

+    FirstResource->SpecificFlag         = 0;            // non-prefetchable

+    FirstResource->AddrSpaceGranularity = 32;           // 32-bit aperture

+    FirstResource->AddrRangeMax         = SIZE_2MB - 1; // align at 2MB

+    FirstResource->AddrLen              = SIZE_2MB;     // 2MB padding

+  }

+

+  //

+  // Output a copy of ReservationRequest from the lowest-address populated

+  // entry until the end of the structure (including

+  // ReservationRequest.EndDesc). If no reservations are necessary, we'll only

+  // output the End Tag.

+  //

+  *Padding = AllocateCopyPool (

+               (UINT8 *)(&ReservationRequest + 1) - (UINT8 *)FirstResource,

+               FirstResource

+               );

   if (*Padding == NULL) {

     return EFI_OUT_OF_RESOURCES;

   }

diff --git a/OvmfPkg/PciHotPlugInitDxe/PciHotPlugInit.inf b/OvmfPkg/PciHotPlugInitDxe/PciHotPlugInit.inf
index ea19206219..91729ae1ed 100644
--- a/OvmfPkg/PciHotPlugInitDxe/PciHotPlugInit.inf
+++ b/OvmfPkg/PciHotPlugInitDxe/PciHotPlugInit.inf
@@ -29,6 +29,7 @@
   MdePkg/MdePkg.dec

 

 [LibraryClasses]

+  BaseMemoryLib

   DebugLib

   DevicePathLib

   MemoryAllocationLib