From 093cceaf79b5d16880050a08e4bd465954ea6a97 Mon Sep 17 00:00:00 2001
From: Nikita Leshenko <nikita.leshchenko@oracle.com>
Date: Tue, 5 May 2020 00:06:01 +0300
Subject: [PATCH] OvmfPkg/MptScsiDxe: Report targets and one LUN

The controller supports up to 8 targets in practice (Not reported by the
controller, but based on the implementation of the virtual device),
report them in GetNextTarget and GetNextTargetLun. The firmware will
then try to communicate with them and create a block device for each one
that responds.

Support for multiple LUNs will be implemented in another series.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2390
Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200504210607.144434-7-nikita.leshchenko@oracle.com>
---
 OvmfPkg/MptScsiDxe/MptScsi.c      | 63 ++++++++++++++++++++++++++++++-
 OvmfPkg/MptScsiDxe/MptScsiDxe.inf |  5 +++
 OvmfPkg/OvmfPkg.dec               |  4 ++
 3 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/OvmfPkg/MptScsiDxe/MptScsi.c b/OvmfPkg/MptScsiDxe/MptScsi.c
index 40d392c234..d396bff85c 100644
--- a/OvmfPkg/MptScsiDxe/MptScsi.c
+++ b/OvmfPkg/MptScsiDxe/MptScsi.c
@@ -11,8 +11,10 @@
 
 #include <IndustryStandard/FusionMptScsi.h>
 #include <IndustryStandard/Pci.h>
+#include <Library/BaseMemoryLib.h>
 #include <Library/DebugLib.h>
 #include <Library/MemoryAllocationLib.h>
+#include <Library/PcdLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/UefiLib.h>
 #include <Protocol/PciIo.h>
@@ -34,6 +36,7 @@ typedef struct {
   UINT32                          Signature;
   EFI_EXT_SCSI_PASS_THRU_PROTOCOL PassThru;
   EFI_EXT_SCSI_PASS_THRU_MODE     PassThruMode;
+  UINT8                           MaxTarget;
 } MPT_SCSI_DEV;
 
 #define MPT_SCSI_FROM_PASS_THRU(PassThruPtr) \
@@ -57,6 +60,22 @@ MptScsiPassThru (
   return EFI_UNSUPPORTED;
 }
 
+STATIC
+BOOLEAN
+IsTargetInitialized (
+  IN UINT8                                          *Target
+  )
+{
+  UINTN Idx;
+
+  for (Idx = 0; Idx < TARGET_MAX_BYTES; ++Idx) {
+    if (Target[Idx] != 0xFF) {
+      return TRUE;
+    }
+  }
+  return FALSE;
+}
+
 STATIC
 EFI_STATUS
 EFIAPI
@@ -66,7 +85,28 @@ MptScsiGetNextTargetLun (
   IN OUT UINT64                                     *Lun
   )
 {
-  return EFI_UNSUPPORTED;
+  MPT_SCSI_DEV *Dev;
+
+  Dev = MPT_SCSI_FROM_PASS_THRU (This);
+  //
+  // Currently support only LUN 0, so hardcode it
+  //
+  if (!IsTargetInitialized (*Target)) {
+    ZeroMem (*Target, TARGET_MAX_BYTES);
+    *Lun = 0;
+  } else if (**Target > Dev->MaxTarget || *Lun > 0) {
+    return EFI_INVALID_PARAMETER;
+  } else if (**Target < Dev->MaxTarget) {
+    //
+    // This device interface support 256 targets only, so it's enough to
+    // increment the LSB of Target, as it will never overflow.
+    //
+    **Target += 1;
+  } else {
+    return EFI_NOT_FOUND;
+  }
+
+  return EFI_SUCCESS;
 }
 
 STATIC
@@ -77,7 +117,24 @@ MptScsiGetNextTarget (
   IN OUT UINT8                                     **Target
   )
 {
-  return EFI_UNSUPPORTED;
+  MPT_SCSI_DEV *Dev;
+
+  Dev = MPT_SCSI_FROM_PASS_THRU (This);
+  if (!IsTargetInitialized (*Target)) {
+    ZeroMem (*Target, TARGET_MAX_BYTES);
+  } else if (**Target > Dev->MaxTarget) {
+    return EFI_INVALID_PARAMETER;
+  } else if (**Target < Dev->MaxTarget) {
+    //
+    // This device interface support 256 targets only, so it's enough to
+    // increment the LSB of Target, as it will never overflow.
+    //
+    **Target += 1;
+  } else {
+    return EFI_NOT_FOUND;
+  }
+
+  return EFI_SUCCESS;
 }
 
 STATIC
@@ -206,6 +263,8 @@ MptScsiControllerStart (
 
   Dev->Signature = MPT_SCSI_DEV_SIGNATURE;
 
+  Dev->MaxTarget = PcdGet8 (PcdMptScsiMaxTargetLimit);
+
   //
   // Host adapter channel, doesn't exist
   //
diff --git a/OvmfPkg/MptScsiDxe/MptScsiDxe.inf b/OvmfPkg/MptScsiDxe/MptScsiDxe.inf
index 9f7c98829e..d5fd2516e4 100644
--- a/OvmfPkg/MptScsiDxe/MptScsiDxe.inf
+++ b/OvmfPkg/MptScsiDxe/MptScsiDxe.inf
@@ -24,8 +24,10 @@
   OvmfPkg/OvmfPkg.dec
 
 [LibraryClasses]
+  BaseMemoryLib
   DebugLib
   MemoryAllocationLib
+  PcdLib
   UefiBootServicesTableLib
   UefiDriverEntryPoint
   UefiLib
@@ -33,3 +35,6 @@
 [Protocols]
   gEfiExtScsiPassThruProtocolGuid        ## BY_START
   gEfiPciIoProtocolGuid                  ## TO_START
+
+[FixedPcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdMptScsiMaxTargetLimit   ## CONSUMES
diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index 8a46fe7334..723a779c03 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -167,6 +167,10 @@
   #  polling loop iteration.
   gUefiOvmfPkgTokenSpaceGuid.PcdPvScsiWaitForCmpStallInUsecs|5|UINT32|0x38
 
+  ## Set the *inclusive* number of targets that MptScsi exposes for scan
+  #  by ScsiBusDxe.
+  gUefiOvmfPkgTokenSpaceGuid.PcdMptScsiMaxTargetLimit|7|UINT8|0x39
+
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageEventLogBase|0x0|UINT32|0x8
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageEventLogSize|0x0|UINT32|0x9
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFirmwareFdSize|0x0|UINT32|0xa
-- 
2.39.2