OvmfPkg/LsiScsiDxe: Report Targets and LUNs

Implement LsiScsiGetNextTargetLun(), LsiScsiBuildDevicePath(),
LsiScsiGetTargetLun(), and LsiScsiGetNextTarget() to report Targets and
LUNs and build the device path.

This commit also introduces two PCD value: PcdLsiScsiMaxTargetLimit and
PcdLsiScsiMaxLunLimit as the limits for Targets and LUNs.

v3:
  - Update the range of LUN in the assertioin
  - Squash the spurious newline into the previous commit
v2:
  - Zero out (*Target) in LsiScsiGetTargetLun()
  - Use CopyMem() instead of the one-byte shortcut to copy target from
    ScsiDevicePath->Pun
  - Add asserts for PcdLsiScsiMaxTargetLimit and PcdLsiScsiMaxLunLimit

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Gary Lin <glin@suse.com>
Message-Id: <20200717061130.8881-7-glin@suse.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

OvmfPkg/LsiScsiDxe/LsiScsi.c

@@ -15,6 +15,7 @@
 #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>
@@ -53,6 +54,49 @@ LsiScsiGetNextTargetLun (
   IN OUT UINT64                      *Lun
   )
 {
+  LSI_SCSI_DEV *Dev;
+  UINTN        Idx;
+  UINT8        *Target;
+  UINT16       LastTarget;
+
+  //
+  // the TargetPointer input parameter is unnecessarily a pointer-to-pointer
+  //
+  Target = *TargetPointer;
+
+  //
+  // Search for first non-0xFF byte. If not found, return first target & LUN.
+  //
+  for (Idx = 0; Idx < TARGET_MAX_BYTES && Target[Idx] == 0xFF; ++Idx)
+    ;
+  if (Idx == TARGET_MAX_BYTES) {
+    SetMem (Target, TARGET_MAX_BYTES, 0x00);
+    *Lun = 0;
+    return EFI_SUCCESS;
+  }
+
+  CopyMem (&LastTarget, Target, sizeof LastTarget);
+
+  //
+  // increment (target, LUN) pair if valid on input
+  //
+  Dev = LSI_SCSI_FROM_PASS_THRU (This);
+  if (LastTarget > Dev->MaxTarget || *Lun > Dev->MaxLun) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (*Lun < Dev->MaxLun) {
+    ++*Lun;
+    return EFI_SUCCESS;
+  }
+
+  if (LastTarget < Dev->MaxTarget) {
+    *Lun = 0;
+    ++LastTarget;
+    CopyMem (Target, &LastTarget, sizeof LastTarget);
+    return EFI_SUCCESS;
+  }
+
   return EFI_NOT_FOUND;
 }
 
@@ -65,7 +109,34 @@ LsiScsiBuildDevicePath (
   IN OUT EFI_DEVICE_PATH_PROTOCOL    **DevicePath
   )
 {
-  return EFI_NOT_FOUND;
+  UINT16           TargetValue;
+  LSI_SCSI_DEV     *Dev;
+  SCSI_DEVICE_PATH *ScsiDevicePath;
+
+  if (DevicePath == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  CopyMem (&TargetValue, Target, sizeof TargetValue);
+  Dev = LSI_SCSI_FROM_PASS_THRU (This);
+  if (TargetValue > Dev->MaxTarget || Lun > Dev->MaxLun || Lun > 0xFFFF) {
+    return EFI_NOT_FOUND;
+  }
+
+  ScsiDevicePath = AllocatePool (sizeof *ScsiDevicePath);
+  if (ScsiDevicePath == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  ScsiDevicePath->Header.Type      = MESSAGING_DEVICE_PATH;
+  ScsiDevicePath->Header.SubType   = MSG_SCSI_DP;
+  ScsiDevicePath->Header.Length[0] = (UINT8)  sizeof *ScsiDevicePath;
+  ScsiDevicePath->Header.Length[1] = (UINT8) (sizeof *ScsiDevicePath >> 8);
+  ScsiDevicePath->Pun              = TargetValue;
+  ScsiDevicePath->Lun              = (UINT16) Lun;
+
+  *DevicePath = &ScsiDevicePath->Header;
+  return EFI_SUCCESS;
 }
 
 EFI_STATUS
@@ -77,7 +148,33 @@ LsiScsiGetTargetLun (
   OUT UINT64                          *Lun
   )
 {
-  return EFI_UNSUPPORTED;
+  SCSI_DEVICE_PATH *ScsiDevicePath;
+  LSI_SCSI_DEV     *Dev;
+  UINT8            *Target;
+
+  if (DevicePath == NULL || TargetPointer == NULL || *TargetPointer == NULL ||
+      Lun == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (DevicePath->Type    != MESSAGING_DEVICE_PATH ||
+      DevicePath->SubType != MSG_SCSI_DP) {
+    return EFI_UNSUPPORTED;
+  }
+
+  ScsiDevicePath = (SCSI_DEVICE_PATH *) DevicePath;
+  Dev = LSI_SCSI_FROM_PASS_THRU (This);
+  if (ScsiDevicePath->Pun > Dev->MaxTarget ||
+      ScsiDevicePath->Lun > Dev->MaxLun) {
+    return EFI_NOT_FOUND;
+  }
+
+  Target = *TargetPointer;
+  ZeroMem (Target, TARGET_MAX_BYTES);
+  CopyMem (Target, &ScsiDevicePath->Pun, sizeof ScsiDevicePath->Pun);
+  *Lun = ScsiDevicePath->Lun;
+
+  return EFI_SUCCESS;
 }
 
 EFI_STATUS
@@ -107,6 +204,42 @@ LsiScsiGetNextTarget (
   IN OUT UINT8                       **TargetPointer
   )
 {
+  LSI_SCSI_DEV *Dev;
+  UINTN        Idx;
+  UINT8        *Target;
+  UINT16       LastTarget;
+
+  //
+  // the TargetPointer input parameter is unnecessarily a pointer-to-pointer
+  //
+  Target = *TargetPointer;
+
+  //
+  // Search for first non-0xFF byte. If not found, return first target.
+  //
+  for (Idx = 0; Idx < TARGET_MAX_BYTES && Target[Idx] == 0xFF; ++Idx)
+    ;
+  if (Idx == TARGET_MAX_BYTES) {
+    SetMem (Target, TARGET_MAX_BYTES, 0x00);
+    return EFI_SUCCESS;
+  }
+
+  CopyMem (&LastTarget, Target, sizeof LastTarget);
+
+  //
+  // increment target if valid on input
+  //
+  Dev = LSI_SCSI_FROM_PASS_THRU (This);
+  if (LastTarget > Dev->MaxTarget) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (LastTarget < Dev->MaxTarget) {
+    ++LastTarget;
+    CopyMem (Target, &LastTarget, sizeof LastTarget);
+    return EFI_SUCCESS;
+  }
+
   return EFI_NOT_FOUND;
 }
 
@@ -189,6 +322,17 @@ LsiScsiControllerStart (
 
   Dev->Signature = LSI_SCSI_DEV_SIGNATURE;
 
+  STATIC_ASSERT (
+    FixedPcdGet8 (PcdLsiScsiMaxTargetLimit) < 8,
+    "LSI 53C895A supports targets [0..7]"
+    );
+  STATIC_ASSERT (
+    FixedPcdGet8 (PcdLsiScsiMaxLunLimit) < 128,
+    "LSI 53C895A supports LUNs [0..127]"
+    );
+  Dev->MaxTarget = PcdGet8 (PcdLsiScsiMaxTargetLimit);
+  Dev->MaxLun = PcdGet8 (PcdLsiScsiMaxLunLimit);
+
   //
   // Host adapter channel, doesn't exist
   //

OvmfPkg/LsiScsiDxe/LsiScsi.h

@@ -14,6 +14,8 @@
 
 typedef struct {
   UINT32                          Signature;
+  UINT8                           MaxTarget;
+  UINT8                           MaxLun;
   EFI_EXT_SCSI_PASS_THRU_MODE     PassThruMode;
   EFI_EXT_SCSI_PASS_THRU_PROTOCOL PassThru;
 } LSI_SCSI_DEV;

OvmfPkg/LsiScsiDxe/LsiScsiDxe.inf

@@ -27,7 +27,9 @@
 [LibraryClasses]
   BaseLib
   BaseMemoryLib
+  DebugLib
   MemoryAllocationLib
+  PcdLib
   UefiBootServicesTableLib
   UefiDriverEntryPoint
   UefiLib
@@ -35,3 +37,7 @@
 [Protocols]
   gEfiExtScsiPassThruProtocolGuid        ## BY_START
   gEfiPciIoProtocolGuid                  ## TO_START
+
+[FixedPcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdLsiScsiMaxTargetLimit   ## CONSUMES
+  gUefiOvmfPkgTokenSpaceGuid.PcdLsiScsiMaxLunLimit      ## CONSUMES

OvmfPkg/OvmfPkg.dec

@@ -174,6 +174,11 @@
   ## Microseconds to stall between polling for MptScsi request result
   gUefiOvmfPkgTokenSpaceGuid.PcdMptScsiStallPerPollUsec|5|UINT32|0x3a
 
+  ## Set the *inclusive* number of targets and LUNs that LsiScsi exposes for
+  #  scan by ScsiBusDxe.
+  gUefiOvmfPkgTokenSpaceGuid.PcdLsiScsiMaxTargetLimit|7|UINT8|0x3b
+  gUefiOvmfPkgTokenSpaceGuid.PcdLsiScsiMaxLunLimit|0|UINT8|0x3c
+
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageEventLogBase|0x0|UINT32|0x8
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageEventLogSize|0x0|UINT32|0x9
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFirmwareFdSize|0x0|UINT32|0xa