PPC64LE: boot to shell

- working HDEC-based TimerDxe
- TB-based TimerLib
- Shell needed the unicode collation driver.
- set correct PcdShellFile to have the shell be recognised by BDS
- TB frequency set in Ipl today through the Pcr, at some point
  this should be set through a PCD by a FDT-parsing DXE.

Fixes issue tianocore#2
Closes Milestone UEFI Shell Boot

Signed-off-by: Andrei Warkentin <andrey.warkentin@gmail.com>

MdePkg/Library/BaseLib/BaseLib.inf

@@ -505,6 +505,7 @@
    PPC64/SwitchStack.S
    PPC64/CpuBreakpoint.S
    PPC64/SetJump.S
+   PPC64/CpuPause.S
    Unaligned.c
    Math64.c
 

MdePkg/Library/BaseLib/PPC64/CpuPause.S

@@ -0,0 +1,37 @@
+//
+// Copyright (c) 2015, Andrei Warkentin <andrey.warkentin@gmail.com>
+//
+// 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.
+//
+
+#define SMT_VERY_LOW or 31, 31, 31
+#define SMT_MEDIUM   or 2, 2, 2
+
+/**
+//
+//  Requests CPU to pause for a short period of time.
+//
+//  Requests CPU to pause for a short period of time. Typically used in MP
+//  systems to prevent memory starvation while waiting for a spin lock.
+//
+VOID
+EFIAPI
+CpuPause (
+  VOID
+  )
+**/
+ASM_FUNC(CpuPause)
+        SMT_VERY_LOW
+        nop
+        nop
+        nop
+        nop
+        nop
+        SMT_MEDIUM
+        blr

PPC64Pkg/Drivers/TimerDxe/TimerDxe.c

@@ -11,21 +11,28 @@
 //
 
 #include <PiDxe.h>
-
 #include <Library/BaseLib.h>
 #include <Library/DebugLib.h>
 #include <Library/BaseMemoryLib.h>
 #include <Library/UefiBootServicesTableLib.h>
+#include <Chipset/PPC64Intrinsics.h>
 #include <Library/UefiLib.h>
 #include <Library/PcdLib.h>
 #include <Protocol/Timer.h>
+#include <Protocol/Cpu.h>
+#include <Pcr.h>
+
+// CPU architecture protocol, because timer does not go through XICS.
+EFI_CPU_ARCH_PROTOCOL *gCpu;
 
 // The notification function to call on every timer interrupt.
-EFI_TIMER_NOTIFY      mTimerNotifyFunction     = (EFI_TIMER_NOTIFY)NULL;
-EFI_EVENT             EfiExitBootServicesEvent = (EFI_EVENT)NULL;
+EFI_TIMER_NOTIFY      mTimerNotifyFunction     = (EFI_TIMER_NOTIFY) NULL;
+EFI_EVENT             EfiExitBootServicesEvent = (EFI_EVENT) NULL;
 
 // The current period of the timer interrupt
 UINT64 mTimerPeriod = 0;
+// The latest Timer Tick calculated for mTimerPeriod
+UINT64 mTimerTicks = 0;
 
 /**
   This function registers the handler NotifyFunction so it is called every time
@@ -85,6 +92,7 @@ ExitBootServicesEvent (
   IN VOID       *Context
   )
 {
+  hdec_disable ();
 }
 
 /**
@@ -122,10 +130,37 @@ TimerDriverSetTimerPeriod (
   IN UINT64                   TimerPeriod
   )
 {
+  UINT64  TimerTicks;
+  EFI_TPL OriginalTPL;
+
+  // Always disable the timer
+  hdec_disable ();
+
+  if (TimerPeriod != 0) {
+    TimerTicks = MultU64x32 (TimerPeriod, PcrGet()->TBFreq);
+    TimerTicks = DivU64x32 (TimerTicks, 10000000U) - 1;
+
+    // Raise TPL to update the mTimerTicks and mTimerPeriod to ensure these values
+    // are coherent in the interrupt handler
+    OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
 
-  // Save the new timer period
-  mTimerPeriod   = TimerPeriod;
-  // Reset the elapsed period
+    mTimerTicks    = TimerTicks;
+    mTimerPeriod   = TimerPeriod;
+
+    gBS->RestoreTPL (OriginalTPL);
+
+    //
+    // This is unlikely, so no need to implement it now.
+    //
+    ASSERT(mTimerTicks <= DEC_MAX_USABLE);
+    SET_HDEC(mTimerTicks);
+
+    // Enable the timer
+    hdec_enable ();
+  } else {
+    // Save the new timer period
+    mTimerPeriod = TimerPeriod;
+  }
 
   return EFI_SUCCESS;
 }
@@ -225,6 +260,47 @@ EFI_TIMER_ARCH_PROTOCOL   gTimer = {
   TimerDriverGenerateSoftInterrupt
 };
 
+/**
+
+  C Interrupt Handler called in the interrupt context on timer event
+
+
+  @param InterruptType  Local decrementer exception vector.
+
+  @param SystemContext  Pointer to system register context. Mostly used by debuggers and will
+                        update the system context after the return from the interrupt if
+                        modified. Don't change these values unless you know what you are doing
+
+**/
+VOID
+EFIAPI
+TimerInterruptHandler (
+  IN  EFI_EXCEPTION_TYPE InterruptType,
+  IN  EFI_SYSTEM_CONTEXT SystemContext
+  )
+{
+  EFI_TPL OriginalTPL;
+
+  //
+  // DXE core uses this callback for the EFI timer tick. The DXE core uses locks
+  // that raise to TPL_HIGH and then restore back to current level. Thus we need
+  // to make sure TPL level is set to TPL_HIGH while we are handling the timer tick.
+  //
+  OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
+
+  if (mTimerNotifyFunction) {
+    mTimerNotifyFunction (mTimerPeriod);
+  }
+
+  SET_HDEC(mTimerTicks);
+
+  //
+  // Reload the Timer
+  //
+
+  gBS->RestoreTPL (OriginalTPL);
+}
+
 
 /**
   Initialize the state information for the Timer Architectural Protocol and
@@ -249,17 +325,32 @@ TimerInitialize (
   EFI_HANDLE  Handle = NULL;
   EFI_STATUS  Status;
 
+  // Find the CPU architecture protocol.  ASSERT if not found.
+  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL,
+                                (VOID **)&gCpu);
+  ASSERT_EFI_ERROR (Status);
+
+  // Disable the timer
+  hdec_disable ();
+
+  // Install the handler.
+  Status = gCpu->RegisterInterruptHandler (gCpu, EXCEPT_PPC64_HDEC,
+                                           TimerInterruptHandler);
+  ASSERT_EFI_ERROR (Status);
+
   // Set up default timer
   Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32(PcdTimerPeriod)); // TIMER_DEFAULT_PERIOD
   ASSERT_EFI_ERROR (Status);
 
   // Install the Timer Architectural Protocol onto a new handle
-  Status = gBS->InstallMultipleProtocolInterfaces(
+  Status = gBS->InstallMultipleProtocolInterfaces (
                   &Handle,
-                  &gEfiTimerArchProtocolGuid,      &gTimer,
+                  &gEfiTimerArchProtocolGuid, &gTimer,
                   NULL
                   );
-  ASSERT_EFI_ERROR(Status);
+  ASSERT_EFI_ERROR (Status);
+
+  hdec_enable ();
 
   // Register for an ExitBootServicesEvent
   Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_NOTIFY, ExitBootServicesEvent, NULL, &EfiExitBootServicesEvent);

PPC64Pkg/Include/Chipset/PPC64.h

@@ -114,6 +114,6 @@
  * to the maximum value that doesn't cause an interrupt, which is
  * the value with MSB bit set to 0.
  */
-#define DEC_DISABLE_FOR_A_WHILE 0x7fffffff
+#define DEC_MAX_USABLE 0x7fffffff
 
 #endif // __PPC64_H__

PPC64Pkg/Include/Chipset/PPC64Intrinsics.h

@@ -53,6 +53,14 @@ REG_READ_FN(DSISR)
 #undef _S
 #undef __S
 
+static inline UINT64
+mftb(void)
+{
+  UINT64 tb;
+  asm volatile("mftb %0" : "=r"(tb) : : "memory");
+  return tb;
+}
+
 static inline UINT64
 mfmsr(void)
 {
@@ -70,8 +78,27 @@ mtmsr(UINT64 val)
 }
 
 static inline void  __attribute__((always_inline))
-mtmsrd(UINT64 val, const int l)
+mtmsrd(UINT64 val, const UINTN l)
 {
   asm volatile("mtmsrd %0,%1" : : "r"(val), "i"(l) : "memory");
 }
+
+static inline VOID
+smt_medium(VOID)
+{
+  asm volatile("or 2, 2, 2");
+}
+
+static inline VOID
+hdec_enable(VOID)
+{
+  SET_LPCR(GET_LPCR() | LPCR_HDICE);
+}
+
+static inline VOID
+hdec_disable(VOID)
+{
+  SET_LPCR(GET_LPCR() & ~LPCR_HDICE);
+}
+
 #endif // __PPC64_INTRINSICSH__

PPC64Pkg/Ipl/Ipl.c

@@ -22,6 +22,7 @@
 #include <Guid/LzmaDecompress.h>
 #include <Guid/FdtHob.h>
 #include <libfdt.h>
+#include <Chipset/PPC64Intrinsics.h>
 #include <Endian.h>
 #include <Pcr.h>
 #include "LzmaDecompress.h"
@@ -58,9 +59,17 @@ Log (
 	SerialPortWrite ((UINT8 *) Buffer, Count);
 }
 
+VOID
+CpuInit (
+	VOID
+	)
+{
+  smt_medium ();
+  hdec_disable ();
+}
 
-UINT64
-InitializeSystemMemory (
+VOID
+ParseFDT (
 	IN VOID *DeviceTreeBase
 	)
 {
@@ -70,6 +79,7 @@ InitializeSystemMemory (
 	CONST CHAR8  *Type;
 	INT32        Len;
 	CONST UINT64 *RegProp;
+	CONST UINT32 *RegProp32;
 
 	NewBase = 0;
 	NewSize = 0;
@@ -109,10 +119,13 @@ InitializeSystemMemory (
 					__FUNCTION__));
 			}
 			break;
+		} else if (Type && AsciiStrnCmp (Type, "cpu", Len) == 0) {
+			RegProp32 = fdt_getprop (DeviceTreeBase, Node,
+						 "timebase-frequency", NULL);
+			PcrGet()->TBFreq = fdt32_to_cpu (ReadUnaligned32 (RegProp32));
+			DEBUG ((EFI_D_INFO, "TB %lu Hz\n", PcrGet()->TBFreq));
 		}
 	}
-
-	return NewSize;
 }
 
 
@@ -232,7 +245,9 @@ CEntryPoint (
 	Log (L"PPC64LE UEFI firmware (version %s built at %a on %a)\n",
 	    (CHAR16*) PcdGetPtr (PcdFirmwareVersionString), __TIME__, __DATE__);
 
-	InitializeSystemMemory ((VOID *) FDTBase);
+	CpuInit ();
+
+	ParseFDT ((VOID *) FDTBase);
 	DEBUG ((EFI_D_INFO, "System RAM @ 0x%lx - 0x%lx\n",
 		PcdGet64 (PcdSystemMemoryBase),
 		PcdGet64 (PcdSystemMemoryBase) +