update GetPerformanceCounterProperties() declare

[mirror_edk2.git] / MdePkg / Library / BaseTimerLibLocalApic / x86TimerLib.c

diff --git a/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c b/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c
index 6f78e4e4fd1bb151d18b91dc68690079e4651254..09b614119da174b1d272aa25bfc414935249eb13 100644 (file)
--- a/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c
+++ b/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c
@@ -18,25 +18,114 @@
 \r
 **/\r
 \r
-static\r
+//\r
+// The following 2 arrays are used in calculating the frequency of local APIC\r
+// timer. Refer to IA-32 developers' manual for more details.\r
+//\r
+\r
+GLOBAL_REMOVE_IF_UNREFERENCED\r
+CONST UINT32                          mTimerLibLocalApicFrequencies[] = {\r
+  100000000,\r
+  133000000,\r
+  200000000,\r
+  166000000\r
+};\r
+\r
+GLOBAL_REMOVE_IF_UNREFERENCED\r
+CONST UINT8                           mTimerLibLocalApicDivisor[] = {\r
+  0x02, 0x04, 0x08, 0x10,\r
+  0x02, 0x04, 0x08, 0x10,\r
+  0x20, 0x40, 0x80, 0x01,\r
+  0x20, 0x40, 0x80, 0x01\r
+};\r
+\r
+/**\r
+  Internal function to retrieve the base address of local APIC.\r
+\r
+  Internal function to retrieve the base address of local APIC.\r
+\r
+  @return The base address of local APIC\r
+\r
+**/\r
+STATIC\r
 UINTN\r
-EFIAPI\r
-DelayWorker (\r
-  IN      UINT64                    NDelay\r
+InternalX86GetApicBase (\r
+  VOID\r
   )\r
 {\r
-  UINTN                             Ticks;\r
-\r
-  Ticks = (UINTN)GetPerformanceCounter ();\r
-  Ticks -= (UINTN)DivU64x32 (\r
-                    MultU64x64 (\r
-                      GetPerformanceCounterProperties (NULL, NULL),\r
-                      NDelay\r
-                      ),\r
-                    1000000000u\r
-                    );\r
-  while (Ticks >= GetPerformanceCounter ());\r
-  return Ticks;\r
+  return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;\r
+}\r
+\r
+/**\r
+  Internal function to return the frequency of the local APIC timer.\r
+\r
+  Internal function to return the frequency of the local APIC timer.\r
+\r
+  @param  ApicBase  The base address of memory mapped registers of local APIC.\r
+\r
+  @return The frequency of the timer in Hz.\r
+\r
+**/\r
+STATIC\r
+UINT32\r
+InternalX86GetTimerFrequency (\r
+  IN      UINTN                     ApicBase\r
+  )\r
+{\r
+  return\r
+    mTimerLibLocalApicFrequencies[AsmMsrBitFieldRead32 (44, 16, 18)] /\r
+    mTimerLibLocalApicDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];\r
+}\r
+\r
+/**\r
+  Internal function to read the current tick counter of local APIC.\r
+\r
+  Internal function to read the current tick counter of local APIC.\r
+\r
+  @param  ApicBase  The base address of memory mapped registers of local APIC.\r
+\r
+  @return The tick counter read.\r
+\r
+**/\r
+STATIC\r
+INT32\r
+InternalX86GetTimerTick (\r
+  IN      UINTN                     ApicBase\r
+  )\r
+{\r
+  return MmioRead32 (ApicBase + 0x390);\r
+}\r
+\r
+/**\r
+  Stalls the CPU for at least the given number of ticks.\r
+\r
+  Stalls the CPU for at least the given number of ticks. It's invoked by\r
+  MicroSecondDelay() and NanoSecondDelay().\r
+\r
+  @param  ApicBase  The base address of memory mapped registers of local APIC.\r
+  @param  Delay     A period of time to delay in ticks.\r
+\r
+**/\r
+STATIC\r
+VOID\r
+InternalX86Delay (\r
+  IN      UINTN                     ApicBase,\r
+  IN      UINT32                    Delay\r
+  )\r
+{\r
+  INT32                             Ticks;\r
+\r
+  //\r
+  // The target timer count is calculated here\r
+  //\r
+  Ticks = InternalX86GetTimerTick (ApicBase) - Delay;\r
+\r
+  //\r
+  // Wait until time out\r
+  // Delay > 2^31 could not be handled by this function\r
+  // Timer wrap-arounds are handled correctly by this function\r
+  //\r
+  while (InternalX86GetTimerTick (ApicBase) - Ticks >= 0);\r
 }\r
 \r
 /**\r
@@ -46,7 +135,7 @@ DelayWorker (
 \r
   @param  MicroSeconds  The minimum number of microseconds to delay.\r
 \r
-  @return Return value depends on implementation.\r
+  @return MicroSeconds\r
 \r
 **/\r
 UINTN\r
@@ -55,7 +144,20 @@ MicroSecondDelay (
   IN      UINTN                     MicroSeconds\r
   )\r
 {\r
-  return DelayWorker (MicroSeconds * 1000ull);\r
+  UINTN                             ApicBase;\r
+\r
+  ApicBase = InternalX86GetApicBase ();\r
+  InternalX86Delay (\r
+    ApicBase,\r
+    (UINT32)DivU64x32 (\r
+              MultU64x64 (\r
+                InternalX86GetTimerFrequency (ApicBase),\r
+                MicroSeconds\r
+                ),\r
+              1000000u\r
+              )\r
+    );\r
+  return MicroSeconds;\r
 }\r
 \r
 /**\r
@@ -65,7 +167,7 @@ MicroSecondDelay (
 \r
   @param  NanoSeconds The minimum number of nanoseconds to delay.\r
 \r
-  @return Return value depends on implementation.\r
+  @return NanoSeconds\r
 \r
 **/\r
 UINTN\r
@@ -74,17 +176,20 @@ NanoSecondDelay (
   IN      UINTN                     NanoSeconds\r
   )\r
 {\r
-  return DelayWorker (NanoSeconds);\r
-}\r
+  UINTN                             ApicBase;\r
 \r
-static\r
-UINTN\r
-EFIAPI\r
-GetApicBase (\r
-  VOID\r
-  )\r
-{\r
-  return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;\r
+  ApicBase = InternalX86GetApicBase ();\r
+  InternalX86Delay (\r
+    ApicBase,\r
+    (UINT32)DivU64x32 (\r
+              MultU64x64 (\r
+                InternalX86GetTimerFrequency (ApicBase),\r
+                NanoSeconds\r
+                ),\r
+              1000000000u\r
+              )\r
+    );\r
+  return NanoSeconds;\r
 }\r
 \r
 /**\r
@@ -105,7 +210,7 @@ GetPerformanceCounter (
   VOID\r
   )\r
 {\r
-  return MmioRead32 (GetApicBase () + 0x390);\r
+  return (UINT32)InternalX86GetTimerTick (InternalX86GetApicBase ());\r
 }\r
 \r
 /**\r
@@ -134,26 +239,13 @@ GetPerformanceCounter (
 UINT64\r
 EFIAPI\r
 GetPerformanceCounterProperties (\r
-  IN      UINT64                    *StartValue,\r
-  IN      UINT64                    *EndValue\r
+  OUT      UINT64                    *StartValue,  OPTIONAL\r
+  OUT      UINT64                    *EndValue     OPTIONAL\r
   )\r
 {\r
-  static const UINT32               mFrequencies[] = {\r
-    100000000,\r
-    133000000,\r
-    200000000,\r
-    166000000\r
-  };\r
-  static const UINT8                mDivisor[] = {\r
-    0x02, 0x04, 0x08, 0x10,\r
-    0x02, 0x04, 0x08, 0x10,\r
-    0x20, 0x40, 0x80, 0x01,\r
-    0x20, 0x40, 0x80, 0x01\r
-  };\r
-\r
   UINTN                             ApicBase;\r
 \r
-  ApicBase = GetApicBase ();\r
+  ApicBase = InternalX86GetApicBase ();\r
 \r
   if (StartValue != NULL) {\r
     *StartValue = MmioRead32 (ApicBase + 0x380);\r
@@ -163,6 +255,5 @@ GetPerformanceCounterProperties (
     *EndValue = 0;\r
   }\r
 \r
-  return mFrequencies[AsmMsrBitFieldRead32 (44, 16, 18)] /\r
-         mDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];\r
+  return InternalX86GetTimerFrequency (ApicBase);\r
 }\r