Is it more accurate
if (Multiplicand >= DivU64x64Remainder (MAX_UINT64, Multiplier, NULL)) {
->
if (Multiplicand > DivU64x64Remainder (MAX_UINT64, Multiplier, NULL)) {Thanks, Star -----Original Message----- From: Ni, Ruiyu Sent: Thursday, April 26, 2018 10:24 AM To: [email protected] Cc: Zeng, Star <[email protected]>; Chiu, Chasel <[email protected]> Subject: [PATCH] MdeModulePkg/PciHostBridge: Count the (mm)io overhead when polling RootBridgeIo.PollMem()/PollIo() originally don't count the IO/MMIO access overhead when delaying. The patch changes the implementation to count the access overhead so that the actually delay equals to user required delay. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni <[email protected]> Cc: Star Zeng <[email protected]> Cc: Chasel Chiu <[email protected]> --- .../Bus/Pci/PciHostBridgeDxe/PciHostBridgeDxe.inf | 3 +- .../Bus/Pci/PciHostBridgeDxe/PciRootBridge.h | 3 +- .../Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c | 151 +++++++++++++++------ 3 files changed, 115 insertions(+), 42 deletions(-) diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridgeDxe.inf b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridgeDxe.inf index 42bd8a23cb..2e56959a8f 100644 --- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridgeDxe.inf +++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridgeDxe.inf @@ -1,7 +1,7 @@ ## @file # Generic PCI Host Bridge driver. # -# Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR> +# Copyright (c) 2009 - 2018, Intel Corporation. All rights +reserved.<BR> # # This program and the accompanying materials # are licensed and made available under the terms and conditions of the BSD License @@ -43,6 +43,7 @@ [LibraryClasses] PciSegmentLib UefiLib PciHostBridgeLib + TimerLib [Protocols] gEfiMetronomeArchProtocolGuid ## CONSUMES diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridge.h b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridge.h index d3dfb57fc6..e2f651aee4 100644 --- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridge.h +++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridge.h @@ -2,7 +2,7 @@ The PCI Root Bridge header file. -Copyright (c) 1999 - 2017, Intel Corporation. All rights reserved.<BR> +Copyright (c) 1999 - 2018, Intel Corporation. All rights reserved.<BR> 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 @@ -36,6 +36,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. #include <Library/BaseLib.h> #include <Library/PciSegmentLib.h> #include <Library/UefiLib.h> +#include <Library/TimerLib.h> #include "PciHostResource.h" diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c index 5764c2f49f..459e962fe7 100644 --- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c +++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c @@ -2,7 +2,7 @@ PCI Root Bridge Io Protocol code. -Copyright (c) 1999 - 2017, Intel Corporation. All rights reserved.<BR> +Copyright (c) 1999 - 2018, Intel Corporation. All rights reserved.<BR> 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 @@ -468,6 +468,85 @@ RootBridgeIoGetMemTranslationByAddress ( return EFI_SUCCESS; } +/** + Return the result of (Multiplicand * Multiplier / Divisor). + + @param Multiplicand A 64-bit unsigned value. + @param Multiplier A 64-bit unsigned value. + @param Divisor A 32-bit unsigned value. + @param Remainder A pointer to a 32-bit unsigned value. This parameter is + optional and may be NULL. + + @return Multiplicand * Multiplier / Divisor. +**/ +UINT64 +MultThenDivU64x64x32 ( + IN UINT64 Multiplicand, + IN UINT64 Multiplier, + IN UINT32 Divisor, + OUT UINT32 *Remainder OPTIONAL + ) +{ + UINT64 Uint64; + UINT32 LocalRemainder; + UINT32 Uint32; + if (Multiplicand >= DivU64x64Remainder (MAX_UINT64, Multiplier, NULL)) { + // + // Make sure Multiplicand is the bigger one. + // + if (Multiplicand < Multiplier) { + Uint64 = Multiplicand; + Multiplicand = Multiplier; + Multiplier = Uint64; + } + // + // Because Multiplicand * Multiplier overflows, + // Multiplicand * Multiplier / Divisor + // = (2 * Multiplicand' + 1) * Multiplier / Divisor + // = 2 * (Multiplicand' * Multiplier / Divisor) + Multiplier / Divisor + // + Uint64 = MultThenDivU64x64x32 (RShiftU64 (Multiplicand, 1), Multiplier, Divisor, &LocalRemainder); + Uint64 = LShiftU64 (Uint64, 1); + Uint32 = 0; + if ((Multiplicand & 0x1) == 1) { + Uint64 += DivU64x32Remainder (Multiplier, Divisor, &Uint32); + } + return Uint64 + DivU64x32Remainder (Uint32 + LShiftU64 +(LocalRemainder, 1), Divisor, Remainder); + } else { + return DivU64x32Remainder (MultU64x64 (Multiplicand, Multiplier), +Divisor, Remainder); + } +} + +/** + Return the elapsed tick count from CurrentTick. + + @param CurrentTick On input, the previous tick count. + On output, the current tick count. + @param StartTick The value the performance counter starts with when it + rolls over. + @param EndTick The value that the performance counter ends with before + it rolls over. + + @return The elapsed tick count from CurrentTick. +**/ +UINT64 +GetElapsedTick ( + UINT64 *CurrentTick, + UINT64 StartTick, + UINT64 EndTick + ) +{ + UINT64 PreviousTick; + + PreviousTick = *CurrentTick; + *CurrentTick = GetPerformanceCounter(); + if (StartTick < EndTick) { + return *CurrentTick - PreviousTick; + } else { + return PreviousTick - *CurrentTick; + } +} + /** Polls an address in memory mapped I/O space until an exit condition is met, or a timeout occurs. @@ -517,6 +596,11 @@ RootBridgeIoPollMem ( EFI_STATUS Status; UINT64 NumberOfTicks; UINT32 Remainder; + UINT64 StartTick; + UINT64 EndTick; + UINT64 CurrentTick; + UINT64 ElapsedTick; + UINT64 Frequency; if (Result == NULL) { return EFI_INVALID_PARAMETER; @@ -542,28 +626,18 @@ RootBridgeIoPollMem ( return EFI_SUCCESS; } else { - - // - // Determine the proper # of metronome ticks to wait for polling the - // location. The nuber of ticks is Roundup (Delay / - // mMetronome->TickPeriod)+1 - // The "+1" to account for the possibility of the first tick being short - // because we started in the middle of a tick. // - // BugBug: overriding mMetronome->TickPeriod with UINT32 until Metronome - // protocol definition is updated. + // NumberOfTicks = Frenquency * Delay / EFI_TIMER_PERIOD_SECONDS(1) // - NumberOfTicks = DivU64x32Remainder (Delay, (UINT32) mMetronome->TickPeriod, - &Remainder); - if (Remainder != 0) { - NumberOfTicks += 1; + Frequency = GetPerformanceCounterProperties (&StartTick, &EndTick); + NumberOfTicks = MultThenDivU64x64x32 (Frequency, Delay, (UINT32)EFI_TIMER_PERIOD_SECONDS(1), &Remainder); + if (Remainder >= (UINTN)EFI_TIMER_PERIOD_SECONDS(1) / 2) { + NumberOfTicks++; } - NumberOfTicks += 1; - - while (NumberOfTicks != 0) { - - mMetronome->WaitForTick (mMetronome, 1); - + for ( ElapsedTick = 0, CurrentTick = GetPerformanceCounter() + ; ElapsedTick <= NumberOfTicks + ; ElapsedTick += GetElapsedTick (&CurrentTick, StartTick, EndTick) + ) { Status = This->Mem.Read (This, Width, Address, 1, Result); if (EFI_ERROR (Status)) { return Status; @@ -572,8 +646,6 @@ RootBridgeIoPollMem ( if ((*Result & Mask) == Value) { return EFI_SUCCESS; } - - NumberOfTicks -= 1; } } return EFI_TIMEOUT; @@ -626,6 +698,11 @@ RootBridgeIoPollIo ( EFI_STATUS Status; UINT64 NumberOfTicks; UINT32 Remainder; + UINT64 StartTick; + UINT64 EndTick; + UINT64 CurrentTick; + UINT64 ElapsedTick; + UINT64 Frequency; // // No matter what, always do a single poll. @@ -651,25 +728,18 @@ RootBridgeIoPollIo ( return EFI_SUCCESS; } else { - // - // Determine the proper # of metronome ticks to wait for polling the - // location. The number of ticks is Roundup (Delay / - // mMetronome->TickPeriod)+1 - // The "+1" to account for the possibility of the first tick being short - // because we started in the middle of a tick. + // NumberOfTicks = Frenquency * Delay / EFI_TIMER_PERIOD_SECONDS(1) // - NumberOfTicks = DivU64x32Remainder (Delay, (UINT32)mMetronome->TickPeriod, - &Remainder); - if (Remainder != 0) { - NumberOfTicks += 1; + Frequency = GetPerformanceCounterProperties (&StartTick, &EndTick); + NumberOfTicks = MultThenDivU64x64x32 (Frequency, Delay, (UINT32)EFI_TIMER_PERIOD_SECONDS(1), &Remainder); + if (Remainder >= (UINTN)EFI_TIMER_PERIOD_SECONDS(1) / 2) { + NumberOfTicks++; } - NumberOfTicks += 1; - - while (NumberOfTicks != 0) { - - mMetronome->WaitForTick (mMetronome, 1); - + for ( ElapsedTick = 0, CurrentTick = GetPerformanceCounter() + ; ElapsedTick <= NumberOfTicks + ; ElapsedTick += GetElapsedTick (&CurrentTick, StartTick, EndTick) + ) { Status = This->Io.Read (This, Width, Address, 1, Result); if (EFI_ERROR (Status)) { return Status; @@ -678,13 +748,14 @@ RootBridgeIoPollIo ( if ((*Result & Mask) == Value) { return EFI_SUCCESS; } - - NumberOfTicks -= 1; } } return EFI_TIMEOUT; } + + + /** Enables a PCI driver to access PCI controller registers in the PCI root bridge memory space. -- 2.16.1.windows.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
