* [edk2-devel] [PATCH] ArmPlatformPkg/PL031RealTimeClockLib: remove superfluous instance init steps
@ 2023-10-20 12:17 Laszlo Ersek
2023-10-20 12:27 ` Ard Biesheuvel
0 siblings, 1 reply; 3+ messages in thread
From: Laszlo Ersek @ 2023-10-20 12:17 UTC (permalink / raw)
To: devel; +Cc: Ard Biesheuvel, Leif Lindholm
RealTimeClockLib instances are consumed by edk2's
EmbeddedPkg/RealTimeClockRuntimeDxe driver. In its entry point function
InitializeRealTimeClock(), the driver:
(1) calls LibRtcInitialize(),
(2) sets the GetTime(), SetTime(), GetWakeupTime() and SetWakeupTime()
runtime services to its own similarly-named functions -- where those
functions wrap the corresponding RealTimeClockLib APIs,
(3) installs EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL with a NULL protocol
interface.
Steps (2) and (3) conform to PI v1.8 sections II-9.7.2.4 through
II-9.7.2.7.
However, this means that LibRtcInitialize() (of any RealTimeClockLib
instance) should not itself (a) set the GetTime(), SetTime(),
GetWakeupTime() and SetWakeupTime() runtime services, nor (b) install
EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL. The runtime service pointers will be
overwritten in step (2) anyway, and step (3) will uselessly install a
second (NULL-interface) EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL instance in the
protocol database. (The protocol only serves to notify the DXE Foundation
about said runtime services being available.)
Clean up ArmPlatformPkg/PL031RealTimeClockLib accordingly (it only has
code that's redundant for step (3); it does not try to set "gRT" fields).
(Note that the lib instance INF file already does not list
gEfiRealTimeClockArchProtocolGuid.)
Tested with ArmVirtQemu.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Leif Lindholm <quic_llindhol@quicinc.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4565
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
Notes:
context:-W
ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c | 13 -------------
1 file changed, 13 deletions(-)
diff --git a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
index 9e852696d2fd..1896f9d16d3b 100644
--- a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
+++ b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
@@ -1,34 +1,32 @@
/** @file
Implement EFI RealTimeClock runtime services via RTC Lib.
Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
Copyright (c) 2011 - 2020, Arm Limited. All rights reserved.<BR>
Copyright (c) 2019, Linaro Ltd. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <PiDxe.h>
#include <Guid/EventGroup.h>
#include <Guid/GlobalVariable.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/DxeServicesTableLib.h>
#include <Library/IoLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/PcdLib.h>
#include <Library/RealTimeClockLib.h>
#include <Library/TimeBaseLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiLib.h>
#include <Library/UefiRuntimeServicesTableLib.h>
#include <Library/UefiRuntimeLib.h>
-#include <Protocol/RealTimeClock.h>
-
#include "PL031RealTimeClock.h"
STATIC BOOLEAN mPL031Initialized = FALSE;
@@ -307,52 +305,41 @@ EFIAPI
LibRtcInitialize (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
- EFI_HANDLE Handle;
// Initialize RTC Base Address
mPL031RtcBase = PcdGet32 (PcdPL031RtcBase);
// Declare the controller as EFI_MEMORY_RUNTIME
Status = gDS->AddMemorySpace (
EfiGcdMemoryTypeMemoryMappedIo,
mPL031RtcBase,
SIZE_4KB,
EFI_MEMORY_UC | EFI_MEMORY_RUNTIME
);
if (EFI_ERROR (Status)) {
return Status;
}
Status = gDS->SetMemorySpaceAttributes (mPL031RtcBase, SIZE_4KB, EFI_MEMORY_UC | EFI_MEMORY_RUNTIME);
if (EFI_ERROR (Status)) {
return Status;
}
- // Install the protocol
- Handle = NULL;
- Status = gBS->InstallMultipleProtocolInterfaces (
- &Handle,
- &gEfiRealTimeClockArchProtocolGuid,
- NULL,
- NULL
- );
- ASSERT_EFI_ERROR (Status);
-
//
// Register for the virtual address change event
//
Status = gBS->CreateEventEx (
EVT_NOTIFY_SIGNAL,
TPL_NOTIFY,
VirtualNotifyEvent,
NULL,
&gEfiEventVirtualAddressChangeGuid,
&mRtcVirtualAddrChangeEvent
);
ASSERT_EFI_ERROR (Status);
return Status;
}
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* Re: [edk2-devel] [PATCH] ArmPlatformPkg/PL031RealTimeClockLib: remove superfluous instance init steps
2023-10-20 12:17 [edk2-devel] [PATCH] ArmPlatformPkg/PL031RealTimeClockLib: remove superfluous instance init steps Laszlo Ersek
@ 2023-10-20 12:27 ` Ard Biesheuvel
2023-10-24 16:50 ` Laszlo Ersek
0 siblings, 1 reply; 3+ messages in thread
From: Ard Biesheuvel @ 2023-10-20 12:27 UTC (permalink / raw)
To: Laszlo Ersek; +Cc: devel, Ard Biesheuvel, Leif Lindholm
On Fri, 20 Oct 2023 at 14:17, Laszlo Ersek <lersek@redhat.com> wrote:
>
> RealTimeClockLib instances are consumed by edk2's
> EmbeddedPkg/RealTimeClockRuntimeDxe driver. In its entry point function
> InitializeRealTimeClock(), the driver:
>
> (1) calls LibRtcInitialize(),
>
> (2) sets the GetTime(), SetTime(), GetWakeupTime() and SetWakeupTime()
> runtime services to its own similarly-named functions -- where those
> functions wrap the corresponding RealTimeClockLib APIs,
>
> (3) installs EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL with a NULL protocol
> interface.
>
> Steps (2) and (3) conform to PI v1.8 sections II-9.7.2.4 through
> II-9.7.2.7.
>
> However, this means that LibRtcInitialize() (of any RealTimeClockLib
> instance) should not itself (a) set the GetTime(), SetTime(),
> GetWakeupTime() and SetWakeupTime() runtime services, nor (b) install
> EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL. The runtime service pointers will be
> overwritten in step (2) anyway, and step (3) will uselessly install a
> second (NULL-interface) EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL instance in the
> protocol database. (The protocol only serves to notify the DXE Foundation
> about said runtime services being available.)
>
> Clean up ArmPlatformPkg/PL031RealTimeClockLib accordingly (it only has
> code that's redundant for step (3); it does not try to set "gRT" fields).
>
> (Note that the lib instance INF file already does not list
> gEfiRealTimeClockArchProtocolGuid.)
>
> Tested with ArmVirtQemu.
>
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Leif Lindholm <quic_llindhol@quicinc.com>
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4565
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> ---
>
> Notes:
> context:-W
>
> ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c | 13 -------------
> 1 file changed, 13 deletions(-)
>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Thanks a lot for cleaning up this mess.
> diff --git a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
> index 9e852696d2fd..1896f9d16d3b 100644
> --- a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
> +++ b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
> @@ -1,34 +1,32 @@
> /** @file
> Implement EFI RealTimeClock runtime services via RTC Lib.
>
> Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
> Copyright (c) 2011 - 2020, Arm Limited. All rights reserved.<BR>
> Copyright (c) 2019, Linaro Ltd. All rights reserved.<BR>
>
> SPDX-License-Identifier: BSD-2-Clause-Patent
>
> **/
>
> #include <PiDxe.h>
>
> #include <Guid/EventGroup.h>
> #include <Guid/GlobalVariable.h>
>
> #include <Library/BaseLib.h>
> #include <Library/DebugLib.h>
> #include <Library/DxeServicesTableLib.h>
> #include <Library/IoLib.h>
> #include <Library/MemoryAllocationLib.h>
> #include <Library/PcdLib.h>
> #include <Library/RealTimeClockLib.h>
> #include <Library/TimeBaseLib.h>
> #include <Library/UefiBootServicesTableLib.h>
> #include <Library/UefiLib.h>
> #include <Library/UefiRuntimeServicesTableLib.h>
> #include <Library/UefiRuntimeLib.h>
>
> -#include <Protocol/RealTimeClock.h>
> -
> #include "PL031RealTimeClock.h"
>
> STATIC BOOLEAN mPL031Initialized = FALSE;
> @@ -307,52 +305,41 @@ EFIAPI
> LibRtcInitialize (
> IN EFI_HANDLE ImageHandle,
> IN EFI_SYSTEM_TABLE *SystemTable
> )
> {
> EFI_STATUS Status;
> - EFI_HANDLE Handle;
>
> // Initialize RTC Base Address
> mPL031RtcBase = PcdGet32 (PcdPL031RtcBase);
>
> // Declare the controller as EFI_MEMORY_RUNTIME
> Status = gDS->AddMemorySpace (
> EfiGcdMemoryTypeMemoryMappedIo,
> mPL031RtcBase,
> SIZE_4KB,
> EFI_MEMORY_UC | EFI_MEMORY_RUNTIME
> );
> if (EFI_ERROR (Status)) {
> return Status;
> }
>
> Status = gDS->SetMemorySpaceAttributes (mPL031RtcBase, SIZE_4KB, EFI_MEMORY_UC | EFI_MEMORY_RUNTIME);
> if (EFI_ERROR (Status)) {
> return Status;
> }
>
> - // Install the protocol
> - Handle = NULL;
> - Status = gBS->InstallMultipleProtocolInterfaces (
> - &Handle,
> - &gEfiRealTimeClockArchProtocolGuid,
> - NULL,
> - NULL
> - );
> - ASSERT_EFI_ERROR (Status);
> -
> //
> // Register for the virtual address change event
> //
> Status = gBS->CreateEventEx (
> EVT_NOTIFY_SIGNAL,
> TPL_NOTIFY,
> VirtualNotifyEvent,
> NULL,
> &gEfiEventVirtualAddressChangeGuid,
> &mRtcVirtualAddrChangeEvent
> );
> ASSERT_EFI_ERROR (Status);
>
> return Status;
> }
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* Re: [edk2-devel] [PATCH] ArmPlatformPkg/PL031RealTimeClockLib: remove superfluous instance init steps
2023-10-20 12:27 ` Ard Biesheuvel
@ 2023-10-24 16:50 ` Laszlo Ersek
0 siblings, 0 replies; 3+ messages in thread
From: Laszlo Ersek @ 2023-10-24 16:50 UTC (permalink / raw)
To: devel, ardb; +Cc: Ard Biesheuvel, Leif Lindholm
On 10/20/23 14:27, Ard Biesheuvel wrote:
> On Fri, 20 Oct 2023 at 14:17, Laszlo Ersek <lersek@redhat.com> wrote:
>>
>> RealTimeClockLib instances are consumed by edk2's
>> EmbeddedPkg/RealTimeClockRuntimeDxe driver. In its entry point function
>> InitializeRealTimeClock(), the driver:
>>
>> (1) calls LibRtcInitialize(),
>>
>> (2) sets the GetTime(), SetTime(), GetWakeupTime() and SetWakeupTime()
>> runtime services to its own similarly-named functions -- where those
>> functions wrap the corresponding RealTimeClockLib APIs,
>>
>> (3) installs EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL with a NULL protocol
>> interface.
>>
>> Steps (2) and (3) conform to PI v1.8 sections II-9.7.2.4 through
>> II-9.7.2.7.
>>
>> However, this means that LibRtcInitialize() (of any RealTimeClockLib
>> instance) should not itself (a) set the GetTime(), SetTime(),
>> GetWakeupTime() and SetWakeupTime() runtime services, nor (b) install
>> EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL. The runtime service pointers will be
>> overwritten in step (2) anyway, and step (3) will uselessly install a
>> second (NULL-interface) EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL instance in the
>> protocol database. (The protocol only serves to notify the DXE Foundation
>> about said runtime services being available.)
>>
>> Clean up ArmPlatformPkg/PL031RealTimeClockLib accordingly (it only has
>> code that's redundant for step (3); it does not try to set "gRT" fields).
>>
>> (Note that the lib instance INF file already does not list
>> gEfiRealTimeClockArchProtocolGuid.)
>>
>> Tested with ArmVirtQemu.
>>
>> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
>> Cc: Leif Lindholm <quic_llindhol@quicinc.com>
>> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4565
>> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
>> ---
>>
>> Notes:
>> context:-W
>>
>> ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c | 13 -------------
>> 1 file changed, 13 deletions(-)
>>
>
> Acked-by: Ard Biesheuvel <ardb@kernel.org>
>
> Thanks a lot for cleaning up this mess.
Merged via <https://github.com/tianocore/edk2/pull/4950> as commit
d85bf54b7f46.
Thanks!
Laszlo
>
>
>> diff --git a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
>> index 9e852696d2fd..1896f9d16d3b 100644
>> --- a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
>> +++ b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
>> @@ -1,34 +1,32 @@
>> /** @file
>> Implement EFI RealTimeClock runtime services via RTC Lib.
>>
>> Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
>> Copyright (c) 2011 - 2020, Arm Limited. All rights reserved.<BR>
>> Copyright (c) 2019, Linaro Ltd. All rights reserved.<BR>
>>
>> SPDX-License-Identifier: BSD-2-Clause-Patent
>>
>> **/
>>
>> #include <PiDxe.h>
>>
>> #include <Guid/EventGroup.h>
>> #include <Guid/GlobalVariable.h>
>>
>> #include <Library/BaseLib.h>
>> #include <Library/DebugLib.h>
>> #include <Library/DxeServicesTableLib.h>
>> #include <Library/IoLib.h>
>> #include <Library/MemoryAllocationLib.h>
>> #include <Library/PcdLib.h>
>> #include <Library/RealTimeClockLib.h>
>> #include <Library/TimeBaseLib.h>
>> #include <Library/UefiBootServicesTableLib.h>
>> #include <Library/UefiLib.h>
>> #include <Library/UefiRuntimeServicesTableLib.h>
>> #include <Library/UefiRuntimeLib.h>
>>
>> -#include <Protocol/RealTimeClock.h>
>> -
>> #include "PL031RealTimeClock.h"
>>
>> STATIC BOOLEAN mPL031Initialized = FALSE;
>> @@ -307,52 +305,41 @@ EFIAPI
>> LibRtcInitialize (
>> IN EFI_HANDLE ImageHandle,
>> IN EFI_SYSTEM_TABLE *SystemTable
>> )
>> {
>> EFI_STATUS Status;
>> - EFI_HANDLE Handle;
>>
>> // Initialize RTC Base Address
>> mPL031RtcBase = PcdGet32 (PcdPL031RtcBase);
>>
>> // Declare the controller as EFI_MEMORY_RUNTIME
>> Status = gDS->AddMemorySpace (
>> EfiGcdMemoryTypeMemoryMappedIo,
>> mPL031RtcBase,
>> SIZE_4KB,
>> EFI_MEMORY_UC | EFI_MEMORY_RUNTIME
>> );
>> if (EFI_ERROR (Status)) {
>> return Status;
>> }
>>
>> Status = gDS->SetMemorySpaceAttributes (mPL031RtcBase, SIZE_4KB, EFI_MEMORY_UC | EFI_MEMORY_RUNTIME);
>> if (EFI_ERROR (Status)) {
>> return Status;
>> }
>>
>> - // Install the protocol
>> - Handle = NULL;
>> - Status = gBS->InstallMultipleProtocolInterfaces (
>> - &Handle,
>> - &gEfiRealTimeClockArchProtocolGuid,
>> - NULL,
>> - NULL
>> - );
>> - ASSERT_EFI_ERROR (Status);
>> -
>> //
>> // Register for the virtual address change event
>> //
>> Status = gBS->CreateEventEx (
>> EVT_NOTIFY_SIGNAL,
>> TPL_NOTIFY,
>> VirtualNotifyEvent,
>> NULL,
>> &gEfiEventVirtualAddressChangeGuid,
>> &mRtcVirtualAddrChangeEvent
>> );
>> ASSERT_EFI_ERROR (Status);
>>
>> return Status;
>> }
>
>
>
>
>
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2023-10-20 12:17 [edk2-devel] [PATCH] ArmPlatformPkg/PL031RealTimeClockLib: remove superfluous instance init steps Laszlo Ersek
2023-10-20 12:27 ` Ard Biesheuvel
2023-10-24 16:50 ` Laszlo Ersek
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