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ArmPkg/ArmSmcPsciResetSystemLib: add missing call to ExitBootServices()

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Our poor man's implementation of EnterS3WithImmediateWake () currently
sets a high TPL level to disable interrupts, and simply calls the
PEI entrypoint again after disabling the MMU.

Unfortunately, this is not sufficient: DMA capable devices such as
network controllers or USB controllers may still be enabled and
writing to memory, e.g., in response to incoming network packets.

So instead, do the full ExitBootServices() dance: allocate space and
get the memory map, call ExitBootServices(), and in case it fails, get
the memory map again and call ExitBootServices() again. This ensures
that all cleanup related to DMA capable devices is performed before
doing the warm reset.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
This commit is contained in:
Ard Biesheuvel
2018-11-19 17:53:13 -08:00
parent 8611bf99e0
commit 6556224e1f
6 changed files with 187 additions and 6 deletions
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57
ArmPkg/Library/ArmSmcPsciResetSystemLib/ArmSmcPsciResetSystemLib.c
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@@ -1,7 +1,7 @@
/** @file
ResetSystemLib implementation using PSCI calls
Copyright (c) 2017, Linaro Ltd. All rights reserved.<BR>
Copyright (c) 2017 - 2018, Linaro Ltd. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
@@ -81,6 +81,8 @@ ResetShutdown (
ArmCallSmc (&ArmSmcArgs);
}
VOID DisableMmuAndReenterPei (VOID);
/**
This function causes the system to enter S3 and then wake up immediately.
@@ -92,7 +94,12 @@ EnterS3WithImmediateWake (
VOID
)
{
VOID (*Reset)(VOID);
EFI_PHYSICAL_ADDRESS Alloc;
EFI_MEMORY_DESCRIPTOR *MemMap;
UINTN MemMapSize;
UINTN MapKey, DescriptorSize;
UINT32 DescriptorVersion;
EFI_STATUS Status;
if (FeaturePcdGet (PcdArmReenterPeiForCapsuleWarmReboot) &&
!EfiAtRuntime ()) {
@@ -101,11 +108,49 @@ EnterS3WithImmediateWake (
// immediate wake (which is used by capsule update) by disabling the MMU
// and interrupts, and jumping to the PEI entry point.
//
Reset = (VOID (*)(VOID))(UINTN)FixedPcdGet64 (PcdFvBaseAddress);
gBS->RaiseTPL (TPL_HIGH_LEVEL);
ArmDisableMmu ();
Reset ();
//
// Obtain the size of the memory map
//
MemMapSize = 0;
MemMap = NULL;
Status = gBS->GetMemoryMap (&MemMapSize, MemMap, &MapKey, &DescriptorSize,
&DescriptorVersion);
ASSERT (Status == EFI_BUFFER_TOO_SMALL);
//
// Add some slack to the allocation to cater for changes in the memory
// map if ExitBootServices () fails the first time around.
//
MemMapSize += SIZE_4KB;
Status = gBS->AllocatePages (AllocateAnyPages, EfiBootServicesData,
EFI_SIZE_TO_PAGES (MemMapSize), &Alloc);
ASSERT_EFI_ERROR (Status);
MemMap = (EFI_MEMORY_DESCRIPTOR *)(UINTN)Alloc;
Status = gBS->GetMemoryMap (&MemMapSize, MemMap, &MapKey, &DescriptorSize,
&DescriptorVersion);
ASSERT_EFI_ERROR (Status);
Status = gBS->ExitBootServices (gImageHandle, MapKey);
if (EFI_ERROR (Status)) {
//
// ExitBootServices () may fail the first time around if an event fired
// right after the call to GetMemoryMap() which allocated or freed memory.
// Since that first call to ExitBootServices () will disarm the timer,
// this is guaranteed not to happen again, so one additional attempt
// should suffice.
//
Status = gBS->GetMemoryMap (&MemMapSize, MemMap, &MapKey, &DescriptorSize,
&DescriptorVersion);
ASSERT_EFI_ERROR (Status);
Status = gBS->ExitBootServices (gImageHandle, MapKey);
ASSERT_EFI_ERROR (Status);
}
DisableMmuAndReenterPei ();
}
}