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| author | Cohen, Eugene <eugene@hp.com> | 2016-02-22 21:59:52 +0000 |
|---|---|---|
| committer | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2016-02-23 12:07:11 +0100 |
| commit | 5458faf845a8c0e2ee37499ad410bb8ba1d45b15 (patch) | |
| tree | cc276058d35411bfdf8337f5fe63fe541f9495e8 /MdePkg | |
| parent | e3aa7252ba58aefc0c8780dd20f169bcdbc9a3d3 (diff) | |
| download | edk2-5458faf845a8c0e2ee37499ad410bb8ba1d45b15.tar.gz edk2-5458faf845a8c0e2ee37499ad410bb8ba1d45b15.tar.bz2 edk2-5458faf845a8c0e2ee37499ad410bb8ba1d45b15.zip | |
MdePkg: BaseLib: fix AArch64 DAIF interrupt mask definitions
The AArch64 DAIF bits are different for reading (mrs) versus writing (msr).
The bitmask definitions assumed they were the same causing incorrect
results when trying to determine the current interrupt state through
GetInterruptState.
The logic for interpreting the DAIF read data using the csel instruction
was also incorrect and is fixed.
Replaced the magic numbers in DisableInterrupts.S and EnableInterrupts.S
with definitions for the DAIF write (daifset/daifclr) IRQ field.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Eugene Cohen <eugene@hp.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Diffstat (limited to 'MdePkg')
| -rw-r--r-- | MdePkg/Library/BaseLib/AArch64/DisableInterrupts.S | 4 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/AArch64/EnableInterrupts.S | 3 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/AArch64/GetInterruptsState.S | 8 |
3 files changed, 9 insertions, 6 deletions
diff --git a/MdePkg/Library/BaseLib/AArch64/DisableInterrupts.S b/MdePkg/Library/BaseLib/AArch64/DisableInterrupts.S index 943cc44c70..9985f1cf68 100644 --- a/MdePkg/Library/BaseLib/AArch64/DisableInterrupts.S +++ b/MdePkg/Library/BaseLib/AArch64/DisableInterrupts.S @@ -19,6 +19,8 @@ .p2align 2
GCC_ASM_EXPORT(DisableInterrupts)
+.set DAIF_WR_IRQ_BIT, (1 << 1)
+
#/**
# Disables CPU interrupts.
#
@@ -30,5 +32,5 @@ GCC_ASM_EXPORT(DisableInterrupts) # );
#
ASM_PFX(DisableInterrupts):
- msr daifset, #2
+ msr daifset, #DAIF_WR_IRQ_BIT
ret
diff --git a/MdePkg/Library/BaseLib/AArch64/EnableInterrupts.S b/MdePkg/Library/BaseLib/AArch64/EnableInterrupts.S index a423102535..cdeff9d73d 100644 --- a/MdePkg/Library/BaseLib/AArch64/EnableInterrupts.S +++ b/MdePkg/Library/BaseLib/AArch64/EnableInterrupts.S @@ -19,6 +19,7 @@ .p2align 2
GCC_ASM_EXPORT(EnableInterrupts)
+.set DAIF_WR_IRQ_BIT, (1 << 1)
#/**
# Enables CPU interrupts.
@@ -31,5 +32,5 @@ GCC_ASM_EXPORT(EnableInterrupts) # );
#
ASM_PFX(EnableInterrupts):
- msr daifclr, #2
+ msr daifclr, #DAIF_WR_IRQ_BIT
ret
diff --git a/MdePkg/Library/BaseLib/AArch64/GetInterruptsState.S b/MdePkg/Library/BaseLib/AArch64/GetInterruptsState.S index 037f59acef..771299d1d4 100644 --- a/MdePkg/Library/BaseLib/AArch64/GetInterruptsState.S +++ b/MdePkg/Library/BaseLib/AArch64/GetInterruptsState.S @@ -19,6 +19,8 @@ .p2align 2
GCC_ASM_EXPORT(GetInterruptState)
+.set DAIF_RD_IRQ_BIT, (1 << 7)
+
#/**
# Retrieves the current CPU interrupt state.
#
@@ -38,8 +40,6 @@ GCC_ASM_EXPORT(GetInterruptState) #
ASM_PFX(GetInterruptState):
mrs x0, daif
- tst x0, #2 // Check if IRQ is enabled. Enabled if 0.
- mov w0, #0
- mov w1, #1
- csel w0, w1, w0, ne
+ tst x0, #DAIF_RD_IRQ_BIT // Check IRQ mask; set Z=1 if clear/unmasked
+ cset w0, eq // if Z=1 (eq) return 1, else 0
ret
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