bba9d16231
This patch is inspired by InterlockedCompareExchange32 from the BaseSynchronizationLib. The function will be used in the "OvmfPkg/XenBusDxe: Add Grant Table functions" patch. Change in V3: - Implement both .S and .asm, to get rid of GCC specific asm. - Implement 32bit part of the assembly Change in V2: - Add intel compilation code MSFT code is not compied over because I don't know how it works. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> Reviewed-by: Jordan Justen <jordan.l.justen@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16263 6f19259b-4bc3-4df7-8a09-765794883524
39 lines
1.3 KiB
C
39 lines
1.3 KiB
C
/**
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Assembly implementation of InterlockedCompareExchange16.
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Look at the documentation of InterlockedCompareExchange16.
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**/
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UINT16
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EFIAPI
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InternalSyncCompareExchange16 (
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IN volatile UINT16 *Value,
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IN UINT16 CompareValue,
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IN UINT16 ExchangeValue
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);
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/**
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Performs an atomic compare exchange operation on a 16-bit unsigned integer.
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Performs an atomic compare exchange operation on the 16-bit unsigned integer
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specified by Value. If Value is equal to CompareValue, then Value is set to
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ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
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then Value is returned. The compare exchange operation must be performed using
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MP safe mechanisms.
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If Value is NULL, then ASSERT().
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@param Value A pointer to the 16-bit value for the compare exchange
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operation.
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@param CompareValue 16-bit value used in compare operation.
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@param ExchangeValue 16-bit value used in exchange operation.
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@return The original *Value before exchange.
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**/
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UINT16
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EFIAPI
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InterlockedCompareExchange16 (
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IN OUT UINT16 *Value,
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IN UINT16 CompareValue,
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IN UINT16 ExchangeValue
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);
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