diff options
| author | Jeff Fan <jeff.fan@intel.com> | 2014-07-11 02:36:56 +0000 |
|---|---|---|
| committer | vanjeff <vanjeff@6f19259b-4bc3-4df7-8a09-765794883524> | 2014-07-11 02:36:56 +0000 |
| commit | 9c71e1e05666d274a760e45866f65fafc2ccfbc6 (patch) | |
| tree | d096bf402406e1f7be16fd5e7eeec271cdfa4b01 /UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c | |
| parent | d2ea3b8399243ff46d9c713d4a328aa81a773a3c (diff) | |
| download | edk2-platforms-9c71e1e05666d274a760e45866f65fafc2ccfbc6.tar.xz | |
1. Save/restore ICR high 32bit value and check Delivery Status before sending IPI. It could be fix the interrupted issue between ICR high/low writes by SMI handler.
2. Save/restore CPU Interrupt state around sending IPI. It could avoid sending IPI be interrupted by CPU interrupt handler.
3. Add note for SetApicMode() API that must not be called from an interrupt handler or SMI handler.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Kinney, Michael <michael.d.kinney@intel.com>
Reviewed-by: Mudusuru, Giri <giri.p.mudusuru@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15652 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c')
| -rw-r--r-- | UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c b/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c index 6bf9c43dc9..6f8cd2eb9b 100644 --- a/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c +++ b/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c @@ -139,18 +139,47 @@ SendIpi ( )
{
LOCAL_APIC_ICR_LOW IcrLowReg;
+ UINT32 IcrHigh;
+ BOOLEAN InterruptState;
ASSERT (GetApicMode () == LOCAL_APIC_MODE_XAPIC);
ASSERT (ApicId <= 0xff);
+ InterruptState = SaveAndDisableInterrupts ();
+
+ //
+ // Save existing contents of ICR high 32 bits
+ //
+ IcrHigh = ReadLocalApicReg (XAPIC_ICR_HIGH_OFFSET);
+
+ //
+ // Wait for DeliveryStatus clear in case a previous IPI
+ // is still being sent
+ //
+ do {
+ IcrLowReg.Uint32 = ReadLocalApicReg (XAPIC_ICR_LOW_OFFSET);
+ } while (IcrLowReg.Bits.DeliveryStatus != 0);
+
//
// For xAPIC, the act of writing to the low doubleword of the ICR causes the IPI to be sent.
//
WriteLocalApicReg (XAPIC_ICR_HIGH_OFFSET, ApicId << 24);
WriteLocalApicReg (XAPIC_ICR_LOW_OFFSET, IcrLow);
+
+ //
+ // Wait for DeliveryStatus clear again
+ //
do {
IcrLowReg.Uint32 = ReadLocalApicReg (XAPIC_ICR_LOW_OFFSET);
} while (IcrLowReg.Bits.DeliveryStatus != 0);
+
+ //
+ // And restore old contents of ICR high
+ //
+ WriteLocalApicReg (XAPIC_ICR_HIGH_OFFSET, IcrHigh);
+
+ SetInterruptState (InterruptState);
+
}
//
@@ -193,6 +222,9 @@ GetApicMode ( If the specified local APIC mode can't be set as current, then ASSERT.
@param ApicMode APIC mode to be set.
+
+ @note This API must not be called from an interrupt handler or SMI handler.
+ It may result in unpredictable behavior.
**/
VOID
EFIAPI
|