DpcDxe

Overview

DpcDxe implements the EFI Deferred Procedure Call (DPC) protocol for the UEFI network stack. It allows drivers to schedule callback functions for execution at TPL_CALLBACK level, which is essential for deferring work from interrupt handlers or high-TPL code paths. The driver manages 32 priority levels (0--31), each backed by a doubly-linked list, with a free list of DPC_ENTRY structures for efficient allocation.

Key Functions

• DpcQueueDpc -- Queues a DPC callback at a specified priority level
• DpcDispatchDpc -- Dispatches queued DPC entries at TPL_CALLBACK, draining one priority level at a time
• DpcQueueDepth -- Returns the current number of queued DPC entries
• DpcMaxQueueDepth -- Returns the maximum observed queue depth
• DpcAllocEntry -- Allocates a DPC_ENTRY from the free list or pool
• DpcFreeEntry -- Returns a DPC_ENTRY to the free list

Dependencies

• EFI_DPC_PROTOCOL -- The DPC protocol interface (produced)
• UefiBootServicesTableLib -- Boot services for TPL management
• MemoryAllocationLib -- Pool allocation for DPC entries
• DebugLib -- Debug output support

Platform

• Source: AmiNetworkPkg/UefiNetworkStack/Common/DpcDxe/Dpc.c
• Architecture: X64 (PE32+)
• Formats: PE32+, 6 sections (.text, .rdata, .data, section_3, .xdata, .reloc)
• SHA256: a77c4daf860fb0acbbd347ee525133f49fff29a19749585e40d50666b753f64a