1 # SPDX-License-Identifier: GPL-2.0-only
3 tristate "FMan support"
4 depends on FSL_SOC || ARCH_LAYERSCAPE || COMPILE_TEST
5 select GENERIC_ALLOCATOR
10 Freescale Data-Path Acceleration Architecture Frame Manager
13 config DPAA_ERRATUM_A050385
15 depends on ARM64 && FSL_DPAA
18 DPAA FMan erratum A050385 software workaround implementation:
19 align buffers, data start, SG fragment length to avoid FMan DMA
21 FMAN DMA read or writes under heavy traffic load may cause FMAN
22 internal resource leak thus stopping further packet processing.
23 The FMAN internal queue can overflow when FMAN splits single
24 read or write transactions into multiple smaller transactions
25 such that more than 17 AXI transactions are in flight from FMAN
26 to interconnect. When the FMAN internal queue overflows, it can
27 stall further packet processing. The issue can occur with any
28 one of the following three conditions:
29 1. FMAN AXI transaction crosses 4K address boundary (Errata
31 2. FMAN DMA address for an AXI transaction is not 16 byte
32 aligned, i.e. the last 4 bits of an address are non-zero
33 3. Scatter Gather (SG) frames have more than one SG buffer in
34 the SG list and any one of the buffers, except the last
35 buffer in the SG list has data size that is not a multiple
36 of 16 bytes, i.e., other than 16, 32, 48, 64, etc.
37 With any one of the above three conditions present, there is
38 likelihood of stalled FMAN packet processing, especially under
39 stress with multiple ports injecting line-rate traffic.