ASoC: SOF: Intel: hda: Avoid ACE2+ link DMA stream allocation hazards

On ACE2+ platforms the link DMA stream allocator must avoid two
hardware errata in mlink-capable systems:

- Concurrent (cross-direction) hazard: when SoundWire shares a physical
  link DMA stream index with HDaudio, iDisp or UAOL across the two
  directions, the LLP and timestamp values for the affected stream are
  wrong. SSP and DMIC are not affected because every DMA request from
  those links carries one sample block.

- Sequential (playback only) hazard: once a HDaudio or iDisp link has
  used a playback stream index, that index cannot drive any non
  HDA/iDisp link in the same direction until the next controller
  reset (CRST#).

Track the active link type per direction in two masks (one for SoundWire,
one for HDA/iDisp/UAOL) and the persistent set of playback stream
indices touched by HDA/iDisp in a third mask. The link DMA allocator
skips streams that would violate either rule. Streams are released from
the active masks when the stream is released; all masks are cleared in
hda_dsp_ctrl_init_chip() because the CRST# performed there clears the
hardware state as well.

A new helper hda_bus_ml_link_get_type() returns the link type from the
existing extended link descriptor so the SOF allocator can tell
SoundWire, HDA/iDisp and UAOL apart without duplicating the parsing.

The implementation is generic. On platforms older than ACE2 every link
is reported as HDA, only the sequential mask is ever set and it has no
effect because no other link types are present, so behavior is
unchanged.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Link: https://patch.msgid.link/20260730125130.29887-5-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/include/sound/hda-mlink.h b/include/sound/hda-mlink.h
index d9789b048c61..ba35f03576b9 100644
--- a/include/sound/hda-mlink.h
+++ b/include/sound/hda-mlink.h
@@ -9,6 +9,22 @@
 struct hdac_bus;
 struct hdac_ext_link;
 
+/**
+ * enum hda_bus_ml_link_type - mlink link type, used by SOF link DMA
+ *	allocator constraints (see struct sof_intel_hda_dev).
+ *
+ * @HDA_BUS_ML_LINK_HDA:  non-alt link, i.e. HDA codec or iDisp
+ * @HDA_BUS_ML_LINK_SDW:  alt link, SoundWire
+ * @HDA_BUS_ML_LINK_UAOL: alt link, USB Audio Offload
+ * @HDA_BUS_ML_LINK_OTHER: alt link, SSP or DMIC
+ */
+enum hda_bus_ml_link_type {
+	HDA_BUS_ML_LINK_HDA,
+	HDA_BUS_ML_LINK_SDW,
+	HDA_BUS_ML_LINK_UAOL,
+	HDA_BUS_ML_LINK_OTHER,
+};
+
 #if IS_ENABLED(CONFIG_SND_SOC_SOF_HDA_MLINK)
 
 int hda_bus_ml_init(struct hdac_bus *bus);
@@ -53,6 +69,8 @@ void hda_bus_ml_reset_losidv(struct hdac_bus *bus);
 int hda_bus_ml_resume(struct hdac_bus *bus);
 int hda_bus_ml_suspend(struct hdac_bus *bus);
 
+enum hda_bus_ml_link_type hda_bus_ml_link_get_type(struct hdac_ext_link *hlink);
+
 struct hdac_ext_link *hdac_bus_eml_ssp_get_hlink(struct hdac_bus *bus);
 struct hdac_ext_link *hdac_bus_eml_dmic_get_hlink(struct hdac_bus *bus);
 struct hdac_ext_link *hdac_bus_eml_sdw_get_hlink(struct hdac_bus *bus);
@@ -172,6 +190,9 @@ static inline void hda_bus_ml_reset_losidv(struct hdac_bus *bus) { }
 static inline int hda_bus_ml_resume(struct hdac_bus *bus) { return 0; }
 static inline int hda_bus_ml_suspend(struct hdac_bus *bus) { return 0; }
 
+static inline enum hda_bus_ml_link_type
+hda_bus_ml_link_get_type(struct hdac_ext_link *hlink) { return HDA_BUS_ML_LINK_HDA; }
+
 static inline struct hdac_ext_link *
 hdac_bus_eml_ssp_get_hlink(struct hdac_bus *bus) { return NULL; }