[PATCH 0/6] soc: qcom: Add Qualcomm Page Compression Engine (QPaCE) driver

QPaCE (Qualcomm Page Compression Engine) is a hardware block found on
Qualcomm SoCs that accelerates page compression and decompression for
use with the zram block device. It is composed of multiple compression,
decompression, and copy engines.

This series uses QPaCE's "urgent" (synchronous) path, intended for low-
latency single-page operations. A command is issued by writing the
source and destination DMA addresses to one of several per-CPU urgent
command registers with a single store; completion is then detected by
polling the command's status register.

The hardware also provides a ring-based (asynchronous) path for high-
throughput batched compression, where transfer and event rings allow
multiple descriptors to be queued and submitted with a single doorbell
write, with completion signalled via an interrupt. This path is not
implemented in this series.

The driver integrates with zram through a new "qpace-lz4" zcomp backend.
Both compression and decompression are performed by the QPaCE hardware
via the urgent synchronous path: each request DMA-maps the source and
destination buffers, issues a blocking hardware command, and returns the
result size.

The driver also integrates with the Qualcomm Last Level Cache Controller
(LLCC) to activate dedicated cache slices for compression and decompression
data.

This is validated on next-20260929 with the following patch applied on
top to allow booting completely to the serial console:
https://lore.kernel.org/all/20260911-rsc_read-v2-1-98675c248278@oss.qualcomm.com/ (local)

Georgi Djakov (6):
  dt-bindings: soc: qcom: Add QPaCE binding
  soc: qcom: qpace: Add Qualcomm Page Compression Engine driver
  trace: qpace: Add tracepoints for QPaCE operations
  zram: Add QPaCE zcomp backend
  soc: qcom: qpace: Add LLCC slice support
  arm64: dts: qcom: hawi: Add QPaCE DT node

 .../bindings/soc/qcom/qcom,hawi-qpace.yaml    |  94 ++
 arch/arm64/boot/dts/qcom/hawi.dtsi            |  17 +
 drivers/block/zram/Kconfig                    |  11 +
 drivers/block/zram/Makefile                   |   1 +
 drivers/block/zram/backend_qpace.c            | 134 +++
 drivers/block/zram/backend_qpace.h            |  13 +
 drivers/block/zram/zcomp.c                    |  11 +-
 drivers/soc/qcom/Kconfig                      |  14 +
 drivers/soc/qcom/Makefile                     |   1 +
 drivers/soc/qcom/qpace.c                      | 830 ++++++++++++++++++
 drivers/soc/qcom/qpace_internal.h             |  84 ++
 include/linux/soc/qcom/llcc-qcom.h            |   2 +
 include/linux/soc/qcom/qpace.h                | 154 ++++
 include/trace/events/qpace.h                  |  99 +++
 14 files changed, 1463 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,hawi-qpace.yaml
 create mode 100644 drivers/block/zram/backend_qpace.c
 create mode 100644 drivers/block/zram/backend_qpace.h
 create mode 100644 drivers/soc/qcom/qpace.c
 create mode 100644 drivers/soc/qcom/qpace_internal.h
 create mode 100644 include/linux/soc/qcom/qpace.h
 create mode 100644 include/trace/events/qpace.h