[PATCH v4 00/14] dmaengine: dw-edma: Prepare for PCI EP DMA (part 1/3)

[Koichiro Den <den@valinux.co.jp>]

Hi,

This is v4, part 1 of three series for PCI endpoint DMA.

The three series are:

  * part 1: dmaengine: dw-edma: Prepare for PCI EP DMA
  * part 2: PCI: endpoint: Expose endpoint DMA resources
  * part 3: PCI: endpoint: Add PCI DMA endpoint function

Most v4 changes come from Frank's review of v3 and from the rebase
onto v7.2-rc1 plus the dw-edma groundwork series (v3 was based on
Frank's edma_ll, which this revision no longer depends on); the
delegated channel request helpers moved to part 2, next to their only
users, and a new patch programs the endpoint function number into
each channel.

This series is (re-)based on v7.2-rc1 + my dw-edma groundwork:

  [PATCH 0/7] dmaengine: dw-edma: Fixes and interrupt-path groundwork
  https://lore.kernel.org/dmaengine/20260710080903.2392888-1-den@valinux.co.jp/

and parts 2 and 3 depend on this series. It is independent of Frank's
edma_ll work; the combination of both (edma_ll v5 applied on top) has
been tested on an R-Car S4 endpoint/host pair.

Scope
=====

This series prepares dw-edma and dw-edma-pcie for endpoint-local DMA
channels that are delegated to a PCI host. It does not add the endpoint
metadata format, DesignWare endpoint resource exposure, or the endpoint
function driver; those are added by parts 2 and 3.

This part is the DesignWare dmaengine backend work. The endpoint resource
and endpoint function pieces in parts 2 and 3 keep the generic PCI endpoint
interfaces separate from the DesignWare implementation.

In summary, this series:

  * adds per-channel interrupt routing so a channel can report completion
    either to the local endpoint side or to the remote host side,
  * adds quiesce operations for the resources represented by a dw-edma
    instance,
  * programs the endpoint function number into each channel so DMA
    requests are attributed to the function that owns them,
  * adds partial channel ownership mode for dw-edma instances that share a
    controller with another OS instance, and
  * prepares dw-edma-pcie to describe device-specific DMA layouts through
    match data.

---
Changelog
=========

Changes in v4:
  - Rebase onto v7.2-rc1 plus the dw-edma fixes/groundwork series:
    20260710080903.2392888-1-den@valinux.co.jp.
  - Split the HDMA interrupt setup helper out as a new first patch.
    (Frank)
  - Rework the routing patch per review: default-irq-mode naming and
    call sites simplified, chip->irq_mode dropped. (Frank)
  - Revise the partial-ownership patch: message fixed, validation moved
    into dw_edma_check_partial(). (Frank)
  - Move "dmaengine: dw-edma: Add delegated channel request helpers"
    into part 2, next to its only users.
  - New patch "dmaengine: dw-edma: Program endpoint function numbers",
    so channels delegated to PF1+ issue TLPs attributed to their
    function; this also lifts part 2's v3 PF0-only restriction.

Changes in v3:
  - Replace the public dw-edma hardware-channel filter API with delegated
    channel request/release helpers, keeping the DMAengine filter private
    to dw-edma. (Frank)
  - Rework IRQ routing so local routing is the zero value, existing
    dw-edma-pcie instances stay remote-routed, and delegated endpoint-local
    channels are handed to the remote side explicitly. (Frank/Sashiko)
  - Add HDMA native interrupt routing and allow channel-granular partial
    ownership for HDMA native.
  - Add quiesce operations and use them for delegated-channel reclaim and
    partial-owned remove paths.
  - Reintroduce the IRQ data initialization fix because partial-owned probe
    skips the core_off() reset that previously made the early-IRQ window
    unlikely.
  - Adjust dw-edma-pcie match-data preparation for the CPM6 entry present
    in the new base, and reject dynamic PCI IDs without match data.

Changes in v2:
  - Move non-LL state and platform ops into match data. (Frank)
  - Use a named .driver_data initializer for the Xilinx MDB ID entry and
    fix the vsec_data rename patch title. (Frank)
  - Replace the dma_get_slave_channel() export with a dw-edma channel
    filter for dma_request_channel(). (Sashiko)
  - Rework the IRQ-routing config as dw_edma_irq_config, keep HDMA native
    int config separate, and reject remote IRQ mode on local instances.
    (Sashiko)
  - Report IRQ_HANDLED only for status that was actually serviced and drop
    the lockless free_chan_resources() reset. (Sashiko)
  - Tighten partial ownership: reject unsupported map formats early and
    require direction-wide ownership for supported shared-register
    layouts. (Sashiko)

v3: https://lore.kernel.org/dmaengine/20260620170040.3756043-1-den@valinux.co.jp/
v2: https://lore.kernel.org/dmaengine/20260525062420.3315904-1-den@valinux.co.jp/
v1: https://lore.kernel.org/dmaengine/20260521063115.2842238-1-den@valinux.co.jp/

Best regards,
Koichiro


Koichiro Den (14):
  dmaengine: dw-edma: Factor out HDMA interrupt setup helper
  dmaengine: dw-edma: Add per-channel interrupt routing control
  dmaengine: dw-edma: Add core quiesce operations
  dmaengine: dw-edma: Initialize IRQ data before requesting IRQs
  dmaengine: dw-edma: Add partial channel ownership mode
  dmaengine: dw-edma-pcie: Track non-LL mode in DMA data
  dmaengine: dw-edma-pcie: Add capability match data
  dmaengine: dw-edma-pcie: Rename vsec_data to dma_data
  dmaengine: dw-edma-pcie: Add platform ops to match data
  dmaengine: dw-edma-pcie: Add register offset match flag
  dmaengine: dw-edma-pcie: Factor out descriptor block address lookup
  dmaengine: dw-edma-pcie: Handle optional data blocks
  dmaengine: dw-edma-pcie: Add chip flags to match data
  dmaengine: dw-edma: Program endpoint function numbers

 drivers/dma/dw-edma/dw-edma-core.c    |  89 +++++++--
 drivers/dma/dw-edma/dw-edma-core.h    |  28 +++
 drivers/dma/dw-edma/dw-edma-pcie.c    | 253 +++++++++++++++++---------
 drivers/dma/dw-edma/dw-edma-v0-core.c |  72 +++++++-
 drivers/dma/dw-edma/dw-hdma-v0-core.c |  75 ++++++--
 drivers/dma/dw-edma/dw-hdma-v0-regs.h |   1 +
 include/linux/dma/edma.h              |  42 +++++
 7 files changed, 445 insertions(+), 115 deletions(-)

-- 
2.51.0