Re: [PATCH v7 00/12] dmaengine/soc: Add Texas Instruments UDMA support

Peter Ujfalusi
2019-12-12T08:47:11Z

On 09/12/2019 11.43, Peter Ujfalusi wrote:
> Hi,
>
> Vinod, Nishanth, Tero, Santosh: the ti_sci patch in this series was sent
> upstream over a month ago:
> https://lore.kernel.org/lkml/20191025084715.25098-1-peter.ujfalusi@ti.com/
>
> I'm still waiting on it's fate (Tero has given his r-b).
> The ti_sci patch did not made it to 5.5-rc1, but I included it in the series and
> let the maintainers decide if it can go via DMAengine for 5.6 or to later
> releases (5.6 probably for the ti_sci and 5.7 for the UDMA driver patch).
>
> Changes since v6:
> (https://patchwork.kernel.org/project/linux-dmaengine/list/?series=209455&state=*)
>
> - UDMAP DMAengine driver:
> - Squashed the split patches
> - Squashed the early TX completion handling update
> (https://patchwork.kernel.org/project/linux-dmaengine/list/?series=210713&state=*)
> - Hard reset fix for RX channels to avoid channel lockdown
> - Correct completed descriptor's residue value

I got build failure with allmodconfig:

ERROR: "devm_ti_sci_get_of_resource" [drivers/soc/ti/k3-ringacc.ko]
undefined!
ERROR: "of_msi_get_domain" [drivers/soc/ti/k3-ringacc.ko] undefined!
ERROR: "devm_ti_sci_get_of_resource" [drivers/dma/ti/k3-udma.ko] undefined!
ERROR: "of_msi_get_domain" [drivers/dma/ti/k3-udma.ko] undefined!

They are because both devm_ti_sci_get_of_resource and of_msi_get_domain
is missing EXPORT_SYMBOL_GPL(), so they can not be used from modules.

There were patches in the past to add it for of_msi_get_domain:
https://lore.kernel.org/patchwork/patch/668123/
https://lore.kernel.org/patchwork/patch/716046/

I can not find a reason why these are not merged.
Matthias's patch looks to be the earlier one, is it OK if I resend it
within v8?

> Changes since v5:
> (https://patchwork.kernel.org/project/linux-dmaengine/list/?series=201051&state=*)
> - Based on 5.4
>
> - cppi5 header
> - clear the bits before setting new value with '|='
>
> - UDMAP DT bindings:
> - valid compatibles as single enum list
>
> - UDMAP DMAengine driver:
> - Fix udma_is_chan_running()
> - Use flags for acc32, burst support instead of a bool in udma_match_data
> struct
> - TDTYPE handling (teardown completion handling for j721e) is moved to separate
> patch as the tisci core patch has not moved for over a month.
> Both ti_sci and the iterative patch to udma is included in the series.
>
> Changes since v4
> (https://patchwork.kernel.org/project/linux-dmaengine/list/?series=196619&state=*)
> - Based on 5.4-rc7
>
> - ringacc DT bindings:
> - clarify the meaning of ti,sci-dev-id
>
> - ringacc driver:
> - Remove 'default y' from Kconfig
> - Fix struct comments
> - Move try_module_get() earlier in k3_ringacc_request_ring()
>
> - PSI-L thread database:
> - Add kernel style struct/enum documentation
> - Add missing thread description for sa2ul second interface
> - Change EXPORT_SYMBOL to EXPORT_SYMBOL_GPL
>
> - UDMAP DT bindings:
> - move to dual license
> - change compatible from const to enum
> - items dropped for ti,sci-rm-ranges-*
> - description text moved from literal block when it is sensible
> - example fixed to compile cleanly
> - added parent to provide correct address-cells
> - navss is moved to simple-mfd from simple-bus
>
> - UDMAP DMAengine driver:
> - move fd_ring/r_ring under rflow
> - get rid of unused iomem for rflows
> - Remove 'default y' from Kconfig
> - Use defines for rflow src/dst tag selection
> - Merge the udma_ring_callback() and udma_tr_event_callback() to their
> corresponding interrupt handler
> - Create new defines for tx/rx channel's tisci valid parameter flags
> - Remove re-initialization to 0 of tisci request struct members
> - Make sure that vchan tasklets are also stopped when removing the module
> - Additional checkpatch --strict fixes when it made sense
> - make W=1 was clean
>
> - UDMAP glue layer:
> - Remove 'default y' from Kconfig
> - commit message update for features needing the glue layer
>
> Changes since v3
> (https://patchwork.kernel.org/project/linux-dmaengine/list/?series=180679&state=*):
> - Based on 5.4-rc5
> - Fixed typos pointed out by Tero
> - Added reviewed-by tags from Tero
>
> - ring accelerator driver
> - TODO_GS is removed from the header
> - pm_runtime removed as NAVSS and it's components are always on
> - Check validity of Message mode setup (element size > 8 bytes must use proxy)
>
> - cppi5 header
> - add commit message
>
> - UDMAP DT bindings
> - Drop the psil-config node use on the remote PSI-L side and use only one cell
> which is the remote threadID:
>
> dmas = <&main_udmap 0xc400>, <&main_udmap 0x4400>;
> dma-names = "tx", "rx";
>
> - The PSI-L thread configuration description is moved to kernel as a new module:
> k3-psil/k3-psil-am654/k3-psil-j721e
> - ti,psil-base has been removed and moved to kernel
> - removed the no longer needed dt-bindings/dma/k3-udma.h
> - Convert the document to schema (yaml)
>
> - NEW PSI-L endpoint configuration database
> - a simple database holding the remote end's configuration needed for UDMAP
> configuration. All previous parameters from DT has been moved here and merged
> with the linux only tr mode channel flag.
> - Client drivers can update the remote endpoint configuration as it can be
> different based on system configuration and the endpoint itself is under the
> control of the peripheral driver.
> - database for am654 and j721e
>
> - UDMAP DMAengine driver
> - pm_runtime removed as NAVSS and it's components are always on
> - rchan_oes_offset added to MSI dommain allocation
> - Use the new PSI-L endpoint database for UDMAP configuration
> - Support for waiting for PDMA teardown completion on j721e instead of
> returning right away. depends on:
> https://lkml.org/lkml/2019/10/25/189
> Not included in this series, but it is in the branch I have prepared.
> - psil-base is moved from DT to be part of udma_match_data
> - tr_thread maps is removed and using the PSI-L endpoint configuration for it
>
> - UDMAP glue layer
> - pm_runtime removed as NAVSS and it's components are always on
> - Use the new PSI-L endpoint database for UDMAP configuration
>
> Changes since v2
> (https://patchwork.kernel.org/project/linux-dmaengine/list/?series=152609&state=*)
> - Based on 5.4-rc1
> - Support for Flow only data transfer for the glue layer
>
> - cppi5 header
> - comments converted to kernel-doc style
> - Remove the excessive WARN_ONs and rely on the user for sanity
> - new macro for checking TearDown Completion Message
>
> - ring accelerator driver
> - fixed up th commit message (SoB, TI-SCI)
> - fixed ring reset
> - CONFIG_TI_K3_RINGACC_DEBUG is removed along with the dbg_write/read functions
> and use dev_dbg()
> - k3_ringacc_ring_dump() is moved to static
> - step numbering removed from k3_ringacc_ring_reset_dma()
> - Add clarification comment for shared ring usage in k3_ringacc_ring_cfg()
> - Magic shift values in k3_ringacc_ring_cfg_proxy() got defined
> - K3_RINGACC_RING_MODE_QM is removed as it is not supported
>
> - UDMAP DT bindings
> - Fix property prefixing: s/pdma,/ti,pdma-
> - Add ti,notdpkt property to suppress teardown completion message on tchan
> - example updated accordingly
>
> - UDMAP DMAengine driver
> - Change __raw_readl/writel to readl/writel
> - Split up the udma_tisci_channel_config() into m2m, tx and rx tisci
> configuration functions for clarity
> - DT bindings change: s/pdma,/ti,pdma-
> - Cleanup of udma_tx_status():
> - residue calculation fix for m2m
> - no need to read packet counter as it is not used
> - peer byte counter only available in PDMAs
> - Proper locking to avoid race with interrupt handler (polled m2m fix)
> - Support for ti,notdpkt
> - RFLOW management rework to support data movement without channel:
> - the channel is not controlled by Linux but other core and we only have
> rflows and rings to do the DMA transfers.
> This mode is only supported by the Glue layer for now.
>
> - UDMAP glue layer
> - Debug print improvements
> - Support for rflow/ring only data movement
>
> Changes since v1
> (https://patchwork.kernel.org/project/linux-dmaengine/list/?series=114105&state=*)
> - Added support for j721e
> - Based on 5.3-rc2
> - dropped ti_sci API patch for RM management as it is already upstream
> - dropped dmadev_get_slave_channel() patch, using __dma_request_channel()
> - Added Rob's Reviewed-by to ringacc DT binding document patch
> - DT bindings changes:
> - linux,udma-mode is gone, I have a simple lookup table in the driver to flag
> TR channels.
> - Support for j721e
> - Fix bug in of_node_put() handling in xlate function
>
> Changes since RFC (https://patchwork.kernel.org/cover/10612465/):
> - Based on linux-next (20190506) which now have the ti_sci interrupt support
> - The series can be applied and the UDMA via DMAengine API will be functional
> - Included in the series: ti_sci Resource management API, cppi5 header and
> driver for the ring accelerator.
> - The DMAengine core patches have been updated as per the review comments for
> earlier submittion.
> - The DMAengine driver patch is artificially split up to 6 smaller patches
>
> The k3-udma driver implements the Data Movement Architecture described in
> AM65x TRM (http://www.ti.com/lit/pdf/spruid7) and
> j721e TRM (http://www.ti.com/lit/pdf/spruil1)
>
> This DMA architecture is a big departure from 'traditional' architecture where
> we had either EDMA or sDMA as system DMA.
>
> Packet DMAs were used as dedicated DMAs to service only networking (Kesytone2)
> or USB (am335x) while other peripherals were serviced by EDMA.
>
> In AM65x/j721e the UDMA (Unified DMA) is used for all data movment within the
> SoC, tasked to service all peripherals (UART, McSPI, McASP, networking, etc).
>
> The NAVSS/UDMA is built around CPPI5 (Communications Port Programming Interface)
> and it supports Packet mode (similar to CPPI4.1 in Keystone2 for networking) and
> TR mode (similar to EDMA descriptor).
> The data movement is done within a PSI-L fabric, peripherals (including the
> UDMA-P) are not addressed by their I/O register as with traditional DMAs but
> with their PSI-L thread ID.
>
> In AM65x/j721e we have two main type of peripherals:
> Legacy: McASP, McSPI, UART, etc.
> to provide connectivity they are serviced by PDMA (Peripheral DMA)
> PDMA threads are locked to service a given peripheral, for example PSI-L thread
> 0x4400/0xc400 is to service McASP0 rx/tx.
> The PDMa configuration can be done via the UDMA Real Time Peer registers.
> Native: Networking, security accelerator
> these peripherals have native support for PSI-L.
>
> To be able to use the DMA the following generic steps need to be taken:
> - configure a DMA channel (tchan for TX, rchan for RX)
> - channel mode: Packet or TR mode
> - for memcpy a tchan and rchan pair is used.
> - for packet mode RX we also need to configure a receive flow to configure the
> packet receiption
> - the source and destination threads must be paired
> - at minimum one pair of rings need to be configured:
> - tx: transfer ring and transfer completion ring
> - rx: free descriptor ring and receive ring
> - two interrupts: UDMA-P channel interrupt and ring interrupt for tc_ring/r_ring
> - If the channel is in packet mode or configured to memcpy then we only need
> one interrupt from the ring, events from UDMAP is not used.
>
> When the channel setup is completed we only interract with the rings:
> - TX: push a descriptor to t_ring and wait for it to be pushed to the tc_ring by
> the UDMA-P
> - RX: push a descriptor to the fd_ring and waith for UDMA-P to push it back to
> the r_ring.
>
> Since we have FIFOs in the DMA fabric (UDMA-P, PSI-L and PDMA) which was not the
> case in previous DMAs we need to report the amount of data held in these FIFOs
> to clients (delay calculation for ALSA, UART FIFO flush support).
>
> Metadata support:
> DMAengine user driver was posted upstream based/tested on the v1 of the UDMA
> series: https://lkml.org/lkml/2019/6/28/20
> SA2UL is using the metadata DMAengine API.
>
> Note on the last patch:
> In Keystone2 the networking had dedicated DMA (packet DMA) which is not the case
> anymore and the DMAengine API currently missing support for the features we
> would need to support networking, things like
> - support for receive descriptor 'classification'
> - we need to support several receive queues for a channel.
> - the queues are used for packet priority handling for example, but they can be
> used to have pools of descriptors for different sizes.
> - out of order completion of descriptors on a channel
> - when we have several queues to handle different priority packets the
> descriptors will be completed 'out-of-order'
> - NAPI type of operation (polling instead of interrupt driven transfer)
> - without this we can not sustain gigabit speeds and we need to support NAPI
> - not to limit this to networking, but other high performance operations
>
> It is my intention to work on these to be able to remove the 'glue' layer and
> switch to DMAengine API - or have an API aside of DMAengine to have generic way
> to support networking, but given how controversial and not trivial these changes
> are we need something to support networking.
>
> The series (+DT patches to enabled DMA on AM65x and j721e) on top of 5.5-rc1 is
> available:
> https://github.com/omap-audio/linux-audio.git peter/udma/series_v7-5.5-rc1
>
> Regards,
> Peter
> ---
> Grygorii Strashko (3):
> bindings: soc: ti: add documentation for k3 ringacc
> soc: ti: k3: add navss ringacc driver
> dmaengine: ti: k3-udma: Add glue layer for non DMAengine users
>
> Peter Ujfalusi (9):
> dmaengine: doc: Add sections for per descriptor metadata support
> dmaengine: Add metadata_ops for dma_async_tx_descriptor
> dmaengine: Add support for reporting DMA cached data amount
> dmaengine: ti: Add cppi5 header for K3 NAVSS/UDMA
> dmaengine: ti: k3 PSI-L remote endpoint configuration
> dt-bindings: dma: ti: Add document for K3 UDMA
> dmaengine: ti: New driver for K3 UDMA
> firmware: ti_sci: rm: Add support for tx_tdtype parameter for tx
> channel
> dmaengine: ti: k3-udma: Wait for peer teardown completion if supported
>
> .../devicetree/bindings/dma/ti/k3-udma.yaml | 185 +
> .../devicetree/bindings/soc/ti/k3-ringacc.txt | 59 +
> Documentation/driver-api/dmaengine/client.rst | 75 +
> .../driver-api/dmaengine/provider.rst | 46 +
> drivers/dma/dmaengine.c | 73 +
> drivers/dma/dmaengine.h | 8 +
> drivers/dma/ti/Kconfig | 24 +
> drivers/dma/ti/Makefile | 3 +
> drivers/dma/ti/k3-psil-am654.c | 175 +
> drivers/dma/ti/k3-psil-j721e.c | 222 ++
> drivers/dma/ti/k3-psil-priv.h | 39 +
> drivers/dma/ti/k3-psil.c | 97 +
> drivers/dma/ti/k3-udma-glue.c | 1198 ++++++
> drivers/dma/ti/k3-udma-private.c | 133 +
> drivers/dma/ti/k3-udma.c | 3452 +++++++++++++++++
> drivers/dma/ti/k3-udma.h | 151 +
> drivers/firmware/ti_sci.c | 1 +
> drivers/firmware/ti_sci.h | 7 +
> drivers/soc/ti/Kconfig | 11 +
> drivers/soc/ti/Makefile | 1 +
> drivers/soc/ti/k3-ringacc.c | 1180 ++++++
> include/linux/dma/k3-psil.h | 71 +
> include/linux/dma/k3-udma-glue.h | 134 +
> include/linux/dma/ti-cppi5.h | 1061 +++++
> include/linux/dmaengine.h | 110 +
> include/linux/soc/ti/k3-ringacc.h | 244 ++
> include/linux/soc/ti/ti_sci_protocol.h | 2 +
> 27 files changed, 8762 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/dma/ti/k3-udma.yaml
> create mode 100644 Documentation/devicetree/bindings/soc/ti/k3-ringacc.txt
> create mode 100644 drivers/dma/ti/k3-psil-am654.c
> create mode 100644 drivers/dma/ti/k3-psil-j721e.c
> create mode 100644 drivers/dma/ti/k3-psil-priv.h
> create mode 100644 drivers/dma/ti/k3-psil.c
> create mode 100644 drivers/dma/ti/k3-udma-glue.c
> create mode 100644 drivers/dma/ti/k3-udma-private.c
> create mode 100644 drivers/dma/ti/k3-udma.c
> create mode 100644 drivers/dma/ti/k3-udma.h
> create mode 100644 drivers/soc/ti/k3-ringacc.c
> create mode 100644 include/linux/dma/k3-psil.h
> create mode 100644 include/linux/dma/k3-udma-glue.h
> create mode 100644 include/linux/dma/ti-cppi5.h
> create mode 100644 include/linux/soc/ti/k3-ringacc.h
>

- Péter