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

[Tero Kristo <t-kristo@ti.com>]

On 12/12/2019 10:46, Peter Ujfalusi wrote:
> 
> 
> 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?

You can just send those two patches separately, I can apply them first 
before this series. No need to resend this series.

-Tero

> 
>> 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
> 
> 

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