Subject: Re: [PATCH V10 00/12] IOMMU probe deferral support
To: Sricharan R <sricharan@codeaurora.org>, will.deacon@arm.com,
        joro@8bytes.org, lorenzo.pieralisi@arm.com,
        iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org,
        linux-arm-msm@vger.kernel.org, m.szyprowski@samsung.com,
        bhelgaas@google.com, linux-pci@vger.kernel.org,
        linux-acpi@vger.kernel.org, tn@semihalf.com, hanjun.guo@linaro.org,
        okaya@codeaurora.org, robh+dt@kernel.org, frowand.list@gmail.com,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        sudeep.holla@arm.com, rjw@rjwysocki.net, lenb@kernel.org,
        catalin.marinas@arm.com, arnd@arndb.de, linux-arch@vger.kernel.org,
        gregkh@linuxfoundation.org
References: <1489086061-9356-1-git-send-email-sricharan@codeaurora.org>
 <1491301105-5274-1-git-send-email-sricharan@codeaurora.org>
From: Robin Murphy <robin.murphy@arm.com>
Message-ID: <b0f3a1ec-ea13-7465-1d44-9191e3e803ef@arm.com>
Date: Tue, 4 Apr 2017 13:49:29 +0100
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On 04/04/17 11:18, Sricharan R wrote:
> This series calls the dma ops configuration for the devices
> at a generic place so that it works for all busses.
> The dma_configure_ops for a device is now called during
> the device_attach callback just before the probe of the
> bus/driver is called. Similarly dma_deconfigure is called during
> device/driver_detach path.
> 
> pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>        |                         |
> pci_bus_add_device     (device_add/driver_register)
>        |                         |
> device_attach           device_initial_probe
>        |                         |
> __device_attach_driver    __device_attach_driver
>        |
> driver_probe_device
>        |
> really_probe
>        |
> dma_configure
> 
> Similarly on the device/driver_unregister path __device_release_driver is
> called which inturn calls dma_deconfigure.
> 
> Rebased the series against mainline 4.11-rc5. Applies and builds cleanly
> against mainline and linux-next, iommu-next.
>   
> * Tested with platform and pci devices for probe deferral
>   and reprobe on arm64 based platform.

Sricharan, thanks for keeping this going - I really think we're there now :)

Joerg, I realise that at -rc5 time is getting on a bit already, but even
the non-vintage parts of the series are pretty mature now so it would be
nice to at least give it a spin in -next. If you don't quite share my
confidence for landing it in 4.12, please consider it for early next
cycle to get a full workout.

Thanks,
Robin.

> Previous post of this series [8]. 
> 
> Please note that, i have kept the tested/acked tags intact from V8
> because V9/10 were for more fixes that was added, so the original
> tags that was given for the functional testing remains the same.
> 
>  [V10]
>      * Rebased on top of 4.11-rc5.
>  
>      * Fixed coherent_dma_mask 64bit overflow issue [8]
>        for OF. The fix for OF was added as a separate
>        patch#6, since the issue is true even without probe deferral,
>        but gets reproduced with the probe deferral series.
>        Added Lorenzo's ACPI fix for coherent_dma_mask overflow
>        and the fix for dma_configure getting called more than
>        once for the same device.
> 
>      * Also fixed an build issue caught by kbuild robot for
>        m68k arch. The issue was dma_(de)configure was not
>        getting defined for !CONFIG_HAS_DMA, so fixed that as well.
> 
>  [V9]
>      * Rebased on top of 4.11-rc1.
> 
>      * Merged Robin's fixes for legacy binding issue,
>        pci devices with no iommu-map property and deferencing
>        of_iommu_table after init.
>      
>  [V8]
>      * Picked up all the acks and tested tags from Marek and
>        Hanjun for DT and ACPI patches respectively, since
>        no functional changes was done.
> 
>      * Addressed Minor comments Sinan and Bjorn.
> 
>      * Added Robin's fix for fixing the deferencing NULL for
>        of_iommu_table after init in patch #2.
> 
>      * Rebased it on top of linux-next
> 
>  [V7]
>      * Updated the subject and commit log for patch #6 as per
>        comments from Lorenzo. No functional changes.
> 
>  [V6]
>      * Fixed a bug in dma_configure function pointed out by
>        Robin.
>      * Reordered the patches as per comments from Robin and
>        Lorenzo.
>      * Added Tags.
> 
>  [V5]
>      * Reworked the pci configuration code hanging outside and
>        pushed it to dma_configure as in PATCH#5,6,7.
>        Also added a couple of patches that Lorenzo provided for
>        correcting the Probe deferring mechanism in case of
>        ACPI devices from here [5].
> 
>  [V4]
>      * Took the reworked patches [2] from Robin's branch and
>        rebased on top of Lorenzo's ACPI IORT ARM support series [3].
> 
>      * Added the patches for moving the dma ops configuration of
>        acpi based devices to probe time as well.
>  [V3]
>      * Removed the patch to split dma_masks/dma_ops configuration
>        separately based on review comments that both masks and ops are
>        required only during the device probe time.
> 
>      * Reworked the series based on Generic DT bindings series.
> 
>      * Added call to iommu's remove_device in the cleanup path for arm and
>        arm64.
> 
>      * Removed the notifier trick in arm64 to handle early device
>        registration.
> 
>      * Added reset of dma_ops in cleanup path for arm based on comments.
> 
>      * Fixed the pci_iommu_configure path and tested with PCI device as
>        well.
>  
>      * Fixed a bug to return the correct iommu_ops from patch 7 [4] in
>        last post.
> 
>      * Fixed few other cosmetic comments.
>   
>  [V2]
>      * Updated the Initial post to call dma_configure/deconfigure from
>        generic code
>  
>      * Added iommu add_device callback from of_iommu_configure path
> 
>  [V1]
>      * Initial post from Laurent Pinchart [1]
> 
> [1] http://lists.linuxfoundation.org/pipermail/iommu/2015-May/013016.html
> [2] http://www.linux-arm.org/git?p=linux-rm.git;a=shortlog;h=refs/heads/iommu/defer
> [3] https://lkml.org/lkml/2016/11/21/141
> [4] https://www.mail-archive.com/iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx/msg13940.html
> [5] git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git iommu/probe-deferral
> [6] http://www.spinics.net/lists/linux-pci/msg57992.html
> [7] https://www.spinics.net/lists/arm-kernel/msg556209.html
> [8] http://patchwork.ozlabs.org/patch/743898/
> 
> Laurent Pinchart (3):
>   of: dma: Move range size workaround to of_dma_get_range()
>   of: dma: Make of_dma_deconfigure() public
>   iommu: of: Handle IOMMU lookup failure with deferred probing or error
> 
> Lorenzo Pieralisi (2):
>   ACPI/IORT: Add function to check SMMUs drivers presence
>   ACPI/IORT: Remove linker section for IORT entries probing
> 
> Robin Murphy (3):
>   iommu/of: Refactor of_iommu_configure() for error handling
>   iommu/of: Prepare for deferred IOMMU configuration
>   iommu/arm-smmu: Clean up early-probing workarounds
> 
> Sricharan R (4):
>   of: device: Fix overflow of coherent_dma_mask
>   of/acpi: Configure dma operations at probe time for platform/amba/pci
>     bus devices
>   drivers: acpi: Handle IOMMU lookup failure with deferred probing or
>     error
>   arm64: dma-mapping: Remove the notifier trick to handle early setting
>     of dma_ops
> 
>  arch/arm64/mm/dma-mapping.c       | 142 +++++---------------------------------
>  drivers/acpi/arm64/iort.c         |  48 ++++++++++++-
>  drivers/acpi/glue.c               |   5 --
>  drivers/acpi/scan.c               |  11 ++-
>  drivers/base/dd.c                 |   9 +++
>  drivers/base/dma-mapping.c        |  41 +++++++++++
>  drivers/iommu/arm-smmu-v3.c       |  46 +-----------
>  drivers/iommu/arm-smmu.c          | 110 +++++++++++++----------------
>  drivers/iommu/of_iommu.c          | 126 ++++++++++++++++++++++++---------
>  drivers/of/address.c              |  20 +++++-
>  drivers/of/device.c               |  36 +++++-----
>  drivers/of/platform.c             |  10 +--
>  drivers/pci/probe.c               |  28 --------
>  include/acpi/acpi_bus.h           |   2 +-
>  include/asm-generic/vmlinux.lds.h |   1 -
>  include/linux/acpi.h              |   7 +-
>  include/linux/acpi_iort.h         |   3 -
>  include/linux/dma-mapping.h       |  12 ++++
>  include/linux/of_device.h         |  10 ++-
>  19 files changed, 329 insertions(+), 338 deletions(-)
>