Re: [PATCH V10 00/12] IOMMU probe deferral support

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Tue, Apr 04, 2017 at 01:49:29PM +0100, Robin Murphy wrote:
> 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 :)

FYI, I re-tested this series with ACPI and tried a merge with IORT
patches queued for 4.12 (via arm64) and there does not seem to be any
merge conflicts so it should be ready to go.

Thanks,
Lorenzo

> 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(-)
> > 
>