Re: [PATCH V11 00/11] IOMMU probe deferral support

[Marek Szyprowski]

Hi Sricharan,

On 2017-04-10 13:20, 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 iommu-next and with 3-way merge applies on top of linux-next
> as well (patch #8), because of "ACPI platform MSI support" from
> Hanjun being merged.
>    
> * Tested with platform and pci devices for probe deferral
>    and reprobe on arm64 based platform.

I just noticed that in the meantime the following patch: "arm: dma-mapping:
Reset the device's dma_ops" (https://patchwork.kernel.org/patch/9434105/ )
has been dropped from this series.

Lack of it causes serious issues with deferred probe of devices, which are
under IOMMU on ARM architecture. Please check where it got lost and push it
to Russell's patch tracking system ASAP to get it during v4.12-rcX cycle.

> Previous post of this series [8].
>
> Please note that, i have kept the tested/acked tags intact from V8
> because V9/10/11 were for more fixes that was added, so the original
> tags that was given for the functional testing remains the same.
>
>   [V11]
>       * No functional changes.
>
>       * Rebased on top of 4.11-rc6.
>
>       * Dropped patch#3 from V10, as a result have to make
>         a change in patch#7 to return a 'non-void' to fix a
>         build warning.
>
>       * Added Robin's and Rob's tags.
>
>   [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://lkml.iu.edu/hypermail/linux/kernel/1704.0/01557.html
>
> Laurent Pinchart (2):
>    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/device.c               |  23 +++++-
>   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 ++-
>   18 files changed, 312 insertions(+), 322 deletions(-)

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland