[PATCH v4 00/10] IOMMU probe deferral support

Wed Nov 30 00:19:38 PST 2016

Hi All,

On 2016-11-30 01:22, 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.
>
> Took the reworked patches [2] from Robin's branch and
> rebased on top of Lorenzo's ACPI IORT ARM support series [3].
>
> Tested with platform and pci devices for probe deferral
> and reprobe on arm64 based platform. Added the patches [9,10],
>      drivers: acpi: Configure acpi devices dma operation at probe time
>      drivers: acpi: Handle IOMMU lookup failure with deferred probing or error
> for doing the dma ops configuration at probe time for acpi based platform
> as well. Did not have a acpi based platform to test the changes and with
> my still catching up knowledge on acpi/enumeration those two patches needs
> to be reviewed/tested more.

I've checked this patchset on my development boards: Odroid U3 
(ARM/Exynos4412),
XU3 (ARM/Exynos5422) and TM2 (ARM64/Exynos5433) and my queued patches 
for Exynos
IOMMU driver [1]. Besides the issue with an excessive dev_info, which 
causes NULL
pointer dereference (reported in reply to patch #6), it works fine on 
all those
platforms! Please add (again) my:

Tested-by: Marek Szyprowski <m.szyprowski at samsung.com>

[1] https://www.spinics.net/lists/linux-samsung-soc/msg56354.html

> Previous post of this series [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@lists.linux-foundation.org/msg13940.html
> [5] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-October/460832.html
>
> 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
>
> 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):
>    drivers: platform: Configure dma operations at probe time
>    arm64: dma-mapping: Remove the notifier trick to handle early setting
>      of dma_ops
>    drivers: acpi: Configure acpi devices dma operation at probe time
>    drivers: acpi: Handle IOMMU lookup failure with deferred probing or
>      error
>
>   arch/arm64/mm/dma-mapping.c | 132 ++++----------------------------------------
>   drivers/acpi/arm64/iort.c   |  17 +++++-
>   drivers/acpi/glue.c         |   6 --
>   drivers/acpi/scan.c         |   7 ++-
>   drivers/base/dd.c           |  10 ++++
>   drivers/base/dma-mapping.c  |  32 +++++++++++
>   drivers/iommu/arm-smmu-v3.c |  35 +-----------
>   drivers/iommu/arm-smmu.c    |  58 +++----------------
>   drivers/iommu/dma-iommu.c   |   1 +
>   drivers/iommu/of_iommu.c    | 114 +++++++++++++++++++++++++++-----------
>   drivers/of/address.c        |  20 ++++++-
>   drivers/of/device.c         |  36 ++++++------
>   drivers/of/platform.c       |  10 +---
>   drivers/pci/probe.c         |  17 +++---
>   include/acpi/acpi_bus.h     |   2 +-
>   include/linux/acpi.h        |   7 ++-
>   include/linux/dma-mapping.h |   3 +
>   include/linux/of_device.h   |  10 +++-
>   include/linux/pci.h         |   5 ++
>   19 files changed, 238 insertions(+), 284 deletions(-)
>

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