Re: [PATCH v5 0/5] MdeModulePkg: add support for non-discoverable devices

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 5 December 2016 at 15:35, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> The rationale for this series is the fact that many ARM platforms implement
> some form of PCI 'emulation', to allow non-discoverable devices that implement
> standardized host controller interfaces (i.e., EHCI, AHCI) to be controlled by
> the generic EDK2 drivers, which are layered on top of the PCI I/O protocols
> (even though the respective host controller specifications don't mandate that)
>
> There are a couple of problems with that approach:
> - Most implementations are based on the original code created for BeagleBoard,
>   which is a 32-bit platform. Unlike x86, which usually does not perform PCI
>   DMA above 4 GB, the ARM ecosystem is much more heterogeneous, and platforms
>   that have memory both above and below the 4 GB mark may ship with, e.g., EHCI
>   controllers that do not implement 64-bit DMA addressing.
> - Implementations depend on the DmaLib library class in EmbeddedPkg, of which
>   coherent and non-coherent implementations exists. However, both types of
>   devices may appear on a single platform, requiring several instances of the
>   same driver.
> - Existing implementations do not follow the UEFI driver model, but instantiate
>   a fixed number of PCI I/O protocol handles, and bring up all the devices when
>   doing so. However, the UEFI philosophy is to only instantiate (and thus
>   initialize) devices that are involved in booting.
>
> So instead, let's define a base protocol that simply asserts the presence of
> a certain kind of device at a certain memory offset, allowing platforms to
> instantiate any number of these statically, and leave it to post-DXE driver
> dispatch to actually bind the drivers as usual. This is implemented in patch #1.
> Note that it includes an AMBA device type, which we intend to use in the future
> to move ARM AMBA drivers to the UEFI driver model as well (i.e., LCD controller,
> SD/MMC controller)
>
> Patch #2 implements a utility library to register non-discoverable devices.
>
> Patch #3 implements the UEFI driver that instantiates PCI I/O protocol handles
> for non-discoverable devices that we know can be driven by a generic driver in
> EDK2. The initial version implements coherent DMA only.
>

All,

I am going to go ahead and push patches #1 - #3, given that they are
reviewed by Ray, and that we have other work that depends on it, for
Marvell and AMD Seattle

As far as the remaining patches are concerned: only patch #4 needs a
R-b from Ray, patch #5 is good to go but depends on #4

Thanks,
Ard.


> Patch #4 implements non-coherent DMA for the driver added in patch #3.
>
> Patch #5 is included for reference. It ports the BeagleBoard platform to the
> new driver stack.
>
> Changes in v5:
> - replaced open coded 64-bit shift with RShiftU64() (#3)
> - several fixes for NonCoherentAllocateBuffer()
> - moved misplaced list head initialization from #3 to #4
> - added Ray's Reviewed-by to patches #1 to #3
> - added Marcin's Tested-by to patches #1 to #4
>
> Branch can be found here
> https://git.linaro.org/people/ard.biesheuvel/uefi-next.git/log/?h=non-discoverable-pci-v5
>
> Changes in v4:
> - use GUIDs to describe the type of device (AHCI, EHCI, etc), rathen than en
>   enum, to make the protocol more flexible and futureproof
> - revert special handling of SDHCI, which does not map cleanly onto a single
>   PCI device (SDHCI-PCI may expose several slots, each of which is a full
>   fledged implementation of the SDHCI spec, but the EDK2 SDHCI driver does
>   not model those as a bus)
> - don't treat 64-bit BARs as 2 logical BARs
>
> Branch can be found here
> https://git.linaro.org/people/ard.biesheuvel/uefi-next.git/log/?h=non-discoverable-pci-v4
>
> Changes in v3:
> - Modified the base protocol to describe any number of resources using ACPI
>   resource descriptors. The current crop of targeted peripherals does not
>   require that, but it allows for much more flexibility in the future. This
>   also means that the MMIO region sizes are no longer hard-coded base on the
>   controller type (EHCI, AHCI, etc) but need to be declared when the devices
>   are registered.
> - Update the registration library API to allow multiple MMIO regions to be
>   declared.
> - When performing uncached allocations, record the original memory region
>   attributes so we can restore them correctly on free.
> - Some fixes in the 4GB boundary checks for Map/Unmap
> - Rename gNonDiscoverableDeviceProtocolGuid to
>   gEdkiiNonDiscoverableDeviceProtocolGuid
>
>
> Ard Biesheuvel (5):
>   MdeModulePkg: introduce non-discoverable device protocol
>   MdeModulePkg: introduce helper library to register non-discoverable
>     devices
>   MdeModulePkg: implement generic PCI I/O driver for non-discoverable
>     devices
>   MdeModulePkg/NonDiscoverablePciDeviceDxe: add support for non-coherent
>     DMA
>   Omap35xxPkg/PciEmulation: port to new non-discoverable device
>     infrastructure
>
>  BeagleBoardPkg/BeagleBoardPkg.dsc                                                                  |    2 +
>  BeagleBoardPkg/BeagleBoardPkg.fdf                                                                  |    1 +
>  MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/ComponentName.c                                   |   75 ++
>  MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c                     |  235 ++++
>  MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.inf                   |   54 +
>  MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c                      | 1121 ++++++++++++++++++++
>  MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h                      |  113 ++
>  MdeModulePkg/Include/Guid/NonDiscoverableDevice.h                                                  |   58 +
>  MdeModulePkg/Include/Library/NonDiscoverableDeviceRegistrationLib.h                                |   62 ++
>  MdeModulePkg/Include/Protocol/NonDiscoverableDevice.h                                              |   77 ++
>  MdeModulePkg/Library/NonDiscoverableDeviceRegistrationLib/NonDiscoverableDeviceRegistrationLib.c   |  204 ++++
>  MdeModulePkg/Library/NonDiscoverableDeviceRegistrationLib/NonDiscoverableDeviceRegistrationLib.inf |   46 +
>  MdeModulePkg/MdeModulePkg.dec                                                                      |   18 +
>  MdeModulePkg/MdeModulePkg.dsc                                                                      |    3 +
>  Omap35xxPkg/Omap35xxPkg.dsc                                                                        |    2 +-
>  Omap35xxPkg/PciEmulation/PciEmulation.c                                                            |  578 +---------
>  Omap35xxPkg/PciEmulation/PciEmulation.h                                                            |  292 -----
>  Omap35xxPkg/PciEmulation/PciEmulation.inf                                                          |   16 +-
>  Omap35xxPkg/PciEmulation/PciRootBridgeIo.c                                                         |  306 ------
>  19 files changed, 2102 insertions(+), 1161 deletions(-)
>  create mode 100644 MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/ComponentName.c
>  create mode 100644 MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c
>  create mode 100644 MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.inf
>  create mode 100644 MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c
>  create mode 100644 MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h
>  create mode 100644 MdeModulePkg/Include/Guid/NonDiscoverableDevice.h
>  create mode 100644 MdeModulePkg/Include/Library/NonDiscoverableDeviceRegistrationLib.h
>  create mode 100644 MdeModulePkg/Include/Protocol/NonDiscoverableDevice.h
>  create mode 100644 MdeModulePkg/Library/NonDiscoverableDeviceRegistrationLib/NonDiscoverableDeviceRegistrationLib.c
>  create mode 100644 MdeModulePkg/Library/NonDiscoverableDeviceRegistrationLib/NonDiscoverableDeviceRegistrationLib.inf
>  delete mode 100644 Omap35xxPkg/PciEmulation/PciEmulation.h
>  delete mode 100644 Omap35xxPkg/PciEmulation/PciRootBridgeIo.c
>
> --
> 2.7.4
>