[PATCH v4 0/5] MdeModulePkg: add support for non-discoverable devices

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

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.

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 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                      | 1116 ++++++++++++++++++++
 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, 2097 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