Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
dc3d8f85bb
For normal PHBs IODA PEs are handled on a per-bus basis so all the devices on that bus will share a PE. Which PE specificly is determined by the location of the MMIO BARs for the devices on the bus so we can't actually configure the bus PEs until after MMIO resources are allocated. As a result PEs are currently configured by pcibios_setup_bridge(), which is called just before the bridge windows are programmed into the bus' parent bridge. Configuring the bus PE here causes a few problems: 1. The root bus doesn't have a parent bridge so setting up the PE for the root bus requires some hacks. 2. The PELT-V isn't setup correctly because pnv_ioda_set_peltv() assumes that PEs will be configured in root-to-leaf order. This assumption is broken because resource assignment is performed depth-first so the leaf bridges are setup before their parents are. The hack mentioned in 1) results in the "correct" PELT-V for busses immediately below the root port, but not for devices below a switch. 3. It's possible to break the sysfs PCI rescan feature by removing all the devices on a bus. When the last device is removed from a PE its will be de-configured. Rescanning the devices on a bus does not cause the bridge to be reconfigured rendering the devices on that bus unusable. We can address most of these problems by moving the PE setup out of pcibios_setup_bridge() and into pcibios_bus_add_device(). This fixes 1) and 2) because pcibios_bus_add_device() is called on each device in root-to-leaf order so PEs for parent buses will always be configured before their children. It also fixes 3) by ensuring the PE is configured before initialising DMA for the device. In the event the PE was de-configured due to removing all the devices in that PE it will now be reconfigured when a new device is added since there's no dependecy on the bridge_setup() hook being called. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200417073508.30356-3-oohall@gmail.com |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.