mainlining shenanigans
f735c40ed9
When newer revisions of the Axienet IP are configured for a 64-bit bus, we *need* to write to the MSB part of the an address registers, otherwise the IP won't recognise this as a DMA start condition. This is even true when the actual DMA address comes from the lower 4 GB. To autodetect this configuration, at probe time we write all 1's to such an MSB register, and see if any bits stick. If this is configured for a 32-bit bus, those MSB registers are RES0, so reading back 0 indicates that no MSB writes are necessary. On the other hands reading anything other than 0 indicated the need to write the MSB registers, so we set the respective flag. The actual DMA mask stays at 32-bit for now. To help bisecting, a separate patch will enable allocations from higher addresses. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
||
---|---|---|
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.