forked from Minki/linux
mainlining shenanigans
23b4822528
On SoCs with DMM/TILER, we have two ways to allocate buffers: normal dma_alloc or via DMM (which basically functions as an IOMMU). DMM can map 128MB at a time, and we only map the DMM buffers when they are used (i.e. not at alloc time). If DMM is present, omapdrm always uses DMM. There are use cases that require lots of big buffers that are being used at the same time by different IPs. At the moment the userspace has a hard maximum of 128MB. This patch adds three new flags that can be used by the userspace to solve the situation: OMAP_BO_MEM_CONTIG: The driver will use dma_alloc to get the memory. This can be used to avoid DMM if the userspace knows it needs more than 128M of memory at the same time. OMAP_BO_MEM_DMM: The driver will use DMM to get the memory. There's not much use for this flag at the moment, as on platforms with DMM it is used by default, but it's here for completeness. OMAP_BO_MEM_PIN: The driver will pin the memory at alloc time, and keep it pinned. This can be used to 1) get an error at alloc time if DMM space is full, and 2) get rid of the constant pin/unpin operations which may have some effect on performance. If none of the flags are given, the behavior is the same as currently. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Reviewed-by: Jean-Jacques Hiblot <jjhiblot@ti.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191010120000.1421-9-jjhiblot@ti.com |
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| 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.