linux_dsm_epyc7002/arch/arm
Vladimir Murzin 1c51c429f3 ARM: NOMMU: Introduce dma operations for noMMU
R/M classes of cpus can have memory covered by MPU which in turn might
configure RAM as Normal i.e. bufferable and cacheable. It breaks
dma_alloc_coherent() and friends, since data can stuck in caches now
or be buffered.

This patch factors out DMA support for NOMMU configuration into
separate entity which provides dedicated dma_ops. We have to handle
there several cases:
- configurations with MMU/MPU setup
- configurations without MMU/MPU setup
- special case for M-class, since caches and MPU there are optional

In general we rely on default DMA area for coherent allocations or/and
per-device memory reserves suitable for coherent DMA, so if such
regions are set coherent allocations go from there.

In case MMU/MPU was not setup we fallback to normal page allocator for
DMA memory allocation.

In case we run M-class cpus, for configuration without cache support
(like Cortex-M3/M4) dma operations are forced to be coherent and wired
with dma-noop (such decision is made based on cacheid global
variable); however, if caches are detected there and no DMA coherent
region is given (either default or per-device), dma is disallowed even
MPU is not set - it is because M-class implement system memory map
which defines part of address space as Normal memory.

Reported-by: Alexandre Torgue <alexandre.torgue@st.com>
Reported-by: Andras Szemzo <sza@esh.hu>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Andras Szemzo <sza@esh.hu>
Tested-by: Alexandre TORGUE <alexandre.torgue@st.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
[hch: removed the dma_supported() implementation that isn't required anymore]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-06-30 10:03:09 -07:00
..
boot ARM: SoC fixes 2017-06-19 16:50:09 +08:00
common arm: implement ->dma_supported instead of ->set_dma_mask 2017-06-28 06:54:49 -07:00
configs ARM: configs: add a gemini defconfig 2017-05-18 23:56:47 -07:00
crypto
firmware
include ARM: NOMMU: Introduce dma operations for noMMU 2017-06-30 10:03:09 -07:00
kernel arm64 2nd set of updates for 4.12: 2017-05-11 11:27:54 -07:00
kvm arm: KVM: Allow unaligned accesses at HYP 2017-06-06 22:20:02 +02:00
lib
mach-alpine
mach-artpec
mach-asm9260
mach-aspeed
mach-at91 Merge tag 'at91-4.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux into fixes 2017-06-01 17:07:31 -07:00
mach-axxia
mach-bcm ARM: remove duplicate 'const' annotations' 2017-05-19 10:12:55 +02:00
mach-berlin
mach-clps711x
mach-cns3xxx ARM: remove duplicate 'const' annotations' 2017-05-19 10:12:55 +02:00
mach-davinci ARM: davinci: PM: Do not free useful resources in normal path in 'davinci_pm_init' 2017-05-17 15:25:18 +05:30
mach-digicolor
mach-dove
mach-ebsa110
mach-efm32
mach-ep93xx
mach-exynos
mach-footbridge
mach-gemini
mach-highbank
mach-hisi
mach-imx ARM: SoC driver updates 2017-05-09 10:01:15 -07:00
mach-integrator
mach-iop13xx
mach-iop32x
mach-iop33x
mach-ixp4xx scripts/spelling.txt: add regsiter -> register spelling mistake 2017-05-08 17:15:13 -07:00
mach-keystone
mach-ks8695
mach-lpc18xx
mach-lpc32xx
mach-mediatek
mach-meson
mach-mmp
mach-moxart
mach-mv78xx0
mach-mvebu
mach-mxs
mach-netx
mach-nomadik
mach-nspire
mach-omap1
mach-omap2 ARM: remove duplicate 'const' annotations' 2017-05-19 10:12:55 +02:00
mach-orion5x
mach-oxnas
mach-picoxcell
mach-prima2
mach-pxa
mach-qcom
mach-realview
mach-rockchip
mach-rpc
mach-s3c24xx
mach-s3c64xx
mach-s5pv210
mach-sa1100
mach-shmobile
mach-socfpga
mach-spear ARM: remove duplicate 'const' annotations' 2017-05-19 10:12:55 +02:00
mach-sti
mach-stm32
mach-sunxi
mach-tango
mach-tegra
mach-u300
mach-uniphier
mach-ux500
mach-versatile
mach-vexpress
mach-vt8500
mach-w90x900
mach-zx
mach-zynq
mm ARM: NOMMU: Introduce dma operations for noMMU 2017-06-30 10:03:09 -07:00
net arm: use set_memory.h header 2017-05-08 17:15:13 -07:00
nwfpe
oprofile
plat-iop
plat-omap
plat-orion
plat-pxa
plat-samsung
plat-versatile
probes
tools
vdso
vfp
xen xen-swiotlb: consolidate xen_swiotlb_dma_ops 2017-06-20 11:12:59 +02:00
Kconfig ARM: NOMMU: Introduce dma operations for noMMU 2017-06-30 10:03:09 -07:00
Kconfig-nommu
Kconfig.debug
Makefile