drm/exynos: fix a wrong error checking

Fix a wrong error checking in exynos_drm_dma.c module.

In the exynos_drm_register_dma function, both arm_iommu_create_mapping()
and iommu_get_domain_for_dev() functions are expected to return NULL as
an error.

However, the error checking is performed using the statement
if(IS_ERR(mapping)), which doesn't provide a suitable error value.
So check if 'mapping' is NULL, and if it is, return -ENODEV.

This issue[1] was reported by Dan.

Changelog v1:
- fix build warning.

[1] https://lore.kernel.org/all/33e52277-1349-472b-a55b-ab5c3462bfcf@moroto.mountain/

Reported-by : Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

iommu/dma: Make header private

Now that dma-iommu.h only contains internal interfaces, make it
private to the IOMMU subsytem.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/b237e06c56a101f77af142a54b629b27aa179d22.1660668998.git.robin.murphy@arm.com
[ joro : re-add stub for iommu_dma_get_resv_regions ]
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drm/exynos: Always initialize mapping in exynos_drm_register_dma()

In certain randconfigs, clang warns:

drivers/gpu/drm/exynos/exynos_drm_dma.c:121:19: warning: variable
'mapping' is uninitialized when used here [-Wuninitialized]
priv->mapping = mapping;
^~~~~~~
drivers/gpu/drm/exynos/exynos_drm_dma.c:111:16: note: initialize the
variable 'mapping' to silence this warning
void *mapping;
^
= NULL
1 warning generated.

This occurs when CONFIG_EXYNOS_IOMMU is enabled and both
CONFIG_ARM_DMA_USE_IOMMU and CONFIG_IOMMU_DMA are disabled, which makes
the code look like

void *mapping;

if (0)
mapping = arm_iommu_create_mapping()
else if (0)
mapping = iommu_get_domain_for_dev()

...
priv->mapping = mapping;

Add an else branch that initializes mapping to the -ENODEV error pointer
so that there is no more warning and the driver does not change during
runtime.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

dma-mapping: split <linux/dma-mapping.h>

Split out all the bits that are purely for dma_map_ops implementations
and related code into a new <linux/dma-map-ops.h> header so that they
don't get pulled into all the drivers. That also means the architecture
specific <asm/dma-mapping.h> is not pulled in by <linux/dma-mapping.h>
any more, which leads to a missing includes that were pulled in by the
x86 or arm versions in a few not overly portable drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>

drm/exynos: Fix dma_parms allocation

Since commit 9495b7e92f71 ("driver core: platform: Initialize dma_parms
for platform devices") driver core handles allocation of the dma_parms
structure for platform device, so there is no need to manually allocate
nor free it.

Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drm/exynos: Properly propagate return value in drm_iommu_attach_device()

Propagate the proper error codes from the called functions instead of
unconditionally returning 0.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Merge conflict so merged it manually.
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drm/exynos: Fix cleanup of IOMMU related objects

Store the IOMMU mapping created by the device core of each Exynos DRM
sub-device and restore it when the Exynos DRM driver is unbound. This
fixes IOMMU initialization failure for the second time when a deferred
probe is triggered from the bind() callback of master's compound DRM
driver. This also fixes the following issue found using kmemleak
detector:

unreferenced object 0xc2137640 (size 64):
comm "swapper/0", pid 1, jiffies 4294937900 (age 3127.400s)
hex dump (first 32 bytes):
50 a3 14 c2 80 a2 14 c2 01 00 00 00 20 00 00 00 P........... ...
00 10 00 00 00 80 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<3acd268d>] arch_setup_dma_ops+0x4c/0x104
[<9f7d2cce>] of_dma_configure+0x19c/0x3a4
[<ba07704b>] really_probe+0xb0/0x47c
[<4f510e4f>] driver_probe_device+0x78/0x1c4
[<7481a0cf>] device_driver_attach+0x58/0x60
[<0ff8f5c1>] __driver_attach+0xb8/0x158
[<86006144>] bus_for_each_dev+0x74/0xb4
[<10159dca>] bus_add_driver+0x1c0/0x200
[<8a265265>] driver_register+0x74/0x108
[<e0f3451a>] exynos_drm_init+0xb0/0x134
[<db3fc7ba>] do_one_initcall+0x90/0x458
[<6da35917>] kernel_init_freeable+0x188/0x200
[<db3f74d4>] kernel_init+0x8/0x110
[<1f3cddf9>] ret_from_fork+0x14/0x20
[<8cd12507>] 0x0
unreferenced object 0xc214a280 (size 128):
comm "swapper/0", pid 1, jiffies 4294937900 (age 3127.400s)
hex dump (first 32 bytes):
00 a0 ec ed 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<3acd268d>] arch_setup_dma_ops+0x4c/0x104
[<9f7d2cce>] of_dma_configure+0x19c/0x3a4
[<ba07704b>] really_probe+0xb0/0x47c
[<4f510e4f>] driver_probe_device+0x78/0x1c4
[<7481a0cf>] device_driver_attach+0x58/0x60
[<0ff8f5c1>] __driver_attach+0xb8/0x158
[<86006144>] bus_for_each_dev+0x74/0xb4
[<10159dca>] bus_add_driver+0x1c0/0x200
[<8a265265>] driver_register+0x74/0x108
[<e0f3451a>] exynos_drm_init+0xb0/0x134
[<db3fc7ba>] do_one_initcall+0x90/0x458
[<6da35917>] kernel_init_freeable+0x188/0x200
[<db3f74d4>] kernel_init+0x8/0x110
[<1f3cddf9>] ret_from_fork+0x14/0x20
[<8cd12507>] 0x0
unreferenced object 0xedeca000 (size 4096):
comm "swapper/0", pid 1, jiffies 4294937900 (age 3127.400s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<3acd268d>] arch_setup_dma_ops+0x4c/0x104
[<9f7d2cce>] of_dma_configure+0x19c/0x3a4
[<ba07704b>] really_probe+0xb0/0x47c
[<4f510e4f>] driver_probe_device+0x78/0x1c4
[<7481a0cf>] device_driver_attach+0x58/0x60
[<0ff8f5c1>] __driver_attach+0xb8/0x158
[<86006144>] bus_for_each_dev+0x74/0xb4
[<10159dca>] bus_add_driver+0x1c0/0x200
[<8a265265>] driver_register+0x74/0x108
[<e0f3451a>] exynos_drm_init+0xb0/0x134
[<db3fc7ba>] do_one_initcall+0x90/0x458
[<6da35917>] kernel_init_freeable+0x188/0x200
[<db3f74d4>] kernel_init+0x8/0x110
[<1f3cddf9>] ret_from_fork+0x14/0x20
[<8cd12507>] 0x0
unreferenced object 0xc214a300 (size 128):
comm "swapper/0", pid 1, jiffies 4294937900 (age 3127.400s)
hex dump (first 32 bytes):
00 a3 14 c2 00 a3 14 c2 00 40 18 c2 00 80 18 c2 .........@......
02 00 02 00 ad 4e ad de ff ff ff ff ff ff ff ff .....N..........
backtrace:
[<08cbd8bc>] iommu_domain_alloc+0x24/0x50
[<b835abee>] arm_iommu_create_mapping+0xe4/0x134
[<3acd268d>] arch_setup_dma_ops+0x4c/0x104
[<9f7d2cce>] of_dma_configure+0x19c/0x3a4
[<ba07704b>] really_probe+0xb0/0x47c
[<4f510e4f>] driver_probe_device+0x78/0x1c4
[<7481a0cf>] device_driver_attach+0x58/0x60
[<0ff8f5c1>] __driver_attach+0xb8/0x158
[<86006144>] bus_for_each_dev+0x74/0xb4
[<10159dca>] bus_add_driver+0x1c0/0x200
[<8a265265>] driver_register+0x74/0x108
[<e0f3451a>] exynos_drm_init+0xb0/0x134
[<db3fc7ba>] do_one_initcall+0x90/0x458
[<6da35917>] kernel_init_freeable+0x188/0x200
[<db3f74d4>] kernel_init+0x8/0x110
[<1f3cddf9>] ret_from_fork+0x14/0x20

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drm/exynos: drop drmP.h usage

Drop use of the deprecated drmP.h file.
Replace with forwards / externals as appropriate.

While touching the list of include files divide
them up in blocks and sort them.

v3:
- fix build errors in exynos_drm_g2d.c (Inki Dae)
The exynos_drm_g2d.c file is not built in the
standard configurations and was therefore missed.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
Fixed merge conflict.
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drm/exynos: use DRM_DEV_ERROR to print out error message

This patch just cleans up the use of error log macro, which changes
the log macro to DRM_DEV_ERROR.

Signed-off-by: Inki Dae <inki.dae@samsung.com>

drm/exynos/iommu: merge IOMMU and DMA code

As DMA code is the only user of IOMMU code both files can be merged.
It allows to remove stub functions, after slight adjustment of
exynos_drm_register_dma. Since IOMMU functions are used locally they
can be marked static.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drm/exynos/iommu: integrate IOMMU/DMA internal API

Exynos DRM drivers should work with and without IOMMU. Providing common
API generic to both scenarios should make code cleaner and allow further
code improvements.
The patch removes including of exynos_drm_iommu.h as the file contains
mostly IOMMU specific stuff, instead it exposes exynos_drm_*_dma functions
and puts them into exynos_drm_dma.c.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>