A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus use the corresponding function "kmalloc_array".
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/b71c8fee-8e84-9f1b-8569-f1ae8b879cc5@users.sourceforge.net
Except for nouveau, only legacy drivers need this really. And nouveau
is already marked up with DRIVER_KMS_LEGACY_CONTEXT as the special
case.
I've tried to be careful to leave everything related to modeset still
using the DRIVER_MODESET flag. Otherwise it's a direct replacement of
!DRIVER_MODESET with DRIVER_LEGACY checks. Also helps readability
since fewer negative checks overall.
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Frank Binns <frank.binns@imgtec.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470251470-30830-2-git-send-email-daniel.vetter@ffwll.ch
There can only be one current master, and it's for the overall device.
Render/control minors don't support master-based auth at all.
This simplifies the master logic a lot, at least in my eyes: All these
additional pointer chases are just confusing.
While doing the conversion I spotted some locking fail:
- drm_lock/drm_auth check dev->master without holding the
master_mutex. This is fallout from
commit c996fd0b95
Author: Thomas Hellstrom <thellstrom@vmware.com>
Date: Tue Feb 25 19:57:44 2014 +0100
drm: Protect the master management with a drm_device::master_mutex v3
but I honestly don't care one bit about those old legacy drivers
using this.
- debugfs name info should just grab master_mutex.
- And the fbdev helper looked at it to figure out whether someone is
using KMS. We just need a consistent value, so READ_ONCE. Aside: We
should probably check if anyone has opened a control node too, but I
guess current userspace doesn't really do that yet.
v2: Balance locking, reported by Julia.
v3: Rebase on top of Chris' oops fixes.
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> (v2)
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466499262-18717-1-git-send-email-daniel.vetter@ffwll.ch
And again make sure it's a no-op for modern drivers. Another case of
dev->struct_mutex gone for modern drivers!
Note that the entirety of the legacy addmap interface is now protected
by DRIVER_MODESET. Note that just auditing kernel code is not enough,
since userspace loves to set up legacy maps on it's own for various
things - with ums userspace and kernel space share control over
resources.
v2: Also add a DRIVER_* check like for all other maps functions to
really short-circuit the code. And give drm_legacy_rmmap used by the
dev unregister code the same treatment.
v3:
- remove redundant return; (Alex, Chris)
- don't special case nouveau with DRIVER_KMS_LEGACY_CONTEXT.
v4: Again special case nouveau. The problem is not directly in the
ddx, but that it calls dri1 functions from the X server. And those do
call drmAddMap. Fixed only in
commit b1a630b48210d6a3c44994fce1b73273000ace5c
Author: Dave Airlie <airlied@redhat.com>
Date: Wed Nov 7 14:45:14 2012 +1000
nouveau: drop DRI1 device open interface.
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461741618-12679-1-git-send-email-daniel.vetter@ffwll.ch
Like in
commit 0e975980d4
Author: Peter Antoine <peter.antoine@intel.com>
Date: Tue Jun 23 08:18:49 2015 +0100
drm: Turn off Legacy Context Functions
we need to again make an exception for nouveau, but everyone else
really doesn't need this.
Dave Airlie dug out again why we need this: The problem is the legacy
dri1 open function the nouveau ddx called, and the problematic code is
actually in the X server itself. It was only fixed in
commit b1a630b48210d6a3c44994fce1b73273000ace5c
Author: Dave Airlie <airlied@redhat.com>
Date: Wed Nov 7 14:45:14 2012 +1000
nouveau: drop DRI1 device open interface.
Cc: Peter Antoine <peter.antoine@intel.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-5-git-send-email-daniel.vetter@ffwll.ch
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-6-git-send-email-daniel.vetter@ffwll.ch
We already express the drm/agp depencies correctly in Kconfig, so we
can rip this remnant from the shared drm core days.
Aside: Pretty much all the #ifdefs in radeon/nouveau could be killed
if ttm would provide dummy functions. I'm not going to volunteer for
that though.
v2: Use IS_ENABLED(CONFIG_AGP) as suggested by Ville
v3: Polish from Ville's review.
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com> (v2)
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Also sprinkle the customary legacy_ prefix.
Unfortunately we can't move the other functions since i915 is still
using them. Shame on me for that one :(
v2: Fix patch subject as spotted by David Herrmann.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Also drop the unneeded EXPORT_SYMBOL and sprinkle drm_legacy_ prefixes
where missing.
v2: Drop the confusing _core_ and drop extern, both suggested by
David.
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Move internal declarations to drm_legacy.h and add drm_legacy_*() prefix
to all legacy functions.
[airlied: add a bit of an explaination to drm_legacy.h]
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This object is not used except for static fields in drm_bufs *cough*.
Inline the watermark fields and drop the unused structure definition.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Update pull request with drm core patches. Mostly some polish for the
primary plane stuff and a pile of patches all over from Thierry. Has
survived a few days in drm-intel-nightly without causing ill.
I've frobbed my scripts a bit to also tag my topic branches so that you
have something stable to pull - I've accidentally pushed a bunch more
patches onto this branch before you've taken the old pull request.
* tag 'topic/core-stuff-2014-05-05' of git://anongit.freedesktop.org/drm-intel:
drm: Make drm_crtc_helper_disable() return void
drm: Fix indentation of closing brace
drm/dp: Fix typo in comment
drm: Fixup flip-work kerneldoc
drm/fb: Fix typos
drm/edid: Cleanup kerneldoc
drm/edid: Drop revision argument for drm_mode_std()
drm: Try to acquire modeset lock on panic or sysrq
drm: remove unused argument from drm_open_helper
drm: Handle ->disable_plane failures correctly
drm: Simplify fb refcounting rules around ->update_plane
drm/crtc-helper: gc usless connector loop in disable_unused_functions
drm/plane_helper: don't disable plane in destroy function
drm/plane-helper: Fix primary plane scaling check
drm: make mode_valid callback optional
drm/edid: Fill PAR in AVI infoframe based on CEA mode list
The closing brace of the body of drm_addmap_core() is indented wrongly.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Since really that's all it protects - legacy horror stories in
drm_bufs.c. Since I don't want to waste any more time on this I didn't
bother to actually look at what it protects in there, but it's at
least contained now.
v2: Move the spurious hunk to the right patch (Thierry).
Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Most place actually want to just check for dev->agp (most do, but a
few don't so this fixes a few potential NULL derefs). The only
exception is the agp init code which should check for the AGP driver
feature flag.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Gone with the new gem vma offset manager from David.
We can also ditch the uapi header definition from the enum since
userspace never used this. It ended up in there purely for historical
reasons (for reusing the old drm mmap code essentially), not because
userspace ever needed it.
Cc: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
We might as well have a real ioctl function which checks for the
callbacks. This seems to be a remnant from back in the days when each
drm driver had their own complete ioctl table, with no shared core
drm table at all.
To make really sure no mis-guided user in a kms driver pops up again
explicitly check for that in the new ioctl implementation.
v2: Drop the unused variable I've accidentally left in the code,
spotted by David Herrmann.
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The new arch_phys_wc_add/del functions do the right thing both with
and without MTRR support in the kernel. So we can drop these
additional checks.
David Herrmann suggest to also kill the DRIVER_USE_MTRR flag since
it's now unused, which spurred me to do a bit a better audit of the
affected drivers. David helped a lot in that. Quoting our mail
discussion:
On Wed, Jul 10, 2013 at 5:41 PM, David Herrmann <dh.herrmann@gmail.com> wrote:
> On Wed, Jul 10, 2013 at 5:22 PM, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
>> On Wed, Jul 10, 2013 at 3:51 PM, David Herrmann <dh.herrmann@gmail.com> wrote:
>>>> -#if __OS_HAS_MTRR
>>>> -static inline int drm_core_has_MTRR(struct drm_device *dev)
>>>> -{
>>>> - return drm_core_check_feature(dev, DRIVER_USE_MTRR);
>>>> -}
>>>> -#else
>>>> -#define drm_core_has_MTRR(dev) (0)
>>>> -#endif
>>>> -
>>>
>>> That was the last user of DRIVER_USE_MTRR (apart from drivers setting
>>> it in .driver_features). Any reason to keep it around?
>>
>> Yeah, I guess we could rip things out. Which will also force me to
>> properly audit drivers for the eventual behaviour change this could
>> entail (in case there's an x86 driver which did not ask for an mtrr,
>> but iirc there isn't).
>
> david@david-mb ~/dev/kernel/linux $ for i in drivers/gpu/drm/* ; do if
> test -d "$i" ; then if ! grep -q USE_MTRR -r $i ; then echo $i ; fi ;
> fi ; done
> drivers/gpu/drm/exynos
> drivers/gpu/drm/gma500
> drivers/gpu/drm/i2c
> drivers/gpu/drm/nouveau
> drivers/gpu/drm/omapdrm
> drivers/gpu/drm/qxl
> drivers/gpu/drm/rcar-du
> drivers/gpu/drm/shmobile
> drivers/gpu/drm/tilcdc
> drivers/gpu/drm/ttm
> drivers/gpu/drm/udl
> drivers/gpu/drm/vmwgfx
> david@david-mb ~/dev/kernel/linux $
>
> So for x86 gma500,nouveau,qxl,udl,vmwgfx don't set DRIVER_USE_MTRR.
> But I cannot tell whether they break if we call arch_phys_wc_add/del,
> anyway. At least nouveau seemed to work here, but it doesn't use AGP
> or drm_bufs, I guess.
Cool, thanks a lot for stitching together the list of drivers to look
at. So for real KMS drivers it's the drives responsibility to add an
mtrr if it needs one. nouvea, radeon, mgag200, i915 and vmwgfx do that
already. Somehow the savage driver also ends up doing that, I have no
idea why.
Note that gma500 as a pure KMS driver doesn't need MTRR setup since
the platforms that it supports all support PAT. So no MTRRs needed to
get wc iomappings.
The mtrr support in the drm core is all for legacy mappings of garts,
framebuffers and registers. All legacy drivers set the USE_MTRR flag,
so we're good there.
All in all I think we can really just ditch this
/endquote
v2: Also kill DRIVER_USE_MTRR as suggested by David Herrmann
v3: Rebase on top of David Herrmann's agp setup/cleanup changes.
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Now only legacy ums drivers have the DRIVER_HAVE_DMA driver feature
flag set, so strictly speaking the modesetting check is redundant. But
adding it has the upside that it makes it very clear that the dma
support is legacy stuff.
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
All users of it are now gone!
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
The version offered by the core is ridiculously optimized and
does the same thing. So use it.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
It fiddles the sarea out of the maps which are also handled in
drm_bufs.c
With this drm_drv.c is a notch more legacy free.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@gmail.com>
I didn't fix this in the earlier patch -- it would have broken the
build due to the now-deleted garbage in drm_os_linux.h.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Previously, DRM_FRAME_BUFFER mappings, as well as DRM_REGISTERS
mappings with DRM_WRITE_COMBINING set, resulted in an unconditional
MTRR being added but the actual mappings being created as UC-.
Now these mappings have the MTRR added only if needed, but they will
be mapped with pgprot_writecombine.
The non-WC DRM_REGISTERS case now uses pgprot_noncached instead of
hardcoding the bit twiddling.
The DRM_AGP case is unchanged for now.
[airlied: fix ppc build]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Convert #include "..." to #include <path/...> in drivers/gpu/.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
Absolutely unused. All the values are only ever initialized and
then used at most in some debug printout functions.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This continues the theme started with vm_brk() and vm_munmap():
vm_mmap() does the same thing as do_mmap(), but additionally does the
required VM locking.
This uninlines (and rewrites it to be clearer) do_mmap(), which sadly
duplicates it in mm/mmap.c and mm/nommu.c. But that way we don't have
to export our internal do_mmap_pgoff() function.
Some day we hopefully don't have to export do_mmap() either, if all
modular users can become the simpler vm_mmap() instead. We're actually
very close to that already, with the notable exception of the (broken)
use in i810, and a couple of stragglers in binfmt_elf.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Drivers using multiple framebuffers got broken by commit
41c2e75e60 which ignored the framebuffer
(or register) map offset when looking for existing maps. The rationale
was that the kernel-userspace ABI is fixed at a 32-bit offset, so the
real offsets could not always be handed over for comparison.
Instead of ignoring the offset we will compare the lower 32 bit. Drivers
using multiple framebuffers should just make sure that the lower 32 bit
are different. The existing drivers in question are practically limited
to 32-bit systems so that should be fine for them.
It is assumed that current drivers always specify a correct framebuffer
map offset, even if this offset was ignored since above commit. So this
patch should not change anything for drivers using only one framebuffer.
Drivers needing multiple framebuffers with 64-bit map offsets will need
to cook up something, for instance keeping an ID in the lower bit which
is to be aligned away when it comes to using the offset.
All of above applies to _DRM_REGISTERS as well.
Signed-off-by: Tormod Volden <debian.tormod@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Remove an obsolete Alpha adjustment, and modify another,
to go with the current Alpha architecture support.
Signed-off-by: Jay Estabrook <jay.estabrook@gmail.com>
Tested-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Currently most, if not all, memory allocation in drm_bufs.c is followed by initializing the memory with 0.
Replace the use of kmalloc+memset with kzalloc.
Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
* drm-platform:
drm: Make sure the DRM offset matches the CPU
drm: Add __arm defines to DRM
drm: Add support for platform devices to register as DRM devices
drm: Remove drm_resource wrappers
Add __arm defines to specify behavior specific for
an ARM processor.
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Remove the drm_resource wrappers and directly use the
actual PCI and/or platform functions in their place.
[airlied: fixup nouveau properly to build]
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
drm_pci_alloc() has input of address mask for setting pci dma
mask on the device, which should be properly setup by drm driver.
And leave it as a param for drm_pci_alloc() would cause confusion
or mistake would corrupt the correct dma mask setting, as seen on
intel hw which set wrong dma mask for hw status page. So remove
it from drm_pci_alloc() function.
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Fix the error message: this is add, not rm.
Move the closing brace to proper spot: _DRM_GEM branch should not be
included in the block.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Dave Airlie <airlied@redhat.com>
It hasn't been used in ages, and having the user tell your how much
memory is being freed at free time is a recipe for disaster even if it
was ever used.
Signed-off-by: Eric Anholt <eric@anholt.net>
A driver will use the _DRM_DRIVER map flag to indicate that it wants
to be responsible for removing the map itself, bypassing the DRM's
automagic cleanup code.
Since the multi-master changes this has been broken, resulting in some
drivers having their registers unmapped before it's finished with them.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Currently, userspace can fail to obtain the SAREA mapping (among other
reasons) if it passes SAREA_MAX to drmAddMap without aligning it to the
page size. This breaks for example on PowerPC with 64K pages and radeon
despite the kernel radeon actually doing the right rouding in the first
place.
The way SAREA_MAX is defined with a bunch of ifdef's and duplicated
between libdrm and the X server is gross, ultimately it should be
retrieved by userspace from the kernel, but in the meantime, we have
plenty of existing userspace built with bad values that need to work.
This patch works around broken userspace by rounding the requested size
in drm_addmap_core() of any SHM map to the page size. Since the backing
memory for SHM maps is also allocated within addmap_core, there is no
danger of adjacent memory being exposed due to the increased map size.
The only side effect is that drivers that previously tried to create or
access SHM maps using a size < PAGE_SIZE and failed (getting -EINVAL),
will now succeed at the cost of a little bit more memory used if that
happens to be when the map is created.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Platforms such as sparc64 have D-cache aliasing issues. We
cannot allow virtual mappings in different contexts to be such
that two cache lines can be loaded for the same backing data.
Updates to one cache line won't be seen by accesses to the other
cache line.
Code in sparc64 and other architectures solve this problem by
making sure that all userland mappings of MAP_SHARED objects have
the same virtual address base. They implement this by keying
off of the page offset, and using that to choose a suitably
consistent virtual address for mmap() requests.
Making things even worse, getting this wrong on sparc64 can result
in hangs during DRM lock acquisition. This is because, at least on
UltraSPARC-III, normal loads consult the D-cache but atomics such
as 'cas' (which is what cmpxchg() is implement using) only consult
the L2 cache. So if a D-cache alias is inserted, the load can
see different data than the atomic, and we'll loop forever because
the atomic compare-and-exchange will never complete successfully.
So to make this all work properly, we need to make sure that the
hash address computed by drm_map_handle() preserves the SHMLBA
relevant bits, and that's what this patch does for _DRM_SHM mappings.
As a historical note, many years ago this bug didn't exist because we
used to just use the low 32-bits of the address as the hash and just
hope for the best. This preserved the SHMLBA bits properly. But when
the hashtab code was added to DRM, this was no longer the case.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Paul McQuade