iosys-map: Add offset to iosys_map_memcpy_to()

In certain situations it's useful to be able to write to an
offset of the mapping. Add a dst_offset to iosys_map_memcpy_to().

Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Christian König <christian.koenig@amd.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-2-lucas.demarchi@intel.com

dma-buf-map: Rename to iosys-map

Rename struct dma_buf_map to struct iosys_map and corresponding APIs.
Over time dma-buf-map grew up to more functionality than the one used by
dma-buf: in fact it's just a shim layer to abstract system memory, that
can be accessed via regular load and store, from IO memory that needs to
be acessed via arch helpers.

The idea is to extend this API so it can fulfill other needs, internal
to a single driver. Example: in the i915 driver it's desired to share
the implementation for integrated graphics, which uses mostly system
memory, with discrete graphics, which may need to access IO memory.

The conversion was mostly done with the following semantic patch:

@r1@
@@
- struct dma_buf_map
+ struct iosys_map

@r2@
@@
(
- DMA_BUF_MAP_INIT_VADDR
+ IOSYS_MAP_INIT_VADDR
|
- dma_buf_map_set_vaddr
+ iosys_map_set_vaddr
|
- dma_buf_map_set_vaddr_iomem
+ iosys_map_set_vaddr_iomem
|
- dma_buf_map_is_equal
+ iosys_map_is_equal
|
- dma_buf_map_is_null
+ iosys_map_is_null
|
- dma_buf_map_is_set
+ iosys_map_is_set
|
- dma_buf_map_clear
+ iosys_map_clear
|
- dma_buf_map_memcpy_to
+ iosys_map_memcpy_to
|
- dma_buf_map_incr
+ iosys_map_incr
)

@@
@@
- #include <linux/dma-buf-map.h>
+ #include <linux/iosys-map.h>

Then some files had their includes adjusted and some comments were
update to remove mentions to dma-buf-map.

Since this is not specific to dma-buf anymore, move the documentation to
the "Bus-Independent Device Accesses" section.

v2:
- Squash patches

v3:
- Fix wrong removal of dma-buf.h from MAINTAINERS
- Move documentation from dma-buf.rst to device-io.rst

v4:
- Change documentation title and level

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com

drm: Stop spamming log with drm_cache message

Only x86 and in some cases PPC have support added in drm_cache.c for the
clflush class of functions. However warning once is sufficient to taint
the log instead of spamming it with "Architecture has no drm_cache.c
support" every few millisecond. Switch to WARN_ONCE() so we still get
the log message, but only once, together with the warning. E.g:

------------[ cut here ]------------
Architecture has no drm_cache.c support
WARNING: CPU: 80 PID: 888 at drivers/gpu/drm/drm_cache.c:139 drm_clflush_sg+0x40/0x50 [drm]
...

v2 (Jani): use WARN_ONCE() and keep the message previously on pr_err()

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220131165926.3230642-2-lucas.demarchi@intel.com

mm: don't include <linux/memremap.h> in <linux/mm.h>

Move the check for the actual pgmap types that need the free at refcount
one behavior into the out of line helper, and thus avoid the need to
pull memremap.h into mm.h.

Link: https://lkml.kernel.org/r/20220210072828.2930359-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

treewide: Replace the use of mem_encrypt_active() with cc_platform_has()

Replace uses of mem_encrypt_active() with calls to cc_platform_has() with
the CC_ATTR_MEM_ENCRYPT attribute.

Remove the implementation of mem_encrypt_active() across all arches.

For s390, since the default implementation of the cc_platform_has()
matches the s390 implementation of mem_encrypt_active(), cc_platform_has()
does not need to be implemented in s390 (the config option
ARCH_HAS_CC_PLATFORM is not set).

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210928191009.32551-9-bp@alien8.de

drm: Fix typo in comments

fix typo for drm

v1->v2:
respin with the change "iff ==> implies that"

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730132729.376-1-caihuoqing@baidu.com

drm: Add a prefetching memcpy_from_wc

Reading out of write-combining mapped memory is typically very slow
since the CPU doesn't prefetch. However some archs have special
instructions to do this.

So add a best-effort memcpy_from_wc taking dma-buf-map pointer
arguments that attempts to use a fast prefetching memcpy and
otherwise falls back to ordinary memcopies, taking the iomem tagging
into account.

The code is largely copied from i915_memcpy_from_wc.

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Christian König <christian.koenig@amd.com>
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://lore.kernel.org/r/20210602083818.241793-5-thomas.hellstrom@linux.intel.com
Link: https://patchwork.freedesktop.org/patch/msgid/20210602083818.241793-5-thomas.hellstrom@linux.intel.com

drm: Include <linux/mem_encrypt.h> in drm_cache.c

The function drm_need_swiotbl() needs mem_encrypt_active() from
<linux/mem_encrypt.h>. The include got lost when refactoring the
code recently.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 3abc66706385 ("drm: Implement drm_need_swiotlb() in drm_cache.c")
Reviewed-by: Christian König <christian.koenig@amd.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20210114080535.17132-1-tzimmermann@suse.de

drm: Implement drm_need_swiotlb() in drm_cache.c

The function is declared in drm_cache.h. I also removed the curly
braces from the for loop to adhere to kernel coding style.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210112081035.6882-3-tzimmermann@suse.de

drm: core: fix common struct sg_table related issues

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>

drm/gpu: Fix Memory barrier without comment Issue

-Issue found using checkpatch.pl
-Insert comments for memory barrier usage

Signed-off-by: Bhanusree <bhanusreemahesh@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1571984858-4644-1-git-send-email-bhanusreemahesh@gmail.com

drm/gpu: Fix Missing blank line after declarations

-Insert a blank line after the declarations.
-Issue found using checkpatch.pl

Signed-off-by: Bhanusree <bhanusreemahesh@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1571984833-4596-1-git-send-email-bhanusreemahesh@gmail.com

drm/gpu: Add comment for memory barrier

-Add comment for memory barrier
-Issue found using checkpatch.pl

Signed-off-by: Bhanusree <bhanusreemahesh@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1571891313-14341-1-git-send-email-bhanusreemahesh@gmail.com

gpu: drm: core: Convert printk(KERN_<LEVEL> to pr_<level>

Use a more common logging style.

Miscellanea:

o Coalesce formats and realign arguments

Signed-off-by: Joe Perches <joe@perches.com>
[danvet: Resolve minor conflict in drm_edid.c]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm: Update drm_cache.c to pull in the new drm_cache.h

The prototypes were moved to a new header, but the function definitions
were not updated to pull in the declarations.

drivers/gpu/drm/drm_cache.c:79:1: warning: no previous prototype for ‘drm_clflush_pages’ [-Wmissing-prototypes]
drivers/gpu/drm/drm_cache.c:120:1: warning: no previous prototype for ‘drm_clflush_sg’ [-Wmissing-prototypes]
drivers/gpu/drm/drm_cache.c:152:1: warning: no previous prototype for ‘drm_clflush_virt_range’ [-Wmissing-prototypes]

Fixes: f9a87bd7d5b6 ("drm: Move drm_clflush prototypes to drm_cache header file")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170121181944.24672-1-chris@chris-wilson.co.uk

drm: Document drm_cache interface

Notice that this uncovers an issue with the kernel-doc handling of array
arguments, causing the first parameter of drm_clflush_pages() to not
show up in the rst-generated page. A proposed fix is under review in
linux-doc: <http://www.spinics.net/lists/linux-doc/msg42544.html>

Changes since v1:
- Add section to drm-mm.rst.
- Fix kernel-doc style issues.
- s/memory/kernel memory/.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170109215649.6860-1-krisman@collabora.co.uk

drm: Restore double clflush on the last partial cacheline

This effectively reverts

commit afcd950cafea6e27b739fe7772cbbeed37d05b8b
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed Jun 10 15:58:01 2015 +0100

drm: Avoid the double clflush on the last cache line in drm_clflush_virt_range()

as we have observed issues with serialisation of the clflush operations
on Baytrail+ Atoms with partial updates. Applying the double flush on the
last cacheline forces that clflush to be ordered with respect to the
previous clflush, and the mfence then protects against prefetches crossing
the clflush boundary.

The same issue can be demonstrated in userspace with igt/gem_exec_flush.

Fixes: afcd950cafea6 (drm: Avoid the double clflush on the last cache...)
Testcase: igt/gem_concurrent_blit
Testcase: igt/gem_partial_pread_pwrite
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92845
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: dri-devel@lists.freedesktop.org
Cc: Akash Goel <akash.goel@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jason Ekstrand <jason.ekstrand@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1467880930-23082-6-git-send-email-chris@chris-wilson.co.uk

x86/cpufeature: Remove cpu_has_clflush

Use the fast variant in the DRM code.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dri-devel@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
Link: http://lkml.kernel.org/r/1459266123-21878-7-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

drm: Avoid the double clflush on the last cache line in drm_clflush_virt_range()

As the clflush operates on cache lines, and we can flush any byte
address, in order to flush all bytes given in the range we issue an
extra clflush on the last byte to ensure the last cacheline is flushed.
We can can the iteration to be over the actual cache lines to avoid this
double clflush on the last byte.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/cache: Use wbinvd helpers

When the original drm code was written there were no centralized functions for
doing a coordinated wbinvd across all CPUs. Now (since 2010) there are, so use
them instead of rolling a new one.

v2: On x86 UP systems the wbinvd_on_all_cpus() is defined as a static inline in
smp.h. We must therefore include this file so we don't get compiler errors.
This error was found by 0-DAY kernel test infrastructure. We only need this for
x86.

Cc: Intel GFX <intel-gfx@lists.freedesktop.org>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm: Missed clflushopt in drm_clflush_virt_range

With this commit:

2a0788dc9bc4 x86: Use clflushopt in drm_clflush_virt_range

If clflushopt is available on the system, we use it instead of clflush
in drm_clflush_virt_range. There were two calls to clflush in this
function, but only one was changed to clflushopt. This patch changes
the other clflush call to clflushopt.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Cc: H Peter Anvin <h.peter.anvin@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm: Make drm_clflush_virt_range() void*

Currently drm_cflush_virt_rage() takes a char* so the caller probably
has to do pointless casting to avoid compiler warnings. Make the
argument void* instead to avoid such issues.

v2: Use void* arithmetic (Chris)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

x86: Use clflushopt in drm_clflush_virt_range

If clflushopt is available on the system, use it instead of clflush in
drm_clflush_virt_range.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Link: http://lkml.kernel.org/r/1393441612-19729-5-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

x86: Use clflushopt in drm_clflush_page

If clflushopt is available on the system, use it instead of clflush in
drm_clflush_page.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Link: http://lkml.kernel.org/r/1393441612-19729-4-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

lib/scatterlist: sg_page_iter: support sg lists w/o backing pages

The i915 driver uses sg lists for memory without backing 'struct page'
pages, similarly to other IO memory regions, setting only the DMA
address for these. It does this, so that it can program the HW MMU
tables in a uniform way both for sg lists with and without backing pages.

Without a valid page pointer we can't call nth_page to get the current
page in __sg_page_iter_next, so add a helper that relevant users can
call separately. Also add a helper to get the DMA address of the current
page (idea from Daniel).

Convert all places in i915, to use the new API.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm: handle compact dma scatter lists in drm_clflush_sg()

So far the assumption was that each scatter list entry contains a single
page. This might not hold in the future, when we'll introduce compact
scatter lists, so prepare for this here.

Reference: http://www.spinics.net/lists/dri-devel/msg33917.html
Signed-off-by: Imre Deak <imre.deak@intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/

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>

drm/i915: Replace the array of pages with a scatterlist

Rather than have multiple data structures for describing our page layout
in conjunction with the array of pages, we can migrate all users over to
a scatterlist.

One major advantage, other than unifying the page tracking structures,
this offers is that we replace the vmalloc'ed array (which can be up to
a megabyte in size) with a chain of individual pages which helps reduce
memory pressure.

The disadvantage is that we then do not have a simple array to iterate,
or to access randomly. The common case for this is in the relocation
processing, which will typically fit within a single scatterlist page
and so be almost the same cost as the simple array. For iterating over
the array, the extra function call could be optimised away, but in
reality is an insignificant cost of either binding the pages, or
performing the pwrite/pread.

v2: Fix drm_clflush_sg() to not invoke wbinvd as well! And fix the
trivial compile error from rebasing.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm: micro optimise cache flushing

We hit this a lot with i915 and although we'd like to engineer things to hit
it a lot less, this commit at least makes it consume a few less cycles.

from something containing
movzwl 0x0(%rip),%r10d
to
add %r8,%rdx

I only noticed it while using perf to profile something else.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm: add helper to clflush a virtual address range

Useful when the page is already mapped to copy date in/out.

For -stable because the next patch (fixing phys obj pwrite) needs this
little helper function.

Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm: remove the second argument of k[un]map_atomic()

Signed-off-by: Cong Wang <amwang@redhat.com>

gpu: Add export.h as required to drivers/gpu files.

They need this to get all the EXPORT_SYMBOL variants and THIS_MODULE

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

drm: fix drm_cache.c for arch with no support.

This produces a warn on for architectures where this gets called
but we don't have a cache flushing implementation suitable.

Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/ttm: consolidate cache flushing code in one place.

This merges the TTM and drm cache flushing into one file in the
drm core.

Signed-off-by: Dave Airlie <airlied@redhat.com>

drm: wbinvd is cache coherent.

doing an ipi for the wbinvd case isn't necessary.

Signed-off-by: Dave Airlie <airlied@redhat.com>

drm: Add GEM ("graphics execution manager") to i915 driver.

GEM allows the creation of persistent buffer objects accessible by the
graphics device through new ioctls for managing execution of commands on the
device. The userland API is almost entirely driver-specific to ensure that
any driver building on this model can easily map the interface to individual
driver requirements.

GEM is used by the 2d driver for managing its internal state allocations and
will be used for pixmap storage to reduce memory consumption and enable
zero-copy GLX_EXT_texture_from_pixmap, and in the 3d driver is used to enable
GL_EXT_framebuffer_object and GL_ARB_pixel_buffer_object.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>