Use the ttm_tt pages array for pages allocations, move the list
unwinding into the page allocation functions.
Signed-off-by: NJerome Glisse <jglisse@redhat.com>

. and some comments to make it easier to understand.

Ackedby: Randy Dunlap <randy.dunlap@oracle.com>
[v2: Added some more updates from Randy Dunlap]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This reverts commit 5a893fc2.

This causes a use after free in the ttm free alloc pages path,
when it tries to get the be after the be has been destroyed.
Signed-off-by: NDave Airlie <airlied@redhat.com>

This makes the accounting when using 'debug_dma_dump_mappings()'
and CONFIG_DMA_API_DEBUG=y be assigned to the correct device
instead of 'fallback'.

No functional change - just cosmetic.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

This is right now limited to only non-pool constructs.

[v2: Fixed indentation issues, add review-by tag]
Reviewed-by: NThomas Hellstrom <thomas@shipmail.org>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: NIan Campbell <ian.campbell@citrix.com>

Repeated ttm_page_alloc_init/fini fails noisily because the pool
manager kobj isn't zeroed out between uses (we could do just that but
statically allocated kobjects are generally considered a bad thing).
Move it to kzalloc'ed memory.

Note that this patch drops the refcounting behavior of the pool
allocator init/fini functions: it would have led to a race condition
in its current form, and anyway it was never exploited.

This fixes a regression with reloading kms modules at runtime, since
page allocator was introduced.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Sysfs interface allows user to configure pool allocator functionality and
change limits for the size of pool.
Signed-off-by: NPauli Nieminen <suokkos@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

ttm_page_alloc_debugfs can be registered to output the state
of pools.

Debugfs file will output number of pages freed from the pool,
number of pages in pool now and the lowes number of pages in
pool since previous shrink.
Signed-off-by: NPauli Nieminen <suokkos@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

On AGP system we might allocate/free routinely uncached or wc memory,
changing page from cached (wb) to uc or wc is very expensive and involves
a lot of flushing. To improve performance this allocator use a pool
of uc,wc pages.

Pools are protected with spinlocks to allow multiple threads to allocate pages
simultanously. Expensive operations are done outside of spinlock to maximize
concurrency.

Pools are linked lists of pages that were recently freed. mm shrink callback
allows kernel to claim back pages when they are required for something else.

Fixes:
* set_pages_array_wb handles highmem pages so we don't have to remove them
  from pool.
* Add count parameter to ttm_put_pages to avoid looping in free code.
* Change looping from _safe to normal in pool fill error path.
* Initialize sum variable and make the loop prettier in get_num_unused_pages.

* Moved pages_freed reseting inside the loop in ttm_page_pool_free.
* Add warning comment about spinlock context in ttm_page_pool_free.

Based on Jerome Glisse's and Dave Airlie's pool allocator.
Signed-off-by: NJerome Glisse <jglisse@redhat.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Signed-off-by: NPauli Nieminen <suokkos@gmail.com>
Reviewed-by: NJerome Glisse <jglisse@redhat.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>