drm/radeon/kms: fix indirect buffer management V2

There is 3 different distinct states for an indirect buffer (IB) :
  1- free with no fence
  2- free with a fence
  3- non free (fence doesn't matter)
Previous code mixed case 2 & 3 in a single one leading to possible
catastrophique failure. This patch rework the handling and properly
separate each case. So when you get ib we set the ib as non free and
fence status doesn't matter. Fence become active (ie has a meaning
for the ib code) once the ib is scheduled or free. This patch also
get rid of the alloc bitmap as it was overkill, we know go through
IB pool list like in a ring buffer as the oldest IB is the first
one the will be free.

Fix :
https://bugs.freedesktop.org/show_bug.cgi?id=26438
and likely other bugs.

V2 remove the scheduled list, it's useless now, fix free ib scanning

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

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 993cdf20d8e6..9f35beed13e8 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -97,6 +97,7 @@ extern int radeon_audio;
  * symbol;
  */
 #define RADEON_MAX_USEC_TIMEOUT         100000  /* 100 ms */
+/* RADEON_IB_POOL_SIZE must be a power of 2 */
 #define RADEON_IB_POOL_SIZE             16
 #define RADEON_DEBUGFS_MAX_NUM_FILES    32
 #define RADEONFB_CONN_LIMIT             4
@@ -371,11 +372,12 @@ void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev);
  */
 struct radeon_ib {
         struct list_head        list;
-        unsigned long           idx;
+        unsigned                idx;
         uint64_t                gpu_addr;
         struct radeon_fence     *fence;
-        uint32_t        *ptr;
+        uint32_t                *ptr;
         uint32_t                length_dw;
+        bool                    free;
 };
 
 /*
@@ -385,11 +387,10 @@ struct radeon_ib {
 struct radeon_ib_pool {
         struct mutex            mutex;
         struct radeon_bo        *robj;
-        struct list_head        scheduled_ibs;
         struct list_head        bogus_ib;
         struct radeon_ib        ibs[RADEON_IB_POOL_SIZE];
         bool                    ready;
-        DECLARE_BITMAP(alloc_bm, RADEON_IB_POOL_SIZE);
+        unsigned                head_id;
 };
 
 struct radeon_cp {