TILER: Implement tcm_clear, and initialize TILER container

Implement tcm_clear and initialize TILER container to a blank
page.  This eliminates problems from reading into an unmapped TILER
page that can happen with 3rd party applications.

Signed-off-by: Lajos Molnar <molnar@ti.com>
Signed-off-by: Andy Gross <andy.gross@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>

3 files changed, 36 insertions, 5 deletions

diff --git a/drivers/media/video/tiler/tiler-main.c b/drivers/media/video/tiler/tiler-main.c
index 69e79c30319..cfba30b92af 100644
--- a/drivers/media/video/tiler/tiler-main.c
+++ b/drivers/media/video/tiler/tiler-main.c
@@ -1125,6 +1125,7 @@ static s32 __init tiler_init(void)
         struct tcm_pt div_pt;
         struct tcm *sita = NULL;
         struct tmm *tmm_pat = NULL;
+        struct pat_area area = {0};
 
         tiler.alloc = alloc_block;
         tiler.map = map_block;
@@ -1171,12 +1172,17 @@ static s32 __init tiler_init(void)
         tcm[TILFMT_PAGE]  = sita;
 
         /* Allocate tiler memory manager (must have 1 unique TMM per TCM ) */
-        tmm_pat = tmm_pat_init(0);
+        tmm_pat = tmm_pat_init(0, dmac_va, dmac_pa);
         tmm[TILFMT_8BIT]  = tmm_pat;
         tmm[TILFMT_16BIT] = tmm_pat;
         tmm[TILFMT_32BIT] = tmm_pat;
         tmm[TILFMT_PAGE]  = tmm_pat;
 
+        /* Clear out all PAT entries */
+        area.x1 = tiler.width - 1;
+        area.y1 = tiler.height - 1;
+        tmm_clear(tmm_pat, area);
+
         tiler.nv12_packed = tcm[TILFMT_8BIT] == tcm[TILFMT_16BIT];
 
         tiler_device = kmalloc(sizeof(*tiler_device), GFP_KERNEL);
diff --git a/drivers/media/video/tiler/tmm-pat.c b/drivers/media/video/tiler/tmm-pat.c
index e47f43f3d3d..6f916a89508 100644
--- a/drivers/media/video/tiler/tmm-pat.c
+++ b/drivers/media/video/tiler/tmm-pat.c
@@ -61,6 +61,10 @@ struct fast {
 struct dmm_mem {
         struct list_head fast_list;
         struct dmm *dmm;
+        u32 *dmac_va;           /* coherent memory */
+        u32 dmac_pa;            /* phys.addr of coherent memory */
+        struct page *dummy_pg;  /* dummy page */
+        u32 dummy_pa;           /* phys.addr of dummy page */
 };
 
 /* read mem values for a param */
@@ -163,6 +167,8 @@ static void tmm_pat_deinit(struct tmm *tmm)
         if (--refs == 0)
                 free_page_cache();
 
+        __free_page(pvt->dummy_pg);
+
         mutex_unlock(&mtx);
 }
 
@@ -262,7 +268,20 @@ static s32 tmm_pat_map(struct tmm *tmm, struct pat_area area, u32 page_pa)
         return dmm_pat_refill(pvt->dmm, &pat_desc, MANUAL);
 }
 
-struct tmm *tmm_pat_init(u32 pat_id)
+static void tmm_pat_clear(struct tmm *tmm, struct pat_area area)
+{
+        u16 w = (u8) area.x1 - (u8) area.x0;
+        u16 h = (u8) area.y1 - (u8) area.y0;
+        u16 i = (w + 1) * (h + 1);
+        struct dmm_mem *pvt = (struct dmm_mem *) tmm->pvt;
+
+        while (i--)
+                pvt->dmac_va[i] = pvt->dummy_pa;
+
+        tmm_pat_map(tmm, area, pvt->dmac_pa);
+}
+
+struct tmm *tmm_pat_init(u32 pat_id, u32 *dmac_va, u32 dmac_pa)
 {
         struct tmm *tmm = NULL;
         struct dmm_mem *pvt = NULL;
@@ -272,9 +291,15 @@ struct tmm *tmm_pat_init(u32 pat_id)
                 tmm = kmalloc(sizeof(*tmm), GFP_KERNEL);
         if (tmm)
                 pvt = kmalloc(sizeof(*pvt), GFP_KERNEL);
-        if (pvt) {
+        if (pvt)
+                pvt->dummy_pg = alloc_page(GFP_KERNEL | GFP_DMA);
+        if (pvt->dummy_pg) {
                 /* private data */
                 pvt->dmm = dmm;
+                pvt->dmac_pa = dmac_pa;
+                pvt->dmac_va = dmac_va;
+                pvt->dummy_pa = page_to_phys(pvt->dummy_pg);
+
                 INIT_LIST_HEAD(&pvt->fast_list);
 
                 /* increate tmm_pat references */
@@ -288,7 +313,7 @@ struct tmm *tmm_pat_init(u32 pat_id)
                 tmm->get = tmm_pat_get_pages;
                 tmm->free = tmm_pat_free_pages;
                 tmm->map = tmm_pat_map;
-                tmm->clear = NULL;   /* not yet supported */
+                tmm->clear = tmm_pat_clear;
 
                 return tmm;
         }
diff --git a/drivers/media/video/tiler/tmm.h b/drivers/media/video/tiler/tmm.h
index fbdc1e23d0e..ffe3682b10d 100644
--- a/drivers/media/video/tiler/tmm.h
+++ b/drivers/media/video/tiler/tmm.h
@@ -104,6 +104,6 @@ void tmm_deinit(struct tmm *tmm)
  *
  * Initialize TMM for PAT with given id.
  */
-struct tmm *tmm_pat_init(u32 pat_id);
+struct tmm *tmm_pat_init(u32 pat_id, u32 *dmac_va, u32 dmac_pa);
 
 #endif