Linux-libre 4.6.2-gnu

1 files changed, 45 insertions, 22 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
index dfebdc4aa..de275a5be 100644
--- a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
+++ b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
@@ -79,6 +79,16 @@ static const uint32_t reg[][4] = {
 			DMM_PAT_DESCR__2, DMM_PAT_DESCR__3},
 };
 
+static u32 dmm_read(struct dmm *dmm, u32 reg)
+{
+	return readl(dmm->base + reg);
+}
+
+static void dmm_write(struct dmm *dmm, u32 val, u32 reg)
+{
+	writel(val, dmm->base + reg);
+}
+
 /* simple allocator to grab next 16 byte aligned memory from txn */
 static void *alloc_dma(struct dmm_txn *txn, size_t sz, dma_addr_t *pa)
 {
@@ -108,7 +118,7 @@ static int wait_status(struct refill_engine *engine, uint32_t wait_mask)
 
 	i = DMM_FIXED_RETRY_COUNT;
 	while (true) {
-		r = readl(dmm->base + reg[PAT_STATUS][engine->id]);
+		r = dmm_read(dmm, reg[PAT_STATUS][engine->id]);
 		err = r & DMM_PATSTATUS_ERR;
 		if (err)
 			return -EFAULT;
@@ -140,11 +150,11 @@ static void release_engine(struct refill_engine *engine)
 static irqreturn_t omap_dmm_irq_handler(int irq, void *arg)
 {
 	struct dmm *dmm = arg;
-	uint32_t status = readl(dmm->base + DMM_PAT_IRQSTATUS);
+	uint32_t status = dmm_read(dmm, DMM_PAT_IRQSTATUS);
 	int i;
 
 	/* ack IRQ */
-	writel(status, dmm->base + DMM_PAT_IRQSTATUS);
+	dmm_write(dmm, status, DMM_PAT_IRQSTATUS);
 
 	for (i = 0; i < dmm->num_engines; i++) {
 		if (status & DMM_IRQSTAT_LST) {
@@ -264,7 +274,7 @@ static int dmm_txn_commit(struct dmm_txn *txn, bool wait)
 	txn->last_pat->next_pa = 0;
 
 	/* write to PAT_DESCR to clear out any pending transaction */
-	writel(0x0, dmm->base + reg[PAT_DESCR][engine->id]);
+	dmm_write(dmm, 0x0, reg[PAT_DESCR][engine->id]);
 
 	/* wait for engine ready: */
 	ret = wait_status(engine, DMM_PATSTATUS_READY);
@@ -280,8 +290,7 @@ static int dmm_txn_commit(struct dmm_txn *txn, bool wait)
 	smp_mb();
 
 	/* kick reload */
-	writel(engine->refill_pa,
-		dmm->base + reg[PAT_DESCR][engine->id]);
+	dmm_write(dmm, engine->refill_pa, reg[PAT_DESCR][engine->id]);
 
 	if (wait) {
 		if (!wait_for_completion_timeout(&engine->compl,
@@ -309,6 +318,21 @@ static int fill(struct tcm_area *area, struct page **pages,
 	struct tcm_area slice, area_s;
 	struct dmm_txn *txn;
 
+	/*
+	 * FIXME
+	 *
+	 * Asynchronous fill does not work reliably, as the driver does not
+	 * handle errors in the async code paths. The fill operation may
+	 * silently fail, leading to leaking DMM engines, which may eventually
+	 * lead to deadlock if we run out of DMM engines.
+	 *
+	 * For now, always set 'wait' so that we only use sync fills. Async
+	 * fills should be fixed, or alternatively we could decide to only
+	 * support sync fills and so the whole async code path could be removed.
+	 */
+
+	wait = true;
+
 	txn = dmm_txn_init(omap_dmm, area->tcm);
 	if (IS_ERR_OR_NULL(txn))
 		return -ENOMEM;
@@ -573,10 +597,9 @@ static int omap_dmm_remove(struct platform_device *dev)
 
 		kfree(omap_dmm->engines);
 		if (omap_dmm->refill_va)
-			dma_free_writecombine(omap_dmm->dev,
-				REFILL_BUFFER_SIZE * omap_dmm->num_engines,
-				omap_dmm->refill_va,
-				omap_dmm->refill_pa);
+			dma_free_wc(omap_dmm->dev,
+				    REFILL_BUFFER_SIZE * omap_dmm->num_engines,
+				    omap_dmm->refill_va, omap_dmm->refill_pa);
 		if (omap_dmm->dummy_page)
 			__free_page(omap_dmm->dummy_page);
 
@@ -642,7 +665,7 @@ static int omap_dmm_probe(struct platform_device *dev)
 
 	omap_dmm->dev = &dev->dev;
 
-	hwinfo = readl(omap_dmm->base + DMM_PAT_HWINFO);
+	hwinfo = dmm_read(omap_dmm, DMM_PAT_HWINFO);
 	omap_dmm->num_engines = (hwinfo >> 24) & 0x1F;
 	omap_dmm->num_lut = (hwinfo >> 16) & 0x1F;
 	omap_dmm->container_width = 256;
@@ -651,7 +674,7 @@ static int omap_dmm_probe(struct platform_device *dev)
 	atomic_set(&omap_dmm->engine_counter, omap_dmm->num_engines);
 
 	/* read out actual LUT width and height */
-	pat_geom = readl(omap_dmm->base + DMM_PAT_GEOMETRY);
+	pat_geom = dmm_read(omap_dmm, DMM_PAT_GEOMETRY);
 	omap_dmm->lut_width = ((pat_geom >> 16) & 0xF) << 5;
 	omap_dmm->lut_height = ((pat_geom >> 24) & 0xF) << 5;
 
@@ -661,12 +684,12 @@ static int omap_dmm_probe(struct platform_device *dev)
 		omap_dmm->num_lut++;
 
 	/* initialize DMM registers */
-	writel(0x88888888, omap_dmm->base + DMM_PAT_VIEW__0);
-	writel(0x88888888, omap_dmm->base + DMM_PAT_VIEW__1);
-	writel(0x80808080, omap_dmm->base + DMM_PAT_VIEW_MAP__0);
-	writel(0x80000000, omap_dmm->base + DMM_PAT_VIEW_MAP_BASE);
-	writel(0x88888888, omap_dmm->base + DMM_TILER_OR__0);
-	writel(0x88888888, omap_dmm->base + DMM_TILER_OR__1);
+	dmm_write(omap_dmm, 0x88888888, DMM_PAT_VIEW__0);
+	dmm_write(omap_dmm, 0x88888888, DMM_PAT_VIEW__1);
+	dmm_write(omap_dmm, 0x80808080, DMM_PAT_VIEW_MAP__0);
+	dmm_write(omap_dmm, 0x80000000, DMM_PAT_VIEW_MAP_BASE);
+	dmm_write(omap_dmm, 0x88888888, DMM_TILER_OR__0);
+	dmm_write(omap_dmm, 0x88888888, DMM_TILER_OR__1);
 
 	ret = request_irq(omap_dmm->irq, omap_dmm_irq_handler, IRQF_SHARED,
 				"omap_dmm_irq_handler", omap_dmm);
@@ -684,7 +707,7 @@ static int omap_dmm_probe(struct platform_device *dev)
 	 * buffers for accelerated pan/scroll) and FILL_DSC<n> which
 	 * we just generally don't care about.
 	 */
-	writel(0x7e7e7e7e, omap_dmm->base + DMM_PAT_IRQENABLE_SET);
+	dmm_write(omap_dmm, 0x7e7e7e7e, DMM_PAT_IRQENABLE_SET);
 
 	omap_dmm->dummy_page = alloc_page(GFP_KERNEL | __GFP_DMA32);
 	if (!omap_dmm->dummy_page) {
@@ -701,9 +724,9 @@ static int omap_dmm_probe(struct platform_device *dev)
 	omap_dmm->dummy_pa = page_to_phys(omap_dmm->dummy_page);
 
 	/* alloc refill memory */
-	omap_dmm->refill_va = dma_alloc_writecombine(&dev->dev,
-				REFILL_BUFFER_SIZE * omap_dmm->num_engines,
-				&omap_dmm->refill_pa, GFP_KERNEL);
+	omap_dmm->refill_va = dma_alloc_wc(&dev->dev,
+					   REFILL_BUFFER_SIZE * omap_dmm->num_engines,
+					   &omap_dmm->refill_pa, GFP_KERNEL);
 	if (!omap_dmm->refill_va) {
 		dev_err(&dev->dev, "could not allocate refill memory\n");
 		goto fail;