staging: drm/omap: DMM based hardware scrolling console

Add support for YWRAP scrolling by shuffling pages around in DMM
instead of sw blits.

Note that fbcon only utilizes this mode if the y resolution is
divided evenly by the font height.  So, for example, a 1920x1080
display using a 16 pixel tall font will not utilize this, but a
1280x1024 display would.

Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/omapdrm/omap_dmm_priv.h

@@ -79,12 +79,12 @@
 #define DMM_PATSTATUS_ERR_UPD_DATA	(1<<14)
 #define DMM_PATSTATUS_ERR_ACCESS	(1<<15)
 
+/* note: don't treat DMM_PATSTATUS_ERR_ACCESS as an error */
 #define DMM_PATSTATUS_ERR	(DMM_PATSTATUS_ERR_INV_DESCR | \
 				DMM_PATSTATUS_ERR_INV_DATA | \
 				DMM_PATSTATUS_ERR_UPD_AREA | \
 				DMM_PATSTATUS_ERR_UPD_CTRL | \
-				DMM_PATSTATUS_ERR_UPD_DATA | \
-				DMM_PATSTATUS_ERR_ACCESS)
+				DMM_PATSTATUS_ERR_UPD_DATA)
 
 
 

drivers/staging/omapdrm/omap_dmm_tiler.c

@@ -170,7 +170,7 @@ static struct dmm_txn *dmm_txn_init(struct dmm *dmm, struct tcm *tcm)
  * corresponding slot is cleared (ie. dummy_pa is programmed)
  */
 static int dmm_txn_append(struct dmm_txn *txn, struct pat_area *area,
-			struct page **pages)
+		struct page **pages, uint32_t npages, uint32_t roll)
 {
 	dma_addr_t pat_pa = 0;
 	uint32_t *data;
@@ -197,8 +197,11 @@ static int dmm_txn_append(struct dmm_txn *txn, struct pat_area *area,
 	data = alloc_dma(txn, 4*i, &pat->data_pa);
 
 	while (i--) {
-		data[i] = (pages && pages[i]) ?
-		page_to_phys(pages[i]) : engine->dmm->dummy_pa;
+		int n = i + roll;
+		if (n >= npages)
+			n -= npages;
+		data[i] = (pages && pages[n]) ?
+			page_to_phys(pages[n]) : engine->dmm->dummy_pa;
 	}
 
 	/* fill in lut with new addresses */
@@ -262,7 +265,8 @@ static int dmm_txn_commit(struct dmm_txn *txn, bool wait)
 /*
  * DMM programming
  */
-static int fill(struct tcm_area *area, struct page **pages, bool wait)
+static int fill(struct tcm_area *area, struct page **pages,
+		uint32_t npages, uint32_t roll, bool wait)
 {
 	int ret = 0;
 	struct tcm_area slice, area_s;
@@ -278,12 +282,11 @@ static int fill(struct tcm_area *area, struct page **pages, bool wait)
 				.x1 = slice.p1.x,  .y1 = slice.p1.y,
 		};
 
-		ret = dmm_txn_append(txn, &p_area, pages);
+		ret = dmm_txn_append(txn, &p_area, pages, npages, roll);
 		if (ret)
 			goto fail;
 
-		if (pages)
-			pages += tcm_sizeof(slice);
+		roll += tcm_sizeof(slice);
 	}
 
 	ret = dmm_txn_commit(txn, wait);
@@ -298,11 +301,12 @@ static int fill(struct tcm_area *area, struct page **pages, bool wait)
 
 /* note: slots for which pages[i] == NULL are filled w/ dummy page
  */
-int tiler_pin(struct tiler_block *block, struct page **pages, bool wait)
+int tiler_pin(struct tiler_block *block, struct page **pages,
+		uint32_t npages, uint32_t roll, bool wait)
 {
 	int ret;
 
-	ret = fill(&block->area, pages, wait);
+	ret = fill(&block->area, pages, npages, roll, wait);
 
 	if (ret)
 		tiler_unpin(block);
@@ -312,7 +316,7 @@ int tiler_pin(struct tiler_block *block, struct page **pages, bool wait)
 
 int tiler_unpin(struct tiler_block *block)
 {
-	return fill(&block->area, NULL, false);
+	return fill(&block->area, NULL, 0, 0, false);
 }
 
 /*
@@ -558,8 +562,13 @@ int omap_dmm_init(struct drm_device *dev)
 		goto fail;
 	}
 
-	/* enable some interrupts! */
-	writel(0xfefefefe, omap_dmm->base + DMM_PAT_IRQENABLE_SET);
+	/* Enable all interrupts for each refill engine except
+	 * ERR_LUT_MISS<n> (which is just advisory, and we don't care
+	 * about because we want to be able to refill live scanout
+	 * 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);
 
 	lut_table_size = omap_dmm->lut_width * omap_dmm->lut_height *
 			omap_dmm->num_lut;
@@ -658,7 +667,7 @@ int omap_dmm_init(struct drm_device *dev)
 	/* initialize all LUTs to dummy page entries */
 	for (i = 0; i < omap_dmm->num_lut; i++) {
 		area.tcm = omap_dmm->tcm[i];
-		if (fill(&area, NULL, true))
+		if (fill(&area, NULL, 0, 0, true))
 			dev_err(omap_dmm->dev, "refill failed");
 	}
 

drivers/staging/omapdrm/omap_dmm_tiler.h

@@ -77,7 +77,8 @@ int omap_dmm_init(struct drm_device *dev);
 int omap_dmm_remove(void);
 
 /* pin/unpin */
-int tiler_pin(struct tiler_block *block, struct page **pages, bool wait);
+int tiler_pin(struct tiler_block *block, struct page **pages,
+		uint32_t npages, uint32_t roll, bool wait);
 int tiler_unpin(struct tiler_block *block);
 
 /* reserve/release */

drivers/staging/omapdrm/omap_drv.h

@@ -47,6 +47,8 @@ struct omap_drm_private {
 	struct drm_connector *connectors[8];
 
 	struct drm_fb_helper *fbdev;
+
+	bool has_dmm;
 };
 
 struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev);
@@ -107,6 +109,7 @@ int omap_gem_op_finish(struct drm_gem_object *obj, enum omap_gem_op op);
 int omap_gem_op_sync(struct drm_gem_object *obj, enum omap_gem_op op);
 int omap_gem_op_async(struct drm_gem_object *obj, enum omap_gem_op op,
 		void (*fxn)(void *arg), void *arg);
+int omap_gem_roll(struct drm_gem_object *obj, uint32_t roll);
 int omap_gem_get_paddr(struct drm_gem_object *obj,
 		dma_addr_t *paddr, bool remap);
 int omap_gem_put_paddr(struct drm_gem_object *obj);

drivers/staging/omapdrm/omap_fb.c

@@ -218,25 +218,9 @@ struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
 
 	size = PAGE_ALIGN(mode_cmd->pitch * mode_cmd->height);
 
-	if (bo) {
-		DBG("using existing %d byte buffer (needed %d)", bo->size, size);
-		if (size > bo->size) {
-			dev_err(dev->dev, "provided buffer object is too small!\n");
-			goto fail;
-		}
-	} else {
-		/* for convenience of all the various callers who don't want
-		 * to be bothered to allocate their own buffer..
-		 */
-		union omap_gem_size gsize = {
-				.bytes = size,
-		};
-		DBG("allocating %d bytes for fb %d", size, dev->primary->index);
-		bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
-		if (!bo) {
-			dev_err(dev->dev, "failed to allocate buffer object\n");
-			goto fail;
-		}
+	if (size > bo->size) {
+		dev_err(dev->dev, "provided buffer object is too small!\n");
+		goto fail;
 	}
 
 	omap_fb->bo = bo;

drivers/staging/omapdrm/omap_fbdev.c

@@ -31,9 +31,11 @@
 struct omap_fbdev {
 	struct drm_fb_helper base;
 	struct drm_framebuffer *fb;
+	struct drm_gem_object *bo;
 };
 
 static void omap_fbdev_flush(struct fb_info *fbi, int x, int y, int w, int h);
+static struct drm_fb_helper *get_fb(struct fb_info *fbi);
 
 static ssize_t omap_fbdev_write(struct fb_info *fbi, const char __user *buf,
 		size_t count, loff_t *ppos)
@@ -68,6 +70,31 @@ static void omap_fbdev_imageblit(struct fb_info *fbi,
 				image->width, image->height);
 }
 
+static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
+		struct fb_info *fbi)
+{
+	struct drm_fb_helper *helper = get_fb(fbi);
+	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
+	struct omap_drm_private *priv;
+	int npages;
+
+	if (!helper)
+		goto fallback;
+
+	priv = helper->dev->dev_private;
+	if (!priv->has_dmm)
+		goto fallback;
+
+	/* DMM roll shifts in 4K pages: */
+	npages = fbi->fix.line_length >> PAGE_SHIFT;
+	omap_gem_roll(fbdev->bo, var->yoffset * npages);
+
+	return 0;
+
+fallback:
+	return drm_fb_helper_pan_display(var, fbi);
+}
+
 static struct fb_ops omap_fb_ops = {
 	.owner = THIS_MODULE,
 
@@ -82,7 +109,7 @@ static struct fb_ops omap_fb_ops = {
 
 	.fb_check_var = drm_fb_helper_check_var,
 	.fb_set_par = drm_fb_helper_set_par,
-	.fb_pan_display = drm_fb_helper_pan_display,
+	.fb_pan_display = omap_fbdev_pan_display,
 	.fb_blank = drm_fb_helper_blank,
 	.fb_setcmap = drm_fb_helper_setcmap,
 
@@ -95,7 +122,9 @@ static int omap_fbdev_create(struct drm_fb_helper *helper,
 {
 	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
 	struct drm_device *dev = helper->dev;
+	struct omap_drm_private *priv = dev->dev_private;
 	struct drm_framebuffer *fb = NULL;
+	union omap_gem_size gsize;
 	struct fb_info *fbi = NULL;
 	struct drm_mode_fb_cmd mode_cmd = {0};
 	dma_addr_t paddr;
@@ -109,16 +138,37 @@ static int omap_fbdev_create(struct drm_fb_helper *helper,
 	sizes->surface_bpp = 32;
 	sizes->surface_depth = 32;
 
-	DBG("create fbdev: %dx%d@%d", sizes->surface_width,
-			sizes->surface_height, sizes->surface_bpp);
+	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
+			sizes->surface_height, sizes->surface_bpp,
+			sizes->fb_width, sizes->fb_height);
 
 	mode_cmd.width = sizes->surface_width;
 	mode_cmd.height = sizes->surface_height;
 
 	mode_cmd.bpp = sizes->surface_bpp;
 	mode_cmd.depth = sizes->surface_depth;
 
-	fb = omap_framebuffer_init(dev, &mode_cmd, NULL);
+	mode_cmd.pitch = align_pitch(
+			mode_cmd.width * ((mode_cmd.bpp + 7) / 8),
+			mode_cmd.width, mode_cmd.bpp);
+
+	if (priv->has_dmm) {
+		/* need to align pitch to page size if using DMM scrolling */
+		mode_cmd.pitch = ALIGN(mode_cmd.pitch, PAGE_SIZE);
+	}
+
+	/* allocate backing bo */
+	gsize = (union omap_gem_size){
+		.bytes = PAGE_ALIGN(mode_cmd.pitch * mode_cmd.height),
+	};
+	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
+	fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
+	if (!fbdev->bo) {
+		dev_err(dev->dev, "failed to allocate buffer object\n");
+		goto fail;
+	}
+
+	fb = omap_framebuffer_init(dev, &mode_cmd, fbdev->bo);
 	if (!fb) {
 		dev_err(dev->dev, "failed to allocate fb\n");
 		ret = -ENOMEM;
@@ -153,7 +203,7 @@ static int omap_fbdev_create(struct drm_fb_helper *helper,
 	}
 
 	drm_fb_helper_fill_fix(fbi, fb->pitch, fb->depth);
-	drm_fb_helper_fill_var(fbi, helper, fb->width, fb->height);
+	drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
 
 	size = omap_framebuffer_get_buffer(fb, 0, 0,
 			&vaddr, &paddr, &screen_width);
@@ -165,6 +215,15 @@ static int omap_fbdev_create(struct drm_fb_helper *helper,
 	fbi->fix.smem_start = paddr;
 	fbi->fix.smem_len = size;
 
+	/* if we have DMM, then we can use it for scrolling by just
+	 * shuffling pages around in DMM rather than doing sw blit.
+	 */
+	if (priv->has_dmm) {
+		DRM_INFO("Enabling DMM ywrap scrolling\n");
+		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
+		fbi->fix.ywrapstep = 1;
+	}
+
 	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
 	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
 
@@ -300,5 +359,9 @@ void omap_fbdev_free(struct drm_device *dev)
 
 	kfree(fbdev);
 
+	/* this will free the backing object */
+	if (fbdev->fb)
+		fbdev->fb->funcs->destroy(fbdev->fb);
+
 	priv->fbdev = NULL;
 }