drm/omap: fix TILER on OMAP5

On OMAP5 it is not possible to use TILER buffer with CPU when caching or
write-combining is used. Doing so leads to errors from the memory
manager.

However, on OMAP4, write-combining works fine.

This patch adds platform specific data for the TILER, and a function
tiler_get_cpu_cache_flags() which can be used to get the caching mode to
be used.

Note that without write-combining the use of the TILER buffer with CPU
is unusably slow. It's still good to have it operational for testing
purposes.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_dmm_priv.h b/drivers/gpu/drm/omapdrm/omap_dmm_priv.h
index 58bcd6ae0255..d96660573076 100644
--- a/drivers/gpu/drm/omapdrm/omap_dmm_priv.h
+++ b/drivers/gpu/drm/omapdrm/omap_dmm_priv.h
@@ -153,6 +153,10 @@ struct refill_engine {
 	struct list_head idle_node;
 };
 
+struct dmm_platform_data {
+	uint32_t cpu_cache_flags;
+};
+
 struct dmm {
 	struct device *dev;
 	void __iomem *base;
@@ -183,6 +187,8 @@ struct dmm {
 
 	/* allocation list and lock */
 	struct list_head alloc_head;
+
+	const struct dmm_platform_data *plat_data;
 };
 
 #endif