tegra: host: move stale wait checking into the kernel

The kernel now receives wait tracking data (similar to gathers and
relocs) and compares the current syncpt with the threshold value.

If it's old, it gets a kernel mapping and rewrites the method data
to use a kernel reserved syncpt that is always 0 (so trivially pops
when seen by the HW).

Patch has dependency to the user-space patches

Submitted on behalf of: Chris Johnson <cjohnson@nvidia.com>
original work by: Chris Johnson <cjohnson@nvidia.com>

Change-Id: I4d4e5d3b49cab860485c4172f87247f5b4f5ea6e

1 files changed, 61 insertions, 1 deletions

diff --git a/drivers/video/tegra/host/nvhost_syncpt.c b/drivers/video/tegra/host/nvhost_syncpt.c
index dd2ab0d379e0..1881716ed428 100644
--- a/drivers/video/tegra/host/nvhost_syncpt.c
+++ b/drivers/video/tegra/host/nvhost_syncpt.c
@@ -226,7 +226,7 @@ done:
 }
 
 static const char *s_syncpt_names[32] = {
-	"", "", "", "", "", "", "", "", "", "", "", "",
+	"gfx_host", "", "", "", "", "", "", "", "", "", "", "",
 	"vi_isp_0", "vi_isp_1", "vi_isp_2", "vi_isp_3", "vi_isp_4", "vi_isp_5",
 	"2d_0", "2d_1",
 	"", "",
@@ -254,3 +254,63 @@ void nvhost_syncpt_debug(struct nvhost_syncpt *sp)
 
 	}
 }
+
+/* returns true, if a <= b < c using wrapping comparison */
+static inline bool nvhost_syncpt_is_between(u32 a, u32 b, u32 c)
+{
+	return b-a < c-a;
+}
+
+/* returns true, if x >= y (mod 1 << 32) */
+static bool nvhost_syncpt_wrapping_comparison(u32 x, u32 y)
+{
+	return nvhost_syncpt_is_between(y, x, (1UL<<31UL)+y);
+}
+
+/* check for old WAITs to be removed (avoiding a wrap) */
+int nvhost_syncpt_wait_check(struct nvmap_client *nvmap,
+			struct nvhost_syncpt *sp, u32 waitchk_mask,
+			struct nvhost_waitchk *waitp, u32 waitchks)
+{
+	u32 idx;
+	int err = 0;
+
+	/* get current syncpt values */
+	for (idx = 0; idx < NV_HOST1X_SYNCPT_NB_PTS; idx++) {
+		if (BIT(idx) & waitchk_mask) {
+			nvhost_syncpt_update_min(sp, idx);
+		}
+	}
+
+	BUG_ON(!waitp);
+
+	/* compare syncpt vs wait threshold */
+	while (waitchks) {
+		u32 syncpt, override;
+
+		BUG_ON(waitp->syncpt_id > NV_HOST1X_SYNCPT_NB_PTS);
+
+		syncpt = atomic_read(&sp->min_val[waitp->syncpt_id]);
+		if (nvhost_syncpt_wrapping_comparison(syncpt, waitp->thresh)) {
+
+			/* wait has completed already, so can be removed */
+			dev_dbg(&syncpt_to_dev(sp)->pdev->dev,
+					"drop WAIT id %d (%s) thresh 0x%x, syncpt 0x%x\n",
+					waitp->syncpt_id,  nvhost_syncpt_name(waitp->syncpt_id),
+					waitp->thresh, syncpt);
+
+			/* move wait to a kernel reserved syncpt (that's always 0) */
+			override = nvhost_class_host_wait_syncpt(NVSYNCPT_GRAPHICS_HOST, 0);
+
+			/* patch the wait */
+			err = nvmap_patch_wait(nvmap,
+						(struct nvmap_handle *)waitp->mem,
+						waitp->offset, override);
+			if (err)
+				break;
+		}
+		waitchks--;
+		waitp++;
+	}
+	return err;
+}