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From:   Karol Herbst <kherbst@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     Karol Herbst <kherbst@redhat.com>, Ben Skeggs <bskeggs@redhat.com>,
        David Airlie <airlied@gmail.com>,
        nouveau@lists.freedesktop.org, stable@vger.kernel.org
Subject: [PATCH v2] drm/nouveau/gr: enable memory loads on helper invocation on all channels
Date:   Thu, 22 Jun 2023 17:20:17 +0200
Message-ID: <20230622152017.2512101-1-kherbst@redhat.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

We have a lurking bug where Fragment Shader Helper Invocations can't load
from memory. But this is actually required in OpenGL and is causing random
hangs or failures in random shaders.

It is unknown how widespread this issue is, but shaders hitting this can
end up with infinite loops.

We enable those only on all Kepler and newer GPUs where we use our own
Firmware.

Nvidia's firmware provides a way to set a kernelspace controlled list of
mmio registers in the gr space from push buffers via MME macros.

v2: drop code for gm200 and newer.

Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: David Airlie <airlied@gmail.com>
Cc: nouveau@lists.freedesktop.org
Cc: stable@vger.kernel.org
Signed-off-by: Karol Herbst <kherbst@redhat.com>
---
 drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgf100.h  |  1 +
 drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk104.c  |  4 +++-
 drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk110.c  | 10 ++++++++++
 drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk110b.c |  1 +
 drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk208.c  |  1 +
 drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgm107.c  |  1 +
 6 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgf100.h b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgf100.h
index 00dbeda7e346..de161e7a04aa 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgf100.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgf100.h
@@ -117,6 +117,7 @@ void gk104_grctx_generate_r418800(struct gf100_gr *);
 
 extern const struct gf100_grctx_func gk110_grctx;
 void gk110_grctx_generate_r419eb0(struct gf100_gr *);
+void gk110_grctx_generate_r419f78(struct gf100_gr *);
 
 extern const struct gf100_grctx_func gk110b_grctx;
 extern const struct gf100_grctx_func gk208_grctx;
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk104.c b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk104.c
index 94233d0119df..52a234b1ef01 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk104.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk104.c
@@ -906,7 +906,9 @@ static void
 gk104_grctx_generate_r419f78(struct gf100_gr *gr)
 {
 	struct nvkm_device *device = gr->base.engine.subdev.device;
-	nvkm_mask(device, 0x419f78, 0x00000001, 0x00000000);
+
+	/* bit 3 set disables loads in fp helper invocations, we need it enabled */
+	nvkm_mask(device, 0x419f78, 0x00000009, 0x00000000);
 }
 
 void
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk110.c b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk110.c
index 4391458e1fb2..3acdd9eeb74a 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk110.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk110.c
@@ -820,6 +820,15 @@ gk110_grctx_generate_r419eb0(struct gf100_gr *gr)
 	nvkm_mask(device, 0x419eb0, 0x00001000, 0x00001000);
 }
 
+void
+gk110_grctx_generate_r419f78(struct gf100_gr *gr)
+{
+	struct nvkm_device *device = gr->base.engine.subdev.device;
+
+	/* bit 3 set disables loads in fp helper invocations, we need it enabled */
+	nvkm_mask(device, 0x419f78, 0x00000008, 0x00000000);
+}
+
 const struct gf100_grctx_func
 gk110_grctx = {
 	.main  = gf100_grctx_generate_main,
@@ -854,4 +863,5 @@ gk110_grctx = {
 	.gpc_tpc_nr = gk104_grctx_generate_gpc_tpc_nr,
 	.r418800 = gk104_grctx_generate_r418800,
 	.r419eb0 = gk110_grctx_generate_r419eb0,
+	.r419f78 = gk110_grctx_generate_r419f78,
 };
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk110b.c b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk110b.c
index 7b9a34f9ec3c..5597e87624ac 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk110b.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk110b.c
@@ -103,4 +103,5 @@ gk110b_grctx = {
 	.gpc_tpc_nr = gk104_grctx_generate_gpc_tpc_nr,
 	.r418800 = gk104_grctx_generate_r418800,
 	.r419eb0 = gk110_grctx_generate_r419eb0,
+	.r419f78 = gk110_grctx_generate_r419f78,
 };
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk208.c b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk208.c
index c78d07a8bb7d..612656496541 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk208.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgk208.c
@@ -568,4 +568,5 @@ gk208_grctx = {
 	.dist_skip_table = gf117_grctx_generate_dist_skip_table,
 	.gpc_tpc_nr = gk104_grctx_generate_gpc_tpc_nr,
 	.r418800 = gk104_grctx_generate_r418800,
+	.r419f78 = gk110_grctx_generate_r419f78,
 };
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgm107.c b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgm107.c
index beac66eb2a80..9906974ac3f0 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgm107.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgm107.c
@@ -988,4 +988,5 @@ gm107_grctx = {
 	.r406500 = gm107_grctx_generate_r406500,
 	.gpc_tpc_nr = gk104_grctx_generate_gpc_tpc_nr,
 	.r419e00 = gm107_grctx_generate_r419e00,
+	.r419f78 = gk110_grctx_generate_r419f78,
 };
-- 
2.41.0