[PATCH 09/11] accel: ethosu: Reject unsupported commands

["Rob Herring (Arm)" <robh@kernel.org>]

The command-stream validator does not model U85 branches, indexed DMA,
or OFM transposes. A branch can bypass the linear validation state,
indexed DMA accesses an unchecked index buffer, and a transpose changes
the feature-map address calculation.

Reject those commands and configurations, as well as the reserved DMA
stride mode and feature-map formats. Reject command-stream IRQs because
they can signal job completion before later commands finish.

Fixes: 5a5e9c0228e6 ("accel: Add Arm Ethos-U NPU driver")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
---
 drivers/accel/ethosu/ethosu_device.h |  4 ++++
 drivers/accel/ethosu/ethosu_gem.c    | 17 +++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/drivers/accel/ethosu/ethosu_device.h b/drivers/accel/ethosu/ethosu_device.h
index 1eca8590e68d..c330048dbcca 100644
--- a/drivers/accel/ethosu/ethosu_device.h
+++ b/drivers/accel/ethosu/ethosu_device.h
@@ -86,14 +86,18 @@ struct gen_pool;
 #define PMU_EV_TYPE_CYCLES	0x11
 #define PMU_EV_TYPE_IDLE	0x20
 
+#define NPU_DMA_REGION_INDEX_MODE	BIT(11)
+
 enum ethosu_cmds {
 	NPU_OP_STOP = 0x0,
+	NPU_OP_IRQ = 0x1,
 	NPU_OP_CONV = 0x2,
 	NPU_OP_DEPTHWISE = 0x3,
 	NPU_OP_POOL = 0x5,
 	NPU_OP_ELEMENTWISE = 0x6,
 	NPU_OP_RESIZE = 0x7,	// U85 only
 	NPU_OP_DMA_START = 0x10,
+	NPU_OP_BRANCH = 0x4100,	// U85 only
 	NPU_SET_IFM_PAD_TOP = 0x100,
 	NPU_SET_IFM_PAD_LEFT = 0x101,
 	NPU_SET_IFM_PAD_RIGHT = 0x102,
diff --git a/drivers/accel/ethosu/ethosu_gem.c b/drivers/accel/ethosu/ethosu_gem.c
index 3d1f4121db4f..2aafbfe95a8c 100644
--- a/drivers/accel/ethosu/ethosu_gem.c
+++ b/drivers/accel/ethosu/ethosu_gem.c
@@ -450,6 +450,9 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
 		}
 
 		switch (cmd) {
+		case NPU_OP_BRANCH:
+		case NPU_OP_IRQ:
+			return -EINVAL;
 		case NPU_OP_STOP:
 			if (i != size / 4 - 1)
 				return -EINVAL;
@@ -522,6 +525,8 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
 			st.ifm.depth = param;
 			break;
 		case NPU_SET_IFM_PRECISION:
+			if (((param >> 6) & 0x3) > 1)
+				return -EINVAL;
 			st.ifm.precision = param;
 			break;
 		case NPU_SET_IFM_BROADCAST:
@@ -565,6 +570,10 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
 			st.ofm.depth = param;
 			break;
 		case NPU_SET_OFM_PRECISION:
+			if (((param >> 6) & 0x3) > 1)
+				return -EINVAL;
+			if (!ethosu_is_u65(edev) && (param & GENMASK(13, 11)))
+				return -EINVAL;
 			st.ofm.precision = param;
 			break;
 		case NPU_SET_OFM_REGION:
@@ -599,6 +608,8 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
 			st.ifm2.broadcast = param;
 			break;
 		case NPU_SET_IFM2_PRECISION:
+			if (((param >> 6) & 0x3) > 1)
+				return -EINVAL;
 			st.ifm2.precision = param;
 			break;
 		case NPU_SET_IFM2_REGION:
@@ -673,13 +684,19 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
 			break;
 
 		case NPU_SET_DMA0_SRC_REGION:
+			if (param & NPU_DMA_REGION_INDEX_MODE)
+				return -EINVAL;
 			if (param & 0x100)
 				st.dma.src.region = -1;
 			else
 				st.dma.src.region = param & 0x7;
 			st.dma.mode = (param >> 9) & 0x3;
+			if (st.dma.mode == 3)
+				return -EINVAL;
 			break;
 		case NPU_SET_DMA0_DST_REGION:
+			if (param & NPU_DMA_REGION_INDEX_MODE)
+				return -EINVAL;
 			if (param & 0x100)
 				st.dma.dst.region = -1;
 			else

-- 
2.53.0