[PATCH v4 19/31] accel: ethosu: Reject unsupported commands and params

[Rob Herring (Arm)]

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 any unhandled operation commands or out of range registers, 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@xxxxxxxxxxxxxxx
Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
---
v4:
 - Combine "accel: ethosu: Reject unsupported commands" and "accel:
   ethosu: Reject reserved command encodings"
 - Move NPU_CMD_CTRL_CMD1 to "accel: ethosu: Track command stream register setup"
 - Rework checks for unknown op cmds and reserved bits

v2:
 - no changes
---
 drivers/accel/ethosu/ethosu_device.h |  4 ++++
 drivers/accel/ethosu/ethosu_gem.c    | 33 ++++++++++++++++++++++++++++++++-
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/accel/ethosu/ethosu_device.h b/drivers/accel/ethosu/ethosu_device.h
index 8405e69acb0c..86412c152f4e 100644
--- a/drivers/accel/ethosu/ethosu_device.h
+++ b/drivers/accel/ethosu/ethosu_device.h
@@ -88,6 +88,8 @@ struct gen_pool;
 #define PMU_EV_TYPE_CYCLES	0x11
 #define PMU_EV_TYPE_IDLE	0x20
 
+#define NPU_DMA_REGION_INDEX_MODE	BIT(11)
+
 #define NPU_CMD_CTRL_CMD1		BIT(14)
 
 enum ethosu_cmds {
@@ -98,6 +100,8 @@ enum ethosu_cmds {
 	NPU_OP_ELEMENTWISE = 0x6,
 	NPU_OP_RESIZE = 0x7,	// U85 only
 	NPU_OP_DMA_START = 0x10,
+	NPU_OP_DMA_WAIT = 0x11,
+	NPU_OP_KERNEL_WAIT = 0x12,
 	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 af8a0c45039b..74ef86848a2d 100644
--- a/drivers/accel/ethosu/ethosu_gem.c
+++ b/drivers/accel/ethosu/ethosu_gem.c
@@ -190,6 +190,16 @@ static bool cmd_state_reg_is_set(struct cmd_state *st, u16 cmd)
 	return reg < NPU_CMD0_REGS && test_bit(reg, st->cmd0);
 }
 
+static bool cmd_is_register(u16 cmd)
+{
+	u16 reg = cmd & ~NPU_CMD_CTRL_CMD1;
+
+	if (cmd & NPU_CMD_CTRL_CMD1)
+		return reg < NPU_CMD1_REGS;
+
+	return cmd >= 0x100 && cmd < NPU_CMD0_REGS;
+}
+
 static u64 cmd_to_addr(u32 *cmd)
 {
 	return (((u64)cmd[0] & 0xff0000) << 16) | cmd[1];
@@ -652,6 +662,9 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
 		cmd_state_set_reg(&st, cmd);
 
 		switch (cmd) {
+		case NPU_OP_DMA_WAIT:
+		case NPU_OP_KERNEL_WAIT:
+			break;
 		case NPU_OP_STOP:
 			if (i != size / 4 - 1)
 				return -EINVAL;
@@ -745,6 +758,8 @@ 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:
@@ -788,6 +803,10 @@ 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:
@@ -822,6 +841,8 @@ 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:
@@ -896,18 +917,26 @@ 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.src.mode = (param >> 9) & 0x3;
+			if (st.dma.src.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
 				st.dma.dst.region = param & 0x7;
 			st.dma.dst.mode = (param >> 9) & 0x3;
+			if (st.dma.dst.mode == 3)
+				return -EINVAL;
 			break;
 		case NPU_SET_DMA0_SIZE0:
 			st.dma.size0 = param;
@@ -937,7 +966,9 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
 			st.dma.src.len = st.dma.dst.len = addr;
 			break;
 		default:
-			break;
+			if (cmd_is_register(cmd))
+				break;
+			return -EINVAL;
 		}
 	}
 

-- 
2.53.0