Merge "msm: kgsl: Keep postamble packets in a privileged buffer"

drivers/gpu/msm/adreno.h

@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Copyright (c) 2008-2021, The Linux Foundation. All rights reserved.
- * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2022-2023, Qualcomm Innovation Center, Inc. All rights reserved.
  */
 #ifndef __ADRENO_H
 #define __ADRENO_H
@@ -16,9 +16,6 @@
 #define DEVICE_3D_NAME "kgsl-3d"
 #define DEVICE_3D0_NAME "kgsl-3d0"
 
-/* Index to preemption scratch buffer to store KMD postamble */
-#define KMD_POSTAMBLE_IDX 100
-
 /* ADRENO_DEVICE - Given a kgsl_device return the adreno device struct */
 #define ADRENO_DEVICE(device) \
 		container_of(device, struct adreno_device, dev)

drivers/gpu/msm/adreno_a6xx_preempt.c

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
- * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2022-2023, Qualcomm Innovation Center, Inc. All rights reserved.
  */
 
 #include "adreno.h"
@@ -558,8 +558,8 @@ unsigned int a6xx_preemption_pre_ibsubmit(
 		 * preemption
 		 */
 		if (!adreno_dev->perfcounter) {
-			u64 kmd_postamble_addr =
-			PREEMPT_SCRATCH_ADDR(adreno_dev, KMD_POSTAMBLE_IDX);
+			u64 kmd_postamble_addr = SCRATCH_POSTAMBLE_ADDR
+						(KGSL_DEVICE(adreno_dev));
 
 			*cmds++ = cp_type7_packet(CP_SET_AMBLE, 3);
 			*cmds++ = lower_32_bits(kmd_postamble_addr);
@@ -763,6 +763,8 @@ void a6xx_preemption_close(struct adreno_device *adreno_dev)
 
 int a6xx_preemption_init(struct adreno_device *adreno_dev)
 {
+	u32 flags = ADRENO_FEATURE(adreno_dev, ADRENO_APRIV) ?
+			KGSL_MEMDESC_PRIVILEGED : 0;
 	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);
 	struct adreno_preemption *preempt = &adreno_dev->preempt;
 	struct adreno_ringbuffer *rb;
@@ -777,8 +779,8 @@ int a6xx_preemption_init(struct adreno_device *adreno_dev)
 
 	timer_setup(&preempt->timer, _a6xx_preemption_timer, 0);
 
-	ret = kgsl_allocate_global(device, &preempt->scratch, PAGE_SIZE, 0, 0,
-			"preemption_scratch");
+	ret = kgsl_allocate_global(device, &preempt->scratch, PAGE_SIZE, 0,
+			flags, "preemption_scratch");
 
 	/* Allocate mem for storing preemption switch record */
 	FOR_EACH_RINGBUFFER(adreno_dev, rb, i) {
@@ -788,14 +790,15 @@ int a6xx_preemption_init(struct adreno_device *adreno_dev)
 	}
 
 	/*
-	 * First 8 dwords of the preemption scratch buffer is used to store the
-	 * address for CP to save/restore VPC data. Reserve 11 dwords in the
-	 * preemption scratch buffer from index KMD_POSTAMBLE_IDX for KMD
-	 * postamble pm4 packets
+	 * First 28 dwords of the device scratch buffer are used to store
+	 * shadow rb data. Reserve 11 dwords in the device scratch buffer
+	 * from SCRATCH_POSTAMBLE_OFFSET for KMD postamble pm4 packets.
+	 * This should be in *device->scratch* so that userspace cannot
+	 * access it.
 	 */
 	if (!adreno_dev->perfcounter) {
-		u32 *postamble = preempt->scratch.hostptr +
-					(KMD_POSTAMBLE_IDX * sizeof(u64));
+		u32 *postamble = device->scratch.hostptr +
+				SCRATCH_POSTAMBLE_OFFSET;
 		u32 count = 0;
 
 		postamble[count++] = cp_type7_packet(CP_REG_RMW, 3);

drivers/gpu/msm/kgsl.h

@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Copyright (c) 2008-2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
  */
 #ifndef __KGSL_H
 #define __KGSL_H
@@ -69,6 +70,11 @@
 #define SCRATCH_RPTR_GPU_ADDR(dev, id) \
 	((dev)->scratch.gpuaddr + SCRATCH_RPTR_OFFSET(id))
 
+/* OFFSET to KMD postamble packets in scratch buffer */
+#define SCRATCH_POSTAMBLE_OFFSET (100 * sizeof(u64))
+#define SCRATCH_POSTAMBLE_ADDR(dev) \
+	((dev)->scratch.gpuaddr + SCRATCH_POSTAMBLE_OFFSET)
+
 /* Timestamp window used to detect rollovers (half of integer range) */
 #define KGSL_TIMESTAMP_WINDOW 0x80000000