1 files changed, 107 insertions, 2 deletions

diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.h b/drivers/gpu/drm/msm/adreno/a5xx_gpu.h
index e94451685bf8..6fb8c2f9b9e4 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2016 The Linux Foundation. All rights reserved.
+/* Copyright (c) 2016-2017 The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -35,10 +35,100 @@ struct a5xx_gpu {
 	uint32_t gpmu_dwords;
 
 	uint32_t lm_leakage;
+
+	struct msm_ringbuffer *cur_ring;
+	struct msm_ringbuffer *next_ring;
+
+	struct drm_gem_object *preempt_bo[MSM_GPU_MAX_RINGS];
+	struct a5xx_preempt_record *preempt[MSM_GPU_MAX_RINGS];
+	uint64_t preempt_iova[MSM_GPU_MAX_RINGS];
+
+	atomic_t preempt_state;
+	struct timer_list preempt_timer;
 };
 
 #define to_a5xx_gpu(x) container_of(x, struct a5xx_gpu, base)
 
+/*
+ * In order to do lockless preemption we use a simple state machine to progress
+ * through the process.
+ *
+ * PREEMPT_NONE - no preemption in progress.  Next state START.
+ * PREEMPT_START - The trigger is evaulating if preemption is possible. Next
+ * states: TRIGGERED, NONE
+ * PREEMPT_ABORT - An intermediate state before moving back to NONE. Next
+ * state: NONE.
+ * PREEMPT_TRIGGERED: A preemption has been executed on the hardware. Next
+ * states: FAULTED, PENDING
+ * PREEMPT_FAULTED: A preemption timed out (never completed). This will trigger
+ * recovery.  Next state: N/A
+ * PREEMPT_PENDING: Preemption complete interrupt fired - the callback is
+ * checking the success of the operation. Next state: FAULTED, NONE.
+ */
+
+enum preempt_state {
+	PREEMPT_NONE = 0,
+	PREEMPT_START,
+	PREEMPT_ABORT,
+	PREEMPT_TRIGGERED,
+	PREEMPT_FAULTED,
+	PREEMPT_PENDING,
+};
+
+/*
+ * struct a5xx_preempt_record is a shared buffer between the microcode and the
+ * CPU to store the state for preemption. The record itself is much larger
+ * (64k) but most of that is used by the CP for storage.
+ *
+ * There is a preemption record assigned per ringbuffer. When the CPU triggers a
+ * preemption, it fills out the record with the useful information (wptr, ring
+ * base, etc) and the microcode uses that information to set up the CP following
+ * the preemption.  When a ring is switched out, the CP will save the ringbuffer
+ * state back to the record. In this way, once the records are properly set up
+ * the CPU can quickly switch back and forth between ringbuffers by only
+ * updating a few registers (often only the wptr).
+ *
+ * These are the CPU aware registers in the record:
+ * @magic: Must always be 0x27C4BAFC
+ * @info: Type of the record - written 0 by the CPU, updated by the CP
+ * @data: Data field from SET_RENDER_MODE or a checkpoint. Written and used by
+ * the CP
+ * @cntl: Value of RB_CNTL written by CPU, save/restored by CP
+ * @rptr: Value of RB_RPTR written by CPU, save/restored by CP
+ * @wptr: Value of RB_WPTR written by CPU, save/restored by CP
+ * @rptr_addr: Value of RB_RPTR_ADDR written by CPU, save/restored by CP
+ * @rbase: Value of RB_BASE written by CPU, save/restored by CP
+ * @counter: GPU address of the storage area for the performance counters
+ */
+struct a5xx_preempt_record {
+	uint32_t magic;
+	uint32_t info;
+	uint32_t data;
+	uint32_t cntl;
+	uint32_t rptr;
+	uint32_t wptr;
+	uint64_t rptr_addr;
+	uint64_t rbase;
+	uint64_t counter;
+};
+
+/* Magic identifier for the preemption record */
+#define A5XX_PREEMPT_RECORD_MAGIC 0x27C4BAFCUL
+
+/*
+ * Even though the structure above is only a few bytes, we need a full 64k to
+ * store the entire preemption record from the CP
+ */
+#define A5XX_PREEMPT_RECORD_SIZE (64 * 1024)
+
+/*
+ * The preemption counter block is a storage area for the value of the
+ * preemption counters that are saved immediately before context switch. We
+ * append it on to the end of the allocation for the preemption record.
+ */
+#define A5XX_PREEMPT_COUNTER_SIZE (16 * 4)
+
+
 int a5xx_power_init(struct msm_gpu *gpu);
 void a5xx_gpmu_ucode_init(struct msm_gpu *gpu);
 
@@ -55,7 +145,22 @@ static inline int spin_usecs(struct msm_gpu *gpu, uint32_t usecs,
 	return -ETIMEDOUT;
 }
 
-bool a5xx_idle(struct msm_gpu *gpu);
+bool a5xx_idle(struct msm_gpu *gpu, struct msm_ringbuffer *ring);
 void a5xx_set_hwcg(struct msm_gpu *gpu, bool state);
 
+void a5xx_preempt_init(struct msm_gpu *gpu);
+void a5xx_preempt_hw_init(struct msm_gpu *gpu);
+void a5xx_preempt_trigger(struct msm_gpu *gpu);
+void a5xx_preempt_irq(struct msm_gpu *gpu);
+void a5xx_preempt_fini(struct msm_gpu *gpu);
+
+/* Return true if we are in a preempt state */
+static inline bool a5xx_in_preempt(struct a5xx_gpu *a5xx_gpu)
+{
+	int preempt_state = atomic_read(&a5xx_gpu->preempt_state);
+
+	return !(preempt_state == PREEMPT_NONE ||
+			preempt_state == PREEMPT_ABORT);
+}
+
 #endif /* __A5XX_GPU_H__ */