drivers/gpu/drm/msm/msm_ringbuffer.h

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/msm/msm_ringbuffer.h

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/msm/msm_ringbuffer.h
Extension
.h
Size
3878 bytes
Lines
143
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct msm_gpu_submit_stats {
	u64 cpcycles_start;
	u64 cpcycles_end;
	u64 alwayson_start;
	u64 alwayson_end;
};

#define MSM_GPU_SUBMIT_STATS_COUNT 64

struct msm_rbmemptrs {
	volatile uint32_t rptr;
	volatile uint32_t fence;
	/* Introduced on A7xx */
	volatile uint32_t bv_rptr;
	volatile uint32_t bv_fence;

	volatile struct msm_gpu_submit_stats stats[MSM_GPU_SUBMIT_STATS_COUNT];
	volatile u64 ttbr0;
	volatile u32 context_idr;

	volatile u32 perfcntr_fence;
};

struct msm_cp_state {
	uint64_t ib1_base, ib2_base;
	uint32_t ib1_rem, ib2_rem;
};

struct msm_ringbuffer {
	struct msm_gpu *gpu;
	int id;
	struct drm_gem_object *bo;
	uint32_t *start, *end, *cur, *next;

	/*
	 * The job scheduler for this ring.
	 */
	struct drm_gpu_scheduler sched;

	/*
	 * List of in-flight submits on this ring.  Protected by submit_lock.
	 *
	 * Currently just submits that are already written into the ring, not
	 * submits that are still in drm_gpu_scheduler's queues.  At a later
	 * step we could probably move to letting drm_gpu_scheduler manage
	 * hangcheck detection and keep track of submit jobs that are in-
	 * flight.
	 */
	struct list_head submits;
	spinlock_t submit_lock;

	uint64_t iova;
	uint32_t hangcheck_fence;
	struct msm_rbmemptrs *memptrs;
	uint64_t memptrs_iova;
	struct msm_fence_context *fctx;

	/**
	 * hangcheck_progress_retries:
	 *
	 * The number of extra hangcheck duration cycles that we have given
	 * due to it appearing that the GPU is making forward progress.
	 *
	 * For GPU generations which support progress detection (see.
	 * msm_gpu_funcs::progress()), if the GPU appears to be making progress
	 * (ie. the CP has advanced in the command stream, we'll allow up to
	 * DRM_MSM_HANGCHECK_PROGRESS_RETRIES expirations of the hangcheck timer
	 * before killing the job.  But to detect progress we need two sample
	 * points, so the duration of the hangcheck timer is halved.  In other
	 * words we'll let the submit run for up to:
	 *
	 * (DRM_MSM_HANGCHECK_DEFAULT_PERIOD / 2) * (DRM_MSM_HANGCHECK_PROGRESS_RETRIES + 1)
	 */
	int hangcheck_progress_retries;

	/**
	 * last_cp_state: The state of the CP at the last call to gpu->progress()
	 */
	struct msm_cp_state last_cp_state;

	/*
	 * preempt_lock protects preemption and serializes wptr updates against
	 * preemption.  Can be aquired from irq context.
	 */
	spinlock_t preempt_lock;

	/*
	 * Whether we skipped writing wptr and it needs to be updated in the
	 * future when the ring becomes current.
	 */

Annotation

Implementation Notes