drivers/gpu/drm/i915/gt/intel_ring.h

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/i915/gt/intel_ring.h

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/i915/gt/intel_ring.h
Extension
.h
Size
4140 bytes
Lines
142
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

#ifndef INTEL_RING_H
#define INTEL_RING_H

#include "i915_gem.h" /* GEM_BUG_ON */
#include "i915_request.h"
#include "intel_ring_types.h"

struct intel_engine_cs;

struct intel_ring *
intel_engine_create_ring(struct intel_engine_cs *engine, int size);

u32 *intel_ring_begin(struct i915_request *rq, unsigned int num_dwords);

unsigned int intel_ring_update_space(struct intel_ring *ring);

void __intel_ring_pin(struct intel_ring *ring);
int intel_ring_pin(struct intel_ring *ring, struct i915_gem_ww_ctx *ww);
void intel_ring_unpin(struct intel_ring *ring);
void intel_ring_reset(struct intel_ring *ring, u32 tail);

void intel_ring_free(struct kref *ref);

static inline struct intel_ring *intel_ring_get(struct intel_ring *ring)
{
	kref_get(&ring->ref);
	return ring;
}

static inline void intel_ring_put(struct intel_ring *ring)
{
	kref_put(&ring->ref, intel_ring_free);
}

static inline void intel_ring_advance(struct i915_request *rq, u32 *cs)
{
	/* Dummy function.
	 *
	 * This serves as a placeholder in the code so that the reader
	 * can compare against the preceding intel_ring_begin() and
	 * check that the number of dwords emitted matches the space
	 * reserved for the command packet (i.e. the value passed to
	 * intel_ring_begin()).
	 */
	GEM_BUG_ON((rq->ring->vaddr + rq->ring->emit) != cs);
	GEM_BUG_ON(!IS_ALIGNED(rq->ring->emit, 8)); /* RING_TAIL qword align */
}

static inline u32 intel_ring_wrap(const struct intel_ring *ring, u32 pos)
{
	return pos & (ring->size - 1);
}

static inline int intel_ring_direction(const struct intel_ring *ring,
				       u32 next, u32 prev)
{
	typecheck(typeof(ring->size), next);
	typecheck(typeof(ring->size), prev);
	return (next - prev) << ring->wrap;
}

static inline bool
intel_ring_offset_valid(const struct intel_ring *ring,
			unsigned int pos)
{
	if (pos & -ring->size) /* must be strictly within the ring */
		return false;

	if (!IS_ALIGNED(pos, 8)) /* must be qword aligned */
		return false;

	return true;
}

static inline u32 intel_ring_offset(const struct i915_request *rq, void *addr)
{
	/* Don't write ring->size (equivalent to 0) as that hangs some GPUs. */
	u32 offset = addr - rq->ring->vaddr;

	GEM_BUG_ON(offset > rq->ring->size);
	return intel_ring_wrap(rq->ring, offset);
}

static inline void
assert_ring_tail_valid(const struct intel_ring *ring, unsigned int tail)
{
	unsigned int head = READ_ONCE(ring->head);

	GEM_BUG_ON(!intel_ring_offset_valid(ring, tail));

Annotation

Implementation Notes