/* SPDX-License-Identifier: MIT */
/*
* Copyright © 2019 Intel Corporation
*/
#ifndef INTEL_RING_TYPES_H
#define INTEL_RING_TYPES_H
#include <linux/atomic.h>
#include <linux/kref.h>
#include <linux/types.h>
/*
* Early gen2 devices have a cacheline of just 32 bytes, using 64 is overkill,
* but keeps the logic simple. Indeed, the whole purpose of this macro is just
* to give some inclination as to some of the magic values used in the various
* workarounds!
*/
#define CACHELINE_BYTES 64
#define CACHELINE_DWORDS (CACHELINE_BYTES / sizeof(u32))
struct i915_vma;
struct intel_ring {
struct kref ref;
struct i915_vma *vma;
void *vaddr;
/*
* As we have two types of rings, one global to the engine used
* by ringbuffer submission and those that are exclusive to a
* context used by execlists, we have to play safe and allow
* atomic updates to the pin_count. However, the actual pinning
* of the context is either done during initialisation for
* ringbuffer submission or serialised as part of the context
* pinning for execlists, and so we do not need a mutex ourselves
* to serialise intel_ring_pin/intel_ring_unpin.
*/
atomic_t pin_count;
u32 head; /* updated during retire, loosely tracks RING_HEAD */
u32 tail; /* updated on submission, used for RING_TAIL */
u32 emit; /* updated during request construction */
u32 space;
u32 size;
u32 wrap;
u32 effective_size;
};
#endif /* INTEL_RING_TYPES_H */