blob: 7c4d5158e03bb850c4a0579af83209ef153cd769 [file] [log] [blame]
// SPDX-License-Identifier: MIT
/*
* Copyright © 2019 Intel Corporation
*/
#include "gem/i915_gem_lmem.h"
#include "gem/i915_gem_object.h"
#include "i915_drv.h"
#include "i915_vma.h"
#include "intel_engine.h"
#include "intel_gpu_commands.h"
#include "intel_ring.h"
#include "intel_timeline.h"
unsigned int intel_ring_update_space(struct intel_ring *ring)
{
unsigned int space;
space = __intel_ring_space(ring->head, ring->emit, ring->size);
ring->space = space;
return space;
}
void __intel_ring_pin(struct intel_ring *ring)
{
GEM_BUG_ON(!atomic_read(&ring->pin_count));
atomic_inc(&ring->pin_count);
}
int intel_ring_pin(struct intel_ring *ring, struct i915_gem_ww_ctx *ww)
{
struct i915_vma *vma = ring->vma;
unsigned int flags;
void *addr;
int ret;
if (atomic_fetch_inc(&ring->pin_count))
return 0;
/* Ring wraparound at offset 0 sometimes hangs. No idea why. */
flags = PIN_OFFSET_BIAS | i915_ggtt_pin_bias(vma);
if (i915_gem_object_is_stolen(vma->obj))
flags |= PIN_MAPPABLE;
else
flags |= PIN_HIGH;
ret = i915_ggtt_pin(vma, ww, 0, flags);
if (unlikely(ret))
goto err_unpin;
if (i915_vma_is_map_and_fenceable(vma)) {
addr = (void __force *)i915_vma_pin_iomap(vma);
} else {
int type = i915_coherent_map_type(vma->vm->i915, vma->obj, false);
addr = i915_gem_object_pin_map(vma->obj, type);
}
if (IS_ERR(addr)) {
ret = PTR_ERR(addr);
goto err_ring;
}
i915_vma_make_unshrinkable(vma);
/* Discard any unused bytes beyond that submitted to hw. */
intel_ring_reset(ring, ring->emit);
ring->vaddr = addr;
return 0;
err_ring:
i915_vma_unpin(vma);
err_unpin:
atomic_dec(&ring->pin_count);
return ret;
}
void intel_ring_reset(struct intel_ring *ring, u32 tail)
{
tail = intel_ring_wrap(ring, tail);
ring->tail = tail;
ring->head = tail;
ring->emit = tail;
intel_ring_update_space(ring);
}
void intel_ring_unpin(struct intel_ring *ring)
{
struct i915_vma *vma = ring->vma;
if (!atomic_dec_and_test(&ring->pin_count))
return;
i915_vma_unset_ggtt_write(vma);
if (i915_vma_is_map_and_fenceable(vma))
i915_vma_unpin_iomap(vma);
else
i915_gem_object_unpin_map(vma->obj);
i915_vma_make_purgeable(vma);
i915_vma_unpin(vma);
}
static struct i915_vma *create_ring_vma(struct i915_ggtt *ggtt, int size)
{
struct i915_address_space *vm = &ggtt->vm;
struct drm_i915_private *i915 = vm->i915;
struct drm_i915_gem_object *obj;
struct i915_vma *vma;
obj = i915_gem_object_create_lmem(i915, size, I915_BO_ALLOC_VOLATILE);
if (IS_ERR(obj) && i915_ggtt_has_aperture(ggtt))
obj = i915_gem_object_create_stolen(i915, size);
if (IS_ERR(obj))
obj = i915_gem_object_create_internal(i915, size);
if (IS_ERR(obj))
return ERR_CAST(obj);
/*
* Mark ring buffers as read-only from GPU side (so no stray overwrites)
* if supported by the platform's GGTT.
*/
if (vm->has_read_only)
i915_gem_object_set_readonly(obj);
vma = i915_vma_instance(obj, vm, NULL);
if (IS_ERR(vma))
goto err;
return vma;
err:
i915_gem_object_put(obj);
return vma;
}
struct intel_ring *
intel_engine_create_ring(struct intel_engine_cs *engine, int size)
{
struct drm_i915_private *i915 = engine->i915;
struct intel_ring *ring;
struct i915_vma *vma;
GEM_BUG_ON(!is_power_of_2(size));
GEM_BUG_ON(RING_CTL_SIZE(size) & ~RING_NR_PAGES);
ring = kzalloc(sizeof(*ring), GFP_KERNEL);
if (!ring)
return ERR_PTR(-ENOMEM);
kref_init(&ring->ref);
ring->size = size;
ring->wrap = BITS_PER_TYPE(ring->size) - ilog2(size);
/*
* Workaround an erratum on the i830 which causes a hang if
* the TAIL pointer points to within the last 2 cachelines
* of the buffer.
*/
ring->effective_size = size;
if (IS_I830(i915) || IS_I845G(i915))
ring->effective_size -= 2 * CACHELINE_BYTES;
intel_ring_update_space(ring);
vma = create_ring_vma(engine->gt->ggtt, size);
if (IS_ERR(vma)) {
kfree(ring);
return ERR_CAST(vma);
}
ring->vma = vma;
return ring;
}
void intel_ring_free(struct kref *ref)
{
struct intel_ring *ring = container_of(ref, typeof(*ring), ref);
i915_vma_put(ring->vma);
kfree(ring);
}
static noinline int
wait_for_space(struct intel_ring *ring,
struct intel_timeline *tl,
unsigned int bytes)
{
struct i915_request *target;
long timeout;
if (intel_ring_update_space(ring) >= bytes)
return 0;
GEM_BUG_ON(list_empty(&tl->requests));
list_for_each_entry(target, &tl->requests, link) {
if (target->ring != ring)
continue;
/* Would completion of this request free enough space? */
if (bytes <= __intel_ring_space(target->postfix,
ring->emit, ring->size))
break;
}
if (GEM_WARN_ON(&target->link == &tl->requests))
return -ENOSPC;
timeout = i915_request_wait(target,
I915_WAIT_INTERRUPTIBLE,
MAX_SCHEDULE_TIMEOUT);
if (timeout < 0)
return timeout;
i915_request_retire_upto(target);
intel_ring_update_space(ring);
GEM_BUG_ON(ring->space < bytes);
return 0;
}
u32 *intel_ring_begin(struct i915_request *rq, unsigned int num_dwords)
{
struct intel_ring *ring = rq->ring;
const unsigned int remain_usable = ring->effective_size - ring->emit;
const unsigned int bytes = num_dwords * sizeof(u32);
unsigned int need_wrap = 0;
unsigned int total_bytes;
u32 *cs;
/* Packets must be qword aligned. */
GEM_BUG_ON(num_dwords & 1);
total_bytes = bytes + rq->reserved_space;
GEM_BUG_ON(total_bytes > ring->effective_size);
if (unlikely(total_bytes > remain_usable)) {
const int remain_actual = ring->size - ring->emit;
if (bytes > remain_usable) {
/*
* Not enough space for the basic request. So need to
* flush out the remainder and then wait for
* base + reserved.
*/
total_bytes += remain_actual;
need_wrap = remain_actual | 1;
} else {
/*
* The base request will fit but the reserved space
* falls off the end. So we don't need an immediate
* wrap and only need to effectively wait for the
* reserved size from the start of ringbuffer.
*/
total_bytes = rq->reserved_space + remain_actual;
}
}
if (unlikely(total_bytes > ring->space)) {
int ret;
/*
* Space is reserved in the ringbuffer for finalising the
* request, as that cannot be allowed to fail. During request
* finalisation, reserved_space is set to 0 to stop the
* overallocation and the assumption is that then we never need
* to wait (which has the risk of failing with EINTR).
*
* See also i915_request_alloc() and i915_request_add().
*/
GEM_BUG_ON(!rq->reserved_space);
ret = wait_for_space(ring,
i915_request_timeline(rq),
total_bytes);
if (unlikely(ret))
return ERR_PTR(ret);
}
if (unlikely(need_wrap)) {
need_wrap &= ~1;
GEM_BUG_ON(need_wrap > ring->space);
GEM_BUG_ON(ring->emit + need_wrap > ring->size);
GEM_BUG_ON(!IS_ALIGNED(need_wrap, sizeof(u64)));
/* Fill the tail with MI_NOOP */
memset64(ring->vaddr + ring->emit, 0, need_wrap / sizeof(u64));
ring->space -= need_wrap;
ring->emit = 0;
}
GEM_BUG_ON(ring->emit > ring->size - bytes);
GEM_BUG_ON(ring->space < bytes);
cs = ring->vaddr + ring->emit;
GEM_DEBUG_EXEC(memset32(cs, POISON_INUSE, bytes / sizeof(*cs)));
ring->emit += bytes;
ring->space -= bytes;
return cs;
}
/* Align the ring tail to a cacheline boundary */
int intel_ring_cacheline_align(struct i915_request *rq)
{
int num_dwords;
void *cs;
num_dwords = (rq->ring->emit & (CACHELINE_BYTES - 1)) / sizeof(u32);
if (num_dwords == 0)
return 0;
num_dwords = CACHELINE_DWORDS - num_dwords;
GEM_BUG_ON(num_dwords & 1);
cs = intel_ring_begin(rq, num_dwords);
if (IS_ERR(cs))
return PTR_ERR(cs);
memset64(cs, (u64)MI_NOOP << 32 | MI_NOOP, num_dwords / 2);
intel_ring_advance(rq, cs + num_dwords);
GEM_BUG_ON(rq->ring->emit & (CACHELINE_BYTES - 1));
return 0;
}
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftest_ring.c"
#endif