From 2871ea85c119e6fb1127b30f0061436b285d3a2c Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 24 Oct 2019 11:03:44 +0100 Subject: drm/i915/gt: Split intel_ring_submission Split the legacy submission backend from the common CS ring buffer handling. Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20191024100344.5041-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_ring.c | 321 +++++++++++++++++++++++++++++++++++ 1 file changed, 321 insertions(+) create mode 100644 drivers/gpu/drm/i915/gt/intel_ring.c (limited to 'drivers/gpu/drm/i915/gt/intel_ring.c') diff --git a/drivers/gpu/drm/i915/gt/intel_ring.c b/drivers/gpu/drm/i915/gt/intel_ring.c new file mode 100644 index 000000000000..fa01c1407760 --- /dev/null +++ b/drivers/gpu/drm/i915/gt/intel_ring.c @@ -0,0 +1,321 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2019 Intel Corporation + */ + +#include "gem/i915_gem_object.h" +#include "i915_drv.h" +#include "i915_vma.h" +#include "intel_engine.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; +} + +int intel_ring_pin(struct intel_ring *ring) +{ + struct i915_vma *vma = ring->vma; + unsigned int flags; + void *addr; + int ret; + + if (atomic_fetch_inc(&ring->pin_count)) + return 0; + + flags = PIN_GLOBAL; + + /* Ring wraparound at offset 0 sometimes hangs. No idea why. */ + flags |= PIN_OFFSET_BIAS | i915_ggtt_pin_bias(vma); + + if (vma->obj->stolen) + flags |= PIN_MAPPABLE; + else + flags |= PIN_HIGH; + + ret = i915_vma_pin(vma, 0, 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 + addr = i915_gem_object_pin_map(vma->obj, + i915_coherent_map_type(vma->vm->i915)); + if (IS_ERR(addr)) { + ret = PTR_ERR(addr); + goto err_ring; + } + + i915_vma_make_unshrinkable(vma); + + GEM_BUG_ON(ring->vaddr); + 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; + + /* Discard any unused bytes beyond that submitted to hw. */ + intel_ring_reset(ring, ring->emit); + + 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); + + GEM_BUG_ON(!ring->vaddr); + ring->vaddr = NULL; + + i915_vma_unpin(vma); + i915_vma_make_purgeable(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_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; + + /* + * 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; +} -- cgit v1.2.3