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authorChris Wilson <chris@chris-wilson.co.uk>2019-10-24 11:03:44 +0100
committerChris Wilson <chris@chris-wilson.co.uk>2019-10-24 12:14:21 +0100
commit2871ea85c119e6fb1127b30f0061436b285d3a2c (patch)
treed4e69fc34ae0c8c9301ff5632bb0332965a3bea3 /drivers/gpu/drm/i915/gt/intel_ring.c
parent2c9a49150d90147a098ba0b39ced89d155c32820 (diff)
downloadlinux-sh-2871ea85c119e6fb1127b30f0061436b285d3a2c.tar.gz
drm/i915/gt: Split intel_ring_submission
Split the legacy submission backend from the common CS ring buffer handling. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191024100344.5041-1-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_ring.c')
-rw-r--r--drivers/gpu/drm/i915/gt/intel_ring.c321
1 files changed, 321 insertions, 0 deletions
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;
+}