summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/i915/i915_gem_gtt.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/gpu/drm/i915/i915_gem_gtt.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem_gtt.c')
-rw-r--r--drivers/gpu/drm/i915/i915_gem_gtt.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
new file mode 100644
index 0000000000..7bd1861ddb
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2010 Daniel Vetter
+ * Copyright © 2020 Intel Corporation
+ */
+
+#include <linux/slab.h> /* fault-inject.h is not standalone! */
+
+#include <linux/fault-inject.h>
+#include <linux/log2.h>
+#include <linux/random.h>
+#include <linux/seq_file.h>
+#include <linux/stop_machine.h>
+
+#include <asm/set_memory.h>
+#include <asm/smp.h>
+
+#include "display/intel_frontbuffer.h"
+#include "gt/intel_gt.h"
+#include "gt/intel_gt_requests.h"
+
+#include "i915_drv.h"
+#include "i915_gem_evict.h"
+#include "i915_scatterlist.h"
+#include "i915_trace.h"
+#include "i915_vgpu.h"
+
+int i915_gem_gtt_prepare_pages(struct drm_i915_gem_object *obj,
+ struct sg_table *pages)
+{
+ do {
+ if (dma_map_sg_attrs(obj->base.dev->dev,
+ pages->sgl, pages->nents,
+ DMA_BIDIRECTIONAL,
+ DMA_ATTR_SKIP_CPU_SYNC |
+ DMA_ATTR_NO_KERNEL_MAPPING |
+ DMA_ATTR_NO_WARN))
+ return 0;
+
+ /*
+ * If the DMA remap fails, one cause can be that we have
+ * too many objects pinned in a small remapping table,
+ * such as swiotlb. Incrementally purge all other objects and
+ * try again - if there are no more pages to remove from
+ * the DMA remapper, i915_gem_shrink will return 0.
+ */
+ GEM_BUG_ON(obj->mm.pages == pages);
+ } while (i915_gem_shrink(NULL, to_i915(obj->base.dev),
+ obj->base.size >> PAGE_SHIFT, NULL,
+ I915_SHRINK_BOUND |
+ I915_SHRINK_UNBOUND));
+
+ return -ENOSPC;
+}
+
+void i915_gem_gtt_finish_pages(struct drm_i915_gem_object *obj,
+ struct sg_table *pages)
+{
+ struct drm_i915_private *i915 = to_i915(obj->base.dev);
+ struct i915_ggtt *ggtt = to_gt(i915)->ggtt;
+
+ /* XXX This does not prevent more requests being submitted! */
+ if (unlikely(ggtt->do_idle_maps))
+ /* Wait a bit, in the hope it avoids the hang */
+ usleep_range(100, 250);
+
+ dma_unmap_sg(i915->drm.dev, pages->sgl, pages->nents,
+ DMA_BIDIRECTIONAL);
+}
+
+/**
+ * i915_gem_gtt_reserve - reserve a node in an address_space (GTT)
+ * @vm: the &struct i915_address_space
+ * @ww: An optional struct i915_gem_ww_ctx.
+ * @node: the &struct drm_mm_node (typically i915_vma.mode)
+ * @size: how much space to allocate inside the GTT,
+ * must be #I915_GTT_PAGE_SIZE aligned
+ * @offset: where to insert inside the GTT,
+ * must be #I915_GTT_MIN_ALIGNMENT aligned, and the node
+ * (@offset + @size) must fit within the address space
+ * @color: color to apply to node, if this node is not from a VMA,
+ * color must be #I915_COLOR_UNEVICTABLE
+ * @flags: control search and eviction behaviour
+ *
+ * i915_gem_gtt_reserve() tries to insert the @node at the exact @offset inside
+ * the address space (using @size and @color). If the @node does not fit, it
+ * tries to evict any overlapping nodes from the GTT, including any
+ * neighbouring nodes if the colors do not match (to ensure guard pages between
+ * differing domains). See i915_gem_evict_for_node() for the gory details
+ * on the eviction algorithm. #PIN_NONBLOCK may used to prevent waiting on
+ * evicting active overlapping objects, and any overlapping node that is pinned
+ * or marked as unevictable will also result in failure.
+ *
+ * Returns: 0 on success, -ENOSPC if no suitable hole is found, -EINTR if
+ * asked to wait for eviction and interrupted.
+ */
+int i915_gem_gtt_reserve(struct i915_address_space *vm,
+ struct i915_gem_ww_ctx *ww,
+ struct drm_mm_node *node,
+ u64 size, u64 offset, unsigned long color,
+ unsigned int flags)
+{
+ int err;
+
+ GEM_BUG_ON(!size);
+ GEM_BUG_ON(!IS_ALIGNED(size, I915_GTT_PAGE_SIZE));
+ GEM_BUG_ON(!IS_ALIGNED(offset, I915_GTT_MIN_ALIGNMENT));
+ GEM_BUG_ON(range_overflows(offset, size, vm->total));
+ GEM_BUG_ON(vm == &to_gt(vm->i915)->ggtt->alias->vm);
+ GEM_BUG_ON(drm_mm_node_allocated(node));
+
+ node->size = size;
+ node->start = offset;
+ node->color = color;
+
+ err = drm_mm_reserve_node(&vm->mm, node);
+ if (err != -ENOSPC)
+ return err;
+
+ if (flags & PIN_NOEVICT)
+ return -ENOSPC;
+
+ err = i915_gem_evict_for_node(vm, ww, node, flags);
+ if (err == 0)
+ err = drm_mm_reserve_node(&vm->mm, node);
+
+ return err;
+}
+
+static u64 random_offset(u64 start, u64 end, u64 len, u64 align)
+{
+ u64 range, addr;
+
+ GEM_BUG_ON(range_overflows(start, len, end));
+ GEM_BUG_ON(round_up(start, align) > round_down(end - len, align));
+
+ range = round_down(end - len, align) - round_up(start, align);
+ if (range) {
+ if (sizeof(unsigned long) == sizeof(u64)) {
+ addr = get_random_u64();
+ } else {
+ addr = get_random_u32();
+ if (range > U32_MAX) {
+ addr <<= 32;
+ addr |= get_random_u32();
+ }
+ }
+ div64_u64_rem(addr, range, &addr);
+ start += addr;
+ }
+
+ return round_up(start, align);
+}
+
+/**
+ * i915_gem_gtt_insert - insert a node into an address_space (GTT)
+ * @vm: the &struct i915_address_space
+ * @ww: An optional struct i915_gem_ww_ctx.
+ * @node: the &struct drm_mm_node (typically i915_vma.node)
+ * @size: how much space to allocate inside the GTT,
+ * must be #I915_GTT_PAGE_SIZE aligned
+ * @alignment: required alignment of starting offset, may be 0 but
+ * if specified, this must be a power-of-two and at least
+ * #I915_GTT_MIN_ALIGNMENT
+ * @color: color to apply to node
+ * @start: start of any range restriction inside GTT (0 for all),
+ * must be #I915_GTT_PAGE_SIZE aligned
+ * @end: end of any range restriction inside GTT (U64_MAX for all),
+ * must be #I915_GTT_PAGE_SIZE aligned if not U64_MAX
+ * @flags: control search and eviction behaviour
+ *
+ * i915_gem_gtt_insert() first searches for an available hole into which
+ * is can insert the node. The hole address is aligned to @alignment and
+ * its @size must then fit entirely within the [@start, @end] bounds. The
+ * nodes on either side of the hole must match @color, or else a guard page
+ * will be inserted between the two nodes (or the node evicted). If no
+ * suitable hole is found, first a victim is randomly selected and tested
+ * for eviction, otherwise then the LRU list of objects within the GTT
+ * is scanned to find the first set of replacement nodes to create the hole.
+ * Those old overlapping nodes are evicted from the GTT (and so must be
+ * rebound before any future use). Any node that is currently pinned cannot
+ * be evicted (see i915_vma_pin()). Similar if the node's VMA is currently
+ * active and #PIN_NONBLOCK is specified, that node is also skipped when
+ * searching for an eviction candidate. See i915_gem_evict_something() for
+ * the gory details on the eviction algorithm.
+ *
+ * Returns: 0 on success, -ENOSPC if no suitable hole is found, -EINTR if
+ * asked to wait for eviction and interrupted.
+ */
+int i915_gem_gtt_insert(struct i915_address_space *vm,
+ struct i915_gem_ww_ctx *ww,
+ struct drm_mm_node *node,
+ u64 size, u64 alignment, unsigned long color,
+ u64 start, u64 end, unsigned int flags)
+{
+ enum drm_mm_insert_mode mode;
+ u64 offset;
+ int err;
+
+ lockdep_assert_held(&vm->mutex);
+
+ GEM_BUG_ON(!size);
+ GEM_BUG_ON(!IS_ALIGNED(size, I915_GTT_PAGE_SIZE));
+ GEM_BUG_ON(alignment && !is_power_of_2(alignment));
+ GEM_BUG_ON(alignment && !IS_ALIGNED(alignment, I915_GTT_MIN_ALIGNMENT));
+ GEM_BUG_ON(start >= end);
+ GEM_BUG_ON(start > 0 && !IS_ALIGNED(start, I915_GTT_PAGE_SIZE));
+ GEM_BUG_ON(end < U64_MAX && !IS_ALIGNED(end, I915_GTT_PAGE_SIZE));
+ GEM_BUG_ON(vm == &to_gt(vm->i915)->ggtt->alias->vm);
+ GEM_BUG_ON(drm_mm_node_allocated(node));
+
+ if (unlikely(range_overflows(start, size, end)))
+ return -ENOSPC;
+
+ if (unlikely(round_up(start, alignment) > round_down(end - size, alignment)))
+ return -ENOSPC;
+
+ mode = DRM_MM_INSERT_BEST;
+ if (flags & PIN_HIGH)
+ mode = DRM_MM_INSERT_HIGHEST;
+ if (flags & PIN_MAPPABLE)
+ mode = DRM_MM_INSERT_LOW;
+
+ /* We only allocate in PAGE_SIZE/GTT_PAGE_SIZE (4096) chunks,
+ * so we know that we always have a minimum alignment of 4096.
+ * The drm_mm range manager is optimised to return results
+ * with zero alignment, so where possible use the optimal
+ * path.
+ */
+ BUILD_BUG_ON(I915_GTT_MIN_ALIGNMENT > I915_GTT_PAGE_SIZE);
+ if (alignment <= I915_GTT_MIN_ALIGNMENT)
+ alignment = 0;
+
+ err = drm_mm_insert_node_in_range(&vm->mm, node,
+ size, alignment, color,
+ start, end, mode);
+ if (err != -ENOSPC)
+ return err;
+
+ if (mode & DRM_MM_INSERT_ONCE) {
+ err = drm_mm_insert_node_in_range(&vm->mm, node,
+ size, alignment, color,
+ start, end,
+ DRM_MM_INSERT_BEST);
+ if (err != -ENOSPC)
+ return err;
+ }
+
+ if (flags & PIN_NOEVICT)
+ return -ENOSPC;
+
+ /*
+ * No free space, pick a slot at random.
+ *
+ * There is a pathological case here using a GTT shared between
+ * mmap and GPU (i.e. ggtt/aliasing_ppgtt but not full-ppgtt):
+ *
+ * |<-- 256 MiB aperture -->||<-- 1792 MiB unmappable -->|
+ * (64k objects) (448k objects)
+ *
+ * Now imagine that the eviction LRU is ordered top-down (just because
+ * pathology meets real life), and that we need to evict an object to
+ * make room inside the aperture. The eviction scan then has to walk
+ * the 448k list before it finds one within range. And now imagine that
+ * it has to search for a new hole between every byte inside the memcpy,
+ * for several simultaneous clients.
+ *
+ * On a full-ppgtt system, if we have run out of available space, there
+ * will be lots and lots of objects in the eviction list! Again,
+ * searching that LRU list may be slow if we are also applying any
+ * range restrictions (e.g. restriction to low 4GiB) and so, for
+ * simplicity and similarilty between different GTT, try the single
+ * random replacement first.
+ */
+ offset = random_offset(start, end,
+ size, alignment ?: I915_GTT_MIN_ALIGNMENT);
+ err = i915_gem_gtt_reserve(vm, ww, node, size, offset, color, flags);
+ if (err != -ENOSPC)
+ return err;
+
+ if (flags & PIN_NOSEARCH)
+ return -ENOSPC;
+
+ /* Randomly selected placement is pinned, do a search */
+ err = i915_gem_evict_something(vm, ww, size, alignment, color,
+ start, end, flags);
+ if (err)
+ return err;
+
+ return drm_mm_insert_node_in_range(&vm->mm, node,
+ size, alignment, color,
+ start, end, DRM_MM_INSERT_EVICT);
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/i915_gem_gtt.c"
+#endif