drm/i915: introduce intel_memory_region

Support memory regions, as defined by a given (start, end), and allow
creating GEM objects which are backed by said region. The immediate goal
here is to have something to represent our device memory, but later on
we also want to represent every memory domain with a region, so stolen,
shmem, and of course device. At some point we are probably going to want
use a common struct here, such that we are better aligned with say TTM.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191008160116.18379-2-matthew.auld@intel.com

1 files changed, 191 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
new file mode 100644
index 000000000000..2ef67c397fca
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_memory_region.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include "intel_memory_region.h"
+#include "i915_drv.h"
+
+static u64
+intel_memory_region_free_pages(struct intel_memory_region *mem,
+			       struct list_head *blocks)
+{
+	struct i915_buddy_block *block, *on;
+	u64 size = 0;
+
+	list_for_each_entry_safe(block, on, blocks, link) {
+		size += i915_buddy_block_size(&mem->mm, block);
+		i915_buddy_free(&mem->mm, block);
+	}
+	INIT_LIST_HEAD(blocks);
+
+	return size;
+}
+
+void
+__intel_memory_region_put_pages_buddy(struct intel_memory_region *mem,
+				      struct list_head *blocks)
+{
+	mutex_lock(&mem->mm_lock);
+	intel_memory_region_free_pages(mem, blocks);
+	mutex_unlock(&mem->mm_lock);
+}
+
+void
+__intel_memory_region_put_block_buddy(struct i915_buddy_block *block)
+{
+	struct list_head blocks;
+
+	INIT_LIST_HEAD(&blocks);
+	list_add(&block->link, &blocks);
+	__intel_memory_region_put_pages_buddy(block->private, &blocks);
+}
+
+int
+__intel_memory_region_get_pages_buddy(struct intel_memory_region *mem,
+				      resource_size_t size,
+				      unsigned int flags,
+				      struct list_head *blocks)
+{
+	unsigned long n_pages = size >> ilog2(mem->mm.chunk_size);
+	unsigned int min_order = 0;
+
+	GEM_BUG_ON(!IS_ALIGNED(size, mem->mm.chunk_size));
+	GEM_BUG_ON(!list_empty(blocks));
+
+	if (flags & I915_ALLOC_MIN_PAGE_SIZE) {
+		min_order = ilog2(mem->min_page_size) -
+			    ilog2(mem->mm.chunk_size);
+	}
+
+	mutex_lock(&mem->mm_lock);
+
+	do {
+		struct i915_buddy_block *block;
+		unsigned int order;
+
+		order = fls(n_pages) - 1;
+		GEM_BUG_ON(order > mem->mm.max_order);
+		GEM_BUG_ON(order < min_order);
+
+		do {
+			block = i915_buddy_alloc(&mem->mm, order);
+			if (!IS_ERR(block))
+				break;
+
+			if (order-- == min_order)
+				goto err_free_blocks;
+		} while (1);
+
+		n_pages -= BIT(order);
+
+		block->private = mem;
+		list_add(&block->link, blocks);
+
+		if (!n_pages)
+			break;
+	} while (1);
+
+	mutex_unlock(&mem->mm_lock);
+	return 0;
+
+err_free_blocks:
+	intel_memory_region_free_pages(mem, blocks);
+	mutex_unlock(&mem->mm_lock);
+	return -ENXIO;
+}
+
+struct i915_buddy_block *
+__intel_memory_region_get_block_buddy(struct intel_memory_region *mem,
+				      resource_size_t size,
+				      unsigned int flags)
+{
+	struct i915_buddy_block *block;
+	LIST_HEAD(blocks);
+	int ret;
+
+	ret = __intel_memory_region_get_pages_buddy(mem, size, flags, &blocks);
+	if (ret)
+		return ERR_PTR(ret);
+
+	block = list_first_entry(&blocks, typeof(*block), link);
+	list_del_init(&block->link);
+	return block;
+}
+
+int intel_memory_region_init_buddy(struct intel_memory_region *mem)
+{
+	return i915_buddy_init(&mem->mm, resource_size(&mem->region),
+			       PAGE_SIZE);
+}
+
+void intel_memory_region_release_buddy(struct intel_memory_region *mem)
+{
+	i915_buddy_fini(&mem->mm);
+}
+
+struct intel_memory_region *
+intel_memory_region_create(struct drm_i915_private *i915,
+			   resource_size_t start,
+			   resource_size_t size,
+			   resource_size_t min_page_size,
+			   resource_size_t io_start,
+			   const struct intel_memory_region_ops *ops)
+{
+	struct intel_memory_region *mem;
+	int err;
+
+	mem = kzalloc(sizeof(*mem), GFP_KERNEL);
+	if (!mem)
+		return ERR_PTR(-ENOMEM);
+
+	mem->i915 = i915;
+	mem->region = (struct resource)DEFINE_RES_MEM(start, size);
+	mem->io_start = io_start;
+	mem->min_page_size = min_page_size;
+	mem->ops = ops;
+
+	mutex_init(&mem->mm_lock);
+
+	if (ops->init) {
+		err = ops->init(mem);
+		if (err)
+			goto err_free;
+	}
+
+	kref_init(&mem->kref);
+	return mem;
+
+err_free:
+	kfree(mem);
+	return ERR_PTR(err);
+}
+
+static void __intel_memory_region_destroy(struct kref *kref)
+{
+	struct intel_memory_region *mem =
+		container_of(kref, typeof(*mem), kref);
+
+	if (mem->ops->release)
+		mem->ops->release(mem);
+
+	mutex_destroy(&mem->mm_lock);
+	kfree(mem);
+}
+
+struct intel_memory_region *
+intel_memory_region_get(struct intel_memory_region *mem)
+{
+	kref_get(&mem->kref);
+	return mem;
+}
+
+void intel_memory_region_put(struct intel_memory_region *mem)
+{
+	kref_put(&mem->kref, __intel_memory_region_destroy);
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/intel_memory_region.c"
+#include "selftests/mock_region.c"
+#endif