--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022 Red Hat.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ * Danilo Krummrich <dakr@redhat.com>
+ *
+ */
+
+#include <drm/drm_gpuva_mgr.h>
+
+#include <linux/interval_tree_generic.h>
+#include <linux/mm.h>
+
+/**
+ * DOC: Overview
+ *
+ * The DRM GPU VA Manager, represented by struct drm_gpuva_manager keeps track
+ * of a GPU's virtual address (VA) space and manages the corresponding virtual
+ * mappings represented by &drm_gpuva objects. It also keeps track of the
+ * mapping's backing &drm_gem_object buffers.
+ *
+ * &drm_gem_object buffers maintain a list of &drm_gpuva objects representing
+ * all existent GPU VA mappings using this &drm_gem_object as backing buffer.
+ *
+ * GPU VAs can be flagged as sparse, such that drivers may use GPU VAs to also
+ * keep track of sparse PTEs in order to support Vulkan 'Sparse Resources'.
+ *
+ * The GPU VA manager internally uses a rb-tree to manage the
+ * &drm_gpuva mappings within a GPU's virtual address space.
+ *
+ * The &drm_gpuva_manager contains a special &drm_gpuva representing the
+ * portion of VA space reserved by the kernel. This node is initialized together
+ * with the GPU VA manager instance and removed when the GPU VA manager is
+ * destroyed.
+ *
+ * In a typical application drivers would embed struct drm_gpuva_manager and
+ * struct drm_gpuva within their own driver specific structures, there won't be
+ * any memory allocations of its own nor memory allocations of &drm_gpuva
+ * entries.
+ *
+ * The data structures needed to store &drm_gpuvas within the &drm_gpuva_manager
+ * are contained within struct drm_gpuva already. Hence, for inserting
+ * &drm_gpuva entries from within dma-fence signalling critical sections it is
+ * enough to pre-allocate the &drm_gpuva structures.
+ */
+
+/**
+ * DOC: Split and Merge
+ *
+ * Besides its capability to manage and represent a GPU VA space, the
+ * &drm_gpuva_manager also provides functions to let the &drm_gpuva_manager
+ * calculate a sequence of operations to satisfy a given map or unmap request.
+ *
+ * Therefore the DRM GPU VA manager provides an algorithm implementing splitting
+ * and merging of existent GPU VA mappings with the ones that are requested to
+ * be mapped or unmapped. This feature is required by the Vulkan API to
+ * implement Vulkan 'Sparse Memory Bindings' - drivers UAPIs often refer to this
+ * as VM BIND.
+ *
+ * Drivers can call drm_gpuva_sm_map() to receive a sequence of callbacks
+ * containing map, unmap and remap operations for a given newly requested
+ * mapping. The sequence of callbacks represents the set of operations to
+ * execute in order to integrate the new mapping cleanly into the current state
+ * of the GPU VA space.
+ *
+ * Depending on how the new GPU VA mapping intersects with the existent mappings
+ * of the GPU VA space the &drm_gpuva_fn_ops callbacks contain an arbitrary
+ * amount of unmap operations, a maximum of two remap operations and a single
+ * map operation. The caller might receive no callback at all if no operation is
+ * required, e.g. if the requested mapping already exists in the exact same way.
+ *
+ * The single map operation represents the original map operation requested by
+ * the caller.
+ *
+ * &drm_gpuva_op_unmap contains a 'keep' field, which indicates whether the
+ * &drm_gpuva to unmap is physically contiguous with the original mapping
+ * request. Optionally, if 'keep' is set, drivers may keep the actual page table
+ * entries for this &drm_gpuva, adding the missing page table entries only and
+ * update the &drm_gpuva_manager's view of things accordingly.
+ *
+ * Drivers may do the same optimization, namely delta page table updates, also
+ * for remap operations. This is possible since &drm_gpuva_op_remap consists of
+ * one unmap operation and one or two map operations, such that drivers can
+ * derive the page table update delta accordingly.
+ *
+ * Note that there can't be more than two existent mappings to split up, one at
+ * the beginning and one at the end of the new mapping, hence there is a
+ * maximum of two remap operations.
+ *
+ * Analogous to drm_gpuva_sm_map() drm_gpuva_sm_unmap() uses &drm_gpuva_fn_ops
+ * to call back into the driver in order to unmap a range of GPU VA space. The
+ * logic behind this function is way simpler though: For all existent mappings
+ * enclosed by the given range unmap operations are created. For mappings which
+ * are only partically located within the given range, remap operations are
+ * created such that those mappings are split up and re-mapped partically.
+ *
+ * As an alternative to drm_gpuva_sm_map() and drm_gpuva_sm_unmap(),
+ * drm_gpuva_sm_map_ops_create() and drm_gpuva_sm_unmap_ops_create() can be used
+ * to directly obtain an instance of struct drm_gpuva_ops containing a list of
+ * &drm_gpuva_op, which can be iterated with drm_gpuva_for_each_op(). This list
+ * contains the &drm_gpuva_ops analogous to the callbacks one would receive when
+ * calling drm_gpuva_sm_map() or drm_gpuva_sm_unmap(). While this way requires
+ * more memory (to allocate the &drm_gpuva_ops), it provides drivers a way to
+ * iterate the &drm_gpuva_op multiple times, e.g. once in a context where memory
+ * allocations are possible (e.g. to allocate GPU page tables) and once in the
+ * dma-fence signalling critical path.
+ *
+ * To update the &drm_gpuva_manager's view of the GPU VA space
+ * drm_gpuva_insert() and drm_gpuva_remove() may be used. These functions can
+ * safely be used from &drm_gpuva_fn_ops callbacks originating from
+ * drm_gpuva_sm_map() or drm_gpuva_sm_unmap(). However, it might be more
+ * convenient to use the provided helper functions drm_gpuva_map(),
+ * drm_gpuva_remap() and drm_gpuva_unmap() instead.
+ *
+ * The following diagram depicts the basic relationships of existent GPU VA
+ * mappings, a newly requested mapping and the resulting mappings as implemented
+ * by drm_gpuva_sm_map() - it doesn't cover any arbitrary combinations of these.
+ *
+ * 1) Requested mapping is identical. Replace it, but indicate the backing PTEs
+ * could be kept.
+ *
+ * ::
+ *
+ * 0 a 1
+ * old: |-----------| (bo_offset=n)
+ *
+ * 0 a 1
+ * req: |-----------| (bo_offset=n)
+ *
+ * 0 a 1
+ * new: |-----------| (bo_offset=n)
+ *
+ *
+ * 2) Requested mapping is identical, except for the BO offset, hence replace
+ * the mapping.
+ *
+ * ::
+ *
+ * 0 a 1
+ * old: |-----------| (bo_offset=n)
+ *
+ * 0 a 1
+ * req: |-----------| (bo_offset=m)
+ *
+ * 0 a 1
+ * new: |-----------| (bo_offset=m)
+ *
+ *
+ * 3) Requested mapping is identical, except for the backing BO, hence replace
+ * the mapping.
+ *
+ * ::
+ *
+ * 0 a 1
+ * old: |-----------| (bo_offset=n)
+ *
+ * 0 b 1
+ * req: |-----------| (bo_offset=n)
+ *
+ * 0 b 1
+ * new: |-----------| (bo_offset=n)
+ *
+ *
+ * 4) Existent mapping is a left aligned subset of the requested one, hence
+ * replace the existent one.
+ *
+ * ::
+ *
+ * 0 a 1
+ * old: |-----| (bo_offset=n)
+ *
+ * 0 a 2
+ * req: |-----------| (bo_offset=n)
+ *
+ * 0 a 2
+ * new: |-----------| (bo_offset=n)
+ *
+ * .. note::
+ * We expect to see the same result for a request with a different BO
+ * and/or non-contiguous BO offset.
+ *
+ *
+ * 5) Requested mapping's range is a left aligned subset of the existent one,
+ * but backed by a different BO. Hence, map the requested mapping and split
+ * the existent one adjusting its BO offset.
+ *
+ * ::
+ *
+ * 0 a 2
+ * old: |-----------| (bo_offset=n)
+ *
+ * 0 b 1
+ * req: |-----| (bo_offset=n)
+ *
+ * 0 b 1 a' 2
+ * new: |-----|-----| (b.bo_offset=n, a.bo_offset=n+1)
+ *
+ * .. note::
+ * We expect to see the same result for a request with a different BO
+ * and/or non-contiguous BO offset.
+ *
+ *
+ * 6) Existent mapping is a superset of the requested mapping. Split it up, but
+ * indicate that the backing PTEs could be kept.
+ *
+ * ::
+ *
+ * 0 a 2
+ * old: |-----------| (bo_offset=n)
+ *
+ * 0 a 1
+ * req: |-----| (bo_offset=n)
+ *
+ * 0 a 1 a' 2
+ * new: |-----|-----| (a.bo_offset=n, a'.bo_offset=n+1)
+ *
+ *
+ * 7) Requested mapping's range is a right aligned subset of the existent one,
+ * but backed by a different BO. Hence, map the requested mapping and split
+ * the existent one, without adjusting the BO offset.
+ *
+ * ::
+ *
+ * 0 a 2
+ * old: |-----------| (bo_offset=n)
+ *
+ * 1 b 2
+ * req: |-----| (bo_offset=m)
+ *
+ * 0 a 1 b 2
+ * new: |-----|-----| (a.bo_offset=n,b.bo_offset=m)
+ *
+ *
+ * 8) Existent mapping is a superset of the requested mapping. Split it up, but
+ * indicate that the backing PTEs could be kept.
+ *
+ * ::
+ *
+ * 0 a 2
+ * old: |-----------| (bo_offset=n)
+ *
+ * 1 a 2
+ * req: |-----| (bo_offset=n+1)
+ *
+ * 0 a' 1 a 2
+ * new: |-----|-----| (a'.bo_offset=n, a.bo_offset=n+1)
+ *
+ *
+ * 9) Existent mapping is overlapped at the end by the requested mapping backed
+ * by a different BO. Hence, map the requested mapping and split up the
+ * existent one, without adjusting the BO offset.
+ *
+ * ::
+ *
+ * 0 a 2
+ * old: |-----------| (bo_offset=n)
+ *
+ * 1 b 3
+ * req: |-----------| (bo_offset=m)
+ *
+ * 0 a 1 b 3
+ * new: |-----|-----------| (a.bo_offset=n,b.bo_offset=m)
+ *
+ *
+ * 10) Existent mapping is overlapped by the requested mapping, both having the
+ * same backing BO with a contiguous offset. Indicate the backing PTEs of
+ * the old mapping could be kept.
+ *
+ * ::
+ *
+ * 0 a 2
+ * old: |-----------| (bo_offset=n)
+ *
+ * 1 a 3
+ * req: |-----------| (bo_offset=n+1)
+ *
+ * 0 a' 1 a 3
+ * new: |-----|-----------| (a'.bo_offset=n, a.bo_offset=n+1)
+ *
+ *
+ * 11) Requested mapping's range is a centered subset of the existent one
+ * having a different backing BO. Hence, map the requested mapping and split
+ * up the existent one in two mappings, adjusting the BO offset of the right
+ * one accordingly.
+ *
+ * ::
+ *
+ * 0 a 3
+ * old: |-----------------| (bo_offset=n)
+ *
+ * 1 b 2
+ * req: |-----| (bo_offset=m)
+ *
+ * 0 a 1 b 2 a' 3
+ * new: |-----|-----|-----| (a.bo_offset=n,b.bo_offset=m,a'.bo_offset=n+2)
+ *
+ *
+ * 12) Requested mapping is a contiguous subset of the existent one. Split it
+ * up, but indicate that the backing PTEs could be kept.
+ *
+ * ::
+ *
+ * 0 a 3
+ * old: |-----------------| (bo_offset=n)
+ *
+ * 1 a 2
+ * req: |-----| (bo_offset=n+1)
+ *
+ * 0 a' 1 a 2 a'' 3
+ * old: |-----|-----|-----| (a'.bo_offset=n, a.bo_offset=n+1, a''.bo_offset=n+2)
+ *
+ *
+ * 13) Existent mapping is a right aligned subset of the requested one, hence
+ * replace the existent one.
+ *
+ * ::
+ *
+ * 1 a 2
+ * old: |-----| (bo_offset=n+1)
+ *
+ * 0 a 2
+ * req: |-----------| (bo_offset=n)
+ *
+ * 0 a 2
+ * new: |-----------| (bo_offset=n)
+ *
+ * .. note::
+ * We expect to see the same result for a request with a different bo
+ * and/or non-contiguous bo_offset.
+ *
+ *
+ * 14) Existent mapping is a centered subset of the requested one, hence
+ * replace the existent one.
+ *
+ * ::
+ *
+ * 1 a 2
+ * old: |-----| (bo_offset=n+1)
+ *
+ * 0 a 3
+ * req: |----------------| (bo_offset=n)
+ *
+ * 0 a 3
+ * new: |----------------| (bo_offset=n)
+ *
+ * .. note::
+ * We expect to see the same result for a request with a different bo
+ * and/or non-contiguous bo_offset.
+ *
+ *
+ * 15) Existent mappings is overlapped at the beginning by the requested mapping
+ * backed by a different BO. Hence, map the requested mapping and split up
+ * the existent one, adjusting its BO offset accordingly.
+ *
+ * ::
+ *
+ * 1 a 3
+ * old: |-----------| (bo_offset=n)
+ *
+ * 0 b 2
+ * req: |-----------| (bo_offset=m)
+ *
+ * 0 b 2 a' 3
+ * new: |-----------|-----| (b.bo_offset=m,a.bo_offset=n+2)
+ */
+
+/**
+ * DOC: Locking
+ *
+ * Generally, the GPU VA manager does not take care of locking itself, it is
+ * the drivers responsibility to take care about locking. Drivers might want to
+ * protect the following operations: inserting, removing and iterating
+ * &drm_gpuva objects as well as generating all kinds of operations, such as
+ * split / merge or prefetch.
+ *
+ * The GPU VA manager also does not take care of the locking of the backing
+ * &drm_gem_object buffers GPU VA lists by itself; drivers are responsible to
+ * enforce mutual exclusion using either the GEMs dma_resv lock or alternatively
+ * a driver specific external lock. For the latter see also
+ * drm_gem_gpuva_set_lock().
+ *
+ * However, the GPU VA manager contains lockdep checks to ensure callers of its
+ * API hold the corresponding lock whenever the &drm_gem_objects GPU VA list is
+ * accessed by functions such as drm_gpuva_link() or drm_gpuva_unlink().
+ */
+
+/**
+ * DOC: Examples
+ *
+ * This section gives two examples on how to let the DRM GPUVA Manager generate
+ * &drm_gpuva_op in order to satisfy a given map or unmap request and how to
+ * make use of them.
+ *
+ * The below code is strictly limited to illustrate the generic usage pattern.
+ * To maintain simplicitly, it doesn't make use of any abstractions for common
+ * code, different (asyncronous) stages with fence signalling critical paths,
+ * any other helpers or error handling in terms of freeing memory and dropping
+ * previously taken locks.
+ *
+ * 1) Obtain a list of &drm_gpuva_op to create a new mapping::
+ *
+ * // Allocates a new &drm_gpuva.
+ * struct drm_gpuva * driver_gpuva_alloc(void);
+ *
+ * // Typically drivers would embedd the &drm_gpuva_manager and &drm_gpuva
+ * // structure in individual driver structures and lock the dma-resv with
+ * // drm_exec or similar helpers.
+ * int driver_mapping_create(struct drm_gpuva_manager *mgr,
+ * u64 addr, u64 range,
+ * struct drm_gem_object *obj, u64 offset)
+ * {
+ * struct drm_gpuva_ops *ops;
+ * struct drm_gpuva_op *op
+ *
+ * driver_lock_va_space();
+ * ops = drm_gpuva_sm_map_ops_create(mgr, addr, range,
+ * obj, offset);
+ * if (IS_ERR(ops))
+ * return PTR_ERR(ops);
+ *
+ * drm_gpuva_for_each_op(op, ops) {
+ * struct drm_gpuva *va;
+ *
+ * switch (op->op) {
+ * case DRM_GPUVA_OP_MAP:
+ * va = driver_gpuva_alloc();
+ * if (!va)
+ * ; // unwind previous VA space updates,
+ * // free memory and unlock
+ *
+ * driver_vm_map();
+ * drm_gpuva_map(mgr, va, &op->map);
+ * drm_gpuva_link(va);
+ *
+ * break;
+ * case DRM_GPUVA_OP_REMAP: {
+ * struct drm_gpuva *prev = NULL, *next = NULL;
+ *
+ * va = op->remap.unmap->va;
+ *
+ * if (op->remap.prev) {
+ * prev = driver_gpuva_alloc();
+ * if (!prev)
+ * ; // unwind previous VA space
+ * // updates, free memory and
+ * // unlock
+ * }
+ *
+ * if (op->remap.next) {
+ * next = driver_gpuva_alloc();
+ * if (!next)
+ * ; // unwind previous VA space
+ * // updates, free memory and
+ * // unlock
+ * }
+ *
+ * driver_vm_remap();
+ * drm_gpuva_remap(prev, next, &op->remap);
+ *
+ * drm_gpuva_unlink(va);
+ * if (prev)
+ * drm_gpuva_link(prev);
+ * if (next)
+ * drm_gpuva_link(next);
+ *
+ * break;
+ * }
+ * case DRM_GPUVA_OP_UNMAP:
+ * va = op->unmap->va;
+ *
+ * driver_vm_unmap();
+ * drm_gpuva_unlink(va);
+ * drm_gpuva_unmap(&op->unmap);
+ *
+ * break;
+ * default:
+ * break;
+ * }
+ * }
+ * driver_unlock_va_space();
+ *
+ * return 0;
+ * }
+ *
+ * 2) Receive a callback for each &drm_gpuva_op to create a new mapping::
+ *
+ * struct driver_context {
+ * struct drm_gpuva_manager *mgr;
+ * struct drm_gpuva *new_va;
+ * struct drm_gpuva *prev_va;
+ * struct drm_gpuva *next_va;
+ * };
+ *
+ * // ops to pass to drm_gpuva_manager_init()
+ * static const struct drm_gpuva_fn_ops driver_gpuva_ops = {
+ * .sm_step_map = driver_gpuva_map,
+ * .sm_step_remap = driver_gpuva_remap,
+ * .sm_step_unmap = driver_gpuva_unmap,
+ * };
+ *
+ * // Typically drivers would embedd the &drm_gpuva_manager and &drm_gpuva
+ * // structure in individual driver structures and lock the dma-resv with
+ * // drm_exec or similar helpers.
+ * int driver_mapping_create(struct drm_gpuva_manager *mgr,
+ * u64 addr, u64 range,
+ * struct drm_gem_object *obj, u64 offset)
+ * {
+ * struct driver_context ctx;
+ * struct drm_gpuva_ops *ops;
+ * struct drm_gpuva_op *op;
+ * int ret = 0;
+ *
+ * ctx.mgr = mgr;
+ *
+ * ctx.new_va = kzalloc(sizeof(*ctx.new_va), GFP_KERNEL);
+ * ctx.prev_va = kzalloc(sizeof(*ctx.prev_va), GFP_KERNEL);
+ * ctx.next_va = kzalloc(sizeof(*ctx.next_va), GFP_KERNEL);
+ * if (!ctx.new_va || !ctx.prev_va || !ctx.next_va) {
+ * ret = -ENOMEM;
+ * goto out;
+ * }
+ *
+ * driver_lock_va_space();
+ * ret = drm_gpuva_sm_map(mgr, &ctx, addr, range, obj, offset);
+ * driver_unlock_va_space();
+ *
+ * out:
+ * kfree(ctx.new_va);
+ * kfree(ctx.prev_va);
+ * kfree(ctx.next_va);
+ * return ret;
+ * }
+ *
+ * int driver_gpuva_map(struct drm_gpuva_op *op, void *__ctx)
+ * {
+ * struct driver_context *ctx = __ctx;
+ *
+ * drm_gpuva_map(ctx->mgr, ctx->new_va, &op->map);
+ *
+ * drm_gpuva_link(ctx->new_va);
+ *
+ * // prevent the new GPUVA from being freed in
+ * // driver_mapping_create()
+ * ctx->new_va = NULL;
+ *
+ * return 0;
+ * }
+ *
+ * int driver_gpuva_remap(struct drm_gpuva_op *op, void *__ctx)
+ * {
+ * struct driver_context *ctx = __ctx;
+ *
+ * drm_gpuva_remap(ctx->prev_va, ctx->next_va, &op->remap);
+ *
+ * drm_gpuva_unlink(op->remap.unmap->va);
+ * kfree(op->remap.unmap->va);
+ *
+ * if (op->remap.prev) {
+ * drm_gpuva_link(ctx->prev_va);
+ * ctx->prev_va = NULL;
+ * }
+ *
+ * if (op->remap.next) {
+ * drm_gpuva_link(ctx->next_va);
+ * ctx->next_va = NULL;
+ * }
+ *
+ * return 0;
+ * }
+ *
+ * int driver_gpuva_unmap(struct drm_gpuva_op *op, void *__ctx)
+ * {
+ * drm_gpuva_unlink(op->unmap.va);
+ * drm_gpuva_unmap(&op->unmap);
+ * kfree(op->unmap.va);
+ *
+ * return 0;
+ * }
+ */
+
+#define to_drm_gpuva(__node) container_of((__node), struct drm_gpuva, rb.node)
+
+#define GPUVA_START(node) ((node)->va.addr)
+#define GPUVA_LAST(node) ((node)->va.addr + (node)->va.range - 1)
+
+/* We do not actually use drm_gpuva_it_next(), tell the compiler to not complain
+ * about this.
+ */
+INTERVAL_TREE_DEFINE(struct drm_gpuva, rb.node, u64, rb.__subtree_last,
+ GPUVA_START, GPUVA_LAST, static __maybe_unused,
+ drm_gpuva_it)
+
+static int __drm_gpuva_insert(struct drm_gpuva_manager *mgr,
+ struct drm_gpuva *va);
+static void __drm_gpuva_remove(struct drm_gpuva *va);
+
+static bool
+drm_gpuva_check_overflow(u64 addr, u64 range)
+{
+ u64 end;
+
+ return WARN(check_add_overflow(addr, range, &end),
+ "GPUVA address limited to %lu bytes.\n", sizeof(end));
+}
+
+static bool
+drm_gpuva_in_mm_range(struct drm_gpuva_manager *mgr, u64 addr, u64 range)
+{
+ u64 end = addr + range;
+ u64 mm_start = mgr->mm_start;
+ u64 mm_end = mm_start + mgr->mm_range;
+
+ return addr >= mm_start && end <= mm_end;
+}
+
+static bool
+drm_gpuva_in_kernel_node(struct drm_gpuva_manager *mgr, u64 addr, u64 range)
+{
+ u64 end = addr + range;
+ u64 kstart = mgr->kernel_alloc_node.va.addr;
+ u64 krange = mgr->kernel_alloc_node.va.range;
+ u64 kend = kstart + krange;
+
+ return krange && addr < kend && kstart < end;
+}
+
+static bool
+drm_gpuva_range_valid(struct drm_gpuva_manager *mgr,
+ u64 addr, u64 range)
+{
+ return !drm_gpuva_check_overflow(addr, range) &&
+ drm_gpuva_in_mm_range(mgr, addr, range) &&
+ !drm_gpuva_in_kernel_node(mgr, addr, range);
+}
+
+/**
+ * drm_gpuva_manager_init() - initialize a &drm_gpuva_manager
+ * @mgr: pointer to the &drm_gpuva_manager to initialize
+ * @name: the name of the GPU VA space
+ * @start_offset: the start offset of the GPU VA space
+ * @range: the size of the GPU VA space
+ * @reserve_offset: the start of the kernel reserved GPU VA area
+ * @reserve_range: the size of the kernel reserved GPU VA area
+ * @ops: &drm_gpuva_fn_ops called on &drm_gpuva_sm_map / &drm_gpuva_sm_unmap
+ *
+ * The &drm_gpuva_manager must be initialized with this function before use.
+ *
+ * Note that @mgr must be cleared to 0 before calling this function. The given
+ * &name is expected to be managed by the surrounding driver structures.
+ */
+void
+drm_gpuva_manager_init(struct drm_gpuva_manager *mgr,
+ const char *name,
+ u64 start_offset, u64 range,
+ u64 reserve_offset, u64 reserve_range,
+ const struct drm_gpuva_fn_ops *ops)
+{
+ mgr->rb.tree = RB_ROOT_CACHED;
+ INIT_LIST_HEAD(&mgr->rb.list);
+
+ drm_gpuva_check_overflow(start_offset, range);
+ mgr->mm_start = start_offset;
+ mgr->mm_range = range;
+
+ mgr->name = name ? name : "unknown";
+ mgr->ops = ops;
+
+ memset(&mgr->kernel_alloc_node, 0, sizeof(struct drm_gpuva));
+
+ if (reserve_range) {
+ mgr->kernel_alloc_node.va.addr = reserve_offset;
+ mgr->kernel_alloc_node.va.range = reserve_range;
+
+ if (likely(!drm_gpuva_check_overflow(reserve_offset,
+ reserve_range)))
+ __drm_gpuva_insert(mgr, &mgr->kernel_alloc_node);
+ }
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_manager_init);
+
+/**
+ * drm_gpuva_manager_destroy() - cleanup a &drm_gpuva_manager
+ * @mgr: pointer to the &drm_gpuva_manager to clean up
+ *
+ * Note that it is a bug to call this function on a manager that still
+ * holds GPU VA mappings.
+ */
+void
+drm_gpuva_manager_destroy(struct drm_gpuva_manager *mgr)
+{
+ mgr->name = NULL;
+
+ if (mgr->kernel_alloc_node.va.range)
+ __drm_gpuva_remove(&mgr->kernel_alloc_node);
+
+ WARN(!RB_EMPTY_ROOT(&mgr->rb.tree.rb_root),
+ "GPUVA tree is not empty, potentially leaking memory.");
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_manager_destroy);
+
+static int
+__drm_gpuva_insert(struct drm_gpuva_manager *mgr,
+ struct drm_gpuva *va)
+{
+ struct rb_node *node;
+ struct list_head *head;
+
+ if (drm_gpuva_it_iter_first(&mgr->rb.tree,
+ GPUVA_START(va),
+ GPUVA_LAST(va)))
+ return -EEXIST;
+
+ va->mgr = mgr;
+
+ drm_gpuva_it_insert(va, &mgr->rb.tree);
+
+ node = rb_prev(&va->rb.node);
+ if (node)
+ head = &(to_drm_gpuva(node))->rb.entry;
+ else
+ head = &mgr->rb.list;
+
+ list_add(&va->rb.entry, head);
+
+ return 0;
+}
+
+/**
+ * drm_gpuva_insert() - insert a &drm_gpuva
+ * @mgr: the &drm_gpuva_manager to insert the &drm_gpuva in
+ * @va: the &drm_gpuva to insert
+ *
+ * Insert a &drm_gpuva with a given address and range into a
+ * &drm_gpuva_manager.
+ *
+ * It is safe to use this function using the safe versions of iterating the GPU
+ * VA space, such as drm_gpuva_for_each_va_safe() and
+ * drm_gpuva_for_each_va_range_safe().
+ *
+ * Returns: 0 on success, negative error code on failure.
+ */
+int
+drm_gpuva_insert(struct drm_gpuva_manager *mgr,
+ struct drm_gpuva *va)
+{
+ u64 addr = va->va.addr;
+ u64 range = va->va.range;
+
+ if (unlikely(!drm_gpuva_range_valid(mgr, addr, range)))
+ return -EINVAL;
+
+ return __drm_gpuva_insert(mgr, va);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_insert);
+
+static void
+__drm_gpuva_remove(struct drm_gpuva *va)
+{
+ drm_gpuva_it_remove(va, &va->mgr->rb.tree);
+ list_del_init(&va->rb.entry);
+}
+
+/**
+ * drm_gpuva_remove() - remove a &drm_gpuva
+ * @va: the &drm_gpuva to remove
+ *
+ * This removes the given &va from the underlaying tree.
+ *
+ * It is safe to use this function using the safe versions of iterating the GPU
+ * VA space, such as drm_gpuva_for_each_va_safe() and
+ * drm_gpuva_for_each_va_range_safe().
+ */
+void
+drm_gpuva_remove(struct drm_gpuva *va)
+{
+ struct drm_gpuva_manager *mgr = va->mgr;
+
+ if (unlikely(va == &mgr->kernel_alloc_node)) {
+ WARN(1, "Can't destroy kernel reserved node.\n");
+ return;
+ }
+
+ __drm_gpuva_remove(va);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_remove);
+
+/**
+ * drm_gpuva_link() - link a &drm_gpuva
+ * @va: the &drm_gpuva to link
+ *
+ * This adds the given &va to the GPU VA list of the &drm_gem_object it is
+ * associated with.
+ *
+ * This function expects the caller to protect the GEM's GPUVA list against
+ * concurrent access using the GEMs dma_resv lock.
+ */
+void
+drm_gpuva_link(struct drm_gpuva *va)
+{
+ struct drm_gem_object *obj = va->gem.obj;
+
+ if (unlikely(!obj))
+ return;
+
+ drm_gem_gpuva_assert_lock_held(obj);
+
+ list_add_tail(&va->gem.entry, &obj->gpuva.list);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_link);
+
+/**
+ * drm_gpuva_unlink() - unlink a &drm_gpuva
+ * @va: the &drm_gpuva to unlink
+ *
+ * This removes the given &va from the GPU VA list of the &drm_gem_object it is
+ * associated with.
+ *
+ * This function expects the caller to protect the GEM's GPUVA list against
+ * concurrent access using the GEMs dma_resv lock.
+ */
+void
+drm_gpuva_unlink(struct drm_gpuva *va)
+{
+ struct drm_gem_object *obj = va->gem.obj;
+
+ if (unlikely(!obj))
+ return;
+
+ drm_gem_gpuva_assert_lock_held(obj);
+
+ list_del_init(&va->gem.entry);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_unlink);
+
+/**
+ * drm_gpuva_find_first() - find the first &drm_gpuva in the given range
+ * @mgr: the &drm_gpuva_manager to search in
+ * @addr: the &drm_gpuvas address
+ * @range: the &drm_gpuvas range
+ *
+ * Returns: the first &drm_gpuva within the given range
+ */
+struct drm_gpuva *
+drm_gpuva_find_first(struct drm_gpuva_manager *mgr,
+ u64 addr, u64 range)
+{
+ u64 last = addr + range - 1;
+
+ return drm_gpuva_it_iter_first(&mgr->rb.tree, addr, last);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_find_first);
+
+/**
+ * drm_gpuva_find() - find a &drm_gpuva
+ * @mgr: the &drm_gpuva_manager to search in
+ * @addr: the &drm_gpuvas address
+ * @range: the &drm_gpuvas range
+ *
+ * Returns: the &drm_gpuva at a given &addr and with a given &range
+ */
+struct drm_gpuva *
+drm_gpuva_find(struct drm_gpuva_manager *mgr,
+ u64 addr, u64 range)
+{
+ struct drm_gpuva *va;
+
+ va = drm_gpuva_find_first(mgr, addr, range);
+ if (!va)
+ goto out;
+
+ if (va->va.addr != addr ||
+ va->va.range != range)
+ goto out;
+
+ return va;
+
+out:
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_find);
+
+/**
+ * drm_gpuva_find_prev() - find the &drm_gpuva before the given address
+ * @mgr: the &drm_gpuva_manager to search in
+ * @start: the given GPU VA's start address
+ *
+ * Find the adjacent &drm_gpuva before the GPU VA with given &start address.
+ *
+ * Note that if there is any free space between the GPU VA mappings no mapping
+ * is returned.
+ *
+ * Returns: a pointer to the found &drm_gpuva or NULL if none was found
+ */
+struct drm_gpuva *
+drm_gpuva_find_prev(struct drm_gpuva_manager *mgr, u64 start)
+{
+ if (!drm_gpuva_range_valid(mgr, start - 1, 1))
+ return NULL;
+
+ return drm_gpuva_it_iter_first(&mgr->rb.tree, start - 1, start);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_find_prev);
+
+/**
+ * drm_gpuva_find_next() - find the &drm_gpuva after the given address
+ * @mgr: the &drm_gpuva_manager to search in
+ * @end: the given GPU VA's end address
+ *
+ * Find the adjacent &drm_gpuva after the GPU VA with given &end address.
+ *
+ * Note that if there is any free space between the GPU VA mappings no mapping
+ * is returned.
+ *
+ * Returns: a pointer to the found &drm_gpuva or NULL if none was found
+ */
+struct drm_gpuva *
+drm_gpuva_find_next(struct drm_gpuva_manager *mgr, u64 end)
+{
+ if (!drm_gpuva_range_valid(mgr, end, 1))
+ return NULL;
+
+ return drm_gpuva_it_iter_first(&mgr->rb.tree, end, end + 1);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_find_next);
+
+/**
+ * drm_gpuva_interval_empty() - indicate whether a given interval of the VA space
+ * is empty
+ * @mgr: the &drm_gpuva_manager to check the range for
+ * @addr: the start address of the range
+ * @range: the range of the interval
+ *
+ * Returns: true if the interval is empty, false otherwise
+ */
+bool
+drm_gpuva_interval_empty(struct drm_gpuva_manager *mgr, u64 addr, u64 range)
+{
+ return !drm_gpuva_find_first(mgr, addr, range);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_interval_empty);
+
+/**
+ * drm_gpuva_map() - helper to insert a &drm_gpuva according to a
+ * &drm_gpuva_op_map
+ * @mgr: the &drm_gpuva_manager
+ * @va: the &drm_gpuva to insert
+ * @op: the &drm_gpuva_op_map to initialize @va with
+ *
+ * Initializes the @va from the @op and inserts it into the given @mgr.
+ */
+void
+drm_gpuva_map(struct drm_gpuva_manager *mgr,
+ struct drm_gpuva *va,
+ struct drm_gpuva_op_map *op)
+{
+ drm_gpuva_init_from_op(va, op);
+ drm_gpuva_insert(mgr, va);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_map);
+
+/**
+ * drm_gpuva_remap() - helper to remap a &drm_gpuva according to a
+ * &drm_gpuva_op_remap
+ * @prev: the &drm_gpuva to remap when keeping the start of a mapping
+ * @next: the &drm_gpuva to remap when keeping the end of a mapping
+ * @op: the &drm_gpuva_op_remap to initialize @prev and @next with
+ *
+ * Removes the currently mapped &drm_gpuva and remaps it using @prev and/or
+ * @next.
+ */
+void
+drm_gpuva_remap(struct drm_gpuva *prev,
+ struct drm_gpuva *next,
+ struct drm_gpuva_op_remap *op)
+{
+ struct drm_gpuva *curr = op->unmap->va;
+ struct drm_gpuva_manager *mgr = curr->mgr;
+
+ drm_gpuva_remove(curr);
+
+ if (op->prev) {
+ drm_gpuva_init_from_op(prev, op->prev);
+ drm_gpuva_insert(mgr, prev);
+ }
+
+ if (op->next) {
+ drm_gpuva_init_from_op(next, op->next);
+ drm_gpuva_insert(mgr, next);
+ }
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_remap);
+
+/**
+ * drm_gpuva_unmap() - helper to remove a &drm_gpuva according to a
+ * &drm_gpuva_op_unmap
+ * @op: the &drm_gpuva_op_unmap specifying the &drm_gpuva to remove
+ *
+ * Removes the &drm_gpuva associated with the &drm_gpuva_op_unmap.
+ */
+void
+drm_gpuva_unmap(struct drm_gpuva_op_unmap *op)
+{
+ drm_gpuva_remove(op->va);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_unmap);
+
+static int
+op_map_cb(const struct drm_gpuva_fn_ops *fn, void *priv,
+ u64 addr, u64 range,
+ struct drm_gem_object *obj, u64 offset)
+{
+ struct drm_gpuva_op op = {};
+
+ op.op = DRM_GPUVA_OP_MAP;
+ op.map.va.addr = addr;
+ op.map.va.range = range;
+ op.map.gem.obj = obj;
+ op.map.gem.offset = offset;
+
+ return fn->sm_step_map(&op, priv);
+}
+
+static int
+op_remap_cb(const struct drm_gpuva_fn_ops *fn, void *priv,
+ struct drm_gpuva_op_map *prev,
+ struct drm_gpuva_op_map *next,
+ struct drm_gpuva_op_unmap *unmap)
+{
+ struct drm_gpuva_op op = {};
+ struct drm_gpuva_op_remap *r;
+
+ op.op = DRM_GPUVA_OP_REMAP;
+ r = &op.remap;
+ r->prev = prev;
+ r->next = next;
+ r->unmap = unmap;
+
+ return fn->sm_step_remap(&op, priv);
+}
+
+static int
+op_unmap_cb(const struct drm_gpuva_fn_ops *fn, void *priv,
+ struct drm_gpuva *va, bool merge)
+{
+ struct drm_gpuva_op op = {};
+
+ op.op = DRM_GPUVA_OP_UNMAP;
+ op.unmap.va = va;
+ op.unmap.keep = merge;
+
+ return fn->sm_step_unmap(&op, priv);
+}
+
+static int
+__drm_gpuva_sm_map(struct drm_gpuva_manager *mgr,
+ const struct drm_gpuva_fn_ops *ops, void *priv,
+ u64 req_addr, u64 req_range,
+ struct drm_gem_object *req_obj, u64 req_offset)
+{
+ struct drm_gpuva *va, *next, *prev = NULL;
+ u64 req_end = req_addr + req_range;
+ int ret;
+
+ if (unlikely(!drm_gpuva_range_valid(mgr, req_addr, req_range)))
+ return -EINVAL;
+
+ drm_gpuva_for_each_va_range_safe(va, next, mgr, req_addr, req_end) {
+ struct drm_gem_object *obj = va->gem.obj;
+ u64 offset = va->gem.offset;
+ u64 addr = va->va.addr;
+ u64 range = va->va.range;
+ u64 end = addr + range;
+ bool merge = !!va->gem.obj;
+
+ if (addr == req_addr) {
+ merge &= obj == req_obj &&
+ offset == req_offset;
+
+ if (end == req_end) {
+ ret = op_unmap_cb(ops, priv, va, merge);
+ if (ret)
+ return ret;
+ break;
+ }
+
+ if (end < req_end) {
+ ret = op_unmap_cb(ops, priv, va, merge);
+ if (ret)
+ return ret;
+ goto next;
+ }
+
+ if (end > req_end) {
+ struct drm_gpuva_op_map n = {
+ .va.addr = req_end,
+ .va.range = range - req_range,
+ .gem.obj = obj,
+ .gem.offset = offset + req_range,
+ };
+ struct drm_gpuva_op_unmap u = {
+ .va = va,
+ .keep = merge,
+ };
+
+ ret = op_remap_cb(ops, priv, NULL, &n, &u);
+ if (ret)
+ return ret;
+ break;
+ }
+ } else if (addr < req_addr) {
+ u64 ls_range = req_addr - addr;
+ struct drm_gpuva_op_map p = {
+ .va.addr = addr,
+ .va.range = ls_range,
+ .gem.obj = obj,
+ .gem.offset = offset,
+ };
+ struct drm_gpuva_op_unmap u = { .va = va };
+
+ merge &= obj == req_obj &&
+ offset + ls_range == req_offset;
+ u.keep = merge;
+
+ if (end == req_end) {
+ ret = op_remap_cb(ops, priv, &p, NULL, &u);
+ if (ret)
+ return ret;
+ break;
+ }
+
+ if (end < req_end) {
+ ret = op_remap_cb(ops, priv, &p, NULL, &u);
+ if (ret)
+ return ret;
+ goto next;
+ }
+
+ if (end > req_end) {
+ struct drm_gpuva_op_map n = {
+ .va.addr = req_end,
+ .va.range = end - req_end,
+ .gem.obj = obj,
+ .gem.offset = offset + ls_range +
+ req_range,
+ };
+
+ ret = op_remap_cb(ops, priv, &p, &n, &u);
+ if (ret)
+ return ret;
+ break;
+ }
+ } else if (addr > req_addr) {
+ merge &= obj == req_obj &&
+ offset == req_offset +
+ (addr - req_addr);
+
+ if (end == req_end) {
+ ret = op_unmap_cb(ops, priv, va, merge);
+ if (ret)
+ return ret;
+ break;
+ }
+
+ if (end < req_end) {
+ ret = op_unmap_cb(ops, priv, va, merge);
+ if (ret)
+ return ret;
+ goto next;
+ }
+
+ if (end > req_end) {
+ struct drm_gpuva_op_map n = {
+ .va.addr = req_end,
+ .va.range = end - req_end,
+ .gem.obj = obj,
+ .gem.offset = offset + req_end - addr,
+ };
+ struct drm_gpuva_op_unmap u = {
+ .va = va,
+ .keep = merge,
+ };
+
+ ret = op_remap_cb(ops, priv, NULL, &n, &u);
+ if (ret)
+ return ret;
+ break;
+ }
+ }
+next:
+ prev = va;
+ }
+
+ return op_map_cb(ops, priv,
+ req_addr, req_range,
+ req_obj, req_offset);
+}
+
+static int
+__drm_gpuva_sm_unmap(struct drm_gpuva_manager *mgr,
+ const struct drm_gpuva_fn_ops *ops, void *priv,
+ u64 req_addr, u64 req_range)
+{
+ struct drm_gpuva *va, *next;
+ u64 req_end = req_addr + req_range;
+ int ret;
+
+ if (unlikely(!drm_gpuva_range_valid(mgr, req_addr, req_range)))
+ return -EINVAL;
+
+ drm_gpuva_for_each_va_range_safe(va, next, mgr, req_addr, req_end) {
+ struct drm_gpuva_op_map prev = {}, next = {};
+ bool prev_split = false, next_split = false;
+ struct drm_gem_object *obj = va->gem.obj;
+ u64 offset = va->gem.offset;
+ u64 addr = va->va.addr;
+ u64 range = va->va.range;
+ u64 end = addr + range;
+
+ if (addr < req_addr) {
+ prev.va.addr = addr;
+ prev.va.range = req_addr - addr;
+ prev.gem.obj = obj;
+ prev.gem.offset = offset;
+
+ prev_split = true;
+ }
+
+ if (end > req_end) {
+ next.va.addr = req_end;
+ next.va.range = end - req_end;
+ next.gem.obj = obj;
+ next.gem.offset = offset + (req_end - addr);
+
+ next_split = true;
+ }
+
+ if (prev_split || next_split) {
+ struct drm_gpuva_op_unmap unmap = { .va = va };
+
+ ret = op_remap_cb(ops, priv,
+ prev_split ? &prev : NULL,
+ next_split ? &next : NULL,
+ &unmap);
+ if (ret)
+ return ret;
+ } else {
+ ret = op_unmap_cb(ops, priv, va, false);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * drm_gpuva_sm_map() - creates the &drm_gpuva_op split/merge steps
+ * @mgr: the &drm_gpuva_manager representing the GPU VA space
+ * @req_addr: the start address of the new mapping
+ * @req_range: the range of the new mapping
+ * @req_obj: the &drm_gem_object to map
+ * @req_offset: the offset within the &drm_gem_object
+ * @priv: pointer to a driver private data structure
+ *
+ * This function iterates the given range of the GPU VA space. It utilizes the
+ * &drm_gpuva_fn_ops to call back into the driver providing the split and merge
+ * steps.
+ *
+ * Drivers may use these callbacks to update the GPU VA space right away within
+ * the callback. In case the driver decides to copy and store the operations for
+ * later processing neither this function nor &drm_gpuva_sm_unmap is allowed to
+ * be called before the &drm_gpuva_manager's view of the GPU VA space was
+ * updated with the previous set of operations. To update the
+ * &drm_gpuva_manager's view of the GPU VA space drm_gpuva_insert(),
+ * drm_gpuva_destroy_locked() and/or drm_gpuva_destroy_unlocked() should be
+ * used.
+ *
+ * A sequence of callbacks can contain map, unmap and remap operations, but
+ * the sequence of callbacks might also be empty if no operation is required,
+ * e.g. if the requested mapping already exists in the exact same way.
+ *
+ * There can be an arbitrary amount of unmap operations, a maximum of two remap
+ * operations and a single map operation. The latter one represents the original
+ * map operation requested by the caller.
+ *
+ * Returns: 0 on success or a negative error code
+ */
+int
+drm_gpuva_sm_map(struct drm_gpuva_manager *mgr, void *priv,
+ u64 req_addr, u64 req_range,
+ struct drm_gem_object *req_obj, u64 req_offset)
+{
+ const struct drm_gpuva_fn_ops *ops = mgr->ops;
+
+ if (unlikely(!(ops && ops->sm_step_map &&
+ ops->sm_step_remap &&
+ ops->sm_step_unmap)))
+ return -EINVAL;
+
+ return __drm_gpuva_sm_map(mgr, ops, priv,
+ req_addr, req_range,
+ req_obj, req_offset);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_sm_map);
+
+/**
+ * drm_gpuva_sm_unmap() - creates the &drm_gpuva_ops to split on unmap
+ * @mgr: the &drm_gpuva_manager representing the GPU VA space
+ * @priv: pointer to a driver private data structure
+ * @req_addr: the start address of the range to unmap
+ * @req_range: the range of the mappings to unmap
+ *
+ * This function iterates the given range of the GPU VA space. It utilizes the
+ * &drm_gpuva_fn_ops to call back into the driver providing the operations to
+ * unmap and, if required, split existent mappings.
+ *
+ * Drivers may use these callbacks to update the GPU VA space right away within
+ * the callback. In case the driver decides to copy and store the operations for
+ * later processing neither this function nor &drm_gpuva_sm_map is allowed to be
+ * called before the &drm_gpuva_manager's view of the GPU VA space was updated
+ * with the previous set of operations. To update the &drm_gpuva_manager's view
+ * of the GPU VA space drm_gpuva_insert(), drm_gpuva_destroy_locked() and/or
+ * drm_gpuva_destroy_unlocked() should be used.
+ *
+ * A sequence of callbacks can contain unmap and remap operations, depending on
+ * whether there are actual overlapping mappings to split.
+ *
+ * There can be an arbitrary amount of unmap operations and a maximum of two
+ * remap operations.
+ *
+ * Returns: 0 on success or a negative error code
+ */
+int
+drm_gpuva_sm_unmap(struct drm_gpuva_manager *mgr, void *priv,
+ u64 req_addr, u64 req_range)
+{
+ const struct drm_gpuva_fn_ops *ops = mgr->ops;
+
+ if (unlikely(!(ops && ops->sm_step_remap &&
+ ops->sm_step_unmap)))
+ return -EINVAL;
+
+ return __drm_gpuva_sm_unmap(mgr, ops, priv,
+ req_addr, req_range);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_sm_unmap);
+
+static struct drm_gpuva_op *
+gpuva_op_alloc(struct drm_gpuva_manager *mgr)
+{
+ const struct drm_gpuva_fn_ops *fn = mgr->ops;
+ struct drm_gpuva_op *op;
+
+ if (fn && fn->op_alloc)
+ op = fn->op_alloc();
+ else
+ op = kzalloc(sizeof(*op), GFP_KERNEL);
+
+ if (unlikely(!op))
+ return NULL;
+
+ return op;
+}
+
+static void
+gpuva_op_free(struct drm_gpuva_manager *mgr,
+ struct drm_gpuva_op *op)
+{
+ const struct drm_gpuva_fn_ops *fn = mgr->ops;
+
+ if (fn && fn->op_free)
+ fn->op_free(op);
+ else
+ kfree(op);
+}
+
+static int
+drm_gpuva_sm_step(struct drm_gpuva_op *__op,
+ void *priv)
+{
+ struct {
+ struct drm_gpuva_manager *mgr;
+ struct drm_gpuva_ops *ops;
+ } *args = priv;
+ struct drm_gpuva_manager *mgr = args->mgr;
+ struct drm_gpuva_ops *ops = args->ops;
+ struct drm_gpuva_op *op;
+
+ op = gpuva_op_alloc(mgr);
+ if (unlikely(!op))
+ goto err;
+
+ memcpy(op, __op, sizeof(*op));
+
+ if (op->op == DRM_GPUVA_OP_REMAP) {
+ struct drm_gpuva_op_remap *__r = &__op->remap;
+ struct drm_gpuva_op_remap *r = &op->remap;
+
+ r->unmap = kmemdup(__r->unmap, sizeof(*r->unmap),
+ GFP_KERNEL);
+ if (unlikely(!r->unmap))
+ goto err_free_op;
+
+ if (__r->prev) {
+ r->prev = kmemdup(__r->prev, sizeof(*r->prev),
+ GFP_KERNEL);
+ if (unlikely(!r->prev))
+ goto err_free_unmap;
+ }
+
+ if (__r->next) {
+ r->next = kmemdup(__r->next, sizeof(*r->next),
+ GFP_KERNEL);
+ if (unlikely(!r->next))
+ goto err_free_prev;
+ }
+ }
+
+ list_add_tail(&op->entry, &ops->list);
+
+ return 0;
+
+err_free_unmap:
+ kfree(op->remap.unmap);
+err_free_prev:
+ kfree(op->remap.prev);
+err_free_op:
+ gpuva_op_free(mgr, op);
+err:
+ return -ENOMEM;
+}
+
+static const struct drm_gpuva_fn_ops gpuva_list_ops = {
+ .sm_step_map = drm_gpuva_sm_step,
+ .sm_step_remap = drm_gpuva_sm_step,
+ .sm_step_unmap = drm_gpuva_sm_step,
+};
+
+/**
+ * drm_gpuva_sm_map_ops_create() - creates the &drm_gpuva_ops to split and merge
+ * @mgr: the &drm_gpuva_manager representing the GPU VA space
+ * @req_addr: the start address of the new mapping
+ * @req_range: the range of the new mapping
+ * @req_obj: the &drm_gem_object to map
+ * @req_offset: the offset within the &drm_gem_object
+ *
+ * This function creates a list of operations to perform splitting and merging
+ * of existent mapping(s) with the newly requested one.
+ *
+ * The list can be iterated with &drm_gpuva_for_each_op and must be processed
+ * in the given order. It can contain map, unmap and remap operations, but it
+ * also can be empty if no operation is required, e.g. if the requested mapping
+ * already exists is the exact same way.
+ *
+ * There can be an arbitrary amount of unmap operations, a maximum of two remap
+ * operations and a single map operation. The latter one represents the original
+ * map operation requested by the caller.
+ *
+ * Note that before calling this function again with another mapping request it
+ * is necessary to update the &drm_gpuva_manager's view of the GPU VA space. The
+ * previously obtained operations must be either processed or abandoned. To
+ * update the &drm_gpuva_manager's view of the GPU VA space drm_gpuva_insert(),
+ * drm_gpuva_destroy_locked() and/or drm_gpuva_destroy_unlocked() should be
+ * used.
+ *
+ * After the caller finished processing the returned &drm_gpuva_ops, they must
+ * be freed with &drm_gpuva_ops_free.
+ *
+ * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
+ */
+struct drm_gpuva_ops *
+drm_gpuva_sm_map_ops_create(struct drm_gpuva_manager *mgr,
+ u64 req_addr, u64 req_range,
+ struct drm_gem_object *req_obj, u64 req_offset)
+{
+ struct drm_gpuva_ops *ops;
+ struct {
+ struct drm_gpuva_manager *mgr;
+ struct drm_gpuva_ops *ops;
+ } args;
+ int ret;
+
+ ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+ if (unlikely(!ops))
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&ops->list);
+
+ args.mgr = mgr;
+ args.ops = ops;
+
+ ret = __drm_gpuva_sm_map(mgr, &gpuva_list_ops, &args,
+ req_addr, req_range,
+ req_obj, req_offset);
+ if (ret)
+ goto err_free_ops;
+
+ return ops;
+
+err_free_ops:
+ drm_gpuva_ops_free(mgr, ops);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_sm_map_ops_create);
+
+/**
+ * drm_gpuva_sm_unmap_ops_create() - creates the &drm_gpuva_ops to split on
+ * unmap
+ * @mgr: the &drm_gpuva_manager representing the GPU VA space
+ * @req_addr: the start address of the range to unmap
+ * @req_range: the range of the mappings to unmap
+ *
+ * This function creates a list of operations to perform unmapping and, if
+ * required, splitting of the mappings overlapping the unmap range.
+ *
+ * The list can be iterated with &drm_gpuva_for_each_op and must be processed
+ * in the given order. It can contain unmap and remap operations, depending on
+ * whether there are actual overlapping mappings to split.
+ *
+ * There can be an arbitrary amount of unmap operations and a maximum of two
+ * remap operations.
+ *
+ * Note that before calling this function again with another range to unmap it
+ * is necessary to update the &drm_gpuva_manager's view of the GPU VA space. The
+ * previously obtained operations must be processed or abandoned. To update the
+ * &drm_gpuva_manager's view of the GPU VA space drm_gpuva_insert(),
+ * drm_gpuva_destroy_locked() and/or drm_gpuva_destroy_unlocked() should be
+ * used.
+ *
+ * After the caller finished processing the returned &drm_gpuva_ops, they must
+ * be freed with &drm_gpuva_ops_free.
+ *
+ * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
+ */
+struct drm_gpuva_ops *
+drm_gpuva_sm_unmap_ops_create(struct drm_gpuva_manager *mgr,
+ u64 req_addr, u64 req_range)
+{
+ struct drm_gpuva_ops *ops;
+ struct {
+ struct drm_gpuva_manager *mgr;
+ struct drm_gpuva_ops *ops;
+ } args;
+ int ret;
+
+ ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+ if (unlikely(!ops))
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&ops->list);
+
+ args.mgr = mgr;
+ args.ops = ops;
+
+ ret = __drm_gpuva_sm_unmap(mgr, &gpuva_list_ops, &args,
+ req_addr, req_range);
+ if (ret)
+ goto err_free_ops;
+
+ return ops;
+
+err_free_ops:
+ drm_gpuva_ops_free(mgr, ops);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_sm_unmap_ops_create);
+
+/**
+ * drm_gpuva_prefetch_ops_create() - creates the &drm_gpuva_ops to prefetch
+ * @mgr: the &drm_gpuva_manager representing the GPU VA space
+ * @addr: the start address of the range to prefetch
+ * @range: the range of the mappings to prefetch
+ *
+ * This function creates a list of operations to perform prefetching.
+ *
+ * The list can be iterated with &drm_gpuva_for_each_op and must be processed
+ * in the given order. It can contain prefetch operations.
+ *
+ * There can be an arbitrary amount of prefetch operations.
+ *
+ * After the caller finished processing the returned &drm_gpuva_ops, they must
+ * be freed with &drm_gpuva_ops_free.
+ *
+ * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
+ */
+struct drm_gpuva_ops *
+drm_gpuva_prefetch_ops_create(struct drm_gpuva_manager *mgr,
+ u64 addr, u64 range)
+{
+ struct drm_gpuva_ops *ops;
+ struct drm_gpuva_op *op;
+ struct drm_gpuva *va;
+ u64 end = addr + range;
+ int ret;
+
+ ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+ if (!ops)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&ops->list);
+
+ drm_gpuva_for_each_va_range(va, mgr, addr, end) {
+ op = gpuva_op_alloc(mgr);
+ if (!op) {
+ ret = -ENOMEM;
+ goto err_free_ops;
+ }
+
+ op->op = DRM_GPUVA_OP_PREFETCH;
+ op->prefetch.va = va;
+ list_add_tail(&op->entry, &ops->list);
+ }
+
+ return ops;
+
+err_free_ops:
+ drm_gpuva_ops_free(mgr, ops);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_prefetch_ops_create);
+
+/**
+ * drm_gpuva_gem_unmap_ops_create() - creates the &drm_gpuva_ops to unmap a GEM
+ * @mgr: the &drm_gpuva_manager representing the GPU VA space
+ * @obj: the &drm_gem_object to unmap
+ *
+ * This function creates a list of operations to perform unmapping for every
+ * GPUVA attached to a GEM.
+ *
+ * The list can be iterated with &drm_gpuva_for_each_op and consists out of an
+ * arbitrary amount of unmap operations.
+ *
+ * After the caller finished processing the returned &drm_gpuva_ops, they must
+ * be freed with &drm_gpuva_ops_free.
+ *
+ * It is the callers responsibility to protect the GEMs GPUVA list against
+ * concurrent access using the GEMs dma_resv lock.
+ *
+ * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
+ */
+struct drm_gpuva_ops *
+drm_gpuva_gem_unmap_ops_create(struct drm_gpuva_manager *mgr,
+ struct drm_gem_object *obj)
+{
+ struct drm_gpuva_ops *ops;
+ struct drm_gpuva_op *op;
+ struct drm_gpuva *va;
+ int ret;
+
+ drm_gem_gpuva_assert_lock_held(obj);
+
+ ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+ if (!ops)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&ops->list);
+
+ drm_gem_for_each_gpuva(va, obj) {
+ op = gpuva_op_alloc(mgr);
+ if (!op) {
+ ret = -ENOMEM;
+ goto err_free_ops;
+ }
+
+ op->op = DRM_GPUVA_OP_UNMAP;
+ op->unmap.va = va;
+ list_add_tail(&op->entry, &ops->list);
+ }
+
+ return ops;
+
+err_free_ops:
+ drm_gpuva_ops_free(mgr, ops);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_gem_unmap_ops_create);
+
+/**
+ * drm_gpuva_ops_free() - free the given &drm_gpuva_ops
+ * @mgr: the &drm_gpuva_manager the ops were created for
+ * @ops: the &drm_gpuva_ops to free
+ *
+ * Frees the given &drm_gpuva_ops structure including all the ops associated
+ * with it.
+ */
+void
+drm_gpuva_ops_free(struct drm_gpuva_manager *mgr,
+ struct drm_gpuva_ops *ops)
+{
+ struct drm_gpuva_op *op, *next;
+
+ drm_gpuva_for_each_op_safe(op, next, ops) {
+ list_del(&op->entry);
+
+ if (op->op == DRM_GPUVA_OP_REMAP) {
+ kfree(op->remap.prev);
+ kfree(op->remap.next);
+ kfree(op->remap.unmap);
+ }
+
+ gpuva_op_free(mgr, op);
+ }
+
+ kfree(ops);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_ops_free);
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __DRM_GPUVA_MGR_H__
+#define __DRM_GPUVA_MGR_H__
+
+/*
+ * Copyright (c) 2022 Red Hat.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <linux/list.h>
+#include <linux/rbtree.h>
+#include <linux/types.h>
+
+#include <drm/drm_gem.h>
+
+struct drm_gpuva_manager;
+struct drm_gpuva_fn_ops;
+
+/**
+ * enum drm_gpuva_flags - flags for struct drm_gpuva
+ */
+enum drm_gpuva_flags {
+ /**
+ * @DRM_GPUVA_INVALIDATED:
+ *
+ * Flag indicating that the &drm_gpuva's backing GEM is invalidated.
+ */
+ DRM_GPUVA_INVALIDATED = (1 << 0),
+
+ /**
+ * @DRM_GPUVA_SPARSE:
+ *
+ * Flag indicating that the &drm_gpuva is a sparse mapping.
+ */
+ DRM_GPUVA_SPARSE = (1 << 1),
+
+ /**
+ * @DRM_GPUVA_USERBITS: user defined bits
+ */
+ DRM_GPUVA_USERBITS = (1 << 2),
+};
+
+/**
+ * struct drm_gpuva - structure to track a GPU VA mapping
+ *
+ * This structure represents a GPU VA mapping and is associated with a
+ * &drm_gpuva_manager.
+ *
+ * Typically, this structure is embedded in bigger driver structures.
+ */
+struct drm_gpuva {
+ /**
+ * @mgr: the &drm_gpuva_manager this object is associated with
+ */
+ struct drm_gpuva_manager *mgr;
+
+ /**
+ * @flags: the &drm_gpuva_flags for this mapping
+ */
+ enum drm_gpuva_flags flags;
+
+ /**
+ * @va: structure containing the address and range of the &drm_gpuva
+ */
+ struct {
+ /**
+ * @addr: the start address
+ */
+ u64 addr;
+
+ /*
+ * @range: the range
+ */
+ u64 range;
+ } va;
+
+ /**
+ * @gem: structure containing the &drm_gem_object and it's offset
+ */
+ struct {
+ /**
+ * @offset: the offset within the &drm_gem_object
+ */
+ u64 offset;
+
+ /**
+ * @obj: the mapped &drm_gem_object
+ */
+ struct drm_gem_object *obj;
+
+ /**
+ * @entry: the &list_head to attach this object to a &drm_gem_object
+ */
+ struct list_head entry;
+ } gem;
+
+ /**
+ * @rb: structure containing data to store &drm_gpuvas in a rb-tree
+ */
+ struct {
+ /**
+ * @rb: the rb-tree node
+ */
+ struct rb_node node;
+
+ /**
+ * @entry: The &list_head to additionally connect &drm_gpuvas
+ * in the same order they appear in the interval tree. This is
+ * useful to keep iterating &drm_gpuvas from a start node found
+ * through the rb-tree while doing modifications on the rb-tree
+ * itself.
+ */
+ struct list_head entry;
+
+ /**
+ * @__subtree_last: needed by the interval tree, holding last-in-subtree
+ */
+ u64 __subtree_last;
+ } rb;
+};
+
+int drm_gpuva_insert(struct drm_gpuva_manager *mgr, struct drm_gpuva *va);
+void drm_gpuva_remove(struct drm_gpuva *va);
+
+void drm_gpuva_link(struct drm_gpuva *va);
+void drm_gpuva_unlink(struct drm_gpuva *va);
+
+struct drm_gpuva *drm_gpuva_find(struct drm_gpuva_manager *mgr,
+ u64 addr, u64 range);
+struct drm_gpuva *drm_gpuva_find_first(struct drm_gpuva_manager *mgr,
+ u64 addr, u64 range);
+struct drm_gpuva *drm_gpuva_find_prev(struct drm_gpuva_manager *mgr, u64 start);
+struct drm_gpuva *drm_gpuva_find_next(struct drm_gpuva_manager *mgr, u64 end);
+
+bool drm_gpuva_interval_empty(struct drm_gpuva_manager *mgr, u64 addr, u64 range);
+
+static inline void drm_gpuva_init(struct drm_gpuva *va, u64 addr, u64 range,
+ struct drm_gem_object *obj, u64 offset)
+{
+ va->va.addr = addr;
+ va->va.range = range;
+ va->gem.obj = obj;
+ va->gem.offset = offset;
+}
+
+/**
+ * drm_gpuva_invalidate() - sets whether the backing GEM of this &drm_gpuva is
+ * invalidated
+ * @va: the &drm_gpuva to set the invalidate flag for
+ * @invalidate: indicates whether the &drm_gpuva is invalidated
+ */
+static inline void drm_gpuva_invalidate(struct drm_gpuva *va, bool invalidate)
+{
+ if (invalidate)
+ va->flags |= DRM_GPUVA_INVALIDATED;
+ else
+ va->flags &= ~DRM_GPUVA_INVALIDATED;
+}
+
+/**
+ * drm_gpuva_invalidated() - indicates whether the backing BO of this &drm_gpuva
+ * is invalidated
+ * @va: the &drm_gpuva to check
+ */
+static inline bool drm_gpuva_invalidated(struct drm_gpuva *va)
+{
+ return va->flags & DRM_GPUVA_INVALIDATED;
+}
+
+/**
+ * struct drm_gpuva_manager - DRM GPU VA Manager
+ *
+ * The DRM GPU VA Manager keeps track of a GPU's virtual address space by using
+ * &maple_tree structures. Typically, this structure is embedded in bigger
+ * driver structures.
+ *
+ * Drivers can pass addresses and ranges in an arbitrary unit, e.g. bytes or
+ * pages.
+ *
+ * There should be one manager instance per GPU virtual address space.
+ */
+struct drm_gpuva_manager {
+ /**
+ * @name: the name of the DRM GPU VA space
+ */
+ const char *name;
+
+ /**
+ * @mm_start: start of the VA space
+ */
+ u64 mm_start;
+
+ /**
+ * @mm_range: length of the VA space
+ */
+ u64 mm_range;
+
+ /**
+ * @rb: structures to track &drm_gpuva entries
+ */
+ struct {
+ /**
+ * @tree: the rb-tree to track GPU VA mappings
+ */
+ struct rb_root_cached tree;
+
+ /**
+ * @list: the &list_head to track GPU VA mappings
+ */
+ struct list_head list;
+ } rb;
+
+ /**
+ * @kernel_alloc_node:
+ *
+ * &drm_gpuva representing the address space cutout reserved for
+ * the kernel
+ */
+ struct drm_gpuva kernel_alloc_node;
+
+ /**
+ * @ops: &drm_gpuva_fn_ops providing the split/merge steps to drivers
+ */
+ const struct drm_gpuva_fn_ops *ops;
+};
+
+void drm_gpuva_manager_init(struct drm_gpuva_manager *mgr,
+ const char *name,
+ u64 start_offset, u64 range,
+ u64 reserve_offset, u64 reserve_range,
+ const struct drm_gpuva_fn_ops *ops);
+void drm_gpuva_manager_destroy(struct drm_gpuva_manager *mgr);
+
+static inline struct drm_gpuva *
+__drm_gpuva_next(struct drm_gpuva *va)
+{
+ if (va && !list_is_last(&va->rb.entry, &va->mgr->rb.list))
+ return list_next_entry(va, rb.entry);
+
+ return NULL;
+}
+
+/**
+ * drm_gpuva_for_each_va_range() - iterate over a range of &drm_gpuvas
+ * @va__: &drm_gpuva structure to assign to in each iteration step
+ * @mgr__: &drm_gpuva_manager to walk over
+ * @start__: starting offset, the first gpuva will overlap this
+ * @end__: ending offset, the last gpuva will start before this (but may
+ * overlap)
+ *
+ * This iterator walks over all &drm_gpuvas in the &drm_gpuva_manager that lie
+ * between @start__ and @end__. It is implemented similarly to list_for_each(),
+ * but is using the &drm_gpuva_manager's internal interval tree to accelerate
+ * the search for the starting &drm_gpuva, and hence isn't safe against removal
+ * of elements. It assumes that @end__ is within (or is the upper limit of) the
+ * &drm_gpuva_manager. This iterator does not skip over the &drm_gpuva_manager's
+ * @kernel_alloc_node.
+ */
+#define drm_gpuva_for_each_va_range(va__, mgr__, start__, end__) \
+ for (va__ = drm_gpuva_find_first((mgr__), (start__), (end__) - (start__)); \
+ va__ && (va__->va.addr < (end__)); \
+ va__ = __drm_gpuva_next(va__))
+
+/**
+ * drm_gpuva_for_each_va_range_safe() - safely iterate over a range of
+ * &drm_gpuvas
+ * @va__: &drm_gpuva to assign to in each iteration step
+ * @next__: another &drm_gpuva to use as temporary storage
+ * @mgr__: &drm_gpuva_manager to walk over
+ * @start__: starting offset, the first gpuva will overlap this
+ * @end__: ending offset, the last gpuva will start before this (but may
+ * overlap)
+ *
+ * This iterator walks over all &drm_gpuvas in the &drm_gpuva_manager that lie
+ * between @start__ and @end__. It is implemented similarly to
+ * list_for_each_safe(), but is using the &drm_gpuva_manager's internal interval
+ * tree to accelerate the search for the starting &drm_gpuva, and hence is safe
+ * against removal of elements. It assumes that @end__ is within (or is the
+ * upper limit of) the &drm_gpuva_manager. This iterator does not skip over the
+ * &drm_gpuva_manager's @kernel_alloc_node.
+ */
+#define drm_gpuva_for_each_va_range_safe(va__, next__, mgr__, start__, end__) \
+ for (va__ = drm_gpuva_find_first((mgr__), (start__), (end__) - (start__)), \
+ next__ = __drm_gpuva_next(va__); \
+ va__ && (va__->va.addr < (end__)); \
+ va__ = next__, next__ = __drm_gpuva_next(va__))
+
+/**
+ * drm_gpuva_for_each_va() - iterate over all &drm_gpuvas
+ * @va__: &drm_gpuva to assign to in each iteration step
+ * @mgr__: &drm_gpuva_manager to walk over
+ *
+ * This iterator walks over all &drm_gpuva structures associated with the given
+ * &drm_gpuva_manager.
+ */
+#define drm_gpuva_for_each_va(va__, mgr__) \
+ list_for_each_entry(va__, &(mgr__)->rb.list, rb.entry)
+
+/**
+ * drm_gpuva_for_each_va_safe() - safely iterate over all &drm_gpuvas
+ * @va__: &drm_gpuva to assign to in each iteration step
+ * @next__: another &drm_gpuva to use as temporary storage
+ * @mgr__: &drm_gpuva_manager to walk over
+ *
+ * This iterator walks over all &drm_gpuva structures associated with the given
+ * &drm_gpuva_manager. It is implemented with list_for_each_entry_safe(), and
+ * hence safe against the removal of elements.
+ */
+#define drm_gpuva_for_each_va_safe(va__, next__, mgr__) \
+ list_for_each_entry_safe(va__, next__, &(mgr__)->rb.list, rb.entry)
+
+/**
+ * enum drm_gpuva_op_type - GPU VA operation type
+ *
+ * Operations to alter the GPU VA mappings tracked by the &drm_gpuva_manager.
+ */
+enum drm_gpuva_op_type {
+ /**
+ * @DRM_GPUVA_OP_MAP: the map op type
+ */
+ DRM_GPUVA_OP_MAP,
+
+ /**
+ * @DRM_GPUVA_OP_REMAP: the remap op type
+ */
+ DRM_GPUVA_OP_REMAP,
+
+ /**
+ * @DRM_GPUVA_OP_UNMAP: the unmap op type
+ */
+ DRM_GPUVA_OP_UNMAP,
+
+ /**
+ * @DRM_GPUVA_OP_PREFETCH: the prefetch op type
+ */
+ DRM_GPUVA_OP_PREFETCH,
+};
+
+/**
+ * struct drm_gpuva_op_map - GPU VA map operation
+ *
+ * This structure represents a single map operation generated by the
+ * DRM GPU VA manager.
+ */
+struct drm_gpuva_op_map {
+ /**
+ * @va: structure containing address and range of a map
+ * operation
+ */
+ struct {
+ /**
+ * @addr: the base address of the new mapping
+ */
+ u64 addr;
+
+ /**
+ * @range: the range of the new mapping
+ */
+ u64 range;
+ } va;
+
+ /**
+ * @gem: structure containing the &drm_gem_object and it's offset
+ */
+ struct {
+ /**
+ * @offset: the offset within the &drm_gem_object
+ */
+ u64 offset;
+
+ /**
+ * @obj: the &drm_gem_object to map
+ */
+ struct drm_gem_object *obj;
+ } gem;
+};
+
+/**
+ * struct drm_gpuva_op_unmap - GPU VA unmap operation
+ *
+ * This structure represents a single unmap operation generated by the
+ * DRM GPU VA manager.
+ */
+struct drm_gpuva_op_unmap {
+ /**
+ * @va: the &drm_gpuva to unmap
+ */
+ struct drm_gpuva *va;
+
+ /**
+ * @keep:
+ *
+ * Indicates whether this &drm_gpuva is physically contiguous with the
+ * original mapping request.
+ *
+ * Optionally, if &keep is set, drivers may keep the actual page table
+ * mappings for this &drm_gpuva, adding the missing page table entries
+ * only and update the &drm_gpuva_manager accordingly.
+ */
+ bool keep;
+};
+
+/**
+ * struct drm_gpuva_op_remap - GPU VA remap operation
+ *
+ * This represents a single remap operation generated by the DRM GPU VA manager.
+ *
+ * A remap operation is generated when an existing GPU VA mmapping is split up
+ * by inserting a new GPU VA mapping or by partially unmapping existent
+ * mapping(s), hence it consists of a maximum of two map and one unmap
+ * operation.
+ *
+ * The @unmap operation takes care of removing the original existing mapping.
+ * @prev is used to remap the preceding part, @next the subsequent part.
+ *
+ * If either a new mapping's start address is aligned with the start address
+ * of the old mapping or the new mapping's end address is aligned with the
+ * end address of the old mapping, either @prev or @next is NULL.
+ *
+ * Note, the reason for a dedicated remap operation, rather than arbitrary
+ * unmap and map operations, is to give drivers the chance of extracting driver
+ * specific data for creating the new mappings from the unmap operations's
+ * &drm_gpuva structure which typically is embedded in larger driver specific
+ * structures.
+ */
+struct drm_gpuva_op_remap {
+ /**
+ * @prev: the preceding part of a split mapping
+ */
+ struct drm_gpuva_op_map *prev;
+
+ /**
+ * @next: the subsequent part of a split mapping
+ */
+ struct drm_gpuva_op_map *next;
+
+ /**
+ * @unmap: the unmap operation for the original existing mapping
+ */
+ struct drm_gpuva_op_unmap *unmap;
+};
+
+/**
+ * struct drm_gpuva_op_prefetch - GPU VA prefetch operation
+ *
+ * This structure represents a single prefetch operation generated by the
+ * DRM GPU VA manager.
+ */
+struct drm_gpuva_op_prefetch {
+ /**
+ * @va: the &drm_gpuva to prefetch
+ */
+ struct drm_gpuva *va;
+};
+
+/**
+ * struct drm_gpuva_op - GPU VA operation
+ *
+ * This structure represents a single generic operation.
+ *
+ * The particular type of the operation is defined by @op.
+ */
+struct drm_gpuva_op {
+ /**
+ * @entry:
+ *
+ * The &list_head used to distribute instances of this struct within
+ * &drm_gpuva_ops.
+ */
+ struct list_head entry;
+
+ /**
+ * @op: the type of the operation
+ */
+ enum drm_gpuva_op_type op;
+
+ union {
+ /**
+ * @map: the map operation
+ */
+ struct drm_gpuva_op_map map;
+
+ /**
+ * @remap: the remap operation
+ */
+ struct drm_gpuva_op_remap remap;
+
+ /**
+ * @unmap: the unmap operation
+ */
+ struct drm_gpuva_op_unmap unmap;
+
+ /**
+ * @prefetch: the prefetch operation
+ */
+ struct drm_gpuva_op_prefetch prefetch;
+ };
+};
+
+/**
+ * struct drm_gpuva_ops - wraps a list of &drm_gpuva_op
+ */
+struct drm_gpuva_ops {
+ /**
+ * @list: the &list_head
+ */
+ struct list_head list;
+};
+
+/**
+ * drm_gpuva_for_each_op() - iterator to walk over &drm_gpuva_ops
+ * @op: &drm_gpuva_op to assign in each iteration step
+ * @ops: &drm_gpuva_ops to walk
+ *
+ * This iterator walks over all ops within a given list of operations.
+ */
+#define drm_gpuva_for_each_op(op, ops) list_for_each_entry(op, &(ops)->list, entry)
+
+/**
+ * drm_gpuva_for_each_op_safe() - iterator to safely walk over &drm_gpuva_ops
+ * @op: &drm_gpuva_op to assign in each iteration step
+ * @next: &next &drm_gpuva_op to store the next step
+ * @ops: &drm_gpuva_ops to walk
+ *
+ * This iterator walks over all ops within a given list of operations. It is
+ * implemented with list_for_each_safe(), so save against removal of elements.
+ */
+#define drm_gpuva_for_each_op_safe(op, next, ops) \
+ list_for_each_entry_safe(op, next, &(ops)->list, entry)
+
+/**
+ * drm_gpuva_for_each_op_from_reverse() - iterate backwards from the given point
+ * @op: &drm_gpuva_op to assign in each iteration step
+ * @ops: &drm_gpuva_ops to walk
+ *
+ * This iterator walks over all ops within a given list of operations beginning
+ * from the given operation in reverse order.
+ */
+#define drm_gpuva_for_each_op_from_reverse(op, ops) \
+ list_for_each_entry_from_reverse(op, &(ops)->list, entry)
+
+/**
+ * drm_gpuva_first_op() - returns the first &drm_gpuva_op from &drm_gpuva_ops
+ * @ops: the &drm_gpuva_ops to get the fist &drm_gpuva_op from
+ */
+#define drm_gpuva_first_op(ops) \
+ list_first_entry(&(ops)->list, struct drm_gpuva_op, entry)
+
+/**
+ * drm_gpuva_last_op() - returns the last &drm_gpuva_op from &drm_gpuva_ops
+ * @ops: the &drm_gpuva_ops to get the last &drm_gpuva_op from
+ */
+#define drm_gpuva_last_op(ops) \
+ list_last_entry(&(ops)->list, struct drm_gpuva_op, entry)
+
+/**
+ * drm_gpuva_prev_op() - previous &drm_gpuva_op in the list
+ * @op: the current &drm_gpuva_op
+ */
+#define drm_gpuva_prev_op(op) list_prev_entry(op, entry)
+
+/**
+ * drm_gpuva_next_op() - next &drm_gpuva_op in the list
+ * @op: the current &drm_gpuva_op
+ */
+#define drm_gpuva_next_op(op) list_next_entry(op, entry)
+
+struct drm_gpuva_ops *
+drm_gpuva_sm_map_ops_create(struct drm_gpuva_manager *mgr,
+ u64 addr, u64 range,
+ struct drm_gem_object *obj, u64 offset);
+struct drm_gpuva_ops *
+drm_gpuva_sm_unmap_ops_create(struct drm_gpuva_manager *mgr,
+ u64 addr, u64 range);
+
+struct drm_gpuva_ops *
+drm_gpuva_prefetch_ops_create(struct drm_gpuva_manager *mgr,
+ u64 addr, u64 range);
+
+struct drm_gpuva_ops *
+drm_gpuva_gem_unmap_ops_create(struct drm_gpuva_manager *mgr,
+ struct drm_gem_object *obj);
+
+void drm_gpuva_ops_free(struct drm_gpuva_manager *mgr,
+ struct drm_gpuva_ops *ops);
+
+static inline void drm_gpuva_init_from_op(struct drm_gpuva *va,
+ struct drm_gpuva_op_map *op)
+{
+ drm_gpuva_init(va, op->va.addr, op->va.range,
+ op->gem.obj, op->gem.offset);
+}
+
+/**
+ * struct drm_gpuva_fn_ops - callbacks for split/merge steps
+ *
+ * This structure defines the callbacks used by &drm_gpuva_sm_map and
+ * &drm_gpuva_sm_unmap to provide the split/merge steps for map and unmap
+ * operations to drivers.
+ */
+struct drm_gpuva_fn_ops {
+ /**
+ * @op_alloc: called when the &drm_gpuva_manager allocates
+ * a struct drm_gpuva_op
+ *
+ * Some drivers may want to embed struct drm_gpuva_op into driver
+ * specific structures. By implementing this callback drivers can
+ * allocate memory accordingly.
+ *
+ * This callback is optional.
+ */
+ struct drm_gpuva_op *(*op_alloc)(void);
+
+ /**
+ * @op_free: called when the &drm_gpuva_manager frees a
+ * struct drm_gpuva_op
+ *
+ * Some drivers may want to embed struct drm_gpuva_op into driver
+ * specific structures. By implementing this callback drivers can
+ * free the previously allocated memory accordingly.
+ *
+ * This callback is optional.
+ */
+ void (*op_free)(struct drm_gpuva_op *op);
+
+ /**
+ * @sm_step_map: called from &drm_gpuva_sm_map to finally insert the
+ * mapping once all previous steps were completed
+ *
+ * The &priv pointer matches the one the driver passed to
+ * &drm_gpuva_sm_map or &drm_gpuva_sm_unmap, respectively.
+ *
+ * Can be NULL if &drm_gpuva_sm_map is used.
+ */
+ int (*sm_step_map)(struct drm_gpuva_op *op, void *priv);
+
+ /**
+ * @sm_step_remap: called from &drm_gpuva_sm_map and
+ * &drm_gpuva_sm_unmap to split up an existent mapping
+ *
+ * This callback is called when existent mapping needs to be split up.
+ * This is the case when either a newly requested mapping overlaps or
+ * is enclosed by an existent mapping or a partial unmap of an existent
+ * mapping is requested.
+ *
+ * The &priv pointer matches the one the driver passed to
+ * &drm_gpuva_sm_map or &drm_gpuva_sm_unmap, respectively.
+ *
+ * Can be NULL if neither &drm_gpuva_sm_map nor &drm_gpuva_sm_unmap is
+ * used.
+ */
+ int (*sm_step_remap)(struct drm_gpuva_op *op, void *priv);
+
+ /**
+ * @sm_step_unmap: called from &drm_gpuva_sm_map and
+ * &drm_gpuva_sm_unmap to unmap an existent mapping
+ *
+ * This callback is called when existent mapping needs to be unmapped.
+ * This is the case when either a newly requested mapping encloses an
+ * existent mapping or an unmap of an existent mapping is requested.
+ *
+ * The &priv pointer matches the one the driver passed to
+ * &drm_gpuva_sm_map or &drm_gpuva_sm_unmap, respectively.
+ *
+ * Can be NULL if neither &drm_gpuva_sm_map nor &drm_gpuva_sm_unmap is
+ * used.
+ */
+ int (*sm_step_unmap)(struct drm_gpuva_op *op, void *priv);
+};
+
+int drm_gpuva_sm_map(struct drm_gpuva_manager *mgr, void *priv,
+ u64 addr, u64 range,
+ struct drm_gem_object *obj, u64 offset);
+
+int drm_gpuva_sm_unmap(struct drm_gpuva_manager *mgr, void *priv,
+ u64 addr, u64 range);
+
+void drm_gpuva_map(struct drm_gpuva_manager *mgr,
+ struct drm_gpuva *va,
+ struct drm_gpuva_op_map *op);
+
+void drm_gpuva_remap(struct drm_gpuva *prev,
+ struct drm_gpuva *next,
+ struct drm_gpuva_op_remap *op);
+
+void drm_gpuva_unmap(struct drm_gpuva_op_unmap *op);
+
+#endif /* __DRM_GPUVA_MGR_H__ */
projects / linux-platform-drivers-x86.git / commitdiff