[Intel-xe] [PATCH 1/3] drm/suballoc: Extract amdgpu_sa.c as generic suballocation helper
Christian König
christian.koenig at amd.com
Thu Feb 23 11:13:14 UTC 2023
Am 23.02.23 um 11:57 schrieb Thomas Hellström:
> From: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>
> Suballocating a buffer object is something that is not driver-specific
> and useful for many drivers.
>
> Use a slightly modified version of amdgpu_sa.c
>
> v2:
> - Style cleanups. (Thomas)
> - Added / Modified documentation (Thomas)
> - Use u64 for the sizes and offset. The code dates back to 2012 and
> using unsigned int will probably soon come back to bite us.
> We can consider size_t as well for better 32-bit efficiency. (Thomas)
> - Add and document gfp, intr and align arguments to drm_suballoc_new()
> (Thomas)
> - Use drm_printer for debug output (Thomas)
>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Co-developed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> ---
> drivers/gpu/drm/Kconfig | 4 +
> drivers/gpu/drm/Makefile | 3 +
> drivers/gpu/drm/drm_suballoc.c | 457 +++++++++++++++++++++++++++++++++
> include/drm/drm_suballoc.h | 106 ++++++++
> 4 files changed, 570 insertions(+)
> create mode 100644 drivers/gpu/drm/drm_suballoc.c
> create mode 100644 include/drm/drm_suballoc.h
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index dc0f94f02a82..8fbe57407c60 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -232,6 +232,10 @@ config DRM_GEM_SHMEM_HELPER
> help
> Choose this if you need the GEM shmem helper functions
>
> +config DRM_SUBALLOC_HELPER
> + tristate
> + depends on DRM
> +
> config DRM_SCHED
> tristate
> depends on DRM
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index ab4460fcd63f..1e04d135e866 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -88,6 +88,9 @@ obj-$(CONFIG_DRM_GEM_DMA_HELPER) += drm_dma_helper.o
> drm_shmem_helper-y := drm_gem_shmem_helper.o
> obj-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_shmem_helper.o
>
> +drm_suballoc_helper-y := drm_suballoc.o
> +obj-$(CONFIG_DRM_SUBALLOC_HELPER) += drm_suballoc_helper.o
> +
> drm_vram_helper-y := drm_gem_vram_helper.o
> obj-$(CONFIG_DRM_VRAM_HELPER) += drm_vram_helper.o
>
> diff --git a/drivers/gpu/drm/drm_suballoc.c b/drivers/gpu/drm/drm_suballoc.c
> new file mode 100644
> index 000000000000..057cd19c44ba
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_suballoc.c
> @@ -0,0 +1,457 @@
> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> +/*
> + * Copyright 2011 Red Hat Inc.
> + * Copyright 2023 Intel Corporation.
> + * All Rights Reserved.
> + *
> + * 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, sub license, 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 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 NON-INFRINGEMENT. IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
> + *
> + * The above copyright notice and this permission notice (including the
> + * next paragraph) shall be included in all copies or substantial portions
> + * of the Software.
> + *
> + */
> +/*
> + * Authors:
> + * Jerome Glisse <glisse at freedesktop.org>
> + */
We should probably update this or just leave it out.
Apart from that Reviewed-by: Christian König <christian.koenig at amd.com>.
Regards,
Christian.
> +/* Algorithm:
> + *
> + * We store the last allocated bo in "hole", we always try to allocate
> + * after the last allocated bo. Principle is that in a linear GPU ring
> + * progression was is after last is the oldest bo we allocated and thus
> + * the first one that should no longer be in use by the GPU.
> + *
> + * If it's not the case we skip over the bo after last to the closest
> + * done bo if such one exist. If none exist and we are not asked to
> + * block we report failure to allocate.
> + *
> + * If we are asked to block we wait on all the oldest fence of all
> + * rings. We just wait for any of those fence to complete.
> + */
> +
> +#include <drm/drm_suballoc.h>
> +#include <drm/drm_print.h>
> +#include <linux/slab.h>
> +#include <linux/sched.h>
> +#include <linux/wait.h>
> +#include <linux/dma-fence.h>
> +
> +static void drm_suballoc_remove_locked(struct drm_suballoc *sa);
> +static void drm_suballoc_try_free(struct drm_suballoc_manager *sa_manager);
> +
> +/**
> + * drm_suballoc_manager_init() - Initialise the drm_suballoc_manager
> + * @sa_manager: pointer to the sa_manager
> + * @size: number of bytes we want to suballocate
> + * @align: alignment for each suballocated chunk
> + *
> + * Prepares the suballocation manager for suballocations.
> + */
> +void drm_suballoc_manager_init(struct drm_suballoc_manager *sa_manager,
> + u64 size, u64 align)
> +{
> + unsigned int i;
> +
> + if (!align)
> + align = 1;
> +
> + /* alignment must be a power of 2 */
> + if (WARN_ON_ONCE(align & (align - 1)))
> + align = roundup_pow_of_two(align);
> +
> + init_waitqueue_head(&sa_manager->wq);
> + sa_manager->size = size;
> + sa_manager->align = align;
> + sa_manager->hole = &sa_manager->olist;
> + INIT_LIST_HEAD(&sa_manager->olist);
> + for (i = 0; i < DRM_SUBALLOC_MAX_QUEUES; ++i)
> + INIT_LIST_HEAD(&sa_manager->flist[i]);
> +}
> +EXPORT_SYMBOL(drm_suballoc_manager_init);
> +
> +/**
> + * drm_suballoc_manager_fini() - Destroy the drm_suballoc_manager
> + * @sa_manager: pointer to the sa_manager
> + *
> + * Cleans up the suballocation manager after use. All fences added
> + * with drm_suballoc_free() must be signaled, or we cannot clean up
> + * the entire manager.
> + */
> +void drm_suballoc_manager_fini(struct drm_suballoc_manager *sa_manager)
> +{
> + struct drm_suballoc *sa, *tmp;
> +
> + if (!sa_manager->size)
> + return;
> +
> + if (!list_empty(&sa_manager->olist)) {
> + sa_manager->hole = &sa_manager->olist;
> + drm_suballoc_try_free(sa_manager);
> + if (!list_empty(&sa_manager->olist))
> + DRM_ERROR("sa_manager is not empty, clearing anyway\n");
> + }
> + list_for_each_entry_safe(sa, tmp, &sa_manager->olist, olist) {
> + drm_suballoc_remove_locked(sa);
> + }
> +
> + sa_manager->size = 0;
> +}
> +EXPORT_SYMBOL(drm_suballoc_manager_fini);
> +
> +static void drm_suballoc_remove_locked(struct drm_suballoc *sa)
> +{
> + struct drm_suballoc_manager *sa_manager = sa->manager;
> +
> + if (sa_manager->hole == &sa->olist)
> + sa_manager->hole = sa->olist.prev;
> +
> + list_del_init(&sa->olist);
> + list_del_init(&sa->flist);
> + dma_fence_put(sa->fence);
> + kfree(sa);
> +}
> +
> +static void drm_suballoc_try_free(struct drm_suballoc_manager *sa_manager)
> +{
> + struct drm_suballoc *sa, *tmp;
> +
> + if (sa_manager->hole->next == &sa_manager->olist)
> + return;
> +
> + sa = list_entry(sa_manager->hole->next, struct drm_suballoc, olist);
> + list_for_each_entry_safe_from(sa, tmp, &sa_manager->olist, olist) {
> + if (!sa->fence || !dma_fence_is_signaled(sa->fence))
> + return;
> +
> + drm_suballoc_remove_locked(sa);
> + }
> +}
> +
> +static u64 drm_suballoc_hole_soffset(struct drm_suballoc_manager *sa_manager)
> +{
> + struct list_head *hole = sa_manager->hole;
> +
> + if (hole != &sa_manager->olist)
> + return list_entry(hole, struct drm_suballoc, olist)->eoffset;
> +
> + return 0;
> +}
> +
> +static u64 drm_suballoc_hole_eoffset(struct drm_suballoc_manager *sa_manager)
> +{
> + struct list_head *hole = sa_manager->hole;
> +
> + if (hole->next != &sa_manager->olist)
> + return list_entry(hole->next, struct drm_suballoc, olist)->soffset;
> + return sa_manager->size;
> +}
> +
> +static bool drm_suballoc_try_alloc(struct drm_suballoc_manager *sa_manager,
> + struct drm_suballoc *sa,
> + u64 size, u64 align)
> +{
> + u64 soffset, eoffset, wasted;
> +
> + soffset = drm_suballoc_hole_soffset(sa_manager);
> + eoffset = drm_suballoc_hole_eoffset(sa_manager);
> + wasted = (align - (soffset % align)) % align;
> +
> + if ((eoffset - soffset) >= (size + wasted)) {
> + soffset += wasted;
> +
> + sa->manager = sa_manager;
> + sa->soffset = soffset;
> + sa->eoffset = soffset + size;
> + list_add(&sa->olist, sa_manager->hole);
> + INIT_LIST_HEAD(&sa->flist);
> + sa_manager->hole = &sa->olist;
> + return true;
> + }
> + return false;
> +}
> +
> +static bool __drm_suballoc_event(struct drm_suballoc_manager *sa_manager,
> + u64 size, u64 align)
> +{
> + u64 soffset, eoffset, wasted;
> + unsigned int i;
> +
> + for (i = 0; i < DRM_SUBALLOC_MAX_QUEUES; ++i)
> + if (!list_empty(&sa_manager->flist[i]))
> + return true;
> +
> + soffset = drm_suballoc_hole_soffset(sa_manager);
> + eoffset = drm_suballoc_hole_eoffset(sa_manager);
> + wasted = (align - (soffset % align)) % align;
> +
> + return ((eoffset - soffset) >= (size + wasted));
> +}
> +
> +/**
> + * drm_suballoc_event() - Check if we can stop waiting
> + * @sa_manager: pointer to the sa_manager
> + * @size: number of bytes we want to allocate
> + * @align: alignment we need to match
> + *
> + * Return: true if either there is a fence we can wait for or
> + * enough free memory to satisfy the allocation directly.
> + * false otherwise.
> + */
> +static bool drm_suballoc_event(struct drm_suballoc_manager *sa_manager,
> + u64 size, u64 align)
> +{
> + bool ret;
> +
> + spin_lock(&sa_manager->wq.lock);
> + ret = __drm_suballoc_event(sa_manager, size, align);
> + spin_unlock(&sa_manager->wq.lock);
> + return ret;
> +}
> +
> +static bool drm_suballoc_next_hole(struct drm_suballoc_manager *sa_manager,
> + struct dma_fence **fences,
> + unsigned int *tries)
> +{
> + struct drm_suballoc *best_bo = NULL;
> + unsigned int i, best_idx;
> + u64 soffset, best, tmp;
> +
> + /* if hole points to the end of the buffer */
> + if (sa_manager->hole->next == &sa_manager->olist) {
> + /* try again with its beginning */
> + sa_manager->hole = &sa_manager->olist;
> + return true;
> + }
> +
> + soffset = drm_suballoc_hole_soffset(sa_manager);
> + /* to handle wrap around we add sa_manager->size */
> + best = sa_manager->size * 2;
> + /* go over all fence list and try to find the closest sa
> + * of the current last
> + */
> + for (i = 0; i < DRM_SUBALLOC_MAX_QUEUES; ++i) {
> + struct drm_suballoc *sa;
> +
> + fences[i] = NULL;
> +
> + if (list_empty(&sa_manager->flist[i]))
> + continue;
> +
> + sa = list_first_entry(&sa_manager->flist[i],
> + struct drm_suballoc, flist);
> +
> + if (!dma_fence_is_signaled(sa->fence)) {
> + fences[i] = sa->fence;
> + continue;
> + }
> +
> + /* limit the number of tries each freelist gets */
> + if (tries[i] > 2)
> + continue;
> +
> + tmp = sa->soffset;
> + if (tmp < soffset) {
> + /* wrap around, pretend it's after */
> + tmp += sa_manager->size;
> + }
> + tmp -= soffset;
> + if (tmp < best) {
> + /* this sa bo is the closest one */
> + best = tmp;
> + best_idx = i;
> + best_bo = sa;
> + }
> + }
> +
> + if (best_bo) {
> + ++tries[best_idx];
> + sa_manager->hole = best_bo->olist.prev;
> +
> + /*
> + * We know that this one is signaled,
> + * so it's safe to remove it.
> + */
> + drm_suballoc_remove_locked(best_bo);
> + return true;
> + }
> + return false;
> +}
> +
> +/**
> + * drm_suballoc_new() - Make a suballocation.
> + * @sa_manager: pointer to the sa_manager
> + * @size: number of bytes we want to suballocate.
> + * @gfp: gfp flags used for memory allocation. Typically GFP_KERNEL but
> + * the argument is provided for suballocations from reclaim context or
> + * where the caller wants to avoid pipelining rather than wait for
> + * reclaim.
> + * @intr: Whether to perform waits interruptible. This should typically
> + * always be true, unless the caller needs to propagate a
> + * non-interruptible context from above layers.
> + * @align: Alignment. Must not exceed the default manager alignment.
> + * If @align is zero, then the manager alignment is used.
> + *
> + * Try to make a suballocation of size @size, which will be rounded
> + * up to the alignment specified in specified in drm_suballoc_manager_init().
> + *
> + * Return: a new suballocated bo, or an ERR_PTR.
> + */
> +struct drm_suballoc *
> +drm_suballoc_new(struct drm_suballoc_manager *sa_manager, u64 size,
> + gfp_t gfp, bool intr, u64 align)
> +{
> + struct dma_fence *fences[DRM_SUBALLOC_MAX_QUEUES];
> + unsigned int tries[DRM_SUBALLOC_MAX_QUEUES];
> + unsigned int count;
> + int i, r;
> + struct drm_suballoc *sa;
> +
> + if (WARN_ON_ONCE(align > sa_manager->align))
> + return ERR_PTR(-EINVAL);
> + if (WARN_ON_ONCE(size > sa_manager->size || !size))
> + return ERR_PTR(-EINVAL);
> +
> + if (!align)
> + align = sa_manager->align;
> +
> + sa = kmalloc(sizeof(*sa), gfp);
> + if (!sa)
> + return ERR_PTR(-ENOMEM);
> + sa->manager = sa_manager;
> + sa->fence = NULL;
> + INIT_LIST_HEAD(&sa->olist);
> + INIT_LIST_HEAD(&sa->flist);
> +
> + spin_lock(&sa_manager->wq.lock);
> + do {
> + for (i = 0; i < DRM_SUBALLOC_MAX_QUEUES; ++i)
> + tries[i] = 0;
> +
> + do {
> + drm_suballoc_try_free(sa_manager);
> +
> + if (drm_suballoc_try_alloc(sa_manager, sa,
> + size, align)) {
> + spin_unlock(&sa_manager->wq.lock);
> + return sa;
> + }
> +
> + /* see if we can skip over some allocations */
> + } while (drm_suballoc_next_hole(sa_manager, fences, tries));
> +
> + for (i = 0, count = 0; i < DRM_SUBALLOC_MAX_QUEUES; ++i)
> + if (fences[i])
> + fences[count++] = dma_fence_get(fences[i]);
> +
> + if (count) {
> + long t;
> +
> + spin_unlock(&sa_manager->wq.lock);
> + t = dma_fence_wait_any_timeout(fences, count, intr,
> + MAX_SCHEDULE_TIMEOUT,
> + NULL);
> + for (i = 0; i < count; ++i)
> + dma_fence_put(fences[i]);
> +
> + r = (t > 0) ? 0 : t;
> + spin_lock(&sa_manager->wq.lock);
> + } else if (intr) {
> + /* if we have nothing to wait for block */
> + r = wait_event_interruptible_locked
> + (sa_manager->wq,
> + __drm_suballoc_event(sa_manager, size, align));
> + } else {
> + spin_unlock(&sa_manager->wq.lock);
> + wait_event(sa_manager->wq,
> + drm_suballoc_event(sa_manager, size, align));
> + r = 0;
> + spin_lock(&sa_manager->wq.lock);
> + }
> + } while (!r);
> +
> + spin_unlock(&sa_manager->wq.lock);
> + kfree(sa);
> + return ERR_PTR(r);
> +}
> +EXPORT_SYMBOL(drm_suballoc_new);
> +
> +/**
> + * drm_suballoc_free - Free a suballocation
> + * @suballoc: pointer to the suballocation
> + * @fence: fence that signals when suballocation is idle
> + *
> + * Free the suballocation. The suballocation can be re-used after @fence signals.
> + */
> +void drm_suballoc_free(struct drm_suballoc *suballoc,
> + struct dma_fence *fence)
> +{
> + struct drm_suballoc_manager *sa_manager;
> +
> + if (!suballoc)
> + return;
> +
> + sa_manager = suballoc->manager;
> +
> + spin_lock(&sa_manager->wq.lock);
> + if (fence && !dma_fence_is_signaled(fence)) {
> + u64 idx;
> +
> + suballoc->fence = dma_fence_get(fence);
> + idx = fence->context % DRM_SUBALLOC_MAX_QUEUES;
> + list_add_tail(&suballoc->flist, &sa_manager->flist[idx]);
> + } else {
> + drm_suballoc_remove_locked(suballoc);
> + }
> + wake_up_all_locked(&sa_manager->wq);
> + spin_unlock(&sa_manager->wq.lock);
> +}
> +EXPORT_SYMBOL(drm_suballoc_free);
> +
> +#ifdef CONFIG_DEBUG_FS
> +void drm_suballoc_dump_debug_info(struct drm_suballoc_manager *sa_manager,
> + struct drm_printer *p, u64 suballoc_base)
> +{
> + struct drm_suballoc *i;
> +
> + spin_lock(&sa_manager->wq.lock);
> + list_for_each_entry(i, &sa_manager->olist, olist) {
> + u64 soffset = i->soffset;
> + u64 eoffset = i->eoffset;
> +
> + if (&i->olist == sa_manager->hole)
> + drm_puts(p, ">");
> + else
> + drm_puts(p, " ");
> +
> + drm_printf(p, "[0x%010llx 0x%010llx] size %8lld",
> + suballoc_base + soffset, suballoc_base + eoffset,
> + eoffset - soffset);
> +
> + if (i->fence)
> + drm_printf(p, " protected by 0x%016llx on context %llu",
> + i->fence->seqno, i->fence->context);
> +
> + drm_puts(p, "\n");
> + }
> + spin_unlock(&sa_manager->wq.lock);
> +}
> +EXPORT_SYMBOL(drm_suballoc_dump_debug_info);
> +#endif
> +MODULE_AUTHOR("Multiple");
> +MODULE_DESCRIPTION("Range suballocator helper");
> +MODULE_LICENSE("Dual MIT/GPL");
> diff --git a/include/drm/drm_suballoc.h b/include/drm/drm_suballoc.h
> new file mode 100644
> index 000000000000..a737f996e5ff
> --- /dev/null
> +++ b/include/drm/drm_suballoc.h
> @@ -0,0 +1,106 @@
> +/* SPDX-License-Identifier: GPL-2.0 OR MIT */
> +/*
> + * Copyright 2011 Red Hat Inc.
> + * Copyright © 2022 Intel Corporation
> + */
> +#ifndef _DRM_SUBALLOC_H_
> +#define _DRM_SUBALLOC_H_
> +
> +#include <drm/drm_mm.h>
> +
> +#include <linux/dma-fence.h>
> +#include <linux/types.h>
> +
> +#define DRM_SUBALLOC_MAX_QUEUES 32
> +/**
> + * struct drm_suballoc_manager - fenced range allocations
> + * @wq: Wait queue for sleeping allocations on contention.
> + * @hole: Pointer to first hole node.
> + * @olist: List of allocated ranges.
> + * @flist: Array[fence context hash] of queues of fenced allocated ranges.
> + * @size: Size of the managed range.
> + * @align: Default alignment for the managed range.
> + */
> +struct drm_suballoc_manager {
> + wait_queue_head_t wq;
> + struct list_head *hole;
> + struct list_head olist;
> + struct list_head flist[DRM_SUBALLOC_MAX_QUEUES];
> + u64 size;
> + u64 align;
> +};
> +
> +/**
> + * struct drm_suballoc - Sub-allocated range
> + * @olist: List link for list of allocated ranges.
> + * @flist: List linkk for the manager fenced allocated ranges queues.
> + * @manager: The drm_suballoc_manager.
> + * @soffset: Start offset.
> + * @eoffset: End offset + 1 so that @eoffset - @soffset = size.
> + * @dma_fence: The fence protecting the allocation.
> + */
> +struct drm_suballoc {
> + struct list_head olist;
> + struct list_head flist;
> + struct drm_suballoc_manager *manager;
> + u64 soffset;
> + u64 eoffset;
> + struct dma_fence *fence;
> +};
> +
> +void drm_suballoc_manager_init(struct drm_suballoc_manager *sa_manager,
> + u64 size, u64 align);
> +
> +void drm_suballoc_manager_fini(struct drm_suballoc_manager *sa_manager);
> +
> +struct drm_suballoc *
> +drm_suballoc_new(struct drm_suballoc_manager *sa_manager, u64 size, gfp_t gfp,
> + bool intr, u64 align);
> +
> +void drm_suballoc_free(struct drm_suballoc *sa, struct dma_fence *fence);
> +
> +/**
> + * drm_suballoc_soffset - Range start.
> + * @sa: The struct drm_suballoc.
> + *
> + * Return: The start of the allocated range.
> + */
> +static inline u64 drm_suballoc_soffset(struct drm_suballoc *sa)
> +{
> + return sa->soffset;
> +}
> +
> +/**
> + * drm_suballoc_eoffset - Range end.
> + * @sa: The struct drm_suballoc.
> + *
> + * Return: The end of the allocated range + 1.
> + */
> +static inline u64 drm_suballoc_eoffset(struct drm_suballoc *sa)
> +{
> + return sa->eoffset;
> +}
> +
> +/**
> + * drm_suballoc_size - Range size.
> + * @sa: The struct drm_suballoc.
> + *
> + * Return: The size of the allocated range.
> + */
> +static inline u64 drm_suballoc_size(struct drm_suballoc *sa)
> +{
> + return sa->eoffset - sa->soffset;
> +}
> +
> +#ifdef CONFIG_DEBUG_FS
> +void drm_suballoc_dump_debug_info(struct drm_suballoc_manager *sa_manager,
> + struct drm_printer *p, u64 suballoc_base);
> +#else
> +static inline void
> +drm_suballoc_dump_debug_info(struct drm_suballoc_manager *sa_manager,
> + struct drm_printer *p, u64 suballoc_base)
> +{ }
> +
> +#endif
> +
> +#endif /* _DRM_SUBALLOC_H_ */
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