[AMD Public Use] Hi Christian, > And where is the patch to switch i915 and remove the Intel copy of this? Creating a patch for the switch. > In general I think that every public function here needs a kerneldoc description what it is all about. Making a kernel doc description for each public function Thanks, Arun -----Original Message----- From: Koenig, Christian <Christian.Koenig@xxxxxxx> Sent: Wednesday, September 22, 2021 12:28 PM To: Paneer Selvam, Arunpravin <Arunpravin.PaneerSelvam@xxxxxxx>; dri-devel@xxxxxxxxxxxxxxxxxxxxx; intel-gfx@xxxxxxxxxxxxxxxxxxxxx; amd-gfx@xxxxxxxxxxxxxxxxxxxxx; matthew.auld@xxxxxxxxx; daniel@xxxxxxxx; Deucher, Alexander <Alexander.Deucher@xxxxxxx> Subject: Re: [PATCH 1/2] Enable buddy memory manager support Am 20.09.21 um 21:20 schrieb Arunpravin: > Port Intel buddy system manager to drm root folder Add CPU > mappable/non-mappable region support to the drm buddy manager And where is the patch to switch i915 and remove the Intel copy of this? In general I think that every public function here needs a kerneldoc description what it is all about. Regards, Christian. > > Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam@xxxxxxx> > --- > drivers/gpu/drm/Makefile | 2 +- > drivers/gpu/drm/drm_buddy.c | 465 ++++++++++++++++++++++++++++++++++++ > include/drm/drm_buddy.h | 154 ++++++++++++ > 3 files changed, 620 insertions(+), 1 deletion(-) > create mode 100644 drivers/gpu/drm/drm_buddy.c > create mode 100644 include/drm/drm_buddy.h > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index > a118692a6df7..fe1a2fc09675 100644 > --- a/drivers/gpu/drm/Makefile > +++ b/drivers/gpu/drm/Makefile > @@ -18,7 +18,7 @@ drm-y := drm_aperture.o drm_auth.o drm_cache.o \ > drm_dumb_buffers.o drm_mode_config.o drm_vblank.o \ > drm_syncobj.o drm_lease.o drm_writeback.o drm_client.o \ > drm_client_modeset.o drm_atomic_uapi.o drm_hdcp.o \ > - drm_managed.o drm_vblank_work.o > + drm_managed.o drm_vblank_work.o drm_buddy.o > > drm-$(CONFIG_DRM_LEGACY) += drm_agpsupport.o drm_bufs.o drm_context.o drm_dma.o \ > drm_legacy_misc.o drm_lock.o drm_memory.o drm_scatter.o \ > diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c > new file mode 100644 index 000000000000..f07919a004b6 > --- /dev/null > +++ b/drivers/gpu/drm/drm_buddy.c > @@ -0,0 +1,465 @@ > +// SPDX-License-Identifier: MIT > +/* > + * Copyright 2021 Intel Corporation */ > + > +#include <linux/kmemleak.h> > +#include <drm/drm_buddy.h> > + > +static struct drm_buddy_block *drm_block_alloc(struct drm_buddy_mm *mm, > + struct drm_buddy_block *parent, unsigned int order, > + u64 offset) > +{ > + struct drm_buddy_block *block; > + > + BUG_ON(order > DRM_BUDDY_MAX_ORDER); > + > + block = kmem_cache_zalloc(mm->slab_blocks, GFP_KERNEL); > + if (!block) > + return NULL; > + > + block->header = offset; > + block->header |= order; > + block->parent = parent; > + block->start = offset >> PAGE_SHIFT; > + block->size = (mm->chunk_size << order) >> PAGE_SHIFT; > + > + BUG_ON(block->header & DRM_BUDDY_HEADER_UNUSED); > + return block; > +} > + > +static void drm_block_free(struct drm_buddy_mm *mm, struct > +drm_buddy_block *block) { > + kmem_cache_free(mm->slab_blocks, block); } > + > +static void add_ordered(struct drm_buddy_mm *mm, struct > +drm_buddy_block *block) { > + struct drm_buddy_block *node; > + > + if (list_empty(&mm->free_list[drm_buddy_block_order(block)])) { > + list_add(&block->link, > + &mm->free_list[drm_buddy_block_order(block)]); > + return; > + } > + > + list_for_each_entry(node, &mm->free_list[drm_buddy_block_order(block)], link) > + if (block->start > node->start) > + break; > + > + __list_add(&block->link, node->link.prev, &node->link); } > + > +static void mark_allocated(struct drm_buddy_block *block) { > + block->header &= ~DRM_BUDDY_HEADER_STATE; > + block->header |= DRM_BUDDY_ALLOCATED; > + > + list_del(&block->link); > +} > + > +static void mark_free(struct drm_buddy_mm *mm, > + struct drm_buddy_block *block) { > + block->header &= ~DRM_BUDDY_HEADER_STATE; > + block->header |= DRM_BUDDY_FREE; > + > + add_ordered(mm, block); > +} > + > +static void mark_split(struct drm_buddy_block *block) { > + block->header &= ~DRM_BUDDY_HEADER_STATE; > + block->header |= DRM_BUDDY_SPLIT; > + > + list_del(&block->link); > +} > + > +int drm_buddy_init(struct drm_buddy_mm *mm, u64 size, u64 chunk_size) > +{ > + unsigned int i; > + u64 offset; > + > + if (size < chunk_size) > + return -EINVAL; > + > + if (chunk_size < PAGE_SIZE) > + return -EINVAL; > + > + if (!is_power_of_2(chunk_size)) > + return -EINVAL; > + > + size = round_down(size, chunk_size); > + > + mm->size = size; > + mm->chunk_size = chunk_size; > + mm->max_order = ilog2(size) - ilog2(chunk_size); > + > + BUG_ON(mm->max_order > DRM_BUDDY_MAX_ORDER); > + > + mm->slab_blocks = KMEM_CACHE(drm_buddy_block, SLAB_HWCACHE_ALIGN); > + > + if (!mm->slab_blocks) > + return -ENOMEM; > + > + mm->free_list = kmalloc_array(mm->max_order + 1, > + sizeof(struct list_head), > + GFP_KERNEL); > + if (!mm->free_list) > + goto out_destroy_slab; > + > + for (i = 0; i <= mm->max_order; ++i) > + INIT_LIST_HEAD(&mm->free_list[i]); > + > + mm->n_roots = hweight64(size); > + > + mm->roots = kmalloc_array(mm->n_roots, > + sizeof(struct drm_buddy_block *), > + GFP_KERNEL); > + if (!mm->roots) > + goto out_free_list; > + > + offset = 0; > + i = 0; > + > + /* > + * Split into power-of-two blocks, in case we are given a size that is > + * not itself a power-of-two. > + */ > + do { > + struct drm_buddy_block *root; > + unsigned int order; > + u64 root_size; > + > + root_size = rounddown_pow_of_two(size); > + order = ilog2(root_size) - ilog2(chunk_size); > + > + root = drm_block_alloc(mm, NULL, order, offset); > + if (!root) > + goto out_free_roots; > + > + mark_free(mm, root); > + > + BUG_ON(i > mm->max_order); > + BUG_ON(drm_buddy_block_size(mm, root) < chunk_size); > + > + mm->roots[i] = root; > + > + offset += root_size; > + size -= root_size; > + i++; > + } while (size); > + > + return 0; > + > +out_free_roots: > + while (i--) > + drm_block_free(mm, mm->roots[i]); > + kfree(mm->roots); > +out_free_list: > + kfree(mm->free_list); > +out_destroy_slab: > + kmem_cache_destroy(mm->slab_blocks); > + return -ENOMEM; > +} > +EXPORT_SYMBOL(drm_buddy_init); > + > +void drm_buddy_fini(struct drm_buddy_mm *mm) { > + int i; > + > + for (i = 0; i < mm->n_roots; ++i) { > + WARN_ON(!drm_buddy_block_is_free(mm->roots[i])); > + drm_block_free(mm, mm->roots[i]); > + } > + > + kfree(mm->roots); > + kfree(mm->free_list); > + kmem_cache_destroy(mm->slab_blocks); > +} > +EXPORT_SYMBOL(drm_buddy_fini); > + > +static int split_block(struct drm_buddy_mm *mm, > + struct drm_buddy_block *block) { > + unsigned int block_order = drm_buddy_block_order(block) - 1; > + u64 offset = drm_buddy_block_offset(block); > + > + BUG_ON(!drm_buddy_block_is_free(block)); > + BUG_ON(!drm_buddy_block_order(block)); > + > + block->left = drm_block_alloc(mm, block, block_order, offset); > + if (!block->left) > + return -ENOMEM; > + > + block->right = drm_block_alloc(mm, block, block_order, > + offset + (mm->chunk_size << block_order)); > + if (!block->right) { > + drm_block_free(mm, block->left); > + return -ENOMEM; > + } > + > + mark_free(mm, block->left); > + mark_free(mm, block->right); > + > + mark_split(block); > + > + return 0; > +} > + > +static struct drm_buddy_block * > +get_buddy(struct drm_buddy_block *block) { > + struct drm_buddy_block *parent; > + > + parent = block->parent; > + if (!parent) > + return NULL; > + > + if (parent->left == block) > + return parent->right; > + > + return parent->left; > +} > + > +static void __drm_buddy_free(struct drm_buddy_mm *mm, > + struct drm_buddy_block *block) { > + struct drm_buddy_block *parent; > + > + while ((parent = block->parent)) { > + struct drm_buddy_block *buddy; > + > + buddy = get_buddy(block); > + > + if (!drm_buddy_block_is_free(buddy)) > + break; > + > + list_del(&buddy->link); > + > + drm_block_free(mm, block); > + drm_block_free(mm, buddy); > + > + block = parent; > + } > + > + mark_free(mm, block); > +} > + > +void drm_buddy_free(struct drm_buddy_mm *mm, > + struct drm_buddy_block *block) { > + BUG_ON(!drm_buddy_block_is_allocated(block)); > + __drm_buddy_free(mm, block); > +} > +EXPORT_SYMBOL(drm_buddy_free); > + > +void drm_buddy_free_list(struct drm_buddy_mm *mm, struct list_head > +*objects) { > + struct drm_buddy_block *block, *on; > + > + list_for_each_entry_safe(block, on, objects, link) { > + drm_buddy_free(mm, block); > + cond_resched(); > + } > + INIT_LIST_HEAD(objects); > +} > +EXPORT_SYMBOL(drm_buddy_free_list); > + > +/* > + * Allocate power-of-two block. The order value here translates to: > + * > + * 0 = 2^0 * mm->chunk_size > + * 1 = 2^1 * mm->chunk_size > + * 2 = 2^2 * mm->chunk_size > + * ... > + */ > +struct drm_buddy_block * > +drm_buddy_alloc(struct drm_buddy_mm *mm, unsigned int order, > + bool bar_enabled, unsigned int limit, > + enum drm_buddy_alloc_mode mode) > +{ > + struct drm_buddy_block *block = NULL; > + unsigned int pages; > + unsigned int i; > + int err; > + > + pages = (mm->chunk_size << order) >> PAGE_SHIFT; > + > + for (i = order; i <= mm->max_order; ++i) { > + if (mode == DRM_BUDDY_TOP_DOWN) { > + if (!list_empty(&mm->free_list[i])) { > + block = list_first_entry(&mm->free_list[i], > + struct drm_buddy_block, link); > + > + if (bar_enabled) { > + if (!(block->start > limit)) > + continue; > + } > + > + break; > + } > + } else if (mode == DRM_BUDDY_BOTTOM_UP) { > + if (!list_empty(&mm->free_list[i])) { > + block = list_last_entry(&mm->free_list[i], > + struct drm_buddy_block, link); > + > + if (bar_enabled) { > + if (!(block->start < limit && > + (block->start + pages) < limit)) > + continue; > + } > + > + break; > + } > + } > + } > + > + if (!block) > + return ERR_PTR(-ENOSPC); > + > + BUG_ON(!drm_buddy_block_is_free(block)); > + > + while (i != order) { > + err = split_block(mm, block); > + if (unlikely(err)) > + goto out_free; > + > + /* Go low */ > + if (mode == DRM_BUDDY_TOP_DOWN) > + block = block->right; > + else > + block = block->left; > + i--; > + } > + > + if (mode == DRM_BUDDY_TOP_DOWN && bar_enabled) { > + if (!(block->start > limit)) > + return ERR_PTR(-ENOSPC); > + } else if (mode == DRM_BUDDY_BOTTOM_UP && bar_enabled) { > + if (!(block->start < limit && > + (block->start + pages) < limit)) > + return ERR_PTR(-ENOSPC); > + } > + > + mark_allocated(block); > + kmemleak_update_trace(block); > + return block; > + > +out_free: > + if (i != order) > + __drm_buddy_free(mm, block); > + return ERR_PTR(err); > +} > +EXPORT_SYMBOL(drm_buddy_alloc); > + > +static inline bool overlaps(u64 s1, u64 e1, u64 s2, u64 e2) { > + return s1 <= e2 && e1 >= s2; > +} > + > +static inline bool contains(u64 s1, u64 e1, u64 s2, u64 e2) { > + return s1 <= s2 && e1 >= e2; > +} > + > +/* > + * Allocate range. Note that it's safe to chain together multiple > +alloc_ranges > + * with the same blocks list. > + * > + * Intended for pre-allocating portions of the address space, for > +example to > + * reserve a block for the initial framebuffer or similar, hence the > +expectation > + * here is that drm_buddy_alloc() is still the main vehicle for > + * allocations, so if that's not the case then the drm_mm range > +allocator is > + * probably a much better fit, and so you should probably go use that instead. > + */ > +int drm_buddy_alloc_range(struct drm_buddy_mm *mm, > + struct list_head *blocks, > + u64 start, u64 size) > +{ > + struct drm_buddy_block *block; > + struct drm_buddy_block *buddy; > + LIST_HEAD(allocated); > + LIST_HEAD(dfs); > + u64 end; > + int err; > + int i; > + > + if (size < mm->chunk_size) > + return -EINVAL; > + > + if (!IS_ALIGNED(size | start, mm->chunk_size)) > + return -EINVAL; > + > + if (range_overflows(start, size, mm->size)) > + return -EINVAL; > + > + for (i = 0; i < mm->n_roots; ++i) > + list_add_tail(&mm->roots[i]->tmp_link, &dfs); > + > + end = start + size - 1; > + > + do { > + u64 block_start; > + u64 block_end; > + > + block = list_first_entry_or_null(&dfs, > + struct drm_buddy_block, > + tmp_link); > + if (!block) > + break; > + > + list_del(&block->tmp_link); > + > + block_start = drm_buddy_block_offset(block); > + block_end = block_start + drm_buddy_block_size(mm, block) - 1; > + > + if (!overlaps(start, end, block_start, block_end)) > + continue; > + > + if (drm_buddy_block_is_allocated(block)) { > + err = -ENOSPC; > + goto err_free; > + } > + > + if (contains(start, end, block_start, block_end)) { > + if (!drm_buddy_block_is_free(block)) { > + err = -ENOSPC; > + goto err_free; > + } > + > + mark_allocated(block); > + list_add_tail(&block->link, &allocated); > + continue; > + } > + > + if (!drm_buddy_block_is_split(block)) { > + err = split_block(mm, block); > + if (unlikely(err)) > + goto err_undo; > + } > + > + list_add(&block->right->tmp_link, &dfs); > + list_add(&block->left->tmp_link, &dfs); > + } while (1); > + > + list_splice_tail(&allocated, blocks); > + return 0; > + > +err_undo: > + /* > + * We really don't want to leave around a bunch of split blocks, since > + * bigger is better, so make sure we merge everything back before we > + * free the allocated blocks. > + */ > + buddy = get_buddy(block); > + if (buddy && > + (drm_buddy_block_is_free(block) && > + drm_buddy_block_is_free(buddy))) > + __drm_buddy_free(mm, block); > + > +err_free: > + drm_buddy_free_list(mm, &allocated); > + return err; > +} > +EXPORT_SYMBOL(drm_buddy_alloc_range); > diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h new > file mode 100644 index 000000000000..50e4d819a3dd > --- /dev/null > +++ b/include/drm/drm_buddy.h > @@ -0,0 +1,154 @@ > +/* SPDX-License-Identifier: MIT */ > +/* > + * Copyright 2021 Intel Corporation */ > + > +#ifndef __DRM_BUDDY_H__ > +#define __DRM_BUDDY_H__ > + > +#include <linux/bitops.h> > +#include <linux/list.h> > +#include <linux/slab.h> > +#include <linux/sched.h> > + > +#define range_overflows(start, size, max) ({ \ > + typeof(start) start__ = (start); \ > + typeof(size) size__ = (size); \ > + typeof(max) max__ = (max); \ > + (void)(&start__ == &size__); \ > + (void)(&start__ == &max__); \ > + start__ >= max__ || size__ > max__ - start__; \ > +}) > + > +enum drm_buddy_alloc_mode { > + DRM_BUDDY_TOP_DOWN = 0, > + DRM_BUDDY_BOTTOM_UP, > + DRM_BUDDY_ALLOC_RANGE > +}; > + > +struct drm_buddy_block { > +#define DRM_BUDDY_HEADER_OFFSET GENMASK_ULL(63, 12) #define > +DRM_BUDDY_HEADER_STATE GENMASK_ULL(11, 10) > +#define DRM_BUDDY_ALLOCATED (1 << 10) > +#define DRM_BUDDY_FREE (2 << 10) > +#define DRM_BUDDY_SPLIT (3 << 10) > +/* Free to be used, if needed in the future */ #define > +DRM_BUDDY_HEADER_UNUSED GENMASK_ULL(9, 6) #define > +DRM_BUDDY_HEADER_ORDER GENMASK_ULL(5, 0) > + u64 header; > + /* Store start and size fields in pages */ > + u64 start; > + u64 size; > + > + struct drm_buddy_block *left; > + struct drm_buddy_block *right; > + struct drm_buddy_block *parent; > + > + void *private; /* owned by creator */ > + > + /* > + * While the block is allocated by the user through drm_buddy_alloc*, > + * the user has ownership of the link, for example to maintain within > + * a list, if so desired. As soon as the block is freed with > + * drm_buddy_free* ownership is given back to the mm. > + */ > + struct list_head link; > + struct list_head tmp_link; > +}; > + > +/* Order-zero must be at least PAGE_SIZE */ #define > +DRM_BUDDY_MAX_ORDER (63 - PAGE_SHIFT) > + > +/* > + * Binary Buddy System. > + * > + * Locking should be handled by the user, a simple mutex around > + * drm_buddy_alloc* and drm_buddy_free* should suffice. > + */ > +struct drm_buddy_mm { > + struct kmem_cache *slab_blocks; > + /* Maintain a free list for each order. */ > + struct list_head *free_list; > + > + /* > + * Maintain explicit binary tree(s) to track the allocation of the > + * address space. This gives us a simple way of finding a buddy block > + * and performing the potentially recursive merge step when freeing a > + * block. Nodes are either allocated or free, in which case they will > + * also exist on the respective free list. > + */ > + struct drm_buddy_block **roots; > + > + /* > + * Anything from here is public, and remains static for the lifetime of > + * the mm. Everything above is considered do-not-touch. > + */ > + unsigned int n_roots; > + unsigned int max_order; > + > + /* Must be at least PAGE_SIZE */ > + u64 chunk_size; > + u64 size; > +}; > + > +static inline u64 > +drm_buddy_block_offset(struct drm_buddy_block *block) { > + return block->header & DRM_BUDDY_HEADER_OFFSET; } > + > +static inline unsigned int > +drm_buddy_block_order(struct drm_buddy_block *block) { > + return block->header & DRM_BUDDY_HEADER_ORDER; } > + > +static inline unsigned int > +drm_buddy_block_state(struct drm_buddy_block *block) { > + return block->header & DRM_BUDDY_HEADER_STATE; } > + > +static inline bool > +drm_buddy_block_is_allocated(struct drm_buddy_block *block) { > + return drm_buddy_block_state(block) == DRM_BUDDY_ALLOCATED; } > + > +static inline bool > +drm_buddy_block_is_free(struct drm_buddy_block *block) { > + return drm_buddy_block_state(block) == DRM_BUDDY_FREE; } > + > +static inline bool > +drm_buddy_block_is_split(struct drm_buddy_block *block) { > + return drm_buddy_block_state(block) == DRM_BUDDY_SPLIT; } > + > +static inline u64 > +drm_buddy_block_size(struct drm_buddy_mm *mm, > + struct drm_buddy_block *block) { > + return mm->chunk_size << drm_buddy_block_order(block); } > + > +int drm_buddy_init(struct drm_buddy_mm *mm, u64 size, u64 > +chunk_size); > + > +void drm_buddy_fini(struct drm_buddy_mm *mm); > + > +struct drm_buddy_block * > +drm_buddy_alloc(struct drm_buddy_mm *mm, unsigned int order, > + bool bar_limit_enabled, unsigned int limit, > + enum drm_buddy_alloc_mode mode); > + > +int drm_buddy_alloc_range(struct drm_buddy_mm *mm, > + struct list_head *blocks, > + u64 start, u64 size); > + > +void drm_buddy_free(struct drm_buddy_mm *mm, struct drm_buddy_block > +*block); > + > +void drm_buddy_free_list(struct drm_buddy_mm *mm, struct list_head > +*objects); > + > +#endif