Re: [PATCH 09/11] lib/interval-tree: convert interval_tree to half closed intervals

["Koenig, Christian" <Christian.Koenig@amd.com>]

Am 04.10.19 um 08:57 schrieb Christian König:
> Am 03.10.19 um 22:18 schrieb Davidlohr Bueso:
>> The generic tree tree really wants [a, b) intervals, not fully closed.
>> As such convert it to use the new interval_tree_gen.h. Most of the
>> conversions are straightforward, with the exception of perhaps
>> radeon_vm_bo_set_addr(), but semantics have been tried to be left
>> untouched.
>
> NAK, the whole thing won't work.
>
> See we need to handle the full device address space which means we 
> have values in the range of 0x0-0xffffffff.
>
> If you make this a closed interval then the end would wrap around to 
> 0x0 if long is only 32bit.

Well I've just now re-read the subject line. From that it sounds like 
you are actually trying to fix the interval tree to use a half closed 
interval, e.g. something like [a, b[

But your code changes sometimes doesn't seem to reflect that.

Regards,
Christian.

>
> Regards,
> Christian.
>
>>
>> Cc: "Christian König" <christian.koenig@amd.com>
>> Cc: Alex Deucher <alexander.deucher@amd.com>
>> Cc: David Airlie <airlied@linux.ie>
>> Cc: Daniel Vetter <daniel@ffwll.ch>
>> Cc: Doug Ledford <dledford@redhat.com>
>> Cc: Joerg Roedel <joro@8bytes.org>
>> Cc: "Jérôme Glisse" <jglisse@redhat.com>
>> Cc: dri-devel@lists.freedesktop.org
>> Cc: linux-rdma@vger.kernel.org
>> Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c      | 12 +++---------
>>   drivers/gpu/drm/i915/gem/i915_gem_userptr.c |  5 +----
>>   drivers/gpu/drm/radeon/radeon_mn.c          | 11 ++++-------
>>   drivers/gpu/drm/radeon/radeon_trace.h       |  2 +-
>>   drivers/gpu/drm/radeon/radeon_vm.c          | 26 
>> +++++++++++++-------------
>>   drivers/infiniband/core/umem_odp.c          | 21 +++++++--------------
>>   drivers/iommu/virtio-iommu.c                |  6 +++---
>>   include/linux/interval_tree.h               |  2 +-
>>   include/rdma/ib_umem_odp.h                  |  4 ++--
>>   lib/interval_tree.c                         |  6 +++---
>>   10 files changed, 38 insertions(+), 57 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
>> index 31d4deb5d294..4bbaa9ffa570 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
>> @@ -205,9 +205,6 @@ amdgpu_mn_sync_pagetables_gfx(struct hmm_mirror 
>> *mirror,
>>       bool blockable = mmu_notifier_range_blockable(update);
>>       struct interval_tree_node *it;
>>   -    /* notification is exclusive, but interval is inclusive */
>> -    end -= 1;
>> -
>>       /* TODO we should be able to split locking for interval tree and
>>        * amdgpu_mn_invalidate_node
>>        */
>> @@ -254,9 +251,6 @@ amdgpu_mn_sync_pagetables_hsa(struct hmm_mirror 
>> *mirror,
>>       bool blockable = mmu_notifier_range_blockable(update);
>>       struct interval_tree_node *it;
>>   -    /* notification is exclusive, but interval is inclusive */
>> -    end -= 1;
>> -
>>       if (amdgpu_mn_read_lock(amn, blockable))
>>           return -EAGAIN;
>>   @@ -374,7 +368,7 @@ struct amdgpu_mn *amdgpu_mn_get(struct 
>> amdgpu_device *adev,
>>    */
>>   int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
>>   {
>> -    unsigned long end = addr + amdgpu_bo_size(bo) - 1;
>> +    unsigned long end = addr + amdgpu_bo_size(bo);
>>       struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
>>       enum amdgpu_mn_type type =
>>           bo->kfd_bo ? AMDGPU_MN_TYPE_HSA : AMDGPU_MN_TYPE_GFX;
>> @@ -400,7 +394,7 @@ int amdgpu_mn_register(struct amdgpu_bo *bo, 
>> unsigned long addr)
>>           node = container_of(it, struct amdgpu_mn_node, it);
>>           interval_tree_remove(&node->it, &amn->objects);
>>           addr = min(it->start, addr);
>> -        end = max(it->last, end);
>> +        end = max(it->end, end);
>>           list_splice(&node->bos, &bos);
>>       }
>>   @@ -412,7 +406,7 @@ int amdgpu_mn_register(struct amdgpu_bo *bo, 
>> unsigned long addr)
>>       bo->mn = amn;
>>         node->it.start = addr;
>> -    node->it.last = end;
>> +    node->it.end = end;
>>       INIT_LIST_HEAD(&node->bos);
>>       list_splice(&bos, &node->bos);
>>       list_add(&bo->mn_list, &node->bos);
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c 
>> b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
>> index 11b231c187c5..818ff6b33102 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
>> @@ -99,9 +99,6 @@ userptr_mn_invalidate_range_start(struct 
>> mmu_notifier *_mn,
>>       if (RB_EMPTY_ROOT(&mn->objects.rb_root))
>>           return 0;
>>   -    /* interval ranges are inclusive, but invalidate range is 
>> exclusive */
>> -    end = range->end - 1;
>> -
>>       spin_lock(&mn->lock);
>>       it = interval_tree_iter_first(&mn->objects, range->start, end);
>>       while (it) {
>> @@ -275,7 +272,7 @@ i915_gem_userptr_init__mmu_notifier(struct 
>> drm_i915_gem_object *obj,
>>       mo->mn = mn;
>>       mo->obj = obj;
>>       mo->it.start = obj->userptr.ptr;
>> -    mo->it.last = obj->userptr.ptr + obj->base.size - 1;
>> +    mo->it.end = obj->userptr.ptr + obj->base.size;
>>       RB_CLEAR_NODE(&mo->it.rb);
>>         obj->userptr.mmu_object = mo;
>> diff --git a/drivers/gpu/drm/radeon/radeon_mn.c 
>> b/drivers/gpu/drm/radeon/radeon_mn.c
>> index dbab9a3a969b..4810421dacc2 100644
>> --- a/drivers/gpu/drm/radeon/radeon_mn.c
>> +++ b/drivers/gpu/drm/radeon/radeon_mn.c
>> @@ -66,12 +66,9 @@ static int radeon_mn_invalidate_range_start(struct 
>> mmu_notifier *mn,
>>       struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn);
>>       struct ttm_operation_ctx ctx = { false, false };
>>       struct interval_tree_node *it;
>> -    unsigned long end;
>> +    unsigned long end = range->end;
>>       int ret = 0;
>>   -    /* notification is exclusive, but interval is inclusive */
>> -    end = range->end - 1;
>> -
>>       /* TODO we should be able to split locking for interval tree and
>>        * the tear down.
>>        */
>> @@ -174,7 +171,7 @@ static const struct mmu_notifier_ops 
>> radeon_mn_ops = {
>>    */
>>   int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
>>   {
>> -    unsigned long end = addr + radeon_bo_size(bo) - 1;
>> +    unsigned long end = addr + radeon_bo_size(bo);
>>       struct mmu_notifier *mn;
>>       struct radeon_mn *rmn;
>>       struct radeon_mn_node *node = NULL;
>> @@ -195,7 +192,7 @@ int radeon_mn_register(struct radeon_bo *bo, 
>> unsigned long addr)
>>           node = container_of(it, struct radeon_mn_node, it);
>>           interval_tree_remove(&node->it, &rmn->objects);
>>           addr = min(it->start, addr);
>> -        end = max(it->last, end);
>> +        end = max(it->end, end);
>>           list_splice(&node->bos, &bos);
>>       }
>>   @@ -210,7 +207,7 @@ int radeon_mn_register(struct radeon_bo *bo, 
>> unsigned long addr)
>>       bo->mn = rmn;
>>         node->it.start = addr;
>> -    node->it.last = end;
>> +    node->it.end = end;
>>       INIT_LIST_HEAD(&node->bos);
>>       list_splice(&bos, &node->bos);
>>       list_add(&bo->mn_list, &node->bos);
>> diff --git a/drivers/gpu/drm/radeon/radeon_trace.h 
>> b/drivers/gpu/drm/radeon/radeon_trace.h
>> index c93f3ab3c4e3..4324f3fc5d82 100644
>> --- a/drivers/gpu/drm/radeon/radeon_trace.h
>> +++ b/drivers/gpu/drm/radeon/radeon_trace.h
>> @@ -73,7 +73,7 @@ TRACE_EVENT(radeon_vm_bo_update,
>>             TP_fast_assign(
>>                  __entry->soffset = bo_va->it.start;
>> -               __entry->eoffset = bo_va->it.last + 1;
>> +               __entry->eoffset = bo_va->it.end;
>>                  __entry->flags = bo_va->flags;
>>                  ),
>>           TP_printk("soffs=%010llx, eoffs=%010llx, flags=%08x",
>> diff --git a/drivers/gpu/drm/radeon/radeon_vm.c 
>> b/drivers/gpu/drm/radeon/radeon_vm.c
>> index e0ad547786e8..b2a54aff21f4 100644
>> --- a/drivers/gpu/drm/radeon/radeon_vm.c
>> +++ b/drivers/gpu/drm/radeon/radeon_vm.c
>> @@ -329,7 +329,7 @@ struct radeon_bo_va *radeon_vm_bo_add(struct 
>> radeon_device *rdev,
>>       bo_va->vm = vm;
>>       bo_va->bo = bo;
>>       bo_va->it.start = 0;
>> -    bo_va->it.last = 0;
>> +    bo_va->it.end = 0;
>>       bo_va->flags = 0;
>>       bo_va->ref_count = 1;
>>       INIT_LIST_HEAD(&bo_va->bo_list);
>> @@ -456,7 +456,7 @@ int radeon_vm_bo_set_addr(struct radeon_device 
>> *rdev,
>>         if (soffset) {
>>           /* make sure object fit at this offset */
>> -        eoffset = soffset + size - 1;
>> +        eoffset = soffset + size;
>>           if (soffset >= eoffset) {
>>               r = -EINVAL;
>>               goto error_unreserve;
>> @@ -486,14 +486,14 @@ int radeon_vm_bo_set_addr(struct radeon_device 
>> *rdev,
>>               /* bo and tmp overlap, invalid offset */
>>               dev_err(rdev->dev, "bo %p va 0x%010Lx conflict with "
>>                   "(bo %p 0x%010lx 0x%010lx)\n", bo_va->bo,
>> -                soffset, tmp->bo, tmp->it.start, tmp->it.last);
>> +                soffset, tmp->bo, tmp->it.start, tmp->it.end);
>>               mutex_unlock(&vm->mutex);
>>               r = -EINVAL;
>>               goto error_unreserve;
>>           }
>>       }
>>   -    if (bo_va->it.start || bo_va->it.last) {
>> +    if (bo_va->it.start || bo_va->it.end) {
>>           /* add a clone of the bo_va to clear the old address */
>>           struct radeon_bo_va *tmp;
>>           tmp = kzalloc(sizeof(struct radeon_bo_va), GFP_KERNEL);
>> @@ -503,14 +503,14 @@ int radeon_vm_bo_set_addr(struct radeon_device 
>> *rdev,
>>               goto error_unreserve;
>>           }
>>           tmp->it.start = bo_va->it.start;
>> -        tmp->it.last = bo_va->it.last;
>> +        tmp->it.end = bo_va->it.end;
>>           tmp->vm = vm;
>>           tmp->bo = radeon_bo_ref(bo_va->bo);
>>             interval_tree_remove(&bo_va->it, &vm->va);
>>           spin_lock(&vm->status_lock);
>>           bo_va->it.start = 0;
>> -        bo_va->it.last = 0;
>> +        bo_va->it.end = 0;
>>           list_del_init(&bo_va->vm_status);
>>           list_add(&tmp->vm_status, &vm->freed);
>>           spin_unlock(&vm->status_lock);
>> @@ -519,7 +519,7 @@ int radeon_vm_bo_set_addr(struct radeon_device 
>> *rdev,
>>       if (soffset || eoffset) {
>>           spin_lock(&vm->status_lock);
>>           bo_va->it.start = soffset;
>> -        bo_va->it.last = eoffset;
>> +        bo_va->it.end = eoffset;
>>           list_add(&bo_va->vm_status, &vm->cleared);
>>           spin_unlock(&vm->status_lock);
>>           interval_tree_insert(&bo_va->it, &vm->va);
>> @@ -964,7 +964,7 @@ int radeon_vm_bo_update(struct radeon_device *rdev,
>>         trace_radeon_vm_bo_update(bo_va);
>>   -    nptes = bo_va->it.last - bo_va->it.start + 1;
>> +    nptes = bo_va->it.end - bo_va->it.start;
>>         /* reserve space for one command every (1 << BLOCK_SIZE) entries
>>          or 2k dwords (whatever is smaller) */
>> @@ -1010,7 +1010,7 @@ int radeon_vm_bo_update(struct radeon_device 
>> *rdev,
>>       }
>>         r = radeon_vm_update_ptes(rdev, vm, &ib, bo_va->it.start,
>> -                  bo_va->it.last + 1, addr,
>> +                  bo_va->it.end, addr,
>>                     radeon_vm_page_flags(bo_va->flags));
>>       if (r) {
>>           radeon_ib_free(rdev, &ib);
>> @@ -1026,7 +1026,7 @@ int radeon_vm_bo_update(struct radeon_device 
>> *rdev,
>>           return r;
>>       }
>>       ib.fence->is_vm_update = true;
>> -    radeon_vm_fence_pts(vm, bo_va->it.start, bo_va->it.last + 1, 
>> ib.fence);
>> +    radeon_vm_fence_pts(vm, bo_va->it.start, bo_va->it.end, ib.fence);
>>       radeon_fence_unref(&bo_va->last_pt_update);
>>       bo_va->last_pt_update = radeon_fence_ref(ib.fence);
>>       radeon_ib_free(rdev, &ib);
>> @@ -1124,12 +1124,12 @@ void radeon_vm_bo_rmv(struct radeon_device 
>> *rdev,
>>       list_del(&bo_va->bo_list);
>>         mutex_lock(&vm->mutex);
>> -    if (bo_va->it.start || bo_va->it.last)
>> +    if (bo_va->it.start || bo_va->it.end)
>>           interval_tree_remove(&bo_va->it, &vm->va);
>>         spin_lock(&vm->status_lock);
>>       list_del(&bo_va->vm_status);
>> -    if (bo_va->it.start || bo_va->it.last) {
>> +    if (bo_va->it.start || bo_va->it.end) {
>>           bo_va->bo = radeon_bo_ref(bo_va->bo);
>>           list_add(&bo_va->vm_status, &vm->freed);
>>       } else {
>> @@ -1158,7 +1158,7 @@ void radeon_vm_bo_invalidate(struct 
>> radeon_device *rdev,
>>       list_for_each_entry(bo_va, &bo->va, bo_list) {
>>           spin_lock(&bo_va->vm->status_lock);
>>           if (list_empty(&bo_va->vm_status) &&
>> -            (bo_va->it.start || bo_va->it.last))
>> +            (bo_va->it.start || bo_va->it.end))
>>               list_add(&bo_va->vm_status, &bo_va->vm->invalidated);
>>           spin_unlock(&bo_va->vm->status_lock);
>>       }
>> diff --git a/drivers/infiniband/core/umem_odp.c 
>> b/drivers/infiniband/core/umem_odp.c
>> index f67a30fda1ed..9b7ac93223d6 100644
>> --- a/drivers/infiniband/core/umem_odp.c
>> +++ b/drivers/infiniband/core/umem_odp.c
>> @@ -219,26 +219,19 @@ static inline int ib_init_umem_odp(struct 
>> ib_umem_odp *umem_odp)
>>               ALIGN_DOWN(umem_odp->umem.address, page_size);
>>           if (check_add_overflow(umem_odp->umem.address,
>>                          (unsigned long)umem_odp->umem.length,
>> -                       &umem_odp->interval_tree.last))
>> +                       &umem_odp->interval_tree.end))
>>               return -EOVERFLOW;
>> -        umem_odp->interval_tree.last =
>> -            ALIGN(umem_odp->interval_tree.last, page_size);
>> -        if (unlikely(umem_odp->interval_tree.last < page_size))
>> +        umem_odp->interval_tree.end =
>> +            ALIGN(umem_odp->interval_tree.end, page_size);
>> +        if (unlikely(umem_odp->interval_tree.end < page_size))
>>               return -EOVERFLOW;
>>   -        pages = (umem_odp->interval_tree.last -
>> +        pages = (umem_odp->interval_tree.end -
>>                umem_odp->interval_tree.start) >>
>>               umem_odp->page_shift;
>>           if (!pages)
>>               return -EINVAL;
>>   -        /*
>> -         * Note that the representation of the intervals in the
>> -         * interval tree considers the ending point as contained in
>> -         * the interval.
>> -         */
>> -        umem_odp->interval_tree.last--;
>> -
>>           umem_odp->page_list = kvcalloc(
>>               pages, sizeof(*umem_odp->page_list), GFP_KERNEL);
>>           if (!umem_odp->page_list)
>> @@ -777,12 +770,12 @@ int rbt_ib_umem_for_each_in_range(struct 
>> rb_root_cached *root,
>>       if (unlikely(start == last))
>>           return ret_val;
>>   -    for (node = interval_tree_iter_first(root, start, last - 1);
>> +    for (node = interval_tree_iter_first(root, start, last);
>>               node; node = next) {
>>           /* TODO move the blockable decision up to the callback */
>>           if (!blockable)
>>               return -EAGAIN;
>> -        next = interval_tree_iter_next(node, start, last - 1);
>> +        next = interval_tree_iter_next(node, start, last);
>>           umem = container_of(node, struct ib_umem_odp, interval_tree);
>>           ret_val = cb(umem, start, last, cookie) || ret_val;
>>       }
>> diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
>> index 3ea9d7682999..771740981f43 100644
>> --- a/drivers/iommu/virtio-iommu.c
>> +++ b/drivers/iommu/virtio-iommu.c
>> @@ -323,7 +323,7 @@ static int viommu_add_mapping(struct 
>> viommu_domain *vdomain, unsigned long iova,
>>         mapping->paddr        = paddr;
>>       mapping->iova.start    = iova;
>> -    mapping->iova.last    = iova + size - 1;
>> +    mapping->iova.end    = iova + size;
>>       mapping->flags        = flags;
>>         spin_lock_irqsave(&vdomain->mappings_lock, irqflags);
>> @@ -348,7 +348,7 @@ static size_t viommu_del_mappings(struct 
>> viommu_domain *vdomain,
>>   {
>>       size_t unmapped = 0;
>>       unsigned long flags;
>> -    unsigned long last = iova + size - 1;
>> +    unsigned long last = iova + size;
>>       struct viommu_mapping *mapping = NULL;
>>       struct interval_tree_node *node, *next;
>>   @@ -367,7 +367,7 @@ static size_t viommu_del_mappings(struct 
>> viommu_domain *vdomain,
>>            * Virtio-iommu doesn't allow UNMAP to split a mapping created
>>            * with a single MAP request, so remove the full mapping.
>>            */
>> -        unmapped += mapping->iova.last - mapping->iova.start + 1;
>> +        unmapped += mapping->iova.end - mapping->iova.start;
>>             interval_tree_remove(node, &vdomain->mappings);
>>           kfree(mapping);
>> diff --git a/include/linux/interval_tree.h 
>> b/include/linux/interval_tree.h
>> index 288c26f50732..f3d1ea9e4003 100644
>> --- a/include/linux/interval_tree.h
>> +++ b/include/linux/interval_tree.h
>> @@ -7,7 +7,7 @@
>>   struct interval_tree_node {
>>       struct rb_node rb;
>>       unsigned long start;    /* Start of interval */
>> -    unsigned long last;    /* Last location _in_ interval */
>> +    unsigned long end;    /* Last location _outside_ interval */
>>       unsigned long __subtree_last;
>>   };
>>   diff --git a/include/rdma/ib_umem_odp.h b/include/rdma/ib_umem_odp.h
>> index 253df1a1fa54..d0ae7aa2139b 100644
>> --- a/include/rdma/ib_umem_odp.h
>> +++ b/include/rdma/ib_umem_odp.h
>> @@ -97,7 +97,7 @@ static inline unsigned long ib_umem_start(struct 
>> ib_umem_odp *umem_odp)
>>   /* Returns the address of the page after the last one of an ODP 
>> umem. */
>>   static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp)
>>   {
>> -    return umem_odp->interval_tree.last + 1;
>> +    return umem_odp->interval_tree.end;
>>   }
>>     static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp 
>> *umem_odp)
>> @@ -165,7 +165,7 @@ rbt_ib_umem_lookup(struct rb_root_cached *root, 
>> u64 addr, u64 length)
>>   {
>>       struct interval_tree_node *node;
>>   -    node = interval_tree_iter_first(root, addr, addr + length - 1);
>> +    node = interval_tree_iter_first(root, addr, addr + length);
>>       if (!node)
>>           return NULL;
>>       return container_of(node, struct ib_umem_odp, interval_tree);
>> diff --git a/lib/interval_tree.c b/lib/interval_tree.c
>> index 593ce56ece50..336ec5113a28 100644
>> --- a/lib/interval_tree.c
>> +++ b/lib/interval_tree.c
>> @@ -1,15 +1,15 @@
>>   // SPDX-License-Identifier: GPL-2.0-only
>>   #include <linux/interval_tree.h>
>> -#include <linux/interval_tree_generic.h>
>> +#include <linux/interval_tree_gen.h>
>>   #include <linux/compiler.h>
>>   #include <linux/export.h>
>>     #define START(node) ((node)->start)
>> -#define LAST(node)  ((node)->last)
>> +#define END(node)  ((node)->end)
>>     INTERVAL_TREE_DEFINE(struct interval_tree_node, rb,
>>                unsigned long, __subtree_last,
>> -             START, LAST,, interval_tree)
>> +             START, END,, interval_tree)
>>     EXPORT_SYMBOL_GPL(interval_tree_insert);
>>   EXPORT_SYMBOL_GPL(interval_tree_remove);
>