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<div class="moz-cite-prefix">On 2021-12-08 3:24 a.m., Felix Kuehling
wrote:<br>
</div>
<blockquote type="cite" cite="mid:20211208082457.918004-1-Felix.Kuehling@amd.com">
<pre class="moz-quote-pre" wrap="">Add null-pointer check after the last svm_range_new call. This was
originally reported by Zhou Qingyang <a class="moz-txt-link-rfc2396E" href="mailto:zhou1615@umn.edu"><zhou1615@umn.edu></a> based on a
static analyzer.
To avoid duplicating the unwinding code from svm_range_handle_overlap,
I merged the two functions into one.
Signed-off-by: Felix Kuehling <a class="moz-txt-link-rfc2396E" href="mailto:Felix.Kuehling@amd.com"><Felix.Kuehling@amd.com></a>
Cc: Zhou Qingyang <a class="moz-txt-link-rfc2396E" href="mailto:zhou1615@umn.edu"><zhou1615@umn.edu></a></pre>
</blockquote>
Reviewed-by: Philip Yang <a class="moz-txt-link-rfc2396E" href="mailto:Philip.Yang@amd.com"><Philip.Yang@amd.com></a>
<blockquote type="cite" cite="mid:20211208082457.918004-1-Felix.Kuehling@amd.com">
<pre class="moz-quote-pre" wrap="">
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 138 ++++++++++-----------------
1 file changed, 49 insertions(+), 89 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index f2db49c7a8fd..ed4430e31307 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -941,7 +941,7 @@ svm_range_split(struct svm_range *prange, uint64_t start, uint64_t last,
}
static int
-svm_range_split_tail(struct svm_range *prange, struct svm_range *new,
+svm_range_split_tail(struct svm_range *prange,
uint64_t new_last, struct list_head *insert_list)
{
struct svm_range *tail;
@@ -953,7 +953,7 @@ svm_range_split_tail(struct svm_range *prange, struct svm_range *new,
}
static int
-svm_range_split_head(struct svm_range *prange, struct svm_range *new,
+svm_range_split_head(struct svm_range *prange,
uint64_t new_start, struct list_head *insert_list)
{
struct svm_range *head;
@@ -1754,49 +1754,54 @@ static struct svm_range *svm_range_clone(struct svm_range *old)
}
/**
- * svm_range_handle_overlap - split overlap ranges
- * @svms: svm range list header
- * @new: range added with this attributes
- * @start: range added start address, in pages
- * @last: range last address, in pages
- * @update_list: output, the ranges attributes are updated. For set_attr, this
- * will do validation and map to GPUs. For unmap, this will be
- * removed and unmap from GPUs
- * @insert_list: output, the ranges will be inserted into svms, attributes are
- * not changes. For set_attr, this will add into svms.
- * @remove_list:output, the ranges will be removed from svms
- * @left: the remaining range after overlap, For set_attr, this will be added
- * as new range.
+ * svm_range_add - add svm range and handle overlap
+ * @p: the range add to this process svms
+ * @start: page size aligned
+ * @size: page size aligned
+ * @nattr: number of attributes
+ * @attrs: array of attributes
+ * @update_list: output, the ranges need validate and update GPU mapping
+ * @insert_list: output, the ranges need insert to svms
+ * @remove_list: output, the ranges are replaced and need remove from svms
*
- * Total have 5 overlap cases.
+ * Check if the virtual address range has overlap with any existing ranges,
+ * split partly overlapping ranges and add new ranges in the gaps. All changes
+ * should be applied to the range_list and interval tree transactionally. If
+ * any range split or allocation fails, the entire update fails. Therefore any
+ * existing overlapping svm_ranges are cloned and the original svm_ranges left
+ * unchanged.
*
- * This function handles overlap of an address interval with existing
- * struct svm_ranges for applying new attributes. This may require
- * splitting existing struct svm_ranges. All changes should be applied to
- * the range_list and interval tree transactionally. If any split operation
- * fails, the entire update fails. Therefore the existing overlapping
- * svm_ranges are cloned and the original svm_ranges left unchanged. If the
- * transaction succeeds, the modified clones are added and the originals
- * freed. Otherwise the clones are removed and the old svm_ranges remain.
+ * If the transaction succeeds, the caller can update and insert clones and
+ * new ranges, then free the originals.
*
- * Context: The caller must hold svms->lock
+ * Otherwise the caller can free the clones and new ranges, while the old
+ * svm_ranges remain unchanged.
+ *
+ * Context: Process context, caller must hold svms->lock
+ *
+ * Return:
+ * 0 - OK, otherwise error code
*/
static int
-svm_range_handle_overlap(struct svm_range_list *svms, struct svm_range *new,
- unsigned long start, unsigned long last,
- struct list_head *update_list,
- struct list_head *insert_list,
- struct list_head *remove_list,
- unsigned long *left)
+svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
+ uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
+ struct list_head *update_list, struct list_head *insert_list,
+ struct list_head *remove_list)
{
+ unsigned long last = start + size - 1UL;
+ struct svm_range_list *svms = &p->svms;
struct interval_tree_node *node;
+ struct svm_range new = {0};
struct svm_range *prange;
struct svm_range *tmp;
int r = 0;
+ pr_debug("svms 0x%p [0x%llx 0x%lx]\n", &p->svms, start, last);
+
INIT_LIST_HEAD(update_list);
INIT_LIST_HEAD(insert_list);
INIT_LIST_HEAD(remove_list);
+ svm_range_apply_attrs(p, &new, nattr, attrs);
node = interval_tree_iter_first(&svms->objects, start, last);
while (node) {
@@ -1824,14 +1829,14 @@ svm_range_handle_overlap(struct svm_range_list *svms, struct svm_range *new,
if (node->start < start) {
pr_debug("change old range start\n");
- r = svm_range_split_head(prange, new, start,
+ r = svm_range_split_head(prange, start,
insert_list);
if (r)
goto out;
}
if (node->last > last) {
pr_debug("change old range last\n");
- r = svm_range_split_tail(prange, new, last,
+ r = svm_range_split_tail(prange, last,
insert_list);
if (r)
goto out;
@@ -1843,7 +1848,7 @@ svm_range_handle_overlap(struct svm_range_list *svms, struct svm_range *new,
prange = old;
}
- if (!svm_range_is_same_attrs(prange, new))
+ if (!svm_range_is_same_attrs(prange, &new))
list_add(&prange->update_list, update_list);
/* insert a new node if needed */
@@ -1863,8 +1868,16 @@ svm_range_handle_overlap(struct svm_range_list *svms, struct svm_range *new,
start = next_start;
}
- if (left && start <= last)
- *left = last - start + 1;
+ /* add a final range at the end if needed */
+ if (start <= last) {
+ prange = svm_range_new(svms, start, last);
+ if (!prange) {
+ r = -ENOMEM;
+ goto out;
+ }
+ list_add(&prange->insert_list, insert_list);
+ list_add(&prange->update_list, update_list);
+ }
out:
if (r)
@@ -2883,59 +2896,6 @@ svm_range_is_valid(struct kfd_process *p, uint64_t start, uint64_t size)
NULL);
}
-/**
- * svm_range_add - add svm range and handle overlap
- * @p: the range add to this process svms
- * @start: page size aligned
- * @size: page size aligned
- * @nattr: number of attributes
- * @attrs: array of attributes
- * @update_list: output, the ranges need validate and update GPU mapping
- * @insert_list: output, the ranges need insert to svms
- * @remove_list: output, the ranges are replaced and need remove from svms
- *
- * Check if the virtual address range has overlap with the registered ranges,
- * split the overlapped range, copy and adjust pages address and vram nodes in
- * old and new ranges.
- *
- * Context: Process context, caller must hold svms->lock
- *
- * Return:
- * 0 - OK, otherwise error code
- */
-static int
-svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
- uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
- struct list_head *update_list, struct list_head *insert_list,
- struct list_head *remove_list)
-{
- uint64_t last = start + size - 1UL;
- struct svm_range_list *svms;
- struct svm_range new = {0};
- struct svm_range *prange;
- unsigned long left = 0;
- int r = 0;
-
- pr_debug("svms 0x%p [0x%llx 0x%llx]\n", &p->svms, start, last);
-
- svm_range_apply_attrs(p, &new, nattr, attrs);
-
- svms = &p->svms;
-
- r = svm_range_handle_overlap(svms, &new, start, last, update_list,
- insert_list, remove_list, &left);
- if (r)
- return r;
-
- if (left) {
- prange = svm_range_new(svms, last - left + 1, last);
- list_add(&prange->insert_list, insert_list);
- list_add(&prange->update_list, update_list);
- }
-
- return 0;
-}
-
/**
* svm_range_best_prefetch_location - decide the best prefetch location
* @prange: svm range structure
</pre>
</blockquote>
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