RDMA/hns: Refactor root BT allocation for MTR

Split the hem_list_alloc_root_bt() into serval small functions to make the
code flow more clear.

Link: https://lore.kernel.org/r/1621589395-2435-3-git-send-email-liweihang@huawei.com
Signed-off-by: Xi Wang <wangxi11@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/hw/hns/hns_roce_hem.c b/drivers/infiniband/hw/hns/hns_roce_hem.c
index cfd2e1b..63776da 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_hem.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hem.c
@@ -1053,7 +1053,7 @@ void hns_roce_cleanup_hem(struct hns_roce_dev *hr_dev)
        hns_roce_cleanup_hem_table(hr_dev, &hr_dev->mr_table.mtpt_table);
 }
 
-struct roce_hem_item {
+struct hns_roce_hem_item {
        struct list_head list; /* link all hems in the same bt level */
        struct list_head sibling; /* link all hems in last hop for mtt */
        void *addr;
@@ -1063,12 +1063,18 @@ struct roce_hem_item {
        int end; /* end buf offset in this hem */
 };
 
-static struct roce_hem_item *hem_list_alloc_item(struct hns_roce_dev *hr_dev,
-                                                  int start, int end,
-                                                  int count, bool exist_bt,
-                                                  int bt_level)
+/* All HEM items are linked in a tree structure */
+struct hns_roce_hem_head {
+       struct list_head branch[HNS_ROCE_MAX_BT_REGION];
+       struct list_head root;
+       struct list_head leaf;
+};
+
+static struct hns_roce_hem_item *
+hem_list_alloc_item(struct hns_roce_dev *hr_dev, int start, int end, int count,
+                   bool exist_bt, int bt_level)
 {
-       struct roce_hem_item *hem;
+       struct hns_roce_hem_item *hem;
 
        hem = kzalloc(sizeof(*hem), GFP_KERNEL);
        if (!hem)
@@ -1093,7 +1099,7 @@ static struct roce_hem_item *hem_list_alloc_item(struct hns_roce_dev *hr_dev,
 }
 
 static void hem_list_free_item(struct hns_roce_dev *hr_dev,
-                              struct roce_hem_item *hem, bool exist_bt)
+                              struct hns_roce_hem_item *hem, bool exist_bt)
 {
        if (exist_bt)
                dma_free_coherent(hr_dev->dev, hem->count * BA_BYTE_LEN,
@@ -1104,7 +1110,7 @@ static void hem_list_free_item(struct hns_roce_dev *hr_dev,
 static void hem_list_free_all(struct hns_roce_dev *hr_dev,
                              struct list_head *head, bool exist_bt)
 {
-       struct roce_hem_item *hem, *temp_hem;
+       struct hns_roce_hem_item *hem, *temp_hem;
 
        list_for_each_entry_safe(hem, temp_hem, head, list) {
                list_del(&hem->list);
@@ -1120,24 +1126,24 @@ static void hem_list_link_bt(struct hns_roce_dev *hr_dev, void *base_addr,
 
 /* assign L0 table address to hem from root bt */
 static void hem_list_assign_bt(struct hns_roce_dev *hr_dev,
-                              struct roce_hem_item *hem, void *cpu_addr,
+                              struct hns_roce_hem_item *hem, void *cpu_addr,
                               u64 phy_addr)
 {
        hem->addr = cpu_addr;
        hem->dma_addr = (dma_addr_t)phy_addr;
 }
 
-static inline bool hem_list_page_is_in_range(struct roce_hem_item *hem,
+static inline bool hem_list_page_is_in_range(struct hns_roce_hem_item *hem,
                                             int offset)
 {
        return (hem->start <= offset && offset <= hem->end);
 }
 
-static struct roce_hem_item *hem_list_search_item(struct list_head *ba_list,
-                                                   int page_offset)
+static struct hns_roce_hem_item *hem_list_search_item(struct list_head *ba_list,
+                                                     int page_offset)
 {
-       struct roce_hem_item *hem, *temp_hem;
-       struct roce_hem_item *found = NULL;
+       struct hns_roce_hem_item *hem, *temp_hem;
+       struct hns_roce_hem_item *found = NULL;
 
        list_for_each_entry_safe(hem, temp_hem, ba_list, list) {
                if (hem_list_page_is_in_range(hem, page_offset)) {
@@ -1227,9 +1233,9 @@ static int hem_list_alloc_mid_bt(struct hns_roce_dev *hr_dev,
                                 int offset, struct list_head *mid_bt,
                                 struct list_head *btm_bt)
 {
-       struct roce_hem_item *hem_ptrs[HNS_ROCE_MAX_BT_LEVEL] = { NULL };
+       struct hns_roce_hem_item *hem_ptrs[HNS_ROCE_MAX_BT_LEVEL] = { NULL };
        struct list_head temp_list[HNS_ROCE_MAX_BT_LEVEL];
-       struct roce_hem_item *cur, *pre;
+       struct hns_roce_hem_item *cur, *pre;
        const int hopnum = r->hopnum;
        int start_aligned;
        int distance;
@@ -1307,56 +1313,96 @@ err_exit:
        return ret;
 }
 
-static int hem_list_alloc_root_bt(struct hns_roce_dev *hr_dev,
-                                 struct hns_roce_hem_list *hem_list, int unit,
-                                 const struct hns_roce_buf_region *regions,
-                                 int region_cnt)
+static struct hns_roce_hem_item *
+alloc_root_hem(struct hns_roce_dev *hr_dev, int unit, int *max_ba_num,
+              const struct hns_roce_buf_region *regions, int region_cnt)
 {
-       struct list_head temp_list[HNS_ROCE_MAX_BT_REGION];
-       struct roce_hem_item *hem, *temp_hem, *root_hem;
        const struct hns_roce_buf_region *r;
-       struct list_head temp_root;
-       struct list_head temp_btm;
-       void *cpu_base;
-       u64 phy_base;
-       int ret = 0;
+       struct hns_roce_hem_item *hem;
        int ba_num;
        int offset;
-       int total;
-       int step;
-       int i;
-
-       r = &regions[0];
-       root_hem = hem_list_search_item(&hem_list->root_bt, r->offset);
-       if (root_hem)
-               return 0;
 
        ba_num = hns_roce_hem_list_calc_root_ba(regions, region_cnt, unit);
        if (ba_num < 1)
-               return -ENOMEM;
+               return ERR_PTR(-ENOMEM);
 
        if (ba_num > unit)
-               return -ENOBUFS;
+               return ERR_PTR(-ENOBUFS);
 
-       ba_num = min_t(int, ba_num, unit);
-       INIT_LIST_HEAD(&temp_root);
-       offset = r->offset;
+       offset = regions[0].offset;
        /* indicate to last region */
        r = &regions[region_cnt - 1];
-       root_hem = hem_list_alloc_item(hr_dev, offset, r->offset + r->count - 1,
-                                      ba_num, true, 0);
-       if (!root_hem)
+       hem = hem_list_alloc_item(hr_dev, offset, r->offset + r->count - 1,
+                                 ba_num, true, 0);
+       if (!hem)
+               return ERR_PTR(-ENOMEM);
+
+       *max_ba_num = ba_num;
+
+       return hem;
+}
+
+static int alloc_fake_root_bt(struct hns_roce_dev *hr_dev, void *cpu_base,
+                             u64 phy_base, const struct hns_roce_buf_region *r,
+                             struct list_head *branch_head,
+                             struct list_head *leaf_head)
+{
+       struct hns_roce_hem_item *hem;
+
+       hem = hem_list_alloc_item(hr_dev, r->offset, r->offset + r->count - 1,
+                                 r->count, false, 0);
+       if (!hem)
                return -ENOMEM;
-       list_add(&root_hem->list, &temp_root);
 
-       hem_list->root_ba = root_hem->dma_addr;
+       hem_list_assign_bt(hr_dev, hem, cpu_base, phy_base);
+       list_add(&hem->list, branch_head);
+       list_add(&hem->sibling, leaf_head);
 
-       INIT_LIST_HEAD(&temp_btm);
-       for (i = 0; i < region_cnt; i++)
-               INIT_LIST_HEAD(&temp_list[i]);
+       return r->count;
+}
+
+static int setup_middle_bt(struct hns_roce_dev *hr_dev, void *cpu_base,
+                          int unit, const struct hns_roce_buf_region *r,
+                          const struct list_head *branch_head)
+{
+       struct hns_roce_hem_item *hem, *temp_hem;
+       int total = 0;
+       int offset;
+       int step;
+
+       step = hem_list_calc_ba_range(r->hopnum, 1, unit);
+       if (step < 1)
+               return -EINVAL;
+
+       /* if exist mid bt, link L1 to L0 */
+       list_for_each_entry_safe(hem, temp_hem, branch_head, list) {
+               offset = (hem->start - r->offset) / step * BA_BYTE_LEN;
+               hem_list_link_bt(hr_dev, cpu_base + offset, hem->dma_addr);
+               total++;
+       }
+
+       return total;
+}
+
+static int
+setup_root_hem(struct hns_roce_dev *hr_dev, struct hns_roce_hem_list *hem_list,
+              int unit, int max_ba_num, struct hns_roce_hem_head *head,
+              const struct hns_roce_buf_region *regions, int region_cnt)
+{
+       const struct hns_roce_buf_region *r;
+       struct hns_roce_hem_item *root_hem;
+       void *cpu_base;
+       u64 phy_base;
+       int i, total;
+       int ret;
+
+       root_hem = list_first_entry(&head->root,
+                                   struct hns_roce_hem_item, list);
+       if (!root_hem)
+               return -ENOMEM;
 
        total = 0;
-       for (i = 0; i < region_cnt && total < ba_num; i++) {
+       for (i = 0; i < region_cnt && total < max_ba_num; i++) {
                r = &regions[i];
                if (!r->count)
                        continue;
@@ -1368,48 +1414,64 @@ static int hem_list_alloc_root_bt(struct hns_roce_dev *hr_dev,
                /* if hopnum is 0 or 1, cut a new fake hem from the root bt
                 * which's address share to all regions.
                 */
-               if (hem_list_is_bottom_bt(r->hopnum, 0)) {
-                       hem = hem_list_alloc_item(hr_dev, r->offset,
-                                                 r->offset + r->count - 1,
-                                                 r->count, false, 0);
-                       if (!hem) {
-                               ret = -ENOMEM;
-                               goto err_exit;
-                       }
-                       hem_list_assign_bt(hr_dev, hem, cpu_base, phy_base);
-                       list_add(&hem->list, &temp_list[i]);
-                       list_add(&hem->sibling, &temp_btm);
-                       total += r->count;
-               } else {
-                       step = hem_list_calc_ba_range(r->hopnum, 1, unit);
-                       if (step < 1) {
-                               ret = -EINVAL;
-                               goto err_exit;
-                       }
-                       /* if exist mid bt, link L1 to L0 */
-                       list_for_each_entry_safe(hem, temp_hem,
-                                         &hem_list->mid_bt[i][1], list) {
-                               offset = (hem->start - r->offset) / step *
-                                         BA_BYTE_LEN;
-                               hem_list_link_bt(hr_dev, cpu_base + offset,
-                                                hem->dma_addr);
-                               total++;
-                       }
-               }
+               if (hem_list_is_bottom_bt(r->hopnum, 0))
+                       ret = alloc_fake_root_bt(hr_dev, cpu_base, phy_base, r,
+                                                &head->branch[i], &head->leaf);
+               else
+                       ret = setup_middle_bt(hr_dev, cpu_base, unit, r,
+                                             &hem_list->mid_bt[i][1]);
+
+               if (ret < 0)
+                       return ret;
+
+               total += ret;
        }
 
-       list_splice(&temp_btm, &hem_list->btm_bt);
-       list_splice(&temp_root, &hem_list->root_bt);
+       list_splice(&head->leaf, &hem_list->btm_bt);
+       list_splice(&head->root, &hem_list->root_bt);
        for (i = 0; i < region_cnt; i++)
-               list_splice(&temp_list[i], &hem_list->mid_bt[i][0]);
+               list_splice(&head->branch[i], &hem_list->mid_bt[i][0]);
 
        return 0;
+}
 
-err_exit:
+static int hem_list_alloc_root_bt(struct hns_roce_dev *hr_dev,
+                                 struct hns_roce_hem_list *hem_list, int unit,
+                                 const struct hns_roce_buf_region *regions,
+                                 int region_cnt)
+{
+       struct hns_roce_hem_item *root_hem;
+       struct hns_roce_hem_head head;
+       int max_ba_num;
+       int ret;
+       int i;
+
+       root_hem = hem_list_search_item(&hem_list->root_bt, regions[0].offset);
+       if (root_hem)
+               return 0;
+
+       max_ba_num = 0;
+       root_hem = alloc_root_hem(hr_dev, unit, &max_ba_num, regions,
+                                 region_cnt);
+       if (IS_ERR(root_hem))
+               return PTR_ERR(root_hem);
+
+       /* List head for storing all allocated HEM items */
+       INIT_LIST_HEAD(&head.root);
+       INIT_LIST_HEAD(&head.leaf);
        for (i = 0; i < region_cnt; i++)
-               hem_list_free_all(hr_dev, &temp_list[i], false);
+               INIT_LIST_HEAD(&head.branch[i]);
 
-       hem_list_free_all(hr_dev, &temp_root, true);
+       hem_list->root_ba = root_hem->dma_addr;
+       list_add(&root_hem->list, &head.root);
+       ret = setup_root_hem(hr_dev, hem_list, unit, max_ba_num, &head, regions,
+                            region_cnt);
+       if (ret) {
+               for (i = 0; i < region_cnt; i++)
+                       hem_list_free_all(hr_dev, &head.branch[i], false);
+
+               hem_list_free_all(hr_dev, &head.root, true);
+       }
 
        return ret;
 }
@@ -1495,7 +1557,7 @@ void *hns_roce_hem_list_find_mtt(struct hns_roce_dev *hr_dev,
                                 int offset, int *mtt_cnt, u64 *phy_addr)
 {
        struct list_head *head = &hem_list->btm_bt;
-       struct roce_hem_item *hem, *temp_hem;
+       struct hns_roce_hem_item *hem, *temp_hem;
        void *cpu_base = NULL;
        u64 phy_base = 0;
        int nr = 0;