RDMA/hns: Simplify 'struct hns_roce_hem' allocation

'struct hns_roce_hem' is used to refer to the last level of
dma buffer managed by the hw, pointed by a single BA(base
address) in the previous level of BT(base table), so the dma
buffer in 'struct hns_roce_hem' must be contiguous.

Right now the size of dma buffer in 'struct hns_roce_hem' is
decided by mhop->buf_chunk_size in get_hem_table_config(),
which ensure the mhop->buf_chunk_size is power of two of
PAGE_SIZE, so there will be only one contiguous dma buffer
allocated in hns_roce_alloc_hem(), which means hem->chunk_list
and chunk->mem for linking multi dma buffers is unnecessary.

This patch removes the hem->chunk_list and chunk->mem and other
related macro and function accordingly.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20240113085935.2838701-7-huangjunxian6@hisilicon.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

diff --git a/drivers/infiniband/hw/hns/hns_roce_hem.c b/drivers/infiniband/hw/hns/hns_roce_hem.c
index c4ac06a..a4b3f19 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_hem.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hem.c
@@ -249,61 +249,34 @@ int hns_roce_calc_hem_mhop(struct hns_roce_dev *hr_dev,
 }
 
 static struct hns_roce_hem *hns_roce_alloc_hem(struct hns_roce_dev *hr_dev,
-                                              int npages,
                                               unsigned long hem_alloc_size,
                                               gfp_t gfp_mask)
 {
-       struct hns_roce_hem_chunk *chunk = NULL;
        struct hns_roce_hem *hem;
-       struct scatterlist *mem;
        int order;
        void *buf;
 
        WARN_ON(gfp_mask & __GFP_HIGHMEM);
 
+       order = get_order(hem_alloc_size);
+       if (PAGE_SIZE << order != hem_alloc_size) {
+               dev_err(hr_dev->dev, "invalid hem_alloc_size: %lu!\n",
+                       hem_alloc_size);
+               return NULL;
+       }
+
        hem = kmalloc(sizeof(*hem),
                      gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
        if (!hem)
                return NULL;
 
-       INIT_LIST_HEAD(&hem->chunk_list);
-
-       order = get_order(hem_alloc_size);
-
-       while (npages > 0) {
-               if (!chunk) {
-                       chunk = kmalloc(sizeof(*chunk),
-                               gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
-                       if (!chunk)
-                               goto fail;
-
-                       sg_init_table(chunk->mem, HNS_ROCE_HEM_CHUNK_LEN);
-                       chunk->npages = 0;
-                       chunk->nsg = 0;
-                       memset(chunk->buf, 0, sizeof(chunk->buf));
-                       list_add_tail(&chunk->list, &hem->chunk_list);
-               }
+       buf = dma_alloc_coherent(hr_dev->dev, hem_alloc_size,
+                                &hem->dma, gfp_mask);
+       if (!buf)
+               goto fail;
 
-               while (1 << order > npages)
-                       --order;
-
-               /*
-                * Alloc memory one time. If failed, don't alloc small block
-                * memory, directly return fail.
-                */
-               mem = &chunk->mem[chunk->npages];
-               buf = dma_alloc_coherent(hr_dev->dev, PAGE_SIZE << order,
-                               &sg_dma_address(mem), gfp_mask);
-               if (!buf)
-                       goto fail;
-
-               chunk->buf[chunk->npages] = buf;
-               sg_dma_len(mem) = PAGE_SIZE << order;
-
-               ++chunk->npages;
-               ++chunk->nsg;
-               npages -= 1 << order;
-       }
+       hem->buf = buf;
+       hem->size = hem_alloc_size;
 
        return hem;
 
@@ -314,20 +287,10 @@ fail:
 
 void hns_roce_free_hem(struct hns_roce_dev *hr_dev, struct hns_roce_hem *hem)
 {
-       struct hns_roce_hem_chunk *chunk, *tmp;
-       int i;
-
        if (!hem)
                return;
 
-       list_for_each_entry_safe(chunk, tmp, &hem->chunk_list, list) {
-               for (i = 0; i < chunk->npages; ++i)
-                       dma_free_coherent(hr_dev->dev,
-                                  sg_dma_len(&chunk->mem[i]),
-                                  chunk->buf[i],
-                                  sg_dma_address(&chunk->mem[i]));
-               kfree(chunk);
-       }
+       dma_free_coherent(hr_dev->dev, hem->size, hem->buf, hem->dma);
 
        kfree(hem);
 }
@@ -415,7 +378,6 @@ static int alloc_mhop_hem(struct hns_roce_dev *hr_dev,
 {
        u32 bt_size = mhop->bt_chunk_size;
        struct device *dev = hr_dev->dev;
-       struct hns_roce_hem_iter iter;
        gfp_t flag;
        u64 bt_ba;
        u32 size;
@@ -456,16 +418,15 @@ static int alloc_mhop_hem(struct hns_roce_dev *hr_dev,
         */
        size = table->type < HEM_TYPE_MTT ? mhop->buf_chunk_size : bt_size;
        flag = GFP_KERNEL | __GFP_NOWARN;
-       table->hem[index->buf] = hns_roce_alloc_hem(hr_dev, size >> PAGE_SHIFT,
-                                                   size, flag);
+       table->hem[index->buf] = hns_roce_alloc_hem(hr_dev, size, flag);
        if (!table->hem[index->buf]) {
                ret = -ENOMEM;
                goto err_alloc_hem;
        }
 
        index->inited |= HEM_INDEX_BUF;
-       hns_roce_hem_first(table->hem[index->buf], &iter);
-       bt_ba = hns_roce_hem_addr(&iter);
+       bt_ba = table->hem[index->buf]->dma;
+
        if (table->type < HEM_TYPE_MTT) {
                if (mhop->hop_num == 2)
                        *(table->bt_l1[index->l1] + mhop->l2_idx) = bt_ba;
@@ -586,7 +547,6 @@ int hns_roce_table_get(struct hns_roce_dev *hr_dev,
        }
 
        table->hem[i] = hns_roce_alloc_hem(hr_dev,
-                                      table->table_chunk_size >> PAGE_SHIFT,
                                       table->table_chunk_size,
                                       GFP_KERNEL | __GFP_NOWARN);
        if (!table->hem[i]) {
@@ -725,7 +685,6 @@ void *hns_roce_table_find(struct hns_roce_dev *hr_dev,
                          struct hns_roce_hem_table *table,
                          unsigned long obj, dma_addr_t *dma_handle)
 {
-       struct hns_roce_hem_chunk *chunk;
        struct hns_roce_hem_mhop mhop;
        struct hns_roce_hem *hem;
        unsigned long mhop_obj = obj;
@@ -734,7 +693,6 @@ void *hns_roce_table_find(struct hns_roce_dev *hr_dev,
        int offset, dma_offset;
        void *addr = NULL;
        u32 hem_idx = 0;
-       int length;
        int i, j;
 
        mutex_lock(&table->mutex);
@@ -767,23 +725,8 @@ void *hns_roce_table_find(struct hns_roce_dev *hr_dev,
        if (!hem)
                goto out;
 
-       list_for_each_entry(chunk, &hem->chunk_list, list) {
-               for (i = 0; i < chunk->npages; ++i) {
-                       length = sg_dma_len(&chunk->mem[i]);
-                       if (dma_handle && dma_offset >= 0) {
-                               if (length > (u32)dma_offset)
-                                       *dma_handle = sg_dma_address(
-                                               &chunk->mem[i]) + dma_offset;
-                               dma_offset -= length;
-                       }
-
-                       if (length > (u32)offset) {
-                               addr = chunk->buf[i] + offset;
-                               goto out;
-                       }
-                       offset -= length;
-               }
-       }
+       *dma_handle = hem->dma + dma_offset;
+       addr = hem->buf + offset;
 
 out:
        mutex_unlock(&table->mutex);

diff --git a/drivers/infiniband/hw/hns/hns_roce_hem.h b/drivers/infiniband/hw/hns/hns_roce_hem.h
index 7d23d3c..6fb51db 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_hem.h
+++ b/drivers/infiniband/hw/hns/hns_roce_hem.h
@@ -56,10 +56,6 @@ enum {
        HEM_TYPE_TRRL,
 };
 
-#define HNS_ROCE_HEM_CHUNK_LEN \
-        ((256 - sizeof(struct list_head) - 2 * sizeof(int)) /   \
-        (sizeof(struct scatterlist) + sizeof(void *)))
-
 #define check_whether_bt_num_3(type, hop_num) \
        (type < HEM_TYPE_MTT && hop_num == 2)
 
@@ -72,25 +68,13 @@ enum {
        (type >= HEM_TYPE_MTT && hop_num == 1) || \
        (type >= HEM_TYPE_MTT && hop_num == HNS_ROCE_HOP_NUM_0))
 
-struct hns_roce_hem_chunk {
-       struct list_head         list;
-       int                      npages;
-       int                      nsg;
-       struct scatterlist       mem[HNS_ROCE_HEM_CHUNK_LEN];
-       void                     *buf[HNS_ROCE_HEM_CHUNK_LEN];
-};
-
 struct hns_roce_hem {
-       struct list_head chunk_list;
+       void *buf;
+       dma_addr_t dma;
+       unsigned long size;
        refcount_t refcount;
 };
 
-struct hns_roce_hem_iter {
-       struct hns_roce_hem              *hem;
-       struct hns_roce_hem_chunk        *chunk;
-       int                              page_idx;
-};
-
 struct hns_roce_hem_mhop {
        u32     hop_num;
        u32     buf_chunk_size;
@@ -133,38 +117,4 @@ void *hns_roce_hem_list_find_mtt(struct hns_roce_dev *hr_dev,
                                 struct hns_roce_hem_list *hem_list,
                                 int offset, int *mtt_cnt);
 
-static inline void hns_roce_hem_first(struct hns_roce_hem *hem,
-                                     struct hns_roce_hem_iter *iter)
-{
-       iter->hem = hem;
-       iter->chunk = list_empty(&hem->chunk_list) ? NULL :
-                                list_entry(hem->chunk_list.next,
-                                           struct hns_roce_hem_chunk, list);
-       iter->page_idx = 0;
-}
-
-static inline int hns_roce_hem_last(struct hns_roce_hem_iter *iter)
-{
-       return !iter->chunk;
-}
-
-static inline void hns_roce_hem_next(struct hns_roce_hem_iter *iter)
-{
-       if (++iter->page_idx >= iter->chunk->nsg) {
-               if (iter->chunk->list.next == &iter->hem->chunk_list) {
-                       iter->chunk = NULL;
-                       return;
-               }
-
-               iter->chunk = list_entry(iter->chunk->list.next,
-                                        struct hns_roce_hem_chunk, list);
-               iter->page_idx = 0;
-       }
-}
-
-static inline dma_addr_t hns_roce_hem_addr(struct hns_roce_hem_iter *iter)
-{
-       return sg_dma_address(&iter->chunk->mem[iter->page_idx]);
-}
-
 #endif /* _HNS_ROCE_HEM_H */

diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
index 94e9e6a..de56dc6 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
@@ -4058,7 +4058,6 @@ static int hns_roce_v2_set_hem(struct hns_roce_dev *hr_dev,
                               struct hns_roce_hem_table *table, int obj,
                               u32 step_idx)
 {
-       struct hns_roce_hem_iter iter;
        struct hns_roce_hem_mhop mhop;
        struct hns_roce_hem *hem;
        unsigned long mhop_obj = obj;
@@ -4095,12 +4094,8 @@ static int hns_roce_v2_set_hem(struct hns_roce_dev *hr_dev,
 
        if (check_whether_last_step(hop_num, step_idx)) {
                hem = table->hem[hem_idx];
-               for (hns_roce_hem_first(hem, &iter);
-                    !hns_roce_hem_last(&iter); hns_roce_hem_next(&iter)) {
-                       bt_ba = hns_roce_hem_addr(&iter);
-                       ret = set_hem_to_hw(hr_dev, obj, bt_ba, table->type,
-                                           step_idx);
-               }
+
+               ret = set_hem_to_hw(hr_dev, obj, hem->dma, table->type, step_idx);
        } else {
                if (step_idx == 0)
                        bt_ba = table->bt_l0_dma_addr[i];