IB: Refactor umem to use linear SG table

This patch refactors the IB core umem code and vendor drivers to use a
linear (chained) SG table instead of chunk list.  With this change the
relevant code becomes clearer—no need for nested loops to build and
use umem.

Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 40 insertions, 40 deletions

diff --git a/drivers/infiniband/hw/mlx5/mem.c b/drivers/infiniband/hw/mlx5/mem.c
index 3a5322870b96..8499aec94db6 100644
--- a/drivers/infiniband/hw/mlx5/mem.c
+++ b/drivers/infiniband/hw/mlx5/mem.c
@@ -44,16 +44,17 @@
 void mlx5_ib_cont_pages(struct ib_umem *umem, u64 addr, int *count, int *shift,
                         int *ncont, int *order)
 {
-        struct ib_umem_chunk *chunk;
         unsigned long tmp;
         unsigned long m;
-        int i, j, k;
+        int i, k;
         u64 base = 0;
         int p = 0;
         int skip;
         int mask;
         u64 len;
         u64 pfn;
+        struct scatterlist *sg;
+        int entry;
 
         addr = addr >> PAGE_SHIFT;
         tmp = (unsigned long)addr;
@@ -61,32 +62,31 @@ void mlx5_ib_cont_pages(struct ib_umem *umem, u64 addr, int *count, int *shift,
         skip = 1 << m;
         mask = skip - 1;
         i = 0;
-        list_for_each_entry(chunk, &umem->chunk_list, list)
-                for (j = 0; j < chunk->nmap; j++) {
-                        len = sg_dma_len(&chunk->page_list[j]) >> PAGE_SHIFT;
-                        pfn = sg_dma_address(&chunk->page_list[j]) >> PAGE_SHIFT;
-                        for (k = 0; k < len; k++) {
-                                if (!(i & mask)) {
-                                        tmp = (unsigned long)pfn;
-                                        m = min(m, find_first_bit(&tmp, sizeof(tmp)));
+        for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
+                len = sg_dma_len(sg) >> PAGE_SHIFT;
+                pfn = sg_dma_address(sg) >> PAGE_SHIFT;
+                for (k = 0; k < len; k++) {
+                        if (!(i & mask)) {
+                                tmp = (unsigned long)pfn;
+                                m = min(m, find_first_bit(&tmp, sizeof(tmp)));
+                                skip = 1 << m;
+                                mask = skip - 1;
+                                base = pfn;
+                                p = 0;
+                        } else {
+                                if (base + p != pfn) {
+                                        tmp = (unsigned long)p;
+                                        m = find_first_bit(&tmp, sizeof(tmp));
                                         skip = 1 << m;
                                         mask = skip - 1;
                                         base = pfn;
                                         p = 0;
-                                } else {
-                                        if (base + p != pfn) {
-                                                tmp = (unsigned long)p;
-                                                m = find_first_bit(&tmp, sizeof(tmp));
-                                                skip = 1 << m;
-                                                mask = skip - 1;
-                                                base = pfn;
-                                                p = 0;
-                                        }
                                 }
-                                p++;
-                                i++;
                         }
+                        p++;
+                        i++;
                 }
+        }
 
         if (i) {
                 m = min_t(unsigned long, ilog2(roundup_pow_of_two(i)), m);
@@ -112,32 +112,32 @@ void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
 {
         int shift = page_shift - PAGE_SHIFT;
         int mask = (1 << shift) - 1;
-        struct ib_umem_chunk *chunk;
-        int i, j, k;
+        int i, k;
         u64 cur = 0;
         u64 base;
         int len;
+        struct scatterlist *sg;
+        int entry;
 
         i = 0;
-        list_for_each_entry(chunk, &umem->chunk_list, list)
-                for (j = 0; j < chunk->nmap; j++) {
-                        len = sg_dma_len(&chunk->page_list[j]) >> PAGE_SHIFT;
-                        base = sg_dma_address(&chunk->page_list[j]);
-                        for (k = 0; k < len; k++) {
-                                if (!(i & mask)) {
-                                        cur = base + (k << PAGE_SHIFT);
-                                        if (umr)
-                                                cur |= 3;
+        for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
+                len = sg_dma_len(sg) >> PAGE_SHIFT;
+                base = sg_dma_address(sg);
+                for (k = 0; k < len; k++) {
+                        if (!(i & mask)) {
+                                cur = base + (k << PAGE_SHIFT);
+                                if (umr)
+                                        cur |= 3;
 
-                                        pas[i >> shift] = cpu_to_be64(cur);
-                                        mlx5_ib_dbg(dev, "pas[%d] 0x%llx\n",
-                                                    i >> shift, be64_to_cpu(pas[i >> shift]));
-                                }  else
-                                        mlx5_ib_dbg(dev, "=====> 0x%llx\n",
-                                                    base + (k << PAGE_SHIFT));
-                                i++;
-                        }
+                                pas[i >> shift] = cpu_to_be64(cur);
+                                mlx5_ib_dbg(dev, "pas[%d] 0x%llx\n",
+                                            i >> shift, be64_to_cpu(pas[i >> shift]));
+                        }  else
+                                mlx5_ib_dbg(dev, "=====> 0x%llx\n",
+                                            base + (k << PAGE_SHIFT));
+                        i++;
                 }
+        }
 }
 
 int mlx5_ib_get_buf_offset(u64 addr, int page_shift, u32 *offset)