mlx5_core: Fix PowerPC support

1. Fix derivation of sub-page index from the dma address in free_4k.
2. Fix the DMA address passed to dma_unmap_page by masking it properly.
Signed-off-by: NEli Cohen <eli@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c

@@ -99,7 +99,7 @@ enum {
 
 enum {
 	MLX5_MAX_RECLAIM_TIME_MILI	= 5000,
-	MLX5_NUM_4K_IN_PAGE		= PAGE_SIZE / 4096,
+	MLX5_NUM_4K_IN_PAGE		= PAGE_SIZE / MLX5_ADAPTER_PAGE_SIZE,
 };
 
 static int insert_page(struct mlx5_core_dev *dev, u64 addr, struct page *page, u16 func_id)
@@ -206,7 +206,7 @@ static int alloc_4k(struct mlx5_core_dev *dev, u64 *addr)
 	if (!fp->free_count)
 		list_del(&fp->list);
 
-	*addr = fp->addr + n * 4096;
+	*addr = fp->addr + n * MLX5_ADAPTER_PAGE_SIZE;
 
 	return 0;
 }
@@ -222,14 +222,15 @@ static void free_4k(struct mlx5_core_dev *dev, u64 addr)
 		return;
 	}
 
-	n = (addr & ~PAGE_MASK) % 4096;
+	n = (addr & ~PAGE_MASK) >> MLX5_ADAPTER_PAGE_SHIFT;
 	fwp->free_count++;
 	set_bit(n, &fwp->bitmask);
 	if (fwp->free_count == MLX5_NUM_4K_IN_PAGE) {
 		rb_erase(&fwp->rb_node, &dev->priv.page_root);
 		if (fwp->free_count != 1)
 			list_del(&fwp->list);
-		dma_unmap_page(&dev->pdev->dev, addr, PAGE_SIZE, DMA_BIDIRECTIONAL);
+		dma_unmap_page(&dev->pdev->dev, addr & PAGE_MASK, PAGE_SIZE,
+			       DMA_BIDIRECTIONAL);
 		__free_page(fwp->page);
 		kfree(fwp);
 	} else if (fwp->free_count == 1) {

include/linux/mlx5/device.h

@@ -234,7 +234,8 @@ enum {
 };
 
 enum {
-	MLX5_ADAPTER_PAGE_SHIFT		= 12
+	MLX5_ADAPTER_PAGE_SHIFT		= 12,
+	MLX5_ADAPTER_PAGE_SIZE		= 1 << MLX5_ADAPTER_PAGE_SHIFT,
 };
 
 enum {