Commit 313abe55 authored by Jack Morgenstein's avatar Jack Morgenstein Committed by Roland Dreier
Browse files

mlx4_core: For 64-bit systems, vmap() kernel queue buffers 



Since kernel virtual memory is not a problem on 64-bit systems, there
is no reason to use our own 2-layer page mapping scheme for large
kernel queue buffers on such systems.  Instead, map the page list to a
single virtually contiguous buffer with vmap(), so that can we access
buffer memory via direct indexing.

Signed-off-by: default avatarMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: default avatarJack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 1c69fc2a

drivers/net/mlx4/alloc.c

+16 −0
Original line number Diff line number Diff line
@@ -151,6 +151,19 @@ int mlx4_buf_alloc(struct mlx4_dev *dev, int size, int max_direct, 


			memset(buf->u.page_list[i].buf, 0, PAGE_SIZE);

		}



		if (BITS_PER_LONG == 64) {

			struct page **pages;

			pages = kmalloc(sizeof *pages * buf->nbufs, GFP_KERNEL);

			if (!pages)

				goto err_free;

			for (i = 0; i < buf->nbufs; ++i)

				pages[i] = virt_to_page(buf->u.page_list[i].buf);

			buf->u.direct.buf = vmap(pages, buf->nbufs, VM_MAP, PAGE_KERNEL);

			kfree(pages);

			if (!buf->u.direct.buf)

				goto err_free;

		}

	}



	return 0;
@@ -170,6 +183,9 @@ void mlx4_buf_free(struct mlx4_dev *dev, int size, struct mlx4_buf *buf) 
		dma_free_coherent(&dev->pdev->dev, size, buf->u.direct.buf,

				  buf->u.direct.map);

	else {

		if (BITS_PER_LONG == 64)

			vunmap(buf->u.direct.buf);



		for (i = 0; i < buf->nbufs; ++i)

			if (buf->u.page_list[i].buf)

				dma_free_coherent(&dev->pdev->dev, PAGE_SIZE,

include/linux/mlx4/device.h

+2 −2
Original line number Diff line number Diff line
@@ -189,7 +189,7 @@ struct mlx4_buf_list { 
};



struct mlx4_buf {

	union {

	struct {

		struct mlx4_buf_list	direct;

		struct mlx4_buf_list   *page_list;

	} u;
@@ -310,7 +310,7 @@ int mlx4_buf_alloc(struct mlx4_dev *dev, int size, int max_direct, 
void mlx4_buf_free(struct mlx4_dev *dev, int size, struct mlx4_buf *buf);

static inline void *mlx4_buf_offset(struct mlx4_buf *buf, int offset)

{

	if (buf->nbufs == 1)

	if (BITS_PER_LONG == 64 || buf->nbufs == 1)

		return buf->u.direct.buf + offset;

	else

		return buf->u.page_list[offset >> PAGE_SHIFT].buf +

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