[deliverable/linux.git] / net / sunrpc / xprtrdma / physical_ops.c

/*
 * Copyright (c) 2015 Oracle.  All rights reserved.
 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
 */

/* No-op chunk preparation. All client memory is pre-registered.
 * Sometimes referred to as ALLPHYSICAL mode.
 *
 * Physical registration is simple because all client memory is
 * pre-registered and never deregistered. This mode is good for
 * adapter bring up, but is considered not safe: the server is
 * trusted not to abuse its access to client memory not involved
 * in RDMA I/O.
 */

#include "xprt_rdma.h"

#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY	RPCDBG_TRANS
#endif

static int
physical_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
		 struct rpcrdma_create_data_internal *cdata)
{
	struct ib_mr *mr;

	/* Obtain an rkey to use for RPC data payloads.
	 */
	mr = ib_get_dma_mr(ia->ri_pd,
			   IB_ACCESS_LOCAL_WRITE |
			   IB_ACCESS_REMOTE_WRITE |
			   IB_ACCESS_REMOTE_READ);
	if (IS_ERR(mr)) {
		pr_err("%s: ib_get_dma_mr for failed with %lX\n",
		       __func__, PTR_ERR(mr));
		return -ENOMEM;
	}

	ia->ri_dma_mr = mr;
	return 0;
}

/* PHYSICAL memory registration conveys one page per chunk segment.
 */
static size_t
physical_op_maxpages(struct rpcrdma_xprt *r_xprt)
{
	return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
		     rpcrdma_max_segments(r_xprt));
}

static int
physical_op_init(struct rpcrdma_xprt *r_xprt)
{
	return 0;
}

/* The client's physical memory is already exposed for
 * remote access via RDMA READ or RDMA WRITE.
 */
static int
physical_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
		int nsegs, bool writing)
{
	struct rpcrdma_ia *ia = &r_xprt->rx_ia;

	rpcrdma_map_one(ia->ri_device, seg, rpcrdma_data_dir(writing));
	seg->mr_rkey = ia->ri_dma_mr->rkey;
	seg->mr_base = seg->mr_dma;
	seg->mr_nsegs = 1;
	return 1;
}

/* Unmap a memory region, but leave it registered.
 */
static int
physical_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
{
	struct rpcrdma_ia *ia = &r_xprt->rx_ia;

	rpcrdma_unmap_one(ia->ri_device, seg);
	return 1;
}

/* DMA unmap all memory regions that were mapped for "req".
 */
static void
physical_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
{
	struct ib_device *device = r_xprt->rx_ia.ri_device;
	unsigned int i;

	for (i = 0; req->rl_nchunks; --req->rl_nchunks)
		rpcrdma_unmap_one(device, &req->rl_segments[i++]);
}

static void
physical_op_destroy(struct rpcrdma_buffer *buf)
{
}

const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = {
	.ro_map				= physical_op_map,
	.ro_unmap_sync			= physical_op_unmap_sync,
	.ro_unmap			= physical_op_unmap,
	.ro_open			= physical_op_open,
	.ro_maxpages			= physical_op_maxpages,
	.ro_init			= physical_op_init,
	.ro_destroy			= physical_op_destroy,
	.ro_displayname			= "physical",
};
Commit	Line	Data
a0ce85f5 CL	1	/*
	2	* Copyright (c) 2015 Oracle. All rights reserved.
	3	* Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
	4	*/
	5
	6	/* No-op chunk preparation. All client memory is pre-registered.
	7	* Sometimes referred to as ALLPHYSICAL mode.
	8	*
	9	* Physical registration is simple because all client memory is
	10	* pre-registered and never deregistered. This mode is good for
	11	* adapter bring up, but is considered not safe: the server is
	12	* trusted not to abuse its access to client memory not involved
	13	* in RDMA I/O.
	14	*/
	15
	16	#include "xprt_rdma.h"
	17
	18	#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
	19	# define RPCDBG_FACILITY RPCDBG_TRANS
	20	#endif
	21
3968cb58 CL	22	static int
	23	physical_op_open(struct rpcrdma_ia ia, struct rpcrdma_ep ep,
	24	struct rpcrdma_create_data_internal *cdata)
	25	{
d1ed857e CL	26	struct ib_mr *mr;
	27
	28	/* Obtain an rkey to use for RPC data payloads.
	29	*/
	30	mr = ib_get_dma_mr(ia->ri_pd,
	31	IB_ACCESS_LOCAL_WRITE \|
	32	IB_ACCESS_REMOTE_WRITE \|
	33	IB_ACCESS_REMOTE_READ);
	34	if (IS_ERR(mr)) {
	35	pr_err("%s: ib_get_dma_mr for failed with %lX\n",
	36	__func__, PTR_ERR(mr));
	37	return -ENOMEM;
	38	}
d1ed857e	39
bb6c96d7	40	ia->ri_dma_mr = mr;
3968cb58 CL	41	return 0;
	42	}
	43
1c9351ee CL	44	/* PHYSICAL memory registration conveys one page per chunk segment.
	45	*/
	46	static size_t
	47	physical_op_maxpages(struct rpcrdma_xprt *r_xprt)
	48	{
	49	return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
	50	rpcrdma_max_segments(r_xprt));
	51	}
	52
91e70e70 CL	53	static int
	54	physical_op_init(struct rpcrdma_xprt *r_xprt)
	55	{
	56	return 0;
	57	}
	58
9c1b4d77 CL	59	/* The client's physical memory is already exposed for
	60	* remote access via RDMA READ or RDMA WRITE.
	61	*/
	62	static int
	63	physical_op_map(struct rpcrdma_xprt r_xprt, struct rpcrdma_mr_seg seg,
	64	int nsegs, bool writing)
	65	{
	66	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
	67
89e0d112	68	rpcrdma_map_one(ia->ri_device, seg, rpcrdma_data_dir(writing));
d1ed857e	69	seg->mr_rkey = ia->ri_dma_mr->rkey;
9c1b4d77 CL	70	seg->mr_base = seg->mr_dma;
	71	seg->mr_nsegs = 1;
	72	return 1;
	73	}
	74
6814baea CL	75	/* Unmap a memory region, but leave it registered.
	76	*/
	77	static int
	78	physical_op_unmap(struct rpcrdma_xprt r_xprt, struct rpcrdma_mr_seg seg)
	79	{
d654788e CL	80	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
d654788e CL	81
89e0d112	82	rpcrdma_unmap_one(ia->ri_device, seg);
6814baea CL	83	return 1;
	84	}
	85
73eee9b2 CL	86	/* DMA unmap all memory regions that were mapped for "req".
	87	*/
	88	static void
	89	physical_op_unmap_sync(struct rpcrdma_xprt r_xprt, struct rpcrdma_req req)
	90	{
	91	struct ib_device *device = r_xprt->rx_ia.ri_device;
	92	unsigned int i;
	93
	94	for (i = 0; req->rl_nchunks; --req->rl_nchunks)
	95	rpcrdma_unmap_one(device, &req->rl_segments[i++]);
	96	}
	97
4561f347 CL	98	static void
	99	physical_op_destroy(struct rpcrdma_buffer *buf)
	100	{
	101	}
	102
a0ce85f5	103	const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = {
9c1b4d77	104	.ro_map = physical_op_map,
73eee9b2	105	.ro_unmap_sync = physical_op_unmap_sync,
6814baea	106	.ro_unmap = physical_op_unmap,
3968cb58	107	.ro_open = physical_op_open,
1c9351ee	108	.ro_maxpages = physical_op_maxpages,
91e70e70	109	.ro_init = physical_op_init,
4561f347	110	.ro_destroy = physical_op_destroy,
a0ce85f5 CL	111	.ro_displayname = "physical",
a0ce85f5 CL	112	};