drivers/infiniband/hw/mthca/mthca_mr.c - pub/scm/linux/kernel/git/daveh/linux - Git at Google

 /*
  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
  * General Public License (GPL) Version 2, available from the file
  * COPYING in the main directory of this source tree, or the
  * OpenIB.org BSD license below:
  *
  *     Redistribution and use in source and binary forms, with or
  *     without modification, are permitted provided that the following
  *     conditions are met:
  *
  *      - Redistributions of source code must retain the above
  *        copyright notice, this list of conditions and the following
  *        disclaimer.
  *
  *      - Redistributions in binary form must reproduce the above
  *        copyright notice, this list of conditions and the following
  *        disclaimer in the documentation and/or other materials
  *        provided with the distribution.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *
  * $Id: mthca_mr.c 1349 2004-12-16 21:09:43Z roland $
  */

 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/errno.h>

 #include "mthca_dev.h"
 #include "mthca_cmd.h"

 /*
  * Must be packed because mtt_seg is 64 bits but only aligned to 32 bits.
  */
 struct mthca_mpt_entry {
 	u32 flags;
 	u32 page_size;
 	u32 key;
 	u32 pd;
 	u64 start;
 	u64 length;
 	u32 lkey;
 	u32 window_count;
 	u32 window_count_limit;
 	u64 mtt_seg;
 	u32 mtt_sz;		/* Arbel only */
 	u32 reserved[2];
 } __attribute__((packed));

 #define MTHCA_MPT_FLAG_SW_OWNS       (0xfUL << 28)
 #define MTHCA_MPT_FLAG_MIO           (1 << 17)
 #define MTHCA_MPT_FLAG_BIND_ENABLE   (1 << 15)
 #define MTHCA_MPT_FLAG_PHYSICAL      (1 <<  9)
 #define MTHCA_MPT_FLAG_REGION        (1 <<  8)

 #define MTHCA_MTT_FLAG_PRESENT       1

 /*
  * Buddy allocator for MTT segments (currently not very efficient
  * since it doesn't keep a free list and just searches linearly
  * through the bitmaps)
  */

 static u32 mthca_alloc_mtt(struct mthca_dev *dev, int order)
 {
 	int o;
 	int m;
 	u32 seg;

 	spin_lock(&dev->mr_table.mpt_alloc.lock);

 	for (o = order; o <= dev->mr_table.max_mtt_order; ++o) {
 		m = 1 << (dev->mr_table.max_mtt_order - o);
 		seg = find_first_bit(dev->mr_table.mtt_buddy[o], m);
 		if (seg < m)
 			goto found;
 	}

 	spin_unlock(&dev->mr_table.mpt_alloc.lock);
 	return -1;

  found:
 	clear_bit(seg, dev->mr_table.mtt_buddy[o]);

 	while (o > order) {
 		--o;
 		seg <<= 1;
 		set_bit(seg ^ 1, dev->mr_table.mtt_buddy[o]);
 	}

 	spin_unlock(&dev->mr_table.mpt_alloc.lock);

 	seg <<= order;

 	return seg;
 }

 static void mthca_free_mtt(struct mthca_dev *dev, u32 seg, int order)
 {
 	seg >>= order;

 	spin_lock(&dev->mr_table.mpt_alloc.lock);

 	while (test_bit(seg ^ 1, dev->mr_table.mtt_buddy[order])) {
 		clear_bit(seg ^ 1, dev->mr_table.mtt_buddy[order]);
 		seg >>= 1;
 		++order;
 	}

 	set_bit(seg, dev->mr_table.mtt_buddy[order]);

 	spin_unlock(&dev->mr_table.mpt_alloc.lock);
 }

 static inline u32 hw_index_to_key(struct mthca_dev *dev, u32 ind)
 {
 	if (dev->hca_type == ARBEL_NATIVE)
 		return (ind >> 24) | (ind << 8);
 	else
 		return ind;
 }

 static inline u32 key_to_hw_index(struct mthca_dev *dev, u32 key)
 {
 	if (dev->hca_type == ARBEL_NATIVE)
 		return (key << 24) | (key >> 8);
 	else
 		return key;
 }

 int mthca_mr_alloc_notrans(struct mthca_dev *dev, u32 pd,
 			   u32 access, struct mthca_mr *mr)
 {
 	void *mailbox;
 	struct mthca_mpt_entry *mpt_entry;
 	u32 key;
 	int err;
 	u8 status;

 	might_sleep();

 	mr->order = -1;
 	key = mthca_alloc(&dev->mr_table.mpt_alloc);
 	if (key == -1)
 		return -ENOMEM;
 	mr->ibmr.rkey = mr->ibmr.lkey = hw_index_to_key(dev, key);

 	mailbox = kmalloc(sizeof *mpt_entry + MTHCA_CMD_MAILBOX_EXTRA,
 			  GFP_KERNEL);
 	if (!mailbox) {
 		mthca_free(&dev->mr_table.mpt_alloc, mr->ibmr.lkey);
 		return -ENOMEM;
 	}
 	mpt_entry = MAILBOX_ALIGN(mailbox);

 	mpt_entry->flags = cpu_to_be32(MTHCA_MPT_FLAG_SW_OWNS     |
 				       MTHCA_MPT_FLAG_MIO         |
 				       MTHCA_MPT_FLAG_PHYSICAL    |
 				       MTHCA_MPT_FLAG_REGION      |
 				       access);
 	mpt_entry->page_size = 0;
 	mpt_entry->key       = cpu_to_be32(key);
 	mpt_entry->pd        = cpu_to_be32(pd);
 	mpt_entry->start     = 0;
 	mpt_entry->length    = ~0ULL;

 	memset(&mpt_entry->lkey, 0,
 	       sizeof *mpt_entry - offsetof(struct mthca_mpt_entry, lkey));

 	err = mthca_SW2HW_MPT(dev, mpt_entry,
 			      key & (dev->limits.num_mpts - 1),
 			      &status);
 	if (err)
 		mthca_warn(dev, "SW2HW_MPT failed (%d)\n", err);
 	else if (status) {
 		mthca_warn(dev, "SW2HW_MPT returned status 0x%02x\n",
 			   status);
 		err = -EINVAL;
 	}

 	kfree(mailbox);
 	return err;
 }

 int mthca_mr_alloc_phys(struct mthca_dev *dev, u32 pd,
 			u64 *buffer_list, int buffer_size_shift,
 			int list_len, u64 iova, u64 total_size,
 			u32 access, struct mthca_mr *mr)
 {
 	void *mailbox;
 	u64 *mtt_entry;
 	struct mthca_mpt_entry *mpt_entry;
 	u32 key;
 	int err = -ENOMEM;
 	u8 status;
 	int i;

 	might_sleep();
 	WARN_ON(buffer_size_shift >= 32);

 	key = mthca_alloc(&dev->mr_table.mpt_alloc);
 	if (key == -1)
 		return -ENOMEM;
 	mr->ibmr.rkey = mr->ibmr.lkey = hw_index_to_key(dev, key);

 	for (i = dev->limits.mtt_seg_size / 8, mr->order = 0;
 	     i < list_len;
 	     i <<= 1, ++mr->order)
 		; /* nothing */

 	mr->first_seg = mthca_alloc_mtt(dev, mr->order);
 	if (mr->first_seg == -1)
 		goto err_out_mpt_free;

 	/*
 	 * If list_len is odd, we add one more dummy entry for
 	 * firmware efficiency.
 	 */
 	mailbox = kmalloc(max(sizeof *mpt_entry,
 			      (size_t) 8 * (list_len + (list_len & 1) + 2)) +
 			  MTHCA_CMD_MAILBOX_EXTRA,
 			  GFP_KERNEL);
 	if (!mailbox)
 		goto err_out_free_mtt;

 	mtt_entry = MAILBOX_ALIGN(mailbox);

 	mtt_entry[0] = cpu_to_be64(dev->mr_table.mtt_base +
 				   mr->first_seg * dev->limits.mtt_seg_size);
 	mtt_entry[1] = 0;
 	for (i = 0; i < list_len; ++i)
 		mtt_entry[i + 2] = cpu_to_be64(buffer_list[i] |
 					       MTHCA_MTT_FLAG_PRESENT);
 	if (list_len & 1) {
 		mtt_entry[i + 2] = 0;
 		++list_len;
 	}

 	if (0) {
 		mthca_dbg(dev, "Dumping MPT entry\n");
 		for (i = 0; i < list_len + 2; ++i)
 			printk(KERN_ERR "[%2d] %016llx\n",
 			       i, (unsigned long long) be64_to_cpu(mtt_entry[i]));
 	}

 	err = mthca_WRITE_MTT(dev, mtt_entry, list_len, &status);
 	if (err) {
 		mthca_warn(dev, "WRITE_MTT failed (%d)\n", err);
 		goto err_out_mailbox_free;
 	}
 	if (status) {
 		mthca_warn(dev, "WRITE_MTT returned status 0x%02x\n",
 			   status);
 		err = -EINVAL;
 		goto err_out_mailbox_free;
 	}

 	mpt_entry = MAILBOX_ALIGN(mailbox);

 	mpt_entry->flags = cpu_to_be32(MTHCA_MPT_FLAG_SW_OWNS     |
 				       MTHCA_MPT_FLAG_MIO         |
 				       MTHCA_MPT_FLAG_REGION      |
 				       access);

 	mpt_entry->page_size = cpu_to_be32(buffer_size_shift - 12);
 	mpt_entry->key       = cpu_to_be32(key);
 	mpt_entry->pd        = cpu_to_be32(pd);
 	mpt_entry->start     = cpu_to_be64(iova);
 	mpt_entry->length    = cpu_to_be64(total_size);
 	memset(&mpt_entry->lkey, 0,
 	       sizeof *mpt_entry - offsetof(struct mthca_mpt_entry, lkey));
 	mpt_entry->mtt_seg   = cpu_to_be64(dev->mr_table.mtt_base +
 					   mr->first_seg * dev->limits.mtt_seg_size);

 	if (0) {
 		mthca_dbg(dev, "Dumping MPT entry %08x:\n", mr->ibmr.lkey);
 		for (i = 0; i < sizeof (struct mthca_mpt_entry) / 4; ++i) {
 			if (i % 4 == 0)
 				printk("[%02x] ", i * 4);
 			printk(" %08x", be32_to_cpu(((u32 *) mpt_entry)[i]));
 			if ((i + 1) % 4 == 0)
 				printk("\n");
 		}
 	}

 	err = mthca_SW2HW_MPT(dev, mpt_entry,
 			      key & (dev->limits.num_mpts - 1),
 			      &status);
 	if (err)
 		mthca_warn(dev, "SW2HW_MPT failed (%d)\n", err);
 	else if (status) {
 		mthca_warn(dev, "SW2HW_MPT returned status 0x%02x\n",
 			   status);
 		err = -EINVAL;
 	}

 	kfree(mailbox);
 	return err;

  err_out_mailbox_free:
 	kfree(mailbox);

  err_out_free_mtt:
 	mthca_free_mtt(dev, mr->first_seg, mr->order);

  err_out_mpt_free:
 	mthca_free(&dev->mr_table.mpt_alloc, mr->ibmr.lkey);
 	return err;
 }

 void mthca_free_mr(struct mthca_dev *dev, struct mthca_mr *mr)
 {
 	int err;
 	u8 status;

 	might_sleep();

 	err = mthca_HW2SW_MPT(dev, NULL,
 			      key_to_hw_index(dev, mr->ibmr.lkey) &
 			      (dev->limits.num_mpts - 1),
 			      &status);
 	if (err)
 		mthca_warn(dev, "HW2SW_MPT failed (%d)\n", err);
 	else if (status)
 		mthca_warn(dev, "HW2SW_MPT returned status 0x%02x\n",
 			   status);

 	if (mr->order >= 0)
 		mthca_free_mtt(dev, mr->first_seg, mr->order);

 	mthca_free(&dev->mr_table.mpt_alloc, key_to_hw_index(dev, mr->ibmr.lkey));
 }

 int __devinit mthca_init_mr_table(struct mthca_dev *dev)
 {
 	int err;
 	int i, s;

 	err = mthca_alloc_init(&dev->mr_table.mpt_alloc,
 			       dev->limits.num_mpts,
 			       ~0, dev->limits.reserved_mrws);
 	if (err)
 		return err;

 	err = -ENOMEM;

 	for (i = 1, dev->mr_table.max_mtt_order = 0;
 	     i < dev->limits.num_mtt_segs;
 	     i <<= 1, ++dev->mr_table.max_mtt_order)
 		; /* nothing */

 	dev->mr_table.mtt_buddy = kmalloc((dev->mr_table.max_mtt_order + 1) *
 					  sizeof (long *),
 					  GFP_KERNEL);
 	if (!dev->mr_table.mtt_buddy)
 		goto err_out;

 	for (i = 0; i <= dev->mr_table.max_mtt_order; ++i)
 		dev->mr_table.mtt_buddy[i] = NULL;

 	for (i = 0; i <= dev->mr_table.max_mtt_order; ++i) {
 		s = BITS_TO_LONGS(1 << (dev->mr_table.max_mtt_order - i));
 		dev->mr_table.mtt_buddy[i] = kmalloc(s * sizeof (long),
 						     GFP_KERNEL);
 		if (!dev->mr_table.mtt_buddy[i])
 			goto err_out_free;
 		bitmap_zero(dev->mr_table.mtt_buddy[i],
 			    1 << (dev->mr_table.max_mtt_order - i));
 	}

 	set_bit(0, dev->mr_table.mtt_buddy[dev->mr_table.max_mtt_order]);

 	for (i = 0; i < dev->mr_table.max_mtt_order; ++i)
 		if (1 << i >= dev->limits.reserved_mtts)
 			break;

 	if (i == dev->mr_table.max_mtt_order) {
 		mthca_err(dev, "MTT table of order %d is "
 			  "too small.\n", i);
 		goto err_out_free;
 	}

 	(void) mthca_alloc_mtt(dev, i);

 	return 0;

  err_out_free:
 	for (i = 0; i <= dev->mr_table.max_mtt_order; ++i)
 		kfree(dev->mr_table.mtt_buddy[i]);

  err_out:
 	mthca_alloc_cleanup(&dev->mr_table.mpt_alloc);

 	return err;
 }

 void __devexit mthca_cleanup_mr_table(struct mthca_dev *dev)
 {
 	int i;

 	/* XXX check if any MRs are still allocated? */
 	for (i = 0; i <= dev->mr_table.max_mtt_order; ++i)
 		kfree(dev->mr_table.mtt_buddy[i]);
 	kfree(dev->mr_table.mtt_buddy);
 	mthca_alloc_cleanup(&dev->mr_table.mpt_alloc);
 }
	/*
	* Copyright (c) 2004 Topspin Communications. All rights reserved.
	*
	* This software is available to you under a choice of one of two
	* licenses. You may choose to be licensed under the terms of the GNU
	* General Public License (GPL) Version 2, available from the file
	* COPYING in the main directory of this source tree, or the
	* OpenIB.org BSD license below:
	*
	* Redistribution and use in source and binary forms, with or
	* without modification, are permitted provided that the following
	* conditions are met:
	*
	* - Redistributions of source code must retain the above
	* copyright notice, this list of conditions and the following
	* disclaimer.
	*
	* - Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials
	* provided with the distribution.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	* SOFTWARE.
	*
	* $Id: mthca_mr.c 1349 2004-12-16 21:09:43Z roland $
	*/

	#include <linux/slab.h>
	#include <linux/init.h>
	#include <linux/errno.h>

	#include "mthca_dev.h"
	#include "mthca_cmd.h"

	/*
	* Must be packed because mtt_seg is 64 bits but only aligned to 32 bits.
	*/
	struct mthca_mpt_entry {
	u32 flags;
	u32 page_size;
	u32 key;
	u32 pd;
	u64 start;
	u64 length;
	u32 lkey;
	u32 window_count;
	u32 window_count_limit;
	u64 mtt_seg;
	u32 mtt_sz; /* Arbel only */
	u32 reserved[2];
	} __attribute__((packed));

	#define MTHCA_MPT_FLAG_SW_OWNS (0xfUL << 28)
	#define MTHCA_MPT_FLAG_MIO (1 << 17)
	#define MTHCA_MPT_FLAG_BIND_ENABLE (1 << 15)
	#define MTHCA_MPT_FLAG_PHYSICAL (1 << 9)
	#define MTHCA_MPT_FLAG_REGION (1 << 8)

	#define MTHCA_MTT_FLAG_PRESENT 1

	/*
	* Buddy allocator for MTT segments (currently not very efficient
	* since it doesn't keep a free list and just searches linearly
	* through the bitmaps)
	*/

	static u32 mthca_alloc_mtt(struct mthca_dev *dev, int order)
	{
	int o;
	int m;
	u32 seg;

	spin_lock(&dev->mr_table.mpt_alloc.lock);

	for (o = order; o <= dev->mr_table.max_mtt_order; ++o) {
	m = 1 << (dev->mr_table.max_mtt_order - o);
	seg = find_first_bit(dev->mr_table.mtt_buddy[o], m);
	if (seg < m)
	goto found;
	}

	spin_unlock(&dev->mr_table.mpt_alloc.lock);
	return -1;

	found:
	clear_bit(seg, dev->mr_table.mtt_buddy[o]);

	while (o > order) {
	--o;
	seg <<= 1;
	set_bit(seg ^ 1, dev->mr_table.mtt_buddy[o]);
	}

	spin_unlock(&dev->mr_table.mpt_alloc.lock);

	seg <<= order;

	return seg;
	}

	static void mthca_free_mtt(struct mthca_dev *dev, u32 seg, int order)
	{
	seg >>= order;

	spin_lock(&dev->mr_table.mpt_alloc.lock);

	while (test_bit(seg ^ 1, dev->mr_table.mtt_buddy[order])) {
	clear_bit(seg ^ 1, dev->mr_table.mtt_buddy[order]);
	seg >>= 1;
	++order;
	}

	set_bit(seg, dev->mr_table.mtt_buddy[order]);

	spin_unlock(&dev->mr_table.mpt_alloc.lock);
	}

	static inline u32 hw_index_to_key(struct mthca_dev *dev, u32 ind)
	{
	if (dev->hca_type == ARBEL_NATIVE)
	return (ind >> 24) \| (ind << 8);
	else
	return ind;
	}

	static inline u32 key_to_hw_index(struct mthca_dev *dev, u32 key)
	{
	if (dev->hca_type == ARBEL_NATIVE)
	return (key << 24) \| (key >> 8);
	else
	return key;
	}

	int mthca_mr_alloc_notrans(struct mthca_dev *dev, u32 pd,
	u32 access, struct mthca_mr *mr)
	{
	void *mailbox;
	struct mthca_mpt_entry *mpt_entry;
	u32 key;
	int err;
	u8 status;

	might_sleep();

	mr->order = -1;
	key = mthca_alloc(&dev->mr_table.mpt_alloc);
	if (key == -1)
	return -ENOMEM;
	mr->ibmr.rkey = mr->ibmr.lkey = hw_index_to_key(dev, key);

	mailbox = kmalloc(sizeof *mpt_entry + MTHCA_CMD_MAILBOX_EXTRA,
	GFP_KERNEL);
	if (!mailbox) {
	mthca_free(&dev->mr_table.mpt_alloc, mr->ibmr.lkey);
	return -ENOMEM;
	}
	mpt_entry = MAILBOX_ALIGN(mailbox);

	mpt_entry->flags = cpu_to_be32(MTHCA_MPT_FLAG_SW_OWNS \|
	MTHCA_MPT_FLAG_MIO \|
	MTHCA_MPT_FLAG_PHYSICAL \|
	MTHCA_MPT_FLAG_REGION \|
	access);
	mpt_entry->page_size = 0;
	mpt_entry->key = cpu_to_be32(key);
	mpt_entry->pd = cpu_to_be32(pd);
	mpt_entry->start = 0;
	mpt_entry->length = ~0ULL;

	memset(&mpt_entry->lkey, 0,
	sizeof *mpt_entry - offsetof(struct mthca_mpt_entry, lkey));

	err = mthca_SW2HW_MPT(dev, mpt_entry,
	key & (dev->limits.num_mpts - 1),
	&status);
	if (err)
	mthca_warn(dev, "SW2HW_MPT failed (%d)\n", err);
	else if (status) {
	mthca_warn(dev, "SW2HW_MPT returned status 0x%02x\n",
	status);
	err = -EINVAL;
	}

	kfree(mailbox);
	return err;
	}

	int mthca_mr_alloc_phys(struct mthca_dev *dev, u32 pd,
	u64 *buffer_list, int buffer_size_shift,
	int list_len, u64 iova, u64 total_size,
	u32 access, struct mthca_mr *mr)
	{
	void *mailbox;
	u64 *mtt_entry;
	struct mthca_mpt_entry *mpt_entry;
	u32 key;
	int err = -ENOMEM;
	u8 status;
	int i;

	might_sleep();
	WARN_ON(buffer_size_shift >= 32);

	key = mthca_alloc(&dev->mr_table.mpt_alloc);
	if (key == -1)
	return -ENOMEM;
	mr->ibmr.rkey = mr->ibmr.lkey = hw_index_to_key(dev, key);

	for (i = dev->limits.mtt_seg_size / 8, mr->order = 0;
	i < list_len;
	i <<= 1, ++mr->order)
	; /* nothing */

	mr->first_seg = mthca_alloc_mtt(dev, mr->order);
	if (mr->first_seg == -1)
	goto err_out_mpt_free;

	/*
	* If list_len is odd, we add one more dummy entry for
	* firmware efficiency.
	*/
	mailbox = kmalloc(max(sizeof *mpt_entry,
	(size_t) 8 * (list_len + (list_len & 1) + 2)) +
	MTHCA_CMD_MAILBOX_EXTRA,
	GFP_KERNEL);
	if (!mailbox)
	goto err_out_free_mtt;

	mtt_entry = MAILBOX_ALIGN(mailbox);

	mtt_entry[0] = cpu_to_be64(dev->mr_table.mtt_base +
	mr->first_seg * dev->limits.mtt_seg_size);
	mtt_entry[1] = 0;
	for (i = 0; i < list_len; ++i)
	mtt_entry[i + 2] = cpu_to_be64(buffer_list[i] \|
	MTHCA_MTT_FLAG_PRESENT);
	if (list_len & 1) {
	mtt_entry[i + 2] = 0;
	++list_len;
	}

	if (0) {
	mthca_dbg(dev, "Dumping MPT entry\n");
	for (i = 0; i < list_len + 2; ++i)
	printk(KERN_ERR "[%2d] %016llx\n",
	i, (unsigned long long) be64_to_cpu(mtt_entry[i]));
	}

	err = mthca_WRITE_MTT(dev, mtt_entry, list_len, &status);
	if (err) {
	mthca_warn(dev, "WRITE_MTT failed (%d)\n", err);
	goto err_out_mailbox_free;
	}
	if (status) {
	mthca_warn(dev, "WRITE_MTT returned status 0x%02x\n",
	status);
	err = -EINVAL;
	goto err_out_mailbox_free;
	}

	mpt_entry = MAILBOX_ALIGN(mailbox);

	mpt_entry->flags = cpu_to_be32(MTHCA_MPT_FLAG_SW_OWNS \|
	MTHCA_MPT_FLAG_MIO \|
	MTHCA_MPT_FLAG_REGION \|
	access);

	mpt_entry->page_size = cpu_to_be32(buffer_size_shift - 12);
	mpt_entry->key = cpu_to_be32(key);
	mpt_entry->pd = cpu_to_be32(pd);
	mpt_entry->start = cpu_to_be64(iova);
	mpt_entry->length = cpu_to_be64(total_size);
	memset(&mpt_entry->lkey, 0,
	sizeof *mpt_entry - offsetof(struct mthca_mpt_entry, lkey));
	mpt_entry->mtt_seg = cpu_to_be64(dev->mr_table.mtt_base +
	mr->first_seg * dev->limits.mtt_seg_size);

	if (0) {
	mthca_dbg(dev, "Dumping MPT entry %08x:\n", mr->ibmr.lkey);
	for (i = 0; i < sizeof (struct mthca_mpt_entry) / 4; ++i) {
	if (i % 4 == 0)
	printk("[%02x] ", i * 4);
	printk(" %08x", be32_to_cpu(((u32 *) mpt_entry)[i]));
	if ((i + 1) % 4 == 0)
	printk("\n");
	}
	}

	err = mthca_SW2HW_MPT(dev, mpt_entry,
	key & (dev->limits.num_mpts - 1),
	&status);
	if (err)
	mthca_warn(dev, "SW2HW_MPT failed (%d)\n", err);
	else if (status) {
	mthca_warn(dev, "SW2HW_MPT returned status 0x%02x\n",
	status);
	err = -EINVAL;
	}

	kfree(mailbox);
	return err;

	err_out_mailbox_free:
	kfree(mailbox);

	err_out_free_mtt:
	mthca_free_mtt(dev, mr->first_seg, mr->order);

	err_out_mpt_free:
	mthca_free(&dev->mr_table.mpt_alloc, mr->ibmr.lkey);
	return err;
	}

	void mthca_free_mr(struct mthca_dev dev, struct mthca_mr mr)
	{
	int err;
	u8 status;

	might_sleep();

	err = mthca_HW2SW_MPT(dev, NULL,
	key_to_hw_index(dev, mr->ibmr.lkey) &
	(dev->limits.num_mpts - 1),
	&status);
	if (err)
	mthca_warn(dev, "HW2SW_MPT failed (%d)\n", err);
	else if (status)
	mthca_warn(dev, "HW2SW_MPT returned status 0x%02x\n",
	status);

	if (mr->order >= 0)
	mthca_free_mtt(dev, mr->first_seg, mr->order);

	mthca_free(&dev->mr_table.mpt_alloc, key_to_hw_index(dev, mr->ibmr.lkey));
	}

	int __devinit mthca_init_mr_table(struct mthca_dev *dev)
	{
	int err;
	int i, s;

	err = mthca_alloc_init(&dev->mr_table.mpt_alloc,
	dev->limits.num_mpts,
	~0, dev->limits.reserved_mrws);
	if (err)
	return err;

	err = -ENOMEM;

	for (i = 1, dev->mr_table.max_mtt_order = 0;
	i < dev->limits.num_mtt_segs;
	i <<= 1, ++dev->mr_table.max_mtt_order)
	; /* nothing */

	dev->mr_table.mtt_buddy = kmalloc((dev->mr_table.max_mtt_order + 1) *
	sizeof (long *),
	GFP_KERNEL);
	if (!dev->mr_table.mtt_buddy)
	goto err_out;

	for (i = 0; i <= dev->mr_table.max_mtt_order; ++i)
	dev->mr_table.mtt_buddy[i] = NULL;

	for (i = 0; i <= dev->mr_table.max_mtt_order; ++i) {
	s = BITS_TO_LONGS(1 << (dev->mr_table.max_mtt_order - i));
	dev->mr_table.mtt_buddy[i] = kmalloc(s * sizeof (long),
	GFP_KERNEL);
	if (!dev->mr_table.mtt_buddy[i])
	goto err_out_free;
	bitmap_zero(dev->mr_table.mtt_buddy[i],
	1 << (dev->mr_table.max_mtt_order - i));
	}

	set_bit(0, dev->mr_table.mtt_buddy[dev->mr_table.max_mtt_order]);

	for (i = 0; i < dev->mr_table.max_mtt_order; ++i)
	if (1 << i >= dev->limits.reserved_mtts)
	break;

	if (i == dev->mr_table.max_mtt_order) {
	mthca_err(dev, "MTT table of order %d is "
	"too small.\n", i);
	goto err_out_free;
	}

	(void) mthca_alloc_mtt(dev, i);

	return 0;

	err_out_free:
	for (i = 0; i <= dev->mr_table.max_mtt_order; ++i)
	kfree(dev->mr_table.mtt_buddy[i]);

	err_out:
	mthca_alloc_cleanup(&dev->mr_table.mpt_alloc);

	return err;
	}

	void __devexit mthca_cleanup_mr_table(struct mthca_dev *dev)
	{
	int i;

	/* XXX check if any MRs are still allocated? */
	for (i = 0; i <= dev->mr_table.max_mtt_order; ++i)
	kfree(dev->mr_table.mtt_buddy[i]);
	kfree(dev->mr_table.mtt_buddy);
	mthca_alloc_cleanup(&dev->mr_table.mpt_alloc);
	}