[GitHub/MotorolaMobilityLLC/kernel-slsi.git] / mm / hmm.c

/*
 * Copyright 2013 Red Hat Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Authors: JÃ©rÃ´me Glisse <jglisse@redhat.com>
 */
/*
 * Refer to include/linux/hmm.h for information about heterogeneous memory
 * management or HMM for short.
 */
#include <linux/mm.h>
#include <linux/hmm.h>
#include <linux/slab.h>
#include <linux/sched.h>


#ifdef CONFIG_HMM
/*
 * struct hmm - HMM per mm struct
 *
 * @mm: mm struct this HMM struct is bound to
 */
struct hmm {
	struct mm_struct	*mm;
};

/*
 * hmm_register - register HMM against an mm (HMM internal)
 *
 * @mm: mm struct to attach to
 *
 * This is not intended to be used directly by device drivers. It allocates an
 * HMM struct if mm does not have one, and initializes it.
 */
static struct hmm *hmm_register(struct mm_struct *mm)
{
	if (!mm->hmm) {
		struct hmm *hmm = NULL;

		hmm = kmalloc(sizeof(*hmm), GFP_KERNEL);
		if (!hmm)
			return NULL;
		hmm->mm = mm;

		spin_lock(&mm->page_table_lock);
		if (!mm->hmm)
			mm->hmm = hmm;
		else
			kfree(hmm);
		spin_unlock(&mm->page_table_lock);
	}

	/*
	 * The hmm struct can only be freed once the mm_struct goes away,
	 * hence we should always have pre-allocated an new hmm struct
	 * above.
	 */
	return mm->hmm;
}

void hmm_mm_destroy(struct mm_struct *mm)
{
	kfree(mm->hmm);
}
#endif /* CONFIG_HMM */
Commit	Line	Data
133ff0ea JG	1	/*
	2	* Copyright 2013 Red Hat Inc.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* Authors: JÃ©rÃ´me Glisse <jglisse@redhat.com>
	15	*/
	16	/*
	17	* Refer to include/linux/hmm.h for information about heterogeneous memory
	18	* management or HMM for short.
	19	*/
	20	#include <linux/mm.h>
	21	#include <linux/hmm.h>
	22	#include <linux/slab.h>
	23	#include <linux/sched.h>
	24
	25
	26	#ifdef CONFIG_HMM
	27	/*
	28	* struct hmm - HMM per mm struct
	29	*
	30	* @mm: mm struct this HMM struct is bound to
	31	*/
	32	struct hmm {
	33	struct mm_struct *mm;
	34	};
	35
	36	/*
	37	* hmm_register - register HMM against an mm (HMM internal)
	38	*
	39	* @mm: mm struct to attach to
	40	*
	41	* This is not intended to be used directly by device drivers. It allocates an
	42	* HMM struct if mm does not have one, and initializes it.
	43	*/
	44	static struct hmm hmm_register(struct mm_struct mm)
	45	{
	46	if (!mm->hmm) {
	47	struct hmm *hmm = NULL;
	48
	49	hmm = kmalloc(sizeof(*hmm), GFP_KERNEL);
	50	if (!hmm)
	51	return NULL;
	52	hmm->mm = mm;
	53
	54	spin_lock(&mm->page_table_lock);
	55	if (!mm->hmm)
	56	mm->hmm = hmm;
	57	else
	58	kfree(hmm);
	59	spin_unlock(&mm->page_table_lock);
	60	}
	61
	62	/*
	63	* The hmm struct can only be freed once the mm_struct goes away,
	64	* hence we should always have pre-allocated an new hmm struct
65	* above.
66	*/
67	return mm->hmm;
68	}
69
70	void hmm_mm_destroy(struct mm_struct *mm)
71	{
72	kfree(mm->hmm);
73	}
74	#endif /* CONFIG_HMM */