[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / xen / privcmd.c

/******************************************************************************
 * privcmd.c
 *
 * Interface to privileged domain-0 commands.
 *
 * Copyright (c) 2002-2004, K A Fraser, B Dragovic
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/uaccess.h>
#include <linux/swap.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/seq_file.h>
#include <linux/miscdevice.h>

#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/tlb.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>

#include <xen/xen.h>
#include <xen/privcmd.h>
#include <xen/interface/xen.h>
#include <xen/features.h>
#include <xen/page.h>
#include <xen/xen-ops.h>

#include "privcmd.h"

MODULE_LICENSE("GPL");

#ifndef HAVE_ARCH_PRIVCMD_MMAP
static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
#endif

static long privcmd_ioctl_hypercall(void __user *udata)
{
	struct privcmd_hypercall hypercall;
	long ret;

	if (copy_from_user(&hypercall, udata, sizeof(hypercall)))
		return -EFAULT;

	ret = privcmd_call(hypercall.op,
			   hypercall.arg[0], hypercall.arg[1],
			   hypercall.arg[2], hypercall.arg[3],
			   hypercall.arg[4]);

	return ret;
}

static void free_page_list(struct list_head *pages)
{
	struct page *p, *n;

	list_for_each_entry_safe(p, n, pages, lru)
		__free_page(p);

	INIT_LIST_HEAD(pages);
}

/*
 * Given an array of items in userspace, return a list of pages
 * containing the data.  If copying fails, either because of memory
 * allocation failure or a problem reading user memory, return an
 * error code; its up to the caller to dispose of any partial list.
 */
static int gather_array(struct list_head *pagelist,
			unsigned nelem, size_t size,
			const void __user *data)
{
	unsigned pageidx;
	void *pagedata;
	int ret;

	if (size > PAGE_SIZE)
		return 0;

	pageidx = PAGE_SIZE;
	pagedata = NULL;	/* quiet, gcc */
	while (nelem--) {
		if (pageidx > PAGE_SIZE-size) {
			struct page *page = alloc_page(GFP_KERNEL);

			ret = -ENOMEM;
			if (page == NULL)
				goto fail;

			pagedata = page_address(page);

			list_add_tail(&page->lru, pagelist);
			pageidx = 0;
		}

		ret = -EFAULT;
		if (copy_from_user(pagedata + pageidx, data, size))
			goto fail;

		data += size;
		pageidx += size;
	}

	ret = 0;

fail:
	return ret;
}

/*
 * Call function "fn" on each element of the array fragmented
 * over a list of pages.
 */
static int traverse_pages(unsigned nelem, size_t size,
			  struct list_head *pos,
			  int (*fn)(void *data, void *state),
			  void *state)
{
	void *pagedata;
	unsigned pageidx;
	int ret = 0;

	BUG_ON(size > PAGE_SIZE);

	pageidx = PAGE_SIZE;
	pagedata = NULL;	/* hush, gcc */

	while (nelem--) {
		if (pageidx > PAGE_SIZE-size) {
			struct page *page;
			pos = pos->next;
			page = list_entry(pos, struct page, lru);
			pagedata = page_address(page);
			pageidx = 0;
		}

		ret = (*fn)(pagedata + pageidx, state);
		if (ret)
			break;
		pageidx += size;
	}

	return ret;
}

struct mmap_mfn_state {
	unsigned long va;
	struct vm_area_struct *vma;
	domid_t domain;
};

static int mmap_mfn_range(void *data, void *state)
{
	struct privcmd_mmap_entry *msg = data;
	struct mmap_mfn_state *st = state;
	struct vm_area_struct *vma = st->vma;
	int rc;

	/* Do not allow range to wrap the address space. */
	if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) ||
	    ((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va))
		return -EINVAL;

	/* Range chunks must be contiguous in va space. */
	if ((msg->va != st->va) ||
	    ((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end))
		return -EINVAL;

	rc = xen_remap_domain_mfn_range(vma,
					msg->va & PAGE_MASK,
					msg->mfn, msg->npages,
					vma->vm_page_prot,
					st->domain);
	if (rc < 0)
		return rc;

	st->va += msg->npages << PAGE_SHIFT;

	return 0;
}

static long privcmd_ioctl_mmap(void __user *udata)
{
	struct privcmd_mmap mmapcmd;
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma;
	int rc;
	LIST_HEAD(pagelist);
	struct mmap_mfn_state state;

	if (!xen_initial_domain())
		return -EPERM;

	if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
		return -EFAULT;

	rc = gather_array(&pagelist,
			  mmapcmd.num, sizeof(struct privcmd_mmap_entry),
			  mmapcmd.entry);

	if (rc || list_empty(&pagelist))
		goto out;

	down_write(&mm->mmap_sem);

	{
		struct page *page = list_first_entry(&pagelist,
						     struct page, lru);
		struct privcmd_mmap_entry *msg = page_address(page);

		vma = find_vma(mm, msg->va);
		rc = -EINVAL;

		if (!vma || (msg->va != vma->vm_start) ||
		    !privcmd_enforce_singleshot_mapping(vma))
			goto out_up;
	}

	state.va = vma->vm_start;
	state.vma = vma;
	state.domain = mmapcmd.dom;

	rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry),
			    &pagelist,
			    mmap_mfn_range, &state);


out_up:
	up_write(&mm->mmap_sem);

out:
	free_page_list(&pagelist);

	return rc;
}

struct mmap_batch_state {
	domid_t domain;
	unsigned long va;
	struct vm_area_struct *vma;
	/* A tristate:
	 *      0 for no errors
	 *      1 if at least one error has happened (and no
	 *          -ENOENT errors have happened)
	 *      -ENOENT if at least 1 -ENOENT has happened.
	 */
	int global_error;
	/* An array for individual errors */
	int *err;

	/* User-space mfn array to store errors in the second pass for V1. */
	xen_pfn_t __user *user_mfn;
};

static int mmap_batch_fn(void *data, void *state)
{
	xen_pfn_t *mfnp = data;
	struct mmap_batch_state *st = state;
	int ret;

	ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
					 st->vma->vm_page_prot, st->domain);

	/* Store error code for second pass. */
	*(st->err++) = ret;

	/* And see if it affects the global_error. */
	if (ret < 0) {
		if (ret == -ENOENT)
			st->global_error = -ENOENT;
		else {
			/* Record that at least one error has happened. */
			if (st->global_error == 0)
				st->global_error = 1;
		}
	}
	st->va += PAGE_SIZE;

	return 0;
}

static int mmap_return_errors_v1(void *data, void *state)
{
	xen_pfn_t *mfnp = data;
	struct mmap_batch_state *st = state;
	int err = *(st->err++);

	/*
	 * V1 encodes the error codes in the 32bit top nibble of the
	 * mfn (with its known limitations vis-a-vis 64 bit callers).
	 */
	*mfnp |= (err == -ENOENT) ?
				PRIVCMD_MMAPBATCH_PAGED_ERROR :
				PRIVCMD_MMAPBATCH_MFN_ERROR;
	return __put_user(*mfnp, st->user_mfn++);
}

static struct vm_operations_struct privcmd_vm_ops;

static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
{
	int ret;
	struct privcmd_mmapbatch_v2 m;
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma;
	unsigned long nr_pages;
	LIST_HEAD(pagelist);
	int *err_array = NULL;
	struct mmap_batch_state state;

	if (!xen_initial_domain())
		return -EPERM;

	switch (version) {
	case 1:
		if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch)))
			return -EFAULT;
		/* Returns per-frame error in m.arr. */
		m.err = NULL;
		if (!access_ok(VERIFY_WRITE, m.arr, m.num * sizeof(*m.arr)))
			return -EFAULT;
		break;
	case 2:
		if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch_v2)))
			return -EFAULT;
		/* Returns per-frame error code in m.err. */
		if (!access_ok(VERIFY_WRITE, m.err, m.num * (sizeof(*m.err))))
			return -EFAULT;
		break;
	default:
		return -EINVAL;
	}

	nr_pages = m.num;
	if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT)))
		return -EINVAL;

	ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), m.arr);

	if (ret)
		goto out;
	if (list_empty(&pagelist)) {
		ret = -EINVAL;
		goto out;
	}

	err_array = kcalloc(m.num, sizeof(int), GFP_KERNEL);
	if (err_array == NULL) {
		ret = -ENOMEM;
		goto out;
	}

	down_write(&mm->mmap_sem);

	vma = find_vma(mm, m.addr);
	ret = -EINVAL;
	if (!vma ||
	    vma->vm_ops != &privcmd_vm_ops ||
	    (m.addr != vma->vm_start) ||
	    ((m.addr + (nr_pages << PAGE_SHIFT)) != vma->vm_end) ||
	    !privcmd_enforce_singleshot_mapping(vma)) {
		up_write(&mm->mmap_sem);
		goto out;
	}

	state.domain        = m.dom;
	state.vma           = vma;
	state.va            = m.addr;
	state.global_error  = 0;
	state.err           = err_array;

	/* mmap_batch_fn guarantees ret == 0 */
	BUG_ON(traverse_pages(m.num, sizeof(xen_pfn_t),
			     &pagelist, mmap_batch_fn, &state));

	up_write(&mm->mmap_sem);

	if (state.global_error && (version == 1)) {
		/* Write back errors in second pass. */
		state.user_mfn = (xen_pfn_t *)m.arr;
		state.err      = err_array;
		ret = traverse_pages(m.num, sizeof(xen_pfn_t),
				     &pagelist, mmap_return_errors_v1, &state);
	} else if (version == 2) {
		ret = __copy_to_user(m.err, err_array, m.num * sizeof(int));
		if (ret)
			ret = -EFAULT;
	}

	/* If we have not had any EFAULT-like global errors then set the global
	 * error to -ENOENT if necessary. */
	if ((ret == 0) && (state.global_error == -ENOENT))
		ret = -ENOENT;

out:
	kfree(err_array);
	free_page_list(&pagelist);

	return ret;
}

static long privcmd_ioctl(struct file *file,
			  unsigned int cmd, unsigned long data)
{
	int ret = -ENOSYS;
	void __user *udata = (void __user *) data;

	switch (cmd) {
	case IOCTL_PRIVCMD_HYPERCALL:
		ret = privcmd_ioctl_hypercall(udata);
		break;

	case IOCTL_PRIVCMD_MMAP:
		ret = privcmd_ioctl_mmap(udata);
		break;

	case IOCTL_PRIVCMD_MMAPBATCH:
		ret = privcmd_ioctl_mmap_batch(udata, 1);
		break;

	case IOCTL_PRIVCMD_MMAPBATCH_V2:
		ret = privcmd_ioctl_mmap_batch(udata, 2);
		break;

	default:
		ret = -EINVAL;
		break;
	}

	return ret;
}

static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
	       vma, vma->vm_start, vma->vm_end,
	       vmf->pgoff, vmf->virtual_address);

	return VM_FAULT_SIGBUS;
}

static struct vm_operations_struct privcmd_vm_ops = {
	.fault = privcmd_fault
};

static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
{
	/* DONTCOPY is essential for Xen because copy_page_range doesn't know
	 * how to recreate these mappings */
	vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;
	vma->vm_ops = &privcmd_vm_ops;
	vma->vm_private_data = NULL;

	return 0;
}

static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
{
	return (xchg(&vma->vm_private_data, (void *)1) == NULL);
}

const struct file_operations xen_privcmd_fops = {
	.owner = THIS_MODULE,
	.unlocked_ioctl = privcmd_ioctl,
	.mmap = privcmd_mmap,
};
EXPORT_SYMBOL_GPL(xen_privcmd_fops);

static struct miscdevice privcmd_dev = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = "xen/privcmd",
	.fops = &xen_privcmd_fops,
};

static int __init privcmd_init(void)
{
	int err;

	if (!xen_domain())
		return -ENODEV;

	err = misc_register(&privcmd_dev);
	if (err != 0) {
		printk(KERN_ERR "Could not register Xen privcmd device\n");
		return err;
	}
	return 0;
}

static void __exit privcmd_exit(void)
{
	misc_deregister(&privcmd_dev);
}

module_init(privcmd_init);
module_exit(privcmd_exit);
Commit	Line	Data
1c5de193 JF	1	/******************************************************************************
	2	* privcmd.c
	3	*
	4	* Interface to privileged domain-0 commands.
	5	*
	6	* Copyright (c) 2002-2004, K A Fraser, B Dragovic
	7	*/
	8
	9	#include <linux/kernel.h>
d8414d3c	10	#include <linux/module.h>
1c5de193 JF	11	#include <linux/sched.h>
	12	#include <linux/slab.h>
	13	#include <linux/string.h>
	14	#include <linux/errno.h>
	15	#include <linux/mm.h>
	16	#include <linux/mman.h>
	17	#include <linux/uaccess.h>
	18	#include <linux/swap.h>
1c5de193 JF	19	#include <linux/highmem.h>
	20	#include <linux/pagemap.h>
	21	#include <linux/seq_file.h>
d8414d3c	22	#include <linux/miscdevice.h>
1c5de193 JF	23
	24	#include <asm/pgalloc.h>
	25	#include <asm/pgtable.h>
	26	#include <asm/tlb.h>
	27	#include <asm/xen/hypervisor.h>
	28	#include <asm/xen/hypercall.h>
	29
	30	#include <xen/xen.h>
	31	#include <xen/privcmd.h>
	32	#include <xen/interface/xen.h>
	33	#include <xen/features.h>
	34	#include <xen/page.h>
de1ef206	35	#include <xen/xen-ops.h>
f020e290	36
d8414d3c BB	37	#include "privcmd.h"
	38
	39	MODULE_LICENSE("GPL");
	40
1c5de193 JF	41	#ifndef HAVE_ARCH_PRIVCMD_MMAP
	42	static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
	43	#endif
	44
1c5de193 JF	45	static long privcmd_ioctl_hypercall(void __user *udata)
	46	{
	47	struct privcmd_hypercall hypercall;
	48	long ret;
	49
	50	if (copy_from_user(&hypercall, udata, sizeof(hypercall)))
	51	return -EFAULT;
	52
	53	ret = privcmd_call(hypercall.op,
	54	hypercall.arg[0], hypercall.arg[1],
	55	hypercall.arg[2], hypercall.arg[3],
	56	hypercall.arg[4]);
	57
	58	return ret;
	59	}
	60
	61	static void free_page_list(struct list_head *pages)
	62	{
	63	struct page p, n;
	64
	65	list_for_each_entry_safe(p, n, pages, lru)
	66	__free_page(p);
	67
	68	INIT_LIST_HEAD(pages);
	69	}
	70
	71	/*
	72	* Given an array of items in userspace, return a list of pages
	73	* containing the data. If copying fails, either because of memory
	74	* allocation failure or a problem reading user memory, return an
	75	* error code; its up to the caller to dispose of any partial list.
	76	*/
	77	static int gather_array(struct list_head *pagelist,
	78	unsigned nelem, size_t size,
ceb90fa0	79	const void __user *data)
1c5de193 JF	80	{
	81	unsigned pageidx;
	82	void *pagedata;
	83	int ret;
	84
	85	if (size > PAGE_SIZE)
	86	return 0;
	87
	88	pageidx = PAGE_SIZE;
	89	pagedata = NULL; /* quiet, gcc */
	90	while (nelem--) {
	91	if (pageidx > PAGE_SIZE-size) {
	92	struct page *page = alloc_page(GFP_KERNEL);
	93
	94	ret = -ENOMEM;
	95	if (page == NULL)
	96	goto fail;
	97
	98	pagedata = page_address(page);
	99
	100	list_add_tail(&page->lru, pagelist);
	101	pageidx = 0;
	102	}
	103
	104	ret = -EFAULT;
	105	if (copy_from_user(pagedata + pageidx, data, size))
	106	goto fail;
	107
	108	data += size;
	109	pageidx += size;
	110	}
	111
	112	ret = 0;
	113
	114	fail:
	115	return ret;
	116	}
	117
	118	/*
	119	* Call function "fn" on each element of the array fragmented
	120	* over a list of pages.
	121	*/
	122	static int traverse_pages(unsigned nelem, size_t size,
	123	struct list_head *pos,
	124	int (fn)(void data, void *state),
	125	void *state)
	126	{
	127	void *pagedata;
	128	unsigned pageidx;
f020e290	129	int ret = 0;
1c5de193 JF	130
	131	BUG_ON(size > PAGE_SIZE);
	132
	133	pageidx = PAGE_SIZE;
	134	pagedata = NULL; /* hush, gcc */
	135
	136	while (nelem--) {
	137	if (pageidx > PAGE_SIZE-size) {
	138	struct page *page;
	139	pos = pos->next;
	140	page = list_entry(pos, struct page, lru);
	141	pagedata = page_address(page);
	142	pageidx = 0;
	143	}
	144
	145	ret = (*fn)(pagedata + pageidx, state);
	146	if (ret)
	147	break;
	148	pageidx += size;
	149	}
	150
	151	return ret;
	152	}
	153
	154	struct mmap_mfn_state {
	155	unsigned long va;
	156	struct vm_area_struct *vma;
	157	domid_t domain;
	158	};
	159
	160	static int mmap_mfn_range(void data, void state)
	161	{
	162	struct privcmd_mmap_entry *msg = data;
	163	struct mmap_mfn_state *st = state;
	164	struct vm_area_struct *vma = st->vma;
	165	int rc;
	166
	167	/* Do not allow range to wrap the address space. */
	168	if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) \|\|
	169	((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va))
	170	return -EINVAL;
	171
	172	/* Range chunks must be contiguous in va space. */
	173	if ((msg->va != st->va) \|\|
	174	((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end))
	175	return -EINVAL;
	176
de1ef206 IC	177	rc = xen_remap_domain_mfn_range(vma,
	178	msg->va & PAGE_MASK,
	179	msg->mfn, msg->npages,
	180	vma->vm_page_prot,
	181	st->domain);
1c5de193 JF	182	if (rc < 0)
	183	return rc;
	184
	185	st->va += msg->npages << PAGE_SHIFT;
	186
	187	return 0;
	188	}
	189
	190	static long privcmd_ioctl_mmap(void __user *udata)
	191	{
	192	struct privcmd_mmap mmapcmd;
	193	struct mm_struct *mm = current->mm;
	194	struct vm_area_struct *vma;
	195	int rc;
	196	LIST_HEAD(pagelist);
	197	struct mmap_mfn_state state;
	198
	199	if (!xen_initial_domain())
	200	return -EPERM;
	201
	202	if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
	203	return -EFAULT;
	204
	205	rc = gather_array(&pagelist,
	206	mmapcmd.num, sizeof(struct privcmd_mmap_entry),
	207	mmapcmd.entry);
	208
	209	if (rc \|\| list_empty(&pagelist))
	210	goto out;
	211
	212	down_write(&mm->mmap_sem);
	213
	214	{
	215	struct page *page = list_first_entry(&pagelist,
	216	struct page, lru);
	217	struct privcmd_mmap_entry *msg = page_address(page);
	218
	219	vma = find_vma(mm, msg->va);
	220	rc = -EINVAL;
	221
	222	if (!vma \|\| (msg->va != vma->vm_start) \|\|
	223	!privcmd_enforce_singleshot_mapping(vma))
	224	goto out_up;
	225	}
	226
	227	state.va = vma->vm_start;
	228	state.vma = vma;
	229	state.domain = mmapcmd.dom;
	230
	231	rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry),
	232	&pagelist,
	233	mmap_mfn_range, &state);
	234
	235
	236	out_up:
	237	up_write(&mm->mmap_sem);
	238
	239	out:
	240	free_page_list(&pagelist);
	241
	242	return rc;
	243	}
	244
	245	struct mmap_batch_state {
246	domid_t domain;
247	unsigned long va;
248	struct vm_area_struct *vma;
ceb90fa0 ALC	249	/* A tristate:
	250	* 0 for no errors
	251	* 1 if at least one error has happened (and no
	252	* -ENOENT errors have happened)
	253	* -ENOENT if at least 1 -ENOENT has happened.
	254	*/
	255	int global_error;
	256	/* An array for individual errors */
	257	int *err;
	258
	259	/* User-space mfn array to store errors in the second pass for V1. */
	260	xen_pfn_t __user *user_mfn;
1c5de193 JF	261	};
	262
	263	static int mmap_batch_fn(void data, void state)
	264	{
	265	xen_pfn_t *mfnp = data;
	266	struct mmap_batch_state *st = state;
ceb90fa0 ALC	267	int ret;
	268
	269	ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
	270	st->vma->vm_page_prot, st->domain);
1c5de193	271
ceb90fa0 ALC	272	/* Store error code for second pass. */
	273	*(st->err++) = ret;
	274
	275	/* And see if it affects the global_error. */
	276	if (ret < 0) {
	277	if (ret == -ENOENT)
	278	st->global_error = -ENOENT;
	279	else {
	280	/* Record that at least one error has happened. */
	281	if (st->global_error == 0)
	282	st->global_error = 1;
	283	}
1c5de193 JF	284	}
	285	st->va += PAGE_SIZE;
	286
	287	return 0;
	288	}
	289
ceb90fa0	290	static int mmap_return_errors_v1(void data, void state)
1c5de193 JF	291	{
	292	xen_pfn_t *mfnp = data;
	293	struct mmap_batch_state *st = state;
ceb90fa0 ALC	294	int err = *(st->err++);
	295
	296	/*
	297	* V1 encodes the error codes in the 32bit top nibble of the
	298	* mfn (with its known limitations vis-a-vis 64 bit callers).
	299	*/
	300	*mfnp \|= (err == -ENOENT) ?
	301	PRIVCMD_MMAPBATCH_PAGED_ERROR :
	302	PRIVCMD_MMAPBATCH_MFN_ERROR;
	303	return __put_user(*mfnp, st->user_mfn++);
1c5de193 JF	304	}
1c5de193 JF	305
f31fdf51 JF	306	static struct vm_operations_struct privcmd_vm_ops;
f31fdf51 JF	307
ceb90fa0	308	static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
1c5de193 JF	309	{
1c5de193 JF	310	int ret;
ceb90fa0	311	struct privcmd_mmapbatch_v2 m;
1c5de193 JF	312	struct mm_struct *mm = current->mm;
	313	struct vm_area_struct *vma;
	314	unsigned long nr_pages;
	315	LIST_HEAD(pagelist);
ceb90fa0	316	int *err_array = NULL;
1c5de193 JF	317	struct mmap_batch_state state;
	318
	319	if (!xen_initial_domain())
	320	return -EPERM;
	321
ceb90fa0 ALC	322	switch (version) {
	323	case 1:
	324	if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch)))
	325	return -EFAULT;
	326	/* Returns per-frame error in m.arr. */
	327	m.err = NULL;
	328	if (!access_ok(VERIFY_WRITE, m.arr, m.num * sizeof(*m.arr)))
	329	return -EFAULT;
	330	break;
	331	case 2:
	332	if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch_v2)))
	333	return -EFAULT;
	334	/* Returns per-frame error code in m.err. */
	335	if (!access_ok(VERIFY_WRITE, m.err, m.num * (sizeof(*m.err))))
	336	return -EFAULT;
	337	break;
	338	default:
	339	return -EINVAL;
	340	}
1c5de193 JF	341
	342	nr_pages = m.num;
	343	if ((m.num <= 0) \|\| (nr_pages > (LONG_MAX >> PAGE_SHIFT)))
	344	return -EINVAL;
	345
ceb90fa0	346	ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), m.arr);
1c5de193	347
ceb90fa0	348	if (ret)
1c5de193	349	goto out;
ceb90fa0 ALC	350	if (list_empty(&pagelist)) {
	351	ret = -EINVAL;
	352	goto out;
	353	}
	354
	355	err_array = kcalloc(m.num, sizeof(int), GFP_KERNEL);
	356	if (err_array == NULL) {
	357	ret = -ENOMEM;
	358	goto out;
	359	}
1c5de193 JF	360
	361	down_write(&mm->mmap_sem);
	362
	363	vma = find_vma(mm, m.addr);
	364	ret = -EINVAL;
	365	if (!vma \|\|
f31fdf51	366	vma->vm_ops != &privcmd_vm_ops \|\|
1c5de193 JF	367	(m.addr != vma->vm_start) \|\|
	368	((m.addr + (nr_pages << PAGE_SHIFT)) != vma->vm_end) \|\|
	369	!privcmd_enforce_singleshot_mapping(vma)) {
	370	up_write(&mm->mmap_sem);
	371	goto out;
	372	}
	373
ceb90fa0 ALC	374	state.domain = m.dom;
	375	state.vma = vma;
	376	state.va = m.addr;
	377	state.global_error = 0;
	378	state.err = err_array;
1c5de193	379
ceb90fa0 ALC	380	/* mmap_batch_fn guarantees ret == 0 */
	381	BUG_ON(traverse_pages(m.num, sizeof(xen_pfn_t),
	382	&pagelist, mmap_batch_fn, &state));
1c5de193 JF	383
	384	up_write(&mm->mmap_sem);
	385
ceb90fa0 ALC	386	if (state.global_error && (version == 1)) {
	387	/* Write back errors in second pass. */
	388	state.user_mfn = (xen_pfn_t *)m.arr;
	389	state.err = err_array;
313e7441	390	ret = traverse_pages(m.num, sizeof(xen_pfn_t),
ceb90fa0	391	&pagelist, mmap_return_errors_v1, &state);
9d2be928	392	} else if (version == 2) {
ceb90fa0	393	ret = __copy_to_user(m.err, err_array, m.num * sizeof(int));
9d2be928 DC	394	if (ret)
	395	ret = -EFAULT;
	396	}
ceb90fa0 ALC	397
	398	/* If we have not had any EFAULT-like global errors then set the global
	399	* error to -ENOENT if necessary. */
	400	if ((ret == 0) && (state.global_error == -ENOENT))
	401	ret = -ENOENT;
1c5de193 JF	402
1c5de193 JF	403	out:
ceb90fa0	404	kfree(err_array);
1c5de193 JF	405	free_page_list(&pagelist);
	406
	407	return ret;
	408	}
	409
	410	static long privcmd_ioctl(struct file *file,
	411	unsigned int cmd, unsigned long data)
	412	{
	413	int ret = -ENOSYS;
	414	void __user udata = (void __user ) data;
	415
	416	switch (cmd) {
	417	case IOCTL_PRIVCMD_HYPERCALL:
	418	ret = privcmd_ioctl_hypercall(udata);
	419	break;
	420
	421	case IOCTL_PRIVCMD_MMAP:
	422	ret = privcmd_ioctl_mmap(udata);
	423	break;
	424
	425	case IOCTL_PRIVCMD_MMAPBATCH:
ceb90fa0 ALC	426	ret = privcmd_ioctl_mmap_batch(udata, 1);
	427	break;
	428
	429	case IOCTL_PRIVCMD_MMAPBATCH_V2:
	430	ret = privcmd_ioctl_mmap_batch(udata, 2);
1c5de193 JF	431	break;
	432
	433	default:
	434	ret = -EINVAL;
	435	break;
	436	}
	437
	438	return ret;
	439	}
	440
1c5de193 JF	441	static int privcmd_fault(struct vm_area_struct vma, struct vm_fault vmf)
1c5de193 JF	442	{
441c7416 JF	443	printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
	444	vma, vma->vm_start, vma->vm_end,
	445	vmf->pgoff, vmf->virtual_address);
	446
1c5de193 JF	447	return VM_FAULT_SIGBUS;
	448	}
	449
	450	static struct vm_operations_struct privcmd_vm_ops = {
	451	.fault = privcmd_fault
	452	};
	453
	454	static int privcmd_mmap(struct file file, struct vm_area_struct vma)
	455	{
e060e7af SS	456	/* DONTCOPY is essential for Xen because copy_page_range doesn't know
	457	* how to recreate these mappings */
	458	vma->vm_flags \|= VM_RESERVED \| VM_IO \| VM_DONTCOPY \| VM_PFNMAP;
1c5de193 JF	459	vma->vm_ops = &privcmd_vm_ops;
	460	vma->vm_private_data = NULL;
	461
	462	return 0;
	463	}
	464
	465	static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
	466	{
	467	return (xchg(&vma->vm_private_data, (void *)1) == NULL);
	468	}
1c5de193	469
d8414d3c BB	470	const struct file_operations xen_privcmd_fops = {
d8414d3c BB	471	.owner = THIS_MODULE,
1c5de193 JF	472	.unlocked_ioctl = privcmd_ioctl,
	473	.mmap = privcmd_mmap,
	474	};
d8414d3c BB	475	EXPORT_SYMBOL_GPL(xen_privcmd_fops);
	476
	477	static struct miscdevice privcmd_dev = {
	478	.minor = MISC_DYNAMIC_MINOR,
	479	.name = "xen/privcmd",
	480	.fops = &xen_privcmd_fops,
	481	};
	482
	483	static int __init privcmd_init(void)
	484	{
	485	int err;
	486
	487	if (!xen_domain())
	488	return -ENODEV;
	489
	490	err = misc_register(&privcmd_dev);
	491	if (err != 0) {
	492	printk(KERN_ERR "Could not register Xen privcmd device\n");
	493	return err;
	494	}
	495	return 0;
	496	}
	497
	498	static void __exit privcmd_exit(void)
	499	{
	500	misc_deregister(&privcmd_dev);
	501	}
	502
	503	module_init(privcmd_init);
	504	module_exit(privcmd_exit);