1#include <linux/bootmem.h>
  2#include <linux/gfp.h>
  3#include <linux/export.h>
  4#include <linux/rwlock.h>
  5#include <linux/slab.h>
  6#include <linux/types.h>
  7#include <linux/dma-mapping.h>
  8#include <linux/vmalloc.h>
  9#include <linux/swiotlb.h>
 10
 11#include <xen/xen.h>
 12#include <xen/interface/memory.h>
 13#include <xen/page.h>
 14#include <xen/swiotlb-xen.h>
 15
 16#include <asm/cacheflush.h>
 17#include <asm/xen/hypercall.h>
 18#include <asm/xen/interface.h>
 19
 20struct xen_p2m_entry {
 21	unsigned long pfn;
 22	unsigned long mfn;
 23	unsigned long nr_pages;
 24	struct rb_node rbnode_phys;
 25};
 26
 27static rwlock_t p2m_lock;
 28struct rb_root phys_to_mach = RB_ROOT;
 29EXPORT_SYMBOL_GPL(phys_to_mach);
 30
 31static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new)
 32{
 33	struct rb_node **link = &phys_to_mach.rb_node;
 34	struct rb_node *parent = NULL;
 35	struct xen_p2m_entry *entry;
 36	int rc = 0;
 37
 38	while (*link) {
 39		parent = *link;
 40		entry = rb_entry(parent, struct xen_p2m_entry, rbnode_phys);
 41
 42		if (new->pfn == entry->pfn)
 43			goto err_out;
 44
 45		if (new->pfn < entry->pfn)
 46			link = &(*link)->rb_left;
 47		else
 48			link = &(*link)->rb_right;
 49	}
 50	rb_link_node(&new->rbnode_phys, parent, link);
 51	rb_insert_color(&new->rbnode_phys, &phys_to_mach);
 52	goto out;
 53
 54err_out:
 55	rc = -EINVAL;
 56	pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n",
 57			__func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn);
 58out:
 59	return rc;
 60}
 61
 62unsigned long __pfn_to_mfn(unsigned long pfn)
 63{
 64	struct rb_node *n = phys_to_mach.rb_node;
 65	struct xen_p2m_entry *entry;
 66	unsigned long irqflags;
 67
 68	read_lock_irqsave(&p2m_lock, irqflags);
 69	while (n) {
 70		entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
 71		if (entry->pfn <= pfn &&
 72				entry->pfn + entry->nr_pages > pfn) {
 73			read_unlock_irqrestore(&p2m_lock, irqflags);
 74			return entry->mfn + (pfn - entry->pfn);
 75		}
 76		if (pfn < entry->pfn)
 77			n = n->rb_left;
 78		else
 79			n = n->rb_right;
 80	}
 81	read_unlock_irqrestore(&p2m_lock, irqflags);
 82
 83	return INVALID_P2M_ENTRY;
 84}
 85EXPORT_SYMBOL_GPL(__pfn_to_mfn);
 86
 87int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
 88			    struct gnttab_map_grant_ref *kmap_ops,
 89			    struct page **pages, unsigned int count)
 90{
 91	int i;
 92
 93	for (i = 0; i < count; i++) {
 94		if (map_ops[i].status)
 95			continue;
 96		set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
 97				    map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT);
 98	}
 99
100	return 0;
101}
102EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping);
103
104int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
105			      struct gnttab_unmap_grant_ref *kunmap_ops,
106			      struct page **pages, unsigned int count)
107{
108	int i;
109
110	for (i = 0; i < count; i++) {
111		set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT,
112				    INVALID_P2M_ENTRY);
113	}
114
115	return 0;
116}
117EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping);
118
119bool __set_phys_to_machine_multi(unsigned long pfn,
120		unsigned long mfn, unsigned long nr_pages)
121{
122	int rc;
123	unsigned long irqflags;
124	struct xen_p2m_entry *p2m_entry;
125	struct rb_node *n = phys_to_mach.rb_node;
126
127	if (mfn == INVALID_P2M_ENTRY) {
128		write_lock_irqsave(&p2m_lock, irqflags);
129		while (n) {
130			p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
131			if (p2m_entry->pfn <= pfn &&
132					p2m_entry->pfn + p2m_entry->nr_pages > pfn) {
133				rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach);
134				write_unlock_irqrestore(&p2m_lock, irqflags);
135				kfree(p2m_entry);
136				return true;
137			}
138			if (pfn < p2m_entry->pfn)
139				n = n->rb_left;
140			else
141				n = n->rb_right;
142		}
143		write_unlock_irqrestore(&p2m_lock, irqflags);
144		return true;
145	}
146
147	p2m_entry = kzalloc(sizeof(struct xen_p2m_entry), GFP_NOWAIT);
148	if (!p2m_entry) {
149		pr_warn("cannot allocate xen_p2m_entry\n");
150		return false;
151	}
152	p2m_entry->pfn = pfn;
153	p2m_entry->nr_pages = nr_pages;
154	p2m_entry->mfn = mfn;
155
156	write_lock_irqsave(&p2m_lock, irqflags);
157	if ((rc = xen_add_phys_to_mach_entry(p2m_entry)) < 0) {
158		write_unlock_irqrestore(&p2m_lock, irqflags);
159		return false;
160	}
161	write_unlock_irqrestore(&p2m_lock, irqflags);
162	return true;
163}
164EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi);
165
166bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
167{
168	return __set_phys_to_machine_multi(pfn, mfn, 1);
169}
170EXPORT_SYMBOL_GPL(__set_phys_to_machine);
171
172static int p2m_init(void)
173{
174	rwlock_init(&p2m_lock);
175	return 0;
176}
177arch_initcall(p2m_init);