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 20 struct xen_p2m_entry { 21 unsigned long pfn; 22 unsigned long mfn; 23 unsigned long nr_pages; 24 struct rb_node rbnode_phys; 25 }; 26 27 static rwlock_t p2m_lock; 28 struct rb_root phys_to_mach = RB_ROOT; 29 EXPORT_SYMBOL_GPL(phys_to_mach); 30 31 static 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 54 err_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); 58 out: 59 return rc; 60 } 61 62 unsigned 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 } 85 EXPORT_SYMBOL_GPL(__pfn_to_mfn); 86 87 int 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 >> PAGE_SHIFT, 97 map_ops[i].dev_bus_addr >> PAGE_SHIFT); 98 } 99 100 return 0; 101 } 102 EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping); 103 104 int 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 >> PAGE_SHIFT, 112 INVALID_P2M_ENTRY); 113 } 114 115 return 0; 116 } 117 EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping); 118 119 bool __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 } 164 EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi); 165 166 bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) 167 { 168 return __set_phys_to_machine_multi(pfn, mfn, 1); 169 } 170 EXPORT_SYMBOL_GPL(__set_phys_to_machine); 171 172 static int p2m_init(void) 173 { 174 rwlock_init(&p2m_lock); 175 return 0; 176 } 177 arch_initcall(p2m_init); 178