1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <linux/memblock.h> 3 #include <linux/gfp.h> 4 #include <linux/export.h> 5 #include <linux/spinlock.h> 6 #include <linux/slab.h> 7 #include <linux/types.h> 8 #include <linux/dma-mapping.h> 9 #include <linux/vmalloc.h> 10 #include <linux/swiotlb.h> 11 12 #include <xen/xen.h> 13 #include <xen/interface/memory.h> 14 #include <xen/grant_table.h> 15 #include <xen/page.h> 16 #include <xen/swiotlb-xen.h> 17 18 #include <asm/cacheflush.h> 19 #include <asm/xen/hypercall.h> 20 #include <asm/xen/interface.h> 21 22 struct xen_p2m_entry { 23 unsigned long pfn; 24 unsigned long mfn; 25 unsigned long nr_pages; 26 struct rb_node rbnode_phys; 27 }; 28 29 static rwlock_t p2m_lock; 30 struct rb_root phys_to_mach = RB_ROOT; 31 EXPORT_SYMBOL_GPL(phys_to_mach); 32 33 static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new) 34 { 35 struct rb_node **link = &phys_to_mach.rb_node; 36 struct rb_node *parent = NULL; 37 struct xen_p2m_entry *entry; 38 int rc = 0; 39 40 while (*link) { 41 parent = *link; 42 entry = rb_entry(parent, struct xen_p2m_entry, rbnode_phys); 43 44 if (new->pfn == entry->pfn) 45 goto err_out; 46 47 if (new->pfn < entry->pfn) 48 link = &(*link)->rb_left; 49 else 50 link = &(*link)->rb_right; 51 } 52 rb_link_node(&new->rbnode_phys, parent, link); 53 rb_insert_color(&new->rbnode_phys, &phys_to_mach); 54 goto out; 55 56 err_out: 57 rc = -EINVAL; 58 pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n", 59 __func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn); 60 out: 61 return rc; 62 } 63 64 unsigned long __pfn_to_mfn(unsigned long pfn) 65 { 66 struct rb_node *n; 67 struct xen_p2m_entry *entry; 68 unsigned long irqflags; 69 70 read_lock_irqsave(&p2m_lock, irqflags); 71 n = phys_to_mach.rb_node; 72 while (n) { 73 entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys); 74 if (entry->pfn <= pfn && 75 entry->pfn + entry->nr_pages > pfn) { 76 unsigned long mfn = entry->mfn + (pfn - entry->pfn); 77 read_unlock_irqrestore(&p2m_lock, irqflags); 78 return mfn; 79 } 80 if (pfn < entry->pfn) 81 n = n->rb_left; 82 else 83 n = n->rb_right; 84 } 85 read_unlock_irqrestore(&p2m_lock, irqflags); 86 87 return INVALID_P2M_ENTRY; 88 } 89 EXPORT_SYMBOL_GPL(__pfn_to_mfn); 90 91 int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, 92 struct gnttab_map_grant_ref *kmap_ops, 93 struct page **pages, unsigned int count) 94 { 95 int i; 96 97 for (i = 0; i < count; i++) { 98 struct gnttab_unmap_grant_ref unmap; 99 int rc; 100 101 if (map_ops[i].status) 102 continue; 103 if (likely(set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT, 104 map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT))) 105 continue; 106 107 /* 108 * Signal an error for this slot. This in turn requires 109 * immediate unmapping. 110 */ 111 map_ops[i].status = GNTST_general_error; 112 unmap.host_addr = map_ops[i].host_addr; 113 unmap.handle = map_ops[i].handle; 114 map_ops[i].handle = INVALID_GRANT_HANDLE; 115 if (map_ops[i].flags & GNTMAP_device_map) 116 unmap.dev_bus_addr = map_ops[i].dev_bus_addr; 117 else 118 unmap.dev_bus_addr = 0; 119 120 /* 121 * Pre-populate the status field, to be recognizable in 122 * the log message below. 123 */ 124 unmap.status = 1; 125 126 rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, 127 &unmap, 1); 128 if (rc || unmap.status != GNTST_okay) 129 pr_err_once("gnttab unmap failed: rc=%d st=%d\n", 130 rc, unmap.status); 131 } 132 133 return 0; 134 } 135 136 int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, 137 struct gnttab_unmap_grant_ref *kunmap_ops, 138 struct page **pages, unsigned int count) 139 { 140 int i; 141 142 for (i = 0; i < count; i++) { 143 set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT, 144 INVALID_P2M_ENTRY); 145 } 146 147 return 0; 148 } 149 150 bool __set_phys_to_machine_multi(unsigned long pfn, 151 unsigned long mfn, unsigned long nr_pages) 152 { 153 int rc; 154 unsigned long irqflags; 155 struct xen_p2m_entry *p2m_entry; 156 struct rb_node *n; 157 158 if (mfn == INVALID_P2M_ENTRY) { 159 write_lock_irqsave(&p2m_lock, irqflags); 160 n = phys_to_mach.rb_node; 161 while (n) { 162 p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys); 163 if (p2m_entry->pfn <= pfn && 164 p2m_entry->pfn + p2m_entry->nr_pages > pfn) { 165 rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach); 166 write_unlock_irqrestore(&p2m_lock, irqflags); 167 kfree(p2m_entry); 168 return true; 169 } 170 if (pfn < p2m_entry->pfn) 171 n = n->rb_left; 172 else 173 n = n->rb_right; 174 } 175 write_unlock_irqrestore(&p2m_lock, irqflags); 176 return true; 177 } 178 179 p2m_entry = kzalloc(sizeof(*p2m_entry), GFP_NOWAIT); 180 if (!p2m_entry) 181 return false; 182 183 p2m_entry->pfn = pfn; 184 p2m_entry->nr_pages = nr_pages; 185 p2m_entry->mfn = mfn; 186 187 write_lock_irqsave(&p2m_lock, irqflags); 188 rc = xen_add_phys_to_mach_entry(p2m_entry); 189 if (rc < 0) { 190 write_unlock_irqrestore(&p2m_lock, irqflags); 191 kfree(p2m_entry); 192 return false; 193 } 194 write_unlock_irqrestore(&p2m_lock, irqflags); 195 return true; 196 } 197 EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi); 198 199 bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) 200 { 201 return __set_phys_to_machine_multi(pfn, mfn, 1); 202 } 203 EXPORT_SYMBOL_GPL(__set_phys_to_machine); 204 205 static int p2m_init(void) 206 { 207 rwlock_init(&p2m_lock); 208 return 0; 209 } 210 arch_initcall(p2m_init); 211