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 = phys_to_mach.rb_node; 67 struct xen_p2m_entry *entry; 68 unsigned long irqflags; 69 70 read_lock_irqsave(&p2m_lock, irqflags); 71 while (n) { 72 entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys); 73 if (entry->pfn <= pfn && 74 entry->pfn + entry->nr_pages > pfn) { 75 unsigned long mfn = entry->mfn + (pfn - entry->pfn); 76 read_unlock_irqrestore(&p2m_lock, irqflags); 77 return mfn; 78 } 79 if (pfn < entry->pfn) 80 n = n->rb_left; 81 else 82 n = n->rb_right; 83 } 84 read_unlock_irqrestore(&p2m_lock, irqflags); 85 86 return INVALID_P2M_ENTRY; 87 } 88 EXPORT_SYMBOL_GPL(__pfn_to_mfn); 89 90 int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, 91 struct gnttab_map_grant_ref *kmap_ops, 92 struct page **pages, unsigned int count) 93 { 94 int i; 95 96 for (i = 0; i < count; i++) { 97 struct gnttab_unmap_grant_ref unmap; 98 int rc; 99 100 if (map_ops[i].status) 101 continue; 102 if (likely(set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT, 103 map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT))) 104 continue; 105 106 /* 107 * Signal an error for this slot. This in turn requires 108 * immediate unmapping. 109 */ 110 map_ops[i].status = GNTST_general_error; 111 unmap.host_addr = map_ops[i].host_addr, 112 unmap.handle = map_ops[i].handle; 113 map_ops[i].handle = INVALID_GRANT_HANDLE; 114 if (map_ops[i].flags & GNTMAP_device_map) 115 unmap.dev_bus_addr = map_ops[i].dev_bus_addr; 116 else 117 unmap.dev_bus_addr = 0; 118 119 /* 120 * Pre-populate the status field, to be recognizable in 121 * the log message below. 122 */ 123 unmap.status = 1; 124 125 rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, 126 &unmap, 1); 127 if (rc || unmap.status != GNTST_okay) 128 pr_err_once("gnttab unmap failed: rc=%d st=%d\n", 129 rc, unmap.status); 130 } 131 132 return 0; 133 } 134 135 int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, 136 struct gnttab_unmap_grant_ref *kunmap_ops, 137 struct page **pages, unsigned int count) 138 { 139 int i; 140 141 for (i = 0; i < count; i++) { 142 set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT, 143 INVALID_P2M_ENTRY); 144 } 145 146 return 0; 147 } 148 149 bool __set_phys_to_machine_multi(unsigned long pfn, 150 unsigned long mfn, unsigned long nr_pages) 151 { 152 int rc; 153 unsigned long irqflags; 154 struct xen_p2m_entry *p2m_entry; 155 struct rb_node *n = phys_to_mach.rb_node; 156 157 if (mfn == INVALID_P2M_ENTRY) { 158 write_lock_irqsave(&p2m_lock, irqflags); 159 while (n) { 160 p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys); 161 if (p2m_entry->pfn <= pfn && 162 p2m_entry->pfn + p2m_entry->nr_pages > pfn) { 163 rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach); 164 write_unlock_irqrestore(&p2m_lock, irqflags); 165 kfree(p2m_entry); 166 return true; 167 } 168 if (pfn < p2m_entry->pfn) 169 n = n->rb_left; 170 else 171 n = n->rb_right; 172 } 173 write_unlock_irqrestore(&p2m_lock, irqflags); 174 return true; 175 } 176 177 p2m_entry = kzalloc(sizeof(*p2m_entry), GFP_NOWAIT); 178 if (!p2m_entry) 179 return false; 180 181 p2m_entry->pfn = pfn; 182 p2m_entry->nr_pages = nr_pages; 183 p2m_entry->mfn = mfn; 184 185 write_lock_irqsave(&p2m_lock, irqflags); 186 rc = xen_add_phys_to_mach_entry(p2m_entry); 187 if (rc < 0) { 188 write_unlock_irqrestore(&p2m_lock, irqflags); 189 kfree(p2m_entry); 190 return false; 191 } 192 write_unlock_irqrestore(&p2m_lock, irqflags); 193 return true; 194 } 195 EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi); 196 197 bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) 198 { 199 return __set_phys_to_machine_multi(pfn, mfn, 1); 200 } 201 EXPORT_SYMBOL_GPL(__set_phys_to_machine); 202 203 static int p2m_init(void) 204 { 205 rwlock_init(&p2m_lock); 206 return 0; 207 } 208 arch_initcall(p2m_init); 209