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/page.h> 15 #include <xen/swiotlb-xen.h> 16 17 #include <asm/cacheflush.h> 18 #include <asm/xen/hypercall.h> 19 #include <asm/xen/interface.h> 20 21 struct xen_p2m_entry { 22 unsigned long pfn; 23 unsigned long mfn; 24 unsigned long nr_pages; 25 struct rb_node rbnode_phys; 26 }; 27 28 static rwlock_t p2m_lock; 29 struct rb_root phys_to_mach = RB_ROOT; 30 EXPORT_SYMBOL_GPL(phys_to_mach); 31 32 static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new) 33 { 34 struct rb_node **link = &phys_to_mach.rb_node; 35 struct rb_node *parent = NULL; 36 struct xen_p2m_entry *entry; 37 int rc = 0; 38 39 while (*link) { 40 parent = *link; 41 entry = rb_entry(parent, struct xen_p2m_entry, rbnode_phys); 42 43 if (new->pfn == entry->pfn) 44 goto err_out; 45 46 if (new->pfn < entry->pfn) 47 link = &(*link)->rb_left; 48 else 49 link = &(*link)->rb_right; 50 } 51 rb_link_node(&new->rbnode_phys, parent, link); 52 rb_insert_color(&new->rbnode_phys, &phys_to_mach); 53 goto out; 54 55 err_out: 56 rc = -EINVAL; 57 pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n", 58 __func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn); 59 out: 60 return rc; 61 } 62 63 unsigned long __pfn_to_mfn(unsigned long pfn) 64 { 65 struct rb_node *n = phys_to_mach.rb_node; 66 struct xen_p2m_entry *entry; 67 unsigned long irqflags; 68 69 read_lock_irqsave(&p2m_lock, irqflags); 70 while (n) { 71 entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys); 72 if (entry->pfn <= pfn && 73 entry->pfn + entry->nr_pages > pfn) { 74 unsigned long mfn = entry->mfn + (pfn - entry->pfn); 75 read_unlock_irqrestore(&p2m_lock, irqflags); 76 return mfn; 77 } 78 if (pfn < entry->pfn) 79 n = n->rb_left; 80 else 81 n = n->rb_right; 82 } 83 read_unlock_irqrestore(&p2m_lock, irqflags); 84 85 return INVALID_P2M_ENTRY; 86 } 87 EXPORT_SYMBOL_GPL(__pfn_to_mfn); 88 89 int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, 90 struct gnttab_map_grant_ref *kmap_ops, 91 struct page **pages, unsigned int count) 92 { 93 int i; 94 95 for (i = 0; i < count; i++) { 96 if (map_ops[i].status) 97 continue; 98 set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT, 99 map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT); 100 } 101 102 return 0; 103 } 104 EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping); 105 106 int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, 107 struct gnttab_unmap_grant_ref *kunmap_ops, 108 struct page **pages, unsigned int count) 109 { 110 int i; 111 112 for (i = 0; i < count; i++) { 113 set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT, 114 INVALID_P2M_ENTRY); 115 } 116 117 return 0; 118 } 119 EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping); 120 121 bool __set_phys_to_machine_multi(unsigned long pfn, 122 unsigned long mfn, unsigned long nr_pages) 123 { 124 int rc; 125 unsigned long irqflags; 126 struct xen_p2m_entry *p2m_entry; 127 struct rb_node *n = phys_to_mach.rb_node; 128 129 if (mfn == INVALID_P2M_ENTRY) { 130 write_lock_irqsave(&p2m_lock, irqflags); 131 while (n) { 132 p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys); 133 if (p2m_entry->pfn <= pfn && 134 p2m_entry->pfn + p2m_entry->nr_pages > pfn) { 135 rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach); 136 write_unlock_irqrestore(&p2m_lock, irqflags); 137 kfree(p2m_entry); 138 return true; 139 } 140 if (pfn < p2m_entry->pfn) 141 n = n->rb_left; 142 else 143 n = n->rb_right; 144 } 145 write_unlock_irqrestore(&p2m_lock, irqflags); 146 return true; 147 } 148 149 p2m_entry = kzalloc(sizeof(*p2m_entry), GFP_NOWAIT); 150 if (!p2m_entry) 151 return false; 152 153 p2m_entry->pfn = pfn; 154 p2m_entry->nr_pages = nr_pages; 155 p2m_entry->mfn = mfn; 156 157 write_lock_irqsave(&p2m_lock, irqflags); 158 rc = xen_add_phys_to_mach_entry(p2m_entry); 159 if (rc < 0) { 160 write_unlock_irqrestore(&p2m_lock, irqflags); 161 kfree(p2m_entry); 162 return false; 163 } 164 write_unlock_irqrestore(&p2m_lock, irqflags); 165 return true; 166 } 167 EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi); 168 169 bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) 170 { 171 return __set_phys_to_machine_multi(pfn, mfn, 1); 172 } 173 EXPORT_SYMBOL_GPL(__set_phys_to_machine); 174 175 static int p2m_init(void) 176 { 177 rwlock_init(&p2m_lock); 178 return 0; 179 } 180 arch_initcall(p2m_init); 181