LXR linux/arch/arm/xen/p2m.c

   1#include <linux/bootmem.h>
   2#include <linux/gfp.h>
   3#include <linux/export.h>
   4#include <linux/spinlock.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(*p2m_entry), GFP_NOWAIT);
 148        if (!p2m_entry)
 149                return false;
 150
 151        p2m_entry->pfn = pfn;
 152        p2m_entry->nr_pages = nr_pages;
 153        p2m_entry->mfn = mfn;
 154
 155        write_lock_irqsave(&p2m_lock, irqflags);
 156        rc = xen_add_phys_to_mach_entry(p2m_entry);
 157        if (rc < 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);
 178