uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size, uint8_t lock) { MapCacheEntry *entry, *pentry = NULL; hwaddr address_index; hwaddr address_offset; hwaddr cache_size = size; hwaddr test_bit_size; bool translated = false; tryagain: address_index = phys_addr >> MCACHE_BUCKET_SHIFT; address_offset = phys_addr & (MCACHE_BUCKET_SIZE - 1); trace_xen_map_cache(phys_addr); /* test_bit_size is always a multiple of XC_PAGE_SIZE */ if (size) { test_bit_size = size + (phys_addr & (XC_PAGE_SIZE - 1)); if (test_bit_size % XC_PAGE_SIZE) { test_bit_size += XC_PAGE_SIZE - (test_bit_size % XC_PAGE_SIZE); } } else { test_bit_size = XC_PAGE_SIZE; } if (mapcache->last_entry != NULL && mapcache->last_entry->paddr_index == address_index && !lock && !size && test_bits(address_offset >> XC_PAGE_SHIFT, test_bit_size >> XC_PAGE_SHIFT, mapcache->last_entry->valid_mapping)) { trace_xen_map_cache_return(mapcache->last_entry->vaddr_base + address_offset); return mapcache->last_entry->vaddr_base + address_offset; } /* size is always a multiple of MCACHE_BUCKET_SIZE */ if (size) { cache_size = size + address_offset; if (cache_size % MCACHE_BUCKET_SIZE) { cache_size += MCACHE_BUCKET_SIZE - (cache_size % MCACHE_BUCKET_SIZE); } } else { cache_size = MCACHE_BUCKET_SIZE; } entry = &mapcache->entry[address_index % mapcache->nr_buckets]; while (entry && entry->lock && entry->vaddr_base && (entry->paddr_index != address_index || entry->size != cache_size || !test_bits(address_offset >> XC_PAGE_SHIFT, test_bit_size >> XC_PAGE_SHIFT, entry->valid_mapping))) { pentry = entry; entry = entry->next; } if (!entry) { entry = g_malloc0(sizeof (MapCacheEntry)); pentry->next = entry; xen_remap_bucket(entry, cache_size, address_index); } else if (!entry->lock) { if (!entry->vaddr_base || entry->paddr_index != address_index || entry->size != cache_size || !test_bits(address_offset >> XC_PAGE_SHIFT, test_bit_size >> XC_PAGE_SHIFT, entry->valid_mapping)) { xen_remap_bucket(entry, cache_size, address_index); } } if(!test_bits(address_offset >> XC_PAGE_SHIFT, test_bit_size >> XC_PAGE_SHIFT, entry->valid_mapping)) { mapcache->last_entry = NULL; if (!translated && mapcache->phys_offset_to_gaddr) { phys_addr = mapcache->phys_offset_to_gaddr(phys_addr, size, mapcache->opaque); translated = true; goto tryagain; } trace_xen_map_cache_return(NULL); return NULL; } mapcache->last_entry = entry; if (lock) { MapCacheRev *reventry = g_malloc0(sizeof(MapCacheRev)); entry->lock++; reventry->vaddr_req = mapcache->last_entry->vaddr_base + address_offset; reventry->paddr_index = mapcache->last_entry->paddr_index; reventry->size = entry->size; QTAILQ_INSERT_HEAD(&mapcache->locked_entries, reventry, next); } trace_xen_map_cache_return(mapcache->last_entry->vaddr_base + address_offset); return mapcache->last_entry->vaddr_base + address_offset; }