1 /* 2 * Copyright (c) 2014 Roger Pau Monné <roger.pau@citrix.com> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 #include <sys/param.h> 29 #include <sys/systm.h> 30 #include <sys/bus.h> 31 #include <sys/kernel.h> 32 #include <sys/module.h> 33 #include <sys/pcpu.h> 34 #include <sys/rman.h> 35 #include <sys/smp.h> 36 #include <sys/limits.h> 37 #include <sys/vmmeter.h> 38 39 #include <vm/vm.h> 40 #include <vm/vm_page.h> 41 #include <vm/vm_param.h> 42 #include <vm/vm_phys.h> 43 44 #include <xen/xen-os.h> 45 #include <xen/gnttab.h> 46 47 #include "xenmem_if.h" 48 49 /* 50 * Allocate unused physical memory above 4GB in order to map memory 51 * from foreign domains. We use memory starting at 4GB in order to 52 * prevent clashes with MMIO/ACPI regions. 53 * 54 * Since this is not possible on i386 just use any available memory 55 * chunk above 1MB and hope we don't clash with anything else. 56 * 57 * Other architectures better document MMIO regions and drivers more 58 * reliably reserve them. As such, allow using any unpopulated memory 59 * region. 60 */ 61 #ifdef __amd64__ 62 #define LOW_MEM_LIMIT 0x100000000ul 63 #elif defined(__i386__) 64 #define LOW_MEM_LIMIT 0x100000ul 65 #else 66 #define LOW_MEM_LIMIT 0 67 #endif 68 69 static void 70 xenpv_identify(driver_t *driver, device_t parent) 71 { 72 if (!xen_domain()) 73 return; 74 75 /* Make sure there's only one xenpv device. */ 76 if (devclass_get_device(devclass_find(driver->name), 0)) 77 return; 78 79 /* 80 * The xenpv bus should be the last to attach in order 81 * to properly detect if an ISA bus has already been added. 82 */ 83 if (BUS_ADD_CHILD(parent, UINT_MAX, driver->name, 0) == NULL) 84 panic("Unable to attach xenpv bus."); 85 } 86 87 static int 88 xenpv_probe(device_t dev) 89 { 90 91 device_set_desc(dev, "Xen PV bus"); 92 return (BUS_PROBE_NOWILDCARD); 93 } 94 95 static int 96 xenpv_attach(device_t dev) 97 { 98 int error; 99 100 /* 101 * Let our child drivers identify any child devices that they 102 * can find. Once that is done attach any devices that we 103 * found. 104 */ 105 error = bus_generic_probe(dev); 106 if (error) 107 return (error); 108 109 error = bus_generic_attach(dev); 110 111 return (error); 112 } 113 114 static struct resource * 115 xenpv_alloc_physmem(device_t dev, device_t child, int *res_id, size_t size) 116 { 117 struct resource *res; 118 vm_paddr_t phys_addr; 119 void *virt_addr; 120 int error; 121 122 res = bus_alloc_resource(child, SYS_RES_MEMORY, res_id, LOW_MEM_LIMIT, 123 ~0, size, RF_ACTIVE | RF_UNMAPPED); 124 if (res == NULL) 125 return (NULL); 126 127 phys_addr = rman_get_start(res); 128 error = vm_phys_fictitious_reg_range(phys_addr, phys_addr + size, 129 VM_MEMATTR_XEN); 130 if (error) { 131 bus_release_resource(child, SYS_RES_MEMORY, *res_id, res); 132 return (NULL); 133 } 134 virt_addr = pmap_mapdev_attr(phys_addr, size, VM_MEMATTR_XEN); 135 KASSERT(virt_addr != NULL, ("Failed to create linear mappings")); 136 rman_set_virtual(res, virt_addr); 137 138 return (res); 139 } 140 141 static int 142 xenpv_free_physmem(device_t dev, device_t child, int res_id, struct resource *res) 143 { 144 vm_paddr_t phys_addr; 145 void *virt_addr; 146 size_t size; 147 148 phys_addr = rman_get_start(res); 149 size = rman_get_size(res); 150 virt_addr = rman_get_virtual(res); 151 152 pmap_unmapdev(virt_addr, size); 153 vm_phys_fictitious_unreg_range(phys_addr, phys_addr + size); 154 return (bus_release_resource(child, SYS_RES_MEMORY, res_id, res)); 155 } 156 157 static device_method_t xenpv_methods[] = { 158 /* Device interface */ 159 DEVMETHOD(device_identify, xenpv_identify), 160 DEVMETHOD(device_probe, xenpv_probe), 161 DEVMETHOD(device_attach, xenpv_attach), 162 DEVMETHOD(device_suspend, bus_generic_suspend), 163 DEVMETHOD(device_resume, bus_generic_resume), 164 165 /* Bus interface */ 166 DEVMETHOD(bus_add_child, bus_generic_add_child), 167 DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource), 168 DEVMETHOD(bus_release_resource, bus_generic_release_resource), 169 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), 170 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), 171 172 /* Interface to allocate memory for foreign mappings */ 173 DEVMETHOD(xenmem_alloc, xenpv_alloc_physmem), 174 DEVMETHOD(xenmem_free, xenpv_free_physmem), 175 176 DEVMETHOD_END 177 }; 178 179 static driver_t xenpv_driver = { 180 "xenpv", 181 xenpv_methods, 182 0, 183 }; 184 185 DRIVER_MODULE(xenpv, nexus, xenpv_driver, 0, 0); 186 187 struct resource * 188 xenmem_alloc(device_t dev, int *res_id, size_t size) 189 { 190 device_t parent; 191 192 parent = device_get_parent(dev); 193 if (parent == NULL) 194 return (NULL); 195 return (XENMEM_ALLOC(parent, dev, res_id, size)); 196 } 197 198 int 199 xenmem_free(device_t dev, int res_id, struct resource *res) 200 { 201 device_t parent; 202 203 parent = device_get_parent(dev); 204 if (parent == NULL) 205 return (ENXIO); 206 return (XENMEM_FREE(parent, dev, res_id, res)); 207 } 208