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 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/bus.h> 33 #include <sys/kernel.h> 34 #include <sys/module.h> 35 #include <sys/pcpu.h> 36 #include <sys/rman.h> 37 #include <sys/smp.h> 38 #include <sys/limits.h> 39 #include <sys/vmmeter.h> 40 41 #include <vm/vm.h> 42 #include <vm/vm_page.h> 43 #include <vm/vm_param.h> 44 #include <vm/vm_phys.h> 45 46 #include <xen/xen-os.h> 47 #include <xen/gnttab.h> 48 49 #include "xenmem_if.h" 50 51 /* 52 * Allocate unused physical memory above 4GB in order to map memory 53 * from foreign domains. We use memory starting at 4GB in order to 54 * prevent clashes with MMIO/ACPI regions. 55 * 56 * Since this is not possible on i386 just use any available memory 57 * chunk above 1MB and hope we don't clash with anything else. 58 * 59 * Other architectures better document MMIO regions and drivers more 60 * reliably reserve them. As such, allow using any unpopulated memory 61 * region. 62 */ 63 #ifdef __amd64__ 64 #define LOW_MEM_LIMIT 0x100000000ul 65 #elif defined(__i386__) 66 #define LOW_MEM_LIMIT 0x100000ul 67 #else 68 #define LOW_MEM_LIMIT 0 69 #endif 70 71 static void 72 xenpv_identify(driver_t *driver, device_t parent) 73 { 74 if (!xen_domain()) 75 return; 76 77 /* Make sure there's only one xenpv device. */ 78 if (devclass_get_device(devclass_find(driver->name), 0)) 79 return; 80 81 /* 82 * The xenpv bus should be the last to attach in order 83 * to properly detect if an ISA bus has already been added. 84 */ 85 if (BUS_ADD_CHILD(parent, UINT_MAX, driver->name, 0) == NULL) 86 panic("Unable to attach xenpv bus."); 87 } 88 89 static int 90 xenpv_probe(device_t dev) 91 { 92 93 device_set_desc(dev, "Xen PV bus"); 94 return (BUS_PROBE_NOWILDCARD); 95 } 96 97 static int 98 xenpv_attach(device_t dev) 99 { 100 int error; 101 102 /* 103 * Let our child drivers identify any child devices that they 104 * can find. Once that is done attach any devices that we 105 * found. 106 */ 107 error = bus_generic_probe(dev); 108 if (error) 109 return (error); 110 111 error = bus_generic_attach(dev); 112 113 return (error); 114 } 115 116 static struct resource * 117 xenpv_alloc_physmem(device_t dev, device_t child, int *res_id, size_t size) 118 { 119 struct resource *res; 120 vm_paddr_t phys_addr; 121 void *virt_addr; 122 int error; 123 124 res = bus_alloc_resource(child, SYS_RES_MEMORY, res_id, LOW_MEM_LIMIT, 125 ~0, size, RF_ACTIVE | RF_UNMAPPED); 126 if (res == NULL) 127 return (NULL); 128 129 phys_addr = rman_get_start(res); 130 error = vm_phys_fictitious_reg_range(phys_addr, phys_addr + size, 131 VM_MEMATTR_XEN); 132 if (error) { 133 bus_release_resource(child, SYS_RES_MEMORY, *res_id, res); 134 return (NULL); 135 } 136 virt_addr = pmap_mapdev_attr(phys_addr, size, VM_MEMATTR_XEN); 137 KASSERT(virt_addr != NULL, ("Failed to create linear mappings")); 138 rman_set_virtual(res, virt_addr); 139 140 return (res); 141 } 142 143 static int 144 xenpv_free_physmem(device_t dev, device_t child, int res_id, struct resource *res) 145 { 146 vm_paddr_t phys_addr; 147 void *virt_addr; 148 size_t size; 149 150 phys_addr = rman_get_start(res); 151 size = rman_get_size(res); 152 virt_addr = rman_get_virtual(res); 153 154 pmap_unmapdev(virt_addr, size); 155 vm_phys_fictitious_unreg_range(phys_addr, phys_addr + size); 156 return (bus_release_resource(child, SYS_RES_MEMORY, res_id, res)); 157 } 158 159 static device_method_t xenpv_methods[] = { 160 /* Device interface */ 161 DEVMETHOD(device_identify, xenpv_identify), 162 DEVMETHOD(device_probe, xenpv_probe), 163 DEVMETHOD(device_attach, xenpv_attach), 164 DEVMETHOD(device_suspend, bus_generic_suspend), 165 DEVMETHOD(device_resume, bus_generic_resume), 166 167 /* Bus interface */ 168 DEVMETHOD(bus_add_child, bus_generic_add_child), 169 DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource), 170 DEVMETHOD(bus_release_resource, bus_generic_release_resource), 171 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), 172 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), 173 174 /* Interface to allocate memory for foreign mappings */ 175 DEVMETHOD(xenmem_alloc, xenpv_alloc_physmem), 176 DEVMETHOD(xenmem_free, xenpv_free_physmem), 177 178 DEVMETHOD_END 179 }; 180 181 static driver_t xenpv_driver = { 182 "xenpv", 183 xenpv_methods, 184 0, 185 }; 186 187 DRIVER_MODULE(xenpv, nexus, xenpv_driver, 0, 0); 188 189 struct resource * 190 xenmem_alloc(device_t dev, int *res_id, size_t size) 191 { 192 device_t parent; 193 194 parent = device_get_parent(dev); 195 if (parent == NULL) 196 return (NULL); 197 return (XENMEM_ALLOC(parent, dev, res_id, size)); 198 } 199 200 int 201 xenmem_free(device_t dev, int res_id, struct resource *res) 202 { 203 device_t parent; 204 205 parent = device_get_parent(dev); 206 if (parent == NULL) 207 return (ENXIO); 208 return (XENMEM_FREE(parent, dev, res_id, res)); 209 } 210