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/param.h> 28 #include <sys/systm.h> 29 #include <sys/bus.h> 30 #include <sys/kernel.h> 31 #include <sys/module.h> 32 #include <sys/pcpu.h> 33 #include <sys/rman.h> 34 #include <sys/smp.h> 35 #include <sys/limits.h> 36 #include <sys/vmmeter.h> 37 38 #include <vm/vm.h> 39 #include <vm/vm_page.h> 40 #include <vm/vm_param.h> 41 #include <vm/vm_phys.h> 42 43 #include <xen/xen-os.h> 44 #include <xen/gnttab.h> 45 46 #include "xenmem_if.h" 47 48 /* 49 * Allocate unused physical memory above 4GB in order to map memory 50 * from foreign domains. We use memory starting at 4GB in order to 51 * prevent clashes with MMIO/ACPI regions. 52 * 53 * Since this is not possible on i386 just use any available memory 54 * chunk above 1MB and hope we don't clash with anything else. 55 * 56 * Other architectures better document MMIO regions and drivers more 57 * reliably reserve them. As such, allow using any unpopulated memory 58 * region. 59 */ 60 #ifdef __amd64__ 61 #define LOW_MEM_LIMIT 0x100000000ul 62 #elif defined(__i386__) 63 #define LOW_MEM_LIMIT 0x100000ul 64 #else 65 #define LOW_MEM_LIMIT 0 66 #endif 67 68 static void 69 xenpv_identify(driver_t *driver, device_t parent) 70 { 71 if (!xen_domain()) 72 return; 73 74 /* Make sure there's only one xenpv device. */ 75 if (devclass_get_device(devclass_find(driver->name), 0)) 76 return; 77 78 /* 79 * The xenpv bus should be the last to attach in order 80 * to properly detect if an ISA bus has already been added. 81 */ 82 if (BUS_ADD_CHILD(parent, UINT_MAX, driver->name, 0) == NULL) 83 panic("Unable to attach xenpv bus."); 84 } 85 86 static int 87 xenpv_probe(device_t dev) 88 { 89 90 device_set_desc(dev, "Xen PV bus"); 91 return (BUS_PROBE_NOWILDCARD); 92 } 93 94 static int 95 xenpv_attach(device_t dev) 96 { 97 int error; 98 99 /* 100 * Let our child drivers identify any child devices that they 101 * can find. Once that is done attach any devices that we 102 * found. 103 */ 104 error = bus_generic_probe(dev); 105 if (error) 106 return (error); 107 108 error = bus_generic_attach(dev); 109 110 return (error); 111 } 112 113 static struct resource * 114 xenpv_alloc_physmem(device_t dev, device_t child, int *res_id, size_t size) 115 { 116 struct resource *res; 117 vm_paddr_t phys_addr; 118 void *virt_addr; 119 int error; 120 121 res = bus_alloc_resource(child, SYS_RES_MEMORY, res_id, LOW_MEM_LIMIT, 122 ~0, size, RF_ACTIVE | RF_UNMAPPED); 123 if (res == NULL) 124 return (NULL); 125 126 phys_addr = rman_get_start(res); 127 error = vm_phys_fictitious_reg_range(phys_addr, phys_addr + size, 128 VM_MEMATTR_XEN); 129 if (error) { 130 bus_release_resource(child, SYS_RES_MEMORY, *res_id, res); 131 return (NULL); 132 } 133 virt_addr = pmap_mapdev_attr(phys_addr, size, VM_MEMATTR_XEN); 134 KASSERT(virt_addr != NULL, ("Failed to create linear mappings")); 135 rman_set_virtual(res, virt_addr); 136 137 return (res); 138 } 139 140 static int 141 xenpv_free_physmem(device_t dev, device_t child, int res_id, struct resource *res) 142 { 143 vm_paddr_t phys_addr; 144 void *virt_addr; 145 size_t size; 146 147 phys_addr = rman_get_start(res); 148 size = rman_get_size(res); 149 virt_addr = rman_get_virtual(res); 150 151 pmap_unmapdev(virt_addr, size); 152 vm_phys_fictitious_unreg_range(phys_addr, phys_addr + size); 153 return (bus_release_resource(child, SYS_RES_MEMORY, res_id, res)); 154 } 155 156 static device_method_t xenpv_methods[] = { 157 /* Device interface */ 158 DEVMETHOD(device_identify, xenpv_identify), 159 DEVMETHOD(device_probe, xenpv_probe), 160 DEVMETHOD(device_attach, xenpv_attach), 161 DEVMETHOD(device_suspend, bus_generic_suspend), 162 DEVMETHOD(device_resume, bus_generic_resume), 163 164 /* Bus interface */ 165 DEVMETHOD(bus_add_child, bus_generic_add_child), 166 DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource), 167 DEVMETHOD(bus_release_resource, bus_generic_release_resource), 168 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), 169 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), 170 171 /* Interface to allocate memory for foreign mappings */ 172 DEVMETHOD(xenmem_alloc, xenpv_alloc_physmem), 173 DEVMETHOD(xenmem_free, xenpv_free_physmem), 174 175 DEVMETHOD_END 176 }; 177 178 static driver_t xenpv_driver = { 179 "xenpv", 180 xenpv_methods, 181 0, 182 }; 183 184 DRIVER_MODULE(xenpv, nexus, xenpv_driver, 0, 0); 185 186 struct resource * 187 xenmem_alloc(device_t dev, int *res_id, size_t size) 188 { 189 device_t parent; 190 191 parent = device_get_parent(dev); 192 if (parent == NULL) 193 return (NULL); 194 return (XENMEM_ALLOC(parent, dev, res_id, size)); 195 } 196 197 int 198 xenmem_free(device_t dev, int res_id, struct resource *res) 199 { 200 device_t parent; 201 202 parent = device_get_parent(dev); 203 if (parent == NULL) 204 return (ENXIO); 205 return (XENMEM_FREE(parent, dev, res_id, res)); 206 } 207