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 devclass_t xenpv_devclass; 72 73 static void 74 xenpv_identify(driver_t *driver, device_t parent) 75 { 76 if (!xen_domain()) 77 return; 78 79 /* Make sure there's only one xenpv device. */ 80 if (devclass_get_device(xenpv_devclass, 0)) 81 return; 82 83 /* 84 * The xenpv bus should be the last to attach in order 85 * to properly detect if an ISA bus has already been added. 86 */ 87 if (BUS_ADD_CHILD(parent, UINT_MAX, "xenpv", 0) == NULL) 88 panic("Unable to attach xenpv bus."); 89 } 90 91 static int 92 xenpv_probe(device_t dev) 93 { 94 95 device_set_desc(dev, "Xen PV bus"); 96 return (BUS_PROBE_NOWILDCARD); 97 } 98 99 static int 100 xenpv_attach(device_t dev) 101 { 102 int error; 103 104 /* 105 * Let our child drivers identify any child devices that they 106 * can find. Once that is done attach any devices that we 107 * found. 108 */ 109 error = bus_generic_probe(dev); 110 if (error) 111 return (error); 112 113 error = bus_generic_attach(dev); 114 115 return (error); 116 } 117 118 static struct resource * 119 xenpv_alloc_physmem(device_t dev, device_t child, int *res_id, size_t size) 120 { 121 struct resource *res; 122 vm_paddr_t phys_addr; 123 int error; 124 125 res = bus_alloc_resource(child, SYS_RES_MEMORY, res_id, LOW_MEM_LIMIT, 126 ~0, size, RF_ACTIVE); 127 if (res == NULL) 128 return (NULL); 129 130 phys_addr = rman_get_start(res); 131 error = vm_phys_fictitious_reg_range(phys_addr, phys_addr + size, 132 VM_MEMATTR_XEN); 133 if (error) { 134 bus_release_resource(child, SYS_RES_MEMORY, *res_id, res); 135 return (NULL); 136 } 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 size_t size; 146 147 phys_addr = rman_get_start(res); 148 size = rman_get_size(res); 149 150 vm_phys_fictitious_unreg_range(phys_addr, phys_addr + size); 151 return (bus_release_resource(child, SYS_RES_MEMORY, res_id, res)); 152 } 153 154 static device_method_t xenpv_methods[] = { 155 /* Device interface */ 156 DEVMETHOD(device_identify, xenpv_identify), 157 DEVMETHOD(device_probe, xenpv_probe), 158 DEVMETHOD(device_attach, xenpv_attach), 159 DEVMETHOD(device_suspend, bus_generic_suspend), 160 DEVMETHOD(device_resume, bus_generic_resume), 161 162 /* Bus interface */ 163 DEVMETHOD(bus_add_child, bus_generic_add_child), 164 DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource), 165 DEVMETHOD(bus_release_resource, bus_generic_release_resource), 166 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), 167 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), 168 169 /* Interface to allocate memory for foreign mappings */ 170 DEVMETHOD(xenmem_alloc, xenpv_alloc_physmem), 171 DEVMETHOD(xenmem_free, xenpv_free_physmem), 172 173 DEVMETHOD_END 174 }; 175 176 static driver_t xenpv_driver = { 177 "xenpv", 178 xenpv_methods, 179 0, 180 }; 181 182 DRIVER_MODULE(xenpv, nexus, xenpv_driver, xenpv_devclass, 0, 0); 183 184 struct resource * 185 xenmem_alloc(device_t dev, int *res_id, size_t size) 186 { 187 device_t parent; 188 189 parent = device_get_parent(dev); 190 if (parent == NULL) 191 return (NULL); 192 return (XENMEM_ALLOC(parent, dev, res_id, size)); 193 } 194 195 int 196 xenmem_free(device_t dev, int res_id, struct resource *res) 197 { 198 device_t parent; 199 200 parent = device_get_parent(dev); 201 if (parent == NULL) 202 return (ENXIO); 203 return (XENMEM_FREE(parent, dev, res_id, res)); 204 } 205