1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2023 Arm Ltd 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/bus.h> 32 #include <sys/cpu.h> 33 #include <sys/kernel.h> 34 #include <sys/module.h> 35 36 #include <dev/fdt/simplebus.h> 37 #include <dev/fdt/fdt_common.h> 38 #include <dev/ofw/ofw_bus_subr.h> 39 40 #include <dev/virtio/scmi/virtio_scmi.h> 41 42 #include "scmi.h" 43 #include "scmi_protocols.h" 44 45 #define SCMI_VIRTIO_POLLING_INTERVAL_MS 2 46 47 struct scmi_virtio_softc { 48 struct scmi_softc base; 49 device_t virtio_dev; 50 int cmdq_sz; 51 int evtq_sz; 52 void *p2a_pool; 53 }; 54 55 static void scmi_virtio_callback(void *, unsigned int, void *); 56 static void *scmi_virtio_p2a_pool_init(device_t, unsigned int); 57 static int scmi_virtio_transport_init(device_t); 58 static void scmi_virtio_transport_cleanup(device_t); 59 static int scmi_virtio_xfer_msg(device_t, struct scmi_msg *); 60 static int scmi_virtio_poll_msg(device_t, struct scmi_msg *, unsigned int); 61 static void scmi_virtio_clear_channel(device_t, void *); 62 static int scmi_virtio_probe(device_t); 63 static int scmi_virtio_attach(device_t); 64 65 static void 66 scmi_virtio_callback(void *msg, unsigned int len, void *priv) 67 { 68 struct scmi_virtio_softc *sc; 69 uint32_t hdr; 70 71 sc = priv; 72 73 if (msg == NULL || len < sizeof(hdr)) { 74 device_printf(sc->virtio_dev, "Ignoring malformed message.\n"); 75 return; 76 } 77 78 hdr = le32toh(*((uint32_t *)msg)); 79 scmi_rx_irq_callback(sc->base.dev, msg, hdr); 80 } 81 82 static void * 83 scmi_virtio_p2a_pool_init(device_t dev, unsigned int max_msg) 84 { 85 struct scmi_virtio_softc *sc; 86 void *pool; 87 uint8_t *buf; 88 int i; 89 90 sc = device_get_softc(dev); 91 92 pool = mallocarray(max_msg, SCMI_MAX_MSG_SIZE, M_DEVBUF, 93 M_ZERO | M_WAITOK); 94 95 for (i = 0, buf = pool; i < max_msg; i++, buf += SCMI_MAX_MSG_SIZE) { 96 /* Feed platform with pre-allocated P2A buffers */ 97 virtio_scmi_message_enqueue(sc->virtio_dev, 98 VIRTIO_SCMI_CHAN_P2A, buf, 0, SCMI_MAX_MSG_SIZE); 99 } 100 101 device_printf(dev, 102 "Fed %d initial P2A buffers to platform.\n", max_msg); 103 104 return (pool); 105 } 106 107 static void 108 scmi_virtio_clear_channel(device_t dev, void *msg) 109 { 110 struct scmi_virtio_softc *sc; 111 112 sc = device_get_softc(dev); 113 virtio_scmi_message_enqueue(sc->virtio_dev, VIRTIO_SCMI_CHAN_P2A, 114 msg, 0, SCMI_MAX_MSG_SIZE); 115 } 116 117 static int 118 scmi_virtio_transport_init(device_t dev) 119 { 120 struct scmi_virtio_softc *sc; 121 int ret; 122 123 sc = device_get_softc(dev); 124 125 sc->cmdq_sz = virtio_scmi_channel_size_get(sc->virtio_dev, 126 VIRTIO_SCMI_CHAN_A2P); 127 sc->evtq_sz = virtio_scmi_channel_size_get(sc->virtio_dev, 128 VIRTIO_SCMI_CHAN_P2A); 129 130 if (!sc->cmdq_sz) { 131 device_printf(dev, 132 "VirtIO cmdq virtqueue not found. Aborting.\n"); 133 return (ENXIO); 134 } 135 136 /* 137 * P2A buffers are owned by the platform initially; allocate a feed an 138 * appropriate number of buffers. 139 */ 140 if (sc->evtq_sz != 0) { 141 sc->p2a_pool = scmi_virtio_p2a_pool_init(dev, sc->evtq_sz); 142 if (sc->p2a_pool == NULL) 143 return (ENOMEM); 144 } 145 146 /* Note that setting a callback also enables that VQ interrupts */ 147 ret = virtio_scmi_channel_callback_set(sc->virtio_dev, 148 VIRTIO_SCMI_CHAN_A2P, scmi_virtio_callback, sc); 149 if (ret) { 150 device_printf(dev, "Failed to set VirtIO cmdq callback.\n"); 151 return (ENXIO); 152 } 153 154 device_printf(dev, 155 "VirtIO cmdq virtqueue configured - cmdq_sz:%d\n", sc->cmdq_sz); 156 157 /* P2A channel is optional */ 158 if (sc->evtq_sz) { 159 ret = virtio_scmi_channel_callback_set(sc->virtio_dev, 160 VIRTIO_SCMI_CHAN_P2A, scmi_virtio_callback, sc); 161 if (ret == 0) { 162 device_printf(dev, 163 "VirtIO evtq virtqueue configured - evtq_sz:%d\n", 164 sc->evtq_sz); 165 } else { 166 device_printf(dev, 167 "Failed to set VirtIO evtq callback.Skip.\n"); 168 sc->evtq_sz = 0; 169 } 170 } 171 172 sc->base.trs_desc.reply_timo_ms = 100; 173 174 return (0); 175 } 176 177 static void 178 scmi_virtio_transport_cleanup(device_t dev) 179 { 180 struct scmi_virtio_softc *sc; 181 182 sc = device_get_softc(dev); 183 184 if (sc->evtq_sz != 0) { 185 virtio_scmi_channel_callback_set(sc->virtio_dev, 186 VIRTIO_SCMI_CHAN_P2A, NULL, NULL); 187 free(sc->p2a_pool, M_DEVBUF); 188 } 189 190 virtio_scmi_channel_callback_set(sc->virtio_dev, 191 VIRTIO_SCMI_CHAN_A2P, NULL, NULL); 192 } 193 194 static int 195 scmi_virtio_xfer_msg(device_t dev, struct scmi_msg *msg) 196 { 197 struct scmi_virtio_softc *sc; 198 199 sc = device_get_softc(dev); 200 201 return (virtio_scmi_message_enqueue(sc->virtio_dev, 202 VIRTIO_SCMI_CHAN_A2P, &msg->hdr, msg->tx_len, msg->rx_len)); 203 } 204 205 static int 206 scmi_virtio_poll_msg(device_t dev, struct scmi_msg *msg, unsigned int tmo_ms) 207 { 208 struct scmi_virtio_softc *sc; 209 device_t vdev; 210 int tmo_loops; 211 212 sc = device_get_softc(dev); 213 vdev = sc->virtio_dev; 214 215 tmo_loops = tmo_ms / SCMI_VIRTIO_POLLING_INTERVAL_MS; 216 while (tmo_loops-- && atomic_load_acq_int(&msg->poll_done) == 0) { 217 struct scmi_msg *rx_msg; 218 void *rx_buf; 219 uint32_t rx_len; 220 221 rx_buf = virtio_scmi_message_poll(vdev, &rx_len); 222 if (rx_buf == NULL) { 223 DELAY(SCMI_VIRTIO_POLLING_INTERVAL_MS * 1000); 224 continue; 225 } 226 227 rx_msg = hdr_to_msg(rx_buf); 228 rx_msg->rx_len = rx_len; 229 /* Complete the polling on any poll path */ 230 if (rx_msg->polling) 231 atomic_store_rel_int(&rx_msg->poll_done, 1); 232 233 if (__predict_true(rx_msg == msg)) 234 break; 235 236 /* 237 * Polling returned an unexpected message: either a message 238 * polled by some other thread of execution or a message not 239 * supposed to be polled. 240 */ 241 device_printf(dev, "POLLED OoO HDR:|%08X| - polling:%d\n", 242 rx_msg->hdr, rx_msg->polling); 243 244 if (!rx_msg->polling) 245 scmi_rx_irq_callback(sc->base.dev, rx_msg, rx_msg->hdr); 246 } 247 248 return (tmo_loops > 0 ? 0 : ETIMEDOUT); 249 } 250 251 static int 252 scmi_virtio_probe(device_t dev) 253 { 254 if (!ofw_bus_is_compatible(dev, "arm,scmi-virtio")) 255 return (ENXIO); 256 257 if (!ofw_bus_status_okay(dev)) 258 return (ENXIO); 259 260 device_set_desc(dev, "ARM SCMI VirtIO Transport driver"); 261 262 return (BUS_PROBE_DEFAULT); 263 } 264 265 static int 266 scmi_virtio_attach(device_t dev) 267 { 268 struct scmi_virtio_softc *sc; 269 270 sc = device_get_softc(dev); 271 sc->virtio_dev = virtio_scmi_transport_get(); 272 if (sc->virtio_dev == NULL) 273 return (1); 274 275 /* When attach fails there is nothing to cleanup*/ 276 return (scmi_attach(dev)); 277 } 278 279 static device_method_t scmi_virtio_methods[] = { 280 DEVMETHOD(device_probe, scmi_virtio_probe), 281 DEVMETHOD(device_attach, scmi_virtio_attach), 282 283 /* SCMI interface */ 284 DEVMETHOD(scmi_transport_init, scmi_virtio_transport_init), 285 DEVMETHOD(scmi_transport_cleanup, scmi_virtio_transport_cleanup), 286 DEVMETHOD(scmi_xfer_msg, scmi_virtio_xfer_msg), 287 DEVMETHOD(scmi_poll_msg, scmi_virtio_poll_msg), 288 DEVMETHOD(scmi_clear_channel, scmi_virtio_clear_channel), 289 290 DEVMETHOD_END 291 }; 292 293 DEFINE_CLASS_1(scmi_virtio, scmi_virtio_driver, scmi_virtio_methods, 294 sizeof(struct scmi_virtio_softc), scmi_driver); 295 296 /* Needs to be after the mmio_sram driver */ 297 DRIVER_MODULE(scmi_virtio, simplebus, scmi_virtio_driver, 0, 0); 298 MODULE_VERSION(scmi_virtio, 1); 299