1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AMD Platform Security Processor (PSP) interface 4 * 5 * Copyright (C) 2016,2019 Advanced Micro Devices, Inc. 6 * 7 * Author: Brijesh Singh <brijesh.singh@amd.com> 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/irqreturn.h> 12 #include <linux/mutex.h> 13 #include <linux/bitfield.h> 14 #include <linux/delay.h> 15 16 #include "sp-dev.h" 17 #include "psp-dev.h" 18 #include "sev-dev.h" 19 #include "tee-dev.h" 20 #include "platform-access.h" 21 #include "dbc.h" 22 23 struct psp_device *psp_master; 24 25 #define PSP_C2PMSG_17_CMDRESP_CMD GENMASK(19, 16) 26 27 static int psp_mailbox_poll(const void __iomem *cmdresp_reg, unsigned int *cmdresp, 28 unsigned int timeout_msecs) 29 { 30 while (true) { 31 *cmdresp = ioread32(cmdresp_reg); 32 if (FIELD_GET(PSP_CMDRESP_RESP, *cmdresp)) 33 return 0; 34 35 if (!timeout_msecs--) 36 break; 37 38 usleep_range(1000, 1100); 39 } 40 41 return -ETIMEDOUT; 42 } 43 44 int psp_mailbox_command(struct psp_device *psp, enum psp_cmd cmd, void *cmdbuff, 45 unsigned int timeout_msecs, unsigned int *cmdresp) 46 { 47 void __iomem *cmdresp_reg, *cmdbuff_lo_reg, *cmdbuff_hi_reg; 48 int ret; 49 50 if (!psp || !psp->vdata || !psp->vdata->cmdresp_reg || 51 !psp->vdata->cmdbuff_addr_lo_reg || !psp->vdata->cmdbuff_addr_hi_reg) 52 return -ENODEV; 53 54 cmdresp_reg = psp->io_regs + psp->vdata->cmdresp_reg; 55 cmdbuff_lo_reg = psp->io_regs + psp->vdata->cmdbuff_addr_lo_reg; 56 cmdbuff_hi_reg = psp->io_regs + psp->vdata->cmdbuff_addr_hi_reg; 57 58 mutex_lock(&psp->mailbox_mutex); 59 60 /* Ensure mailbox is ready for a command */ 61 ret = -EBUSY; 62 if (psp_mailbox_poll(cmdresp_reg, cmdresp, 0)) 63 goto unlock; 64 65 if (cmdbuff) { 66 iowrite32(lower_32_bits(__psp_pa(cmdbuff)), cmdbuff_lo_reg); 67 iowrite32(upper_32_bits(__psp_pa(cmdbuff)), cmdbuff_hi_reg); 68 } 69 70 *cmdresp = FIELD_PREP(PSP_C2PMSG_17_CMDRESP_CMD, cmd); 71 iowrite32(*cmdresp, cmdresp_reg); 72 73 ret = psp_mailbox_poll(cmdresp_reg, cmdresp, timeout_msecs); 74 75 unlock: 76 mutex_unlock(&psp->mailbox_mutex); 77 78 return ret; 79 } 80 81 int psp_extended_mailbox_cmd(struct psp_device *psp, unsigned int timeout_msecs, 82 struct psp_ext_request *req) 83 { 84 unsigned int reg; 85 int ret; 86 87 print_hex_dump_debug("->psp ", DUMP_PREFIX_OFFSET, 16, 2, req, 88 req->header.payload_size, false); 89 90 ret = psp_mailbox_command(psp, PSP_CMD_TEE_EXTENDED_CMD, (void *)req, 91 timeout_msecs, ®); 92 if (ret) { 93 return ret; 94 } else if (FIELD_GET(PSP_CMDRESP_STS, reg)) { 95 req->header.status = FIELD_GET(PSP_CMDRESP_STS, reg); 96 return -EIO; 97 } 98 99 print_hex_dump_debug("<-psp ", DUMP_PREFIX_OFFSET, 16, 2, req, 100 req->header.payload_size, false); 101 102 return 0; 103 } 104 105 static struct psp_device *psp_alloc_struct(struct sp_device *sp) 106 { 107 struct device *dev = sp->dev; 108 struct psp_device *psp; 109 110 psp = devm_kzalloc(dev, sizeof(*psp), GFP_KERNEL); 111 if (!psp) 112 return NULL; 113 114 psp->dev = dev; 115 psp->sp = sp; 116 117 snprintf(psp->name, sizeof(psp->name), "psp-%u", sp->ord); 118 119 return psp; 120 } 121 122 static irqreturn_t psp_irq_handler(int irq, void *data) 123 { 124 struct psp_device *psp = data; 125 unsigned int status; 126 127 /* Read the interrupt status: */ 128 status = ioread32(psp->io_regs + psp->vdata->intsts_reg); 129 130 /* Clear the interrupt status by writing the same value we read. */ 131 iowrite32(status, psp->io_regs + psp->vdata->intsts_reg); 132 133 /* invoke subdevice interrupt handlers */ 134 if (status) { 135 if (psp->sev_irq_handler) 136 psp->sev_irq_handler(irq, psp->sev_irq_data, status); 137 } 138 139 return IRQ_HANDLED; 140 } 141 142 static unsigned int psp_get_capability(struct psp_device *psp) 143 { 144 unsigned int val = ioread32(psp->io_regs + psp->vdata->feature_reg); 145 146 /* 147 * Check for a access to the registers. If this read returns 148 * 0xffffffff, it's likely that the system is running a broken 149 * BIOS which disallows access to the device. Stop here and 150 * fail the PSP initialization (but not the load, as the CCP 151 * could get properly initialized). 152 */ 153 if (val == 0xffffffff) { 154 dev_notice(psp->dev, "psp: unable to access the device: you might be running a broken BIOS.\n"); 155 return -ENODEV; 156 } 157 psp->capability = val; 158 159 /* Detect if TSME and SME are both enabled */ 160 if (PSP_CAPABILITY(psp, PSP_SECURITY_REPORTING) && 161 psp->capability & (PSP_SECURITY_TSME_STATUS << PSP_CAPABILITY_PSP_SECURITY_OFFSET) && 162 cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) 163 dev_notice(psp->dev, "psp: Both TSME and SME are active, SME is unnecessary when TSME is active.\n"); 164 165 return 0; 166 } 167 168 static int psp_check_sev_support(struct psp_device *psp) 169 { 170 /* Check if device supports SEV feature */ 171 if (!PSP_CAPABILITY(psp, SEV)) { 172 dev_dbg(psp->dev, "psp does not support SEV\n"); 173 return -ENODEV; 174 } 175 176 return 0; 177 } 178 179 static int psp_check_tee_support(struct psp_device *psp) 180 { 181 /* Check if device supports TEE feature */ 182 if (!PSP_CAPABILITY(psp, TEE)) { 183 dev_dbg(psp->dev, "psp does not support TEE\n"); 184 return -ENODEV; 185 } 186 187 return 0; 188 } 189 190 static int psp_init(struct psp_device *psp) 191 { 192 int ret; 193 194 if (!psp_check_sev_support(psp)) { 195 ret = sev_dev_init(psp); 196 if (ret) 197 return ret; 198 } 199 200 if (!psp_check_tee_support(psp)) { 201 ret = tee_dev_init(psp); 202 if (ret) 203 return ret; 204 } 205 206 if (psp->vdata->platform_access) { 207 ret = platform_access_dev_init(psp); 208 if (ret) 209 return ret; 210 } 211 212 /* dbc must come after platform access as it tests the feature */ 213 if (PSP_FEATURE(psp, DBC) || 214 PSP_CAPABILITY(psp, DBC_THRU_EXT)) { 215 ret = dbc_dev_init(psp); 216 if (ret) 217 return ret; 218 } 219 220 return 0; 221 } 222 223 int psp_dev_init(struct sp_device *sp) 224 { 225 struct device *dev = sp->dev; 226 struct psp_device *psp; 227 int ret; 228 229 ret = -ENOMEM; 230 psp = psp_alloc_struct(sp); 231 if (!psp) 232 goto e_err; 233 234 sp->psp_data = psp; 235 236 psp->vdata = (struct psp_vdata *)sp->dev_vdata->psp_vdata; 237 if (!psp->vdata) { 238 ret = -ENODEV; 239 dev_err(dev, "missing driver data\n"); 240 goto e_err; 241 } 242 243 psp->io_regs = sp->io_map; 244 mutex_init(&psp->mailbox_mutex); 245 246 ret = psp_get_capability(psp); 247 if (ret) 248 goto e_disable; 249 250 /* Disable and clear interrupts until ready */ 251 iowrite32(0, psp->io_regs + psp->vdata->inten_reg); 252 iowrite32(-1, psp->io_regs + psp->vdata->intsts_reg); 253 254 /* Request an irq */ 255 ret = sp_request_psp_irq(psp->sp, psp_irq_handler, psp->name, psp); 256 if (ret) { 257 dev_err(dev, "psp: unable to allocate an IRQ\n"); 258 goto e_err; 259 } 260 261 /* master device must be set for platform access */ 262 if (psp->sp->set_psp_master_device) 263 psp->sp->set_psp_master_device(psp->sp); 264 265 ret = psp_init(psp); 266 if (ret) 267 goto e_irq; 268 269 /* Enable interrupt */ 270 iowrite32(-1, psp->io_regs + psp->vdata->inten_reg); 271 272 dev_notice(dev, "psp enabled\n"); 273 274 return 0; 275 276 e_irq: 277 if (sp->clear_psp_master_device) 278 sp->clear_psp_master_device(sp); 279 280 sp_free_psp_irq(psp->sp, psp); 281 e_err: 282 sp->psp_data = NULL; 283 284 dev_notice(dev, "psp initialization failed\n"); 285 286 return ret; 287 288 e_disable: 289 sp->psp_data = NULL; 290 291 return ret; 292 } 293 294 void psp_dev_destroy(struct sp_device *sp) 295 { 296 struct psp_device *psp = sp->psp_data; 297 298 if (!psp) 299 return; 300 301 sev_dev_destroy(psp); 302 303 tee_dev_destroy(psp); 304 305 dbc_dev_destroy(psp); 306 307 platform_access_dev_destroy(psp); 308 309 sp_free_psp_irq(sp, psp); 310 311 if (sp->clear_psp_master_device) 312 sp->clear_psp_master_device(sp); 313 } 314 315 void psp_set_sev_irq_handler(struct psp_device *psp, psp_irq_handler_t handler, 316 void *data) 317 { 318 psp->sev_irq_data = data; 319 psp->sev_irq_handler = handler; 320 } 321 322 void psp_clear_sev_irq_handler(struct psp_device *psp) 323 { 324 psp_set_sev_irq_handler(psp, NULL, NULL); 325 } 326 327 struct psp_device *psp_get_master_device(void) 328 { 329 struct sp_device *sp = sp_get_psp_master_device(); 330 331 return sp ? sp->psp_data : NULL; 332 } 333 334 void psp_pci_init(void) 335 { 336 psp_master = psp_get_master_device(); 337 338 if (!psp_master) 339 return; 340 341 sev_pci_init(); 342 } 343 344 void psp_pci_exit(void) 345 { 346 if (!psp_master) 347 return; 348 349 sev_pci_exit(); 350 } 351