diff options
Diffstat (limited to 'src/arch/arm64/armv8/secmon/smc.c')
| -rw-r--r-- | src/arch/arm64/armv8/secmon/smc.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/src/arch/arm64/armv8/secmon/smc.c b/src/arch/arm64/armv8/secmon/smc.c new file mode 100644 index 0000000000..3bb52f0311 --- /dev/null +++ b/src/arch/arm64/armv8/secmon/smc.c @@ -0,0 +1,159 @@ +/* + * This file is part of the coreboot project. + * + * Copyright 2014 Google Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA + */ + +#include <string.h> +#include <stdlib.h> +#include <arch/cpu.h> +#include <arch/smc.h> +#include <arch/exception.h> +#include <arch/lib_helpers.h> +#include <console/console.h> + +enum { + EC_SMC32 = 0x13, + EC_SMC64 = 0x17, + + SMC_NUM_RANGES = 8, +}; + +struct smc_range { + uint32_t func_begin; + uint32_t func_end; + int (*handler)(struct smc_call *); +}; + +struct smc_ranges { + size_t used; + struct smc_range handlers[SMC_NUM_RANGES]; +}; + +static struct smc_ranges smc_functions; + +static struct smc_range *smc_handler_by_function(uint32_t fid) +{ + int i; + + for (i = 0; i < smc_functions.used; i++) { + struct smc_range *r = &smc_functions.handlers[i]; + + if (fid >= r->func_begin && fid <= r->func_end) + return r; + } + + return NULL; +} + +int smc_register_range(uint32_t min, uint32_t max, int (*h)(struct smc_call *)) +{ + struct smc_range *r; + + if (smc_functions.used == SMC_NUM_RANGES) + return -1; + + if (min > max) + return -1; + + /* This check isn't exhaustive but it's fairly quick. */ + if (smc_handler_by_function(min) || smc_handler_by_function(max)) + return -1; + + r = &smc_functions.handlers[smc_functions.used]; + r->func_begin = min; + r->func_end = max; + r->handler = h; + smc_functions.used++; + + return 0; +} + +static int smc_cleanup(struct exc_state *state, struct smc_call *smc, int ret) +{ + memcpy(&state->regs.x, &smc->results, ARRAY_SIZE(smc->results)); + + return ret; +} + +static int smc_return_with_error(struct exc_state *state, struct smc_call *smc) +{ + smc32_return(smc, SMC_UNKNOWN_FUNC); + return smc_cleanup(state, smc, EXC_RET_HANDLED); +} + +static int smc_handler(struct exc_state *state, uint64_t vector_id) +{ + struct smc_call smc_storage; + struct smc_call *smc = &smc_storage; + uint32_t exception_class; + uint32_t esr; + struct smc_range *r; + + memcpy(&smc->args, &state->regs.x, ARRAY_SIZE(smc->args)); + memcpy(&smc->results, &state->regs.x, ARRAY_SIZE(smc->results)); + + esr = raw_read_esr_el3(); + exception_class = (esr >> 26) & 0x3f; + + /* No support for 32-bit SMC calls. */ + if (exception_class == EC_SMC32) + smc_return_with_error(state, smc); + + /* Check to ensure this is an SMC from aarch64. */ + if (exception_class != EC_SMC64) + return EXC_RET_IGNORED; + + /* Ensure immediate value is 0. */ + if ((esr & 0xffff) != 0) + smc_return_with_error(state, smc); + + r = smc_handler_by_function(smc_function_id(smc)); + + if (r != NULL) { + if (!r->handler(smc)) + return smc_cleanup(state, smc, EXC_RET_HANDLED); + } + + return smc_return_with_error(state, smc); +} + +/* SMC calls can be generated by 32-bit or 64-bit code. */ +static struct exception_handler smc_handler64 = { + .handler = &smc_handler, +}; + +static struct exception_handler smc_handler32 = { + .handler = &smc_handler, +}; + +void smc_init(void) +{ + uint32_t scr; + + /* Enable SMC */ + scr = raw_read_scr_el3(); + scr &= ~(SCR_SMC_MASK); + scr |= SCR_SMC_ENABLE; + raw_write_scr_el3(scr); + + if (!cpu_is_bsp()) + return; + + /* Register SMC handlers. */ + exception_handler_register(EXC_VID_LOW64_SYNC, &smc_handler64); + exception_handler_register(EXC_VID_LOW32_SYNC, &smc_handler32); +} |