// SPDX-License-Identifier: GPL-2.0-or-later /* * * Procedures for interfacing to the RTAS on CHRP machines. * * Peter Bergner, IBM March 2001. * Copyright (C) 2001 IBM. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* This is here deliberately so it's only used in this file */ void enter_rtas(unsigned long); static inline void do_enter_rtas(unsigned long args) { unsigned long msr; /* * Make sure MSR[RI] is currently enabled as it will be forced later * in enter_rtas. */ msr = mfmsr(); BUG_ON(!(msr & MSR_RI)); BUG_ON(!irqs_disabled()); hard_irq_disable(); /* Ensure MSR[EE] is disabled on PPC64 */ enter_rtas(args); srr_regs_clobbered(); /* rtas uses SRRs, invalidate */ } struct rtas_t rtas = { .lock = __ARCH_SPIN_LOCK_UNLOCKED }; EXPORT_SYMBOL(rtas); DEFINE_SPINLOCK(rtas_data_buf_lock); EXPORT_SYMBOL(rtas_data_buf_lock); char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned; EXPORT_SYMBOL(rtas_data_buf); unsigned long rtas_rmo_buf; /* * If non-NULL, this gets called when the kernel terminates. * This is done like this so rtas_flash can be a module. */ void (*rtas_flash_term_hook)(int); EXPORT_SYMBOL(rtas_flash_term_hook); /* RTAS use home made raw locking instead of spin_lock_irqsave * because those can be called from within really nasty contexts * such as having the timebase stopped which would lockup with * normal locks and spinlock debugging enabled */ static unsigned long lock_rtas(void) { unsigned long flags; local_irq_save(flags); preempt_disable(); arch_spin_lock(&rtas.lock); return flags; } static void unlock_rtas(unsigned long flags) { arch_spin_unlock(&rtas.lock); local_irq_restore(flags); preempt_enable(); } /* * call_rtas_display_status and call_rtas_display_status_delay * are designed only for very early low-level debugging, which * is why the token is hard-coded to 10. */ static void call_rtas_display_status(unsigned char c) { unsigned long s; if (!rtas.base) return; s = lock_rtas(); rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c); unlock_rtas(s); } static void call_rtas_display_status_delay(char c) { static int pending_newline = 0; /* did last write end with unprinted newline? */ static int width = 16; if (c == '\n') { while (width-- > 0) call_rtas_display_status(' '); width = 16; mdelay(500); pending_newline = 1; } else { if (pending_newline) { call_rtas_display_status('\r'); call_rtas_display_status('\n'); } pending_newline = 0; if (width--) { call_rtas_display_status(c); udelay(10000); } } } void __init udbg_init_rtas_panel(void) { udbg_putc = call_rtas_display_status_delay; } #ifdef CONFIG_UDBG_RTAS_CONSOLE /* If you think you're dying before early_init_dt_scan_rtas() does its * work, you can hard code the token values for your firmware here and * hardcode rtas.base/entry etc. */ static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE; static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE; static void udbg_rtascon_putc(char c) { int tries; if (!rtas.base) return; /* Add CRs before LFs */ if (c == '\n') udbg_rtascon_putc('\r'); /* if there is more than one character to be displayed, wait a bit */ for (tries = 0; tries < 16; tries++) { if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0) break; udelay(1000); } } static int udbg_rtascon_getc_poll(void) { int c; if (!rtas.base) return -1; if (rtas_call(rtas_getchar_token, 0, 2, &c)) return -1; return c; } static int udbg_rtascon_getc(void) { int c; while ((c = udbg_rtascon_getc_poll()) == -1) ; return c; } void __init udbg_init_rtas_console(void) { udbg_putc = udbg_rtascon_putc; udbg_getc = udbg_rtascon_getc; udbg_getc_poll = udbg_rtascon_getc_poll; } #endif /* CONFIG_UDBG_RTAS_CONSOLE */ void rtas_progress(char *s, unsigned short hex) { struct device_node *root; int width; const __be32 *p; char *os; static int display_character, set_indicator; static int display_width, display_lines, form_feed; static const int *row_width; static DEFINE_SPINLOCK(progress_lock); static int current_line; static int pending_newline = 0; /* did last write end with unprinted newline? */ if (!rtas.base) return; if (display_width == 0) { display_width = 0x10; if ((root = of_find_node_by_path("/rtas"))) { if ((p = of_get_property(root, "ibm,display-line-length", NULL))) display_width = be32_to_cpu(*p); if ((p = of_get_property(root, "ibm,form-feed", NULL))) form_feed = be32_to_cpu(*p); if ((p = of_get_property(root, "ibm,display-number-of-lines", NULL))) display_lines = be32_to_cpu(*p); row_width = of_get_property(root, "ibm,display-truncation-length", NULL); of_node_put(root); } display_character = rtas_token("display-character"); set_indicator = rtas_token("set-indicator"); } if (display_character == RTAS_UNKNOWN_SERVICE) { /* use hex display if available */ if (set_indicator != RTAS_UNKNOWN_SERVICE) rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex); return; } spin_lock(&progress_lock); /* * Last write ended with newline, but we didn't print it since * it would just clear the bottom line of output. Print it now * instead. * * If no newline is pending and form feed is supported, clear the * display with a form feed; otherwise, print a CR to start output * at the beginning of the line. */ if (pending_newline) { rtas_call(display_character, 1, 1, NULL, '\r'); rtas_call(display_character, 1, 1, NULL, '\n'); pending_newline = 0; } else { current_line = 0; if (form_feed) rtas_call(display_character, 1, 1, NULL, (char)form_feed); else rtas_call(display_character, 1, 1, NULL, '\r'); } if (row_width) width = row_width[current_line]; else width = display_width; os = s; while (*os) { if (*os == '\n' || *os == '\r') { /* If newline is the last character, save it * until next call to avoid bumping up the * display output. */ if (*os == '\n' && !os[1]) { pending_newline = 1; current_line++; if (current_line > display_lines-1) current_line = display_lines-1; spin_unlock(&progress_lock); return; } /* RTAS wants CR-LF, not just LF */ if (*os == '\n') { rtas_call(display_character, 1, 1, NULL, '\r'); rtas_call(display_character, 1, 1, NULL, '\n'); } else { /* CR might be used to re-draw a line, so we'll * leave it alone and not add LF. */ rtas_call(display_character, 1, 1, NULL, *os); } if (row_width) width = row_width[current_line]; else width = display_width; } else { width--; rtas_call(display_character, 1, 1, NULL, *os); } os++; /* if we overwrite the screen length */ if (width <= 0) while ((*os != 0) && (*os != '\n') && (*os != '\r')) os++; } spin_unlock(&progress_lock); } EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */ int rtas_token(const char *service) { const __be32 *tokp; if (rtas.dev == NULL) return RTAS_UNKNOWN_SERVICE; tokp = of_get_property(rtas.dev, service, NULL); return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE; } EXPORT_SYMBOL(rtas_token); int rtas_service_present(const char *service) { return rtas_token(service) != RTAS_UNKNOWN_SERVICE; } EXPORT_SYMBOL(rtas_service_present); #ifdef CONFIG_RTAS_ERROR_LOGGING /* * Return the firmware-specified size of the error log buffer * for all rtas calls that require an error buffer argument. * This includes 'check-exception' and 'rtas-last-error'. */ int rtas_get_error_log_max(void) { static int rtas_error_log_max; if (rtas_error_log_max) return rtas_error_log_max; rtas_error_log_max = rtas_token ("rtas-error-log-max"); if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) || (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) { printk (KERN_WARNING "RTAS: bad log buffer size %d\n", rtas_error_log_max); rtas_error_log_max = RTAS_ERROR_LOG_MAX; } return rtas_error_log_max; } EXPORT_SYMBOL(rtas_get_error_log_max); static char rtas_err_buf[RTAS_ERROR_LOG_MAX]; static int rtas_last_error_token; /** Return a copy of the detailed error text associated with the * most recent failed call to rtas. Because the error text * might go stale if there are any other intervening rtas calls, * this routine must be called atomically with whatever produced * the error (i.e. with rtas.lock still held from the previous call). */ static char *__fetch_rtas_last_error(char *altbuf) { struct rtas_args err_args, save_args; u32 bufsz; char *buf = NULL; if (rtas_last_error_token == -1) return NULL; bufsz = rtas_get_error_log_max(); err_args.token = cpu_to_be32(rtas_last_error_token); err_args.nargs = cpu_to_be32(2); err_args.nret = cpu_to_be32(1); err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf)); err_args.args[1] = cpu_to_be32(bufsz); err_args.args[2] = 0; save_args = rtas.args; rtas.args = err_args; do_enter_rtas(__pa(&rtas.args)); err_args = rtas.args; rtas.args = save_args; /* Log the error in the unlikely case that there was one. */ if (unlikely(err_args.args[2] == 0)) { if (altbuf) { buf = altbuf; } else { buf = rtas_err_buf; if (slab_is_available()) buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC); } if (buf) memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX); } return buf; } #define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL) #else /* CONFIG_RTAS_ERROR_LOGGING */ #define __fetch_rtas_last_error(x) NULL #define get_errorlog_buffer() NULL #endif static void va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, va_list list) { int i; args->token = cpu_to_be32(token); args->nargs = cpu_to_be32(nargs); args->nret = cpu_to_be32(nret); args->rets = &(args->args[nargs]); for (i = 0; i < nargs; ++i) args->args[i] = cpu_to_be32(va_arg(list, __u32)); for (i = 0; i < nret; ++i) args->rets[i] = 0; do_enter_rtas(__pa(args)); } void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...) { va_list list; va_start(list, nret); va_rtas_call_unlocked(args, token, nargs, nret, list); va_end(list); } int rtas_call(int token, int nargs, int nret, int *outputs, ...) { va_list list; int i; unsigned long s; struct rtas_args *rtas_args; char *buff_copy = NULL; int ret; if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) return -1; if ((mfmsr() & (MSR_IR|MSR_DR)) != (MSR_IR|MSR_DR)) { WARN_ON_ONCE(1); return -1; } s = lock_rtas(); /* We use the global rtas args buffer */ rtas_args = &rtas.args; va_start(list, outputs); va_rtas_call_unlocked(rtas_args, token, nargs, nret, list); va_end(list); /* A -1 return code indicates that the last command couldn't be completed due to a hardware error. */ if (be32_to_cpu(rtas_args->rets[0]) == -1) buff_copy = __fetch_rtas_last_error(NULL); if (nret > 1 && outputs != NULL) for (i = 0; i < nret-1; ++i) outputs[i] = be32_to_cpu(rtas_args->rets[i+1]); ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0; unlock_rtas(s); if (buff_copy) { log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0); if (slab_is_available()) kfree(buff_copy); } return ret; } EXPORT_SYMBOL(rtas_call); /** * rtas_busy_delay_time() - From an RTAS status value, calculate the * suggested delay time in milliseconds. * * @status: a value returned from rtas_call() or similar APIs which return * the status of a RTAS function call. * * Context: Any context. * * Return: * * 100000 - If @status is 9905. * * 10000 - If @status is 9904. * * 1000 - If @status is 9903. * * 100 - If @status is 9902. * * 10 - If @status is 9901. * * 1 - If @status is either 9900 or -2. This is "wrong" for -2, but * some callers depend on this behavior, and the worst outcome * is that they will delay for longer than necessary. * * 0 - If @status is not a busy or extended delay value. */ unsigned int rtas_busy_delay_time(int status) { int order; unsigned int ms = 0; if (status == RTAS_BUSY) { ms = 1; } else if (status >= RTAS_EXTENDED_DELAY_MIN && status <= RTAS_EXTENDED_DELAY_MAX) { order = status - RTAS_EXTENDED_DELAY_MIN; for (ms = 1; order > 0; order--) ms *= 10; } return ms; } EXPORT_SYMBOL(rtas_busy_delay_time); /** * rtas_busy_delay() - helper for RTAS busy and extended delay statuses * * @status: a value returned from rtas_call() or similar APIs which return * the status of a RTAS function call. * * Context: Process context. May sleep or schedule. * * Return: * * true - @status is RTAS_BUSY or an extended delay hint. The * caller may assume that the CPU has been yielded if necessary, * and that an appropriate delay for @status has elapsed. * Generally the caller should reattempt the RTAS call which * yielded @status. * * * false - @status is not @RTAS_BUSY nor an extended delay hint. The * caller is responsible for handling @status. */ bool rtas_busy_delay(int status) { unsigned int ms; bool ret; switch (status) { case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX: ret = true; ms = rtas_busy_delay_time(status); /* * The extended delay hint can be as high as 100 seconds. * Surely any function returning such a status is either * buggy or isn't going to be significantly slowed by us * polling at 1HZ. Clamp the sleep time to one second. */ ms = clamp(ms, 1U, 1000U); /* * The delay hint is an order-of-magnitude suggestion, not * a minimum. It is fine, possibly even advantageous, for * us to pause for less time than hinted. For small values, * use usleep_range() to ensure we don't sleep much longer * than actually needed. * * See Documentation/timers/timers-howto.rst for * explanation of the threshold used here. In effect we use * usleep_range() for 9900 and 9901, msleep() for * 9902-9905. */ if (ms <= 20) usleep_range(ms * 100, ms * 1000); else msleep(ms); break; case RTAS_BUSY: ret = true; /* * We should call again immediately if there's no other * work to do. */ cond_resched(); break; default: ret = false; /* * Not a busy or extended delay status; the caller should * handle @status itself. Ensure we warn on misuses in * atomic context regardless. */ might_sleep(); break; } return ret; } EXPORT_SYMBOL(rtas_busy_delay); static int rtas_error_rc(int rtas_rc) { int rc; switch (rtas_rc) { case -1: /* Hardware Error */ rc = -EIO; break; case -3: /* Bad indicator/domain/etc */ rc = -EINVAL; break; case -9000: /* Isolation error */ rc = -EFAULT; break; case -9001: /* Outstanding TCE/PTE */ rc = -EEXIST; break; case -9002: /* No usable slot */ rc = -ENODEV; break; default: printk(KERN_ERR "%s: unexpected RTAS error %d\n", __func__, rtas_rc); rc = -ERANGE; break; } return rc; } int rtas_get_power_level(int powerdomain, int *level) { int token = rtas_token("get-power-level"); int rc; if (token == RTAS_UNKNOWN_SERVICE) return -ENOENT; while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY) udelay(1); if (rc < 0) return rtas_error_rc(rc); return rc; } EXPORT_SYMBOL(rtas_get_power_level); int rtas_set_power_level(int powerdomain, int level, int *setlevel) { int token = rtas_token("set-power-level"); int rc; if (token == RTAS_UNKNOWN_SERVICE) return -ENOENT; do { rc = rtas_call(token, 2, 2, setlevel, powerdomain, level); } while (rtas_busy_delay(rc)); if (rc < 0) return rtas_error_rc(rc); return rc; } EXPORT_SYMBOL(rtas_set_power_level); int rtas_get_sensor(int sensor, int index, int *state) { int token = rtas_token("get-sensor-state"); int rc; if (token == RTAS_UNKNOWN_SERVICE) return -ENOENT; do { rc = rtas_call(token, 2, 2, state, sensor, index); } while (rtas_busy_delay(rc)); if (rc < 0) return rtas_error_rc(rc); return rc; } EXPORT_SYMBOL(rtas_get_sensor); int rtas_get_sensor_fast(int sensor, int index, int *state) { int token = rtas_token("get-sensor-state"); int rc; if (token == RTAS_UNKNOWN_SERVICE) return -ENOENT; rc = rtas_call(token, 2, 2, state, sensor, index); WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN && rc <= RTAS_EXTENDED_DELAY_MAX)); if (rc < 0) return rtas_error_rc(rc); return rc; } bool rtas_indicator_present(int token, int *maxindex) { int proplen, count, i; const struct indicator_elem { __be32 token; __be32 maxindex; } *indicators; indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen); if (!indicators) return false; count = proplen / sizeof(struct indicator_elem); for (i = 0; i < count; i++) { if (__be32_to_cpu(indicators[i].token) != token) continue; if (maxindex) *maxindex = __be32_to_cpu(indicators[i].maxindex); return true; } return false; } EXPORT_SYMBOL(rtas_indicator_present); int rtas_set_indicator(int indicator, int index, int new_value) { int token = rtas_token("set-indicator"); int rc; if (token == RTAS_UNKNOWN_SERVICE) return -ENOENT; do { rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); } while (rtas_busy_delay(rc)); if (rc < 0) return rtas_error_rc(rc); return rc; } EXPORT_SYMBOL(rtas_set_indicator); /* * Ignoring RTAS extended delay */ int rtas_set_indicator_fast(int indicator, int index, int new_value) { int rc; int token = rtas_token("set-indicator"); if (token == RTAS_UNKNOWN_SERVICE) return -ENOENT; rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN && rc <= RTAS_EXTENDED_DELAY_MAX)); if (rc < 0) return rtas_error_rc(rc); return rc; } /** * rtas_ibm_suspend_me() - Call ibm,suspend-me to suspend the LPAR. * * @fw_status: RTAS call status will be placed here if not NULL. * * rtas_ibm_suspend_me() should be called only on a CPU which has * received H_CONTINUE from the H_JOIN hcall. All other active CPUs * should be waiting to return from H_JOIN. * * rtas_ibm_suspend_me() may suspend execution of the OS * indefinitely. Callers should take appropriate measures upon return, such as * resetting watchdog facilities. * * Callers may choose to retry this call if @fw_status is * %RTAS_THREADS_ACTIVE. * * Return: * 0 - The partition has resumed from suspend, possibly after * migration to a different host. * -ECANCELED - The operation was aborted. * -EAGAIN - There were other CPUs not in H_JOIN at the time of the call. * -EBUSY - Some other condition prevented the suspend from succeeding. * -EIO - Hardware/platform error. */ int rtas_ibm_suspend_me(int *fw_status) { int fwrc; int ret; fwrc = rtas_call(rtas_token("ibm,suspend-me"), 0, 1, NULL); switch (fwrc) { case 0: ret = 0; break; case RTAS_SUSPEND_ABORTED: ret = -ECANCELED; break; case RTAS_THREADS_ACTIVE: ret = -EAGAIN; break; case RTAS_NOT_SUSPENDABLE: case RTAS_OUTSTANDING_COPROC: ret = -EBUSY; break; case -1: default: ret = -EIO; break; } if (fw_status) *fw_status = fwrc; return ret; } void __noreturn rtas_restart(char *cmd) { if (rtas_flash_term_hook) rtas_flash_term_hook(SYS_RESTART); printk("RTAS system-reboot returned %d\n", rtas_call(rtas_token("system-reboot"), 0, 1, NULL)); for (;;); } void rtas_power_off(void) { if (rtas_flash_term_hook) rtas_flash_term_hook(SYS_POWER_OFF); /* allow power on only with power button press */ printk("RTAS power-off returned %d\n", rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); for (;;); } void __noreturn rtas_halt(void) { if (rtas_flash_term_hook) rtas_flash_term_hook(SYS_HALT); /* allow power on only with power button press */ printk("RTAS power-off returned %d\n", rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); for (;;); } /* Must be in the RMO region, so we place it here */ static char rtas_os_term_buf[2048]; void rtas_os_term(char *str) { int status; /* * Firmware with the ibm,extended-os-term property is guaranteed * to always return from an ibm,os-term call. Earlier versions without * this property may terminate the partition which we want to avoid * since it interferes with panic_timeout. */ if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") || RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term")) return; snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str); do { status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL, __pa(rtas_os_term_buf)); } while (rtas_busy_delay(status)); if (status != 0) printk(KERN_EMERG "ibm,os-term call failed %d\n", status); } /** * rtas_activate_firmware() - Activate a new version of firmware. * * Context: This function may sleep. * * Activate a new version of partition firmware. The OS must call this * after resuming from a partition hibernation or migration in order * to maintain the ability to perform live firmware updates. It's not * catastrophic for this method to be absent or to fail; just log the * condition in that case. */ void rtas_activate_firmware(void) { int token; int fwrc; token = rtas_token("ibm,activate-firmware"); if (token == RTAS_UNKNOWN_SERVICE) { pr_notice("ibm,activate-firmware method unavailable\n"); return; } do { fwrc = rtas_call(token, 0, 1, NULL); } while (rtas_busy_delay(fwrc)); if (fwrc) pr_err("ibm,activate-firmware failed (%i)\n", fwrc); } #ifdef CONFIG_PPC_PSERIES /** * rtas_call_reentrant() - Used for reentrant rtas calls * @token: Token for desired reentrant RTAS call * @nargs: Number of Input Parameters * @nret: Number of Output Parameters * @outputs: Array of outputs * @...: Inputs for desired RTAS call * * According to LoPAR documentation, only "ibm,int-on", "ibm,int-off", * "ibm,get-xive" and "ibm,set-xive" are currently reentrant. * Reentrant calls need their own rtas_args buffer, so not using rtas.args, but * PACA one instead. * * Return: -1 on error, * First output value of RTAS call if (nret > 0), * 0 otherwise, */ int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...) { va_list list; struct rtas_args *args; unsigned long flags; int i, ret = 0; if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) return -1; local_irq_save(flags); preempt_disable(); /* We use the per-cpu (PACA) rtas args buffer */ args = local_paca->rtas_args_reentrant; va_start(list, outputs); va_rtas_call_unlocked(args, token, nargs, nret, list); va_end(list); if (nret > 1 && outputs) for (i = 0; i < nret - 1; ++i) outputs[i] = be32_to_cpu(args->rets[i + 1]); if (nret > 0) ret = be32_to_cpu(args->rets[0]); local_irq_restore(flags); preempt_enable(); return ret; } #endif /* CONFIG_PPC_PSERIES */ /** * get_pseries_errorlog() - Find a specific pseries error log in an RTAS * extended event log. * @log: RTAS error/event log * @section_id: two character section identifier * * Return: A pointer to the specified errorlog or NULL if not found. */ noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log, uint16_t section_id) { struct rtas_ext_event_log_v6 *ext_log = (struct rtas_ext_event_log_v6 *)log->buffer; struct pseries_errorlog *sect; unsigned char *p, *log_end; uint32_t ext_log_length = rtas_error_extended_log_length(log); uint8_t log_format = rtas_ext_event_log_format(ext_log); uint32_t company_id = rtas_ext_event_company_id(ext_log); /* Check that we understand the format */ if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) || log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG || company_id != RTAS_V6EXT_COMPANY_ID_IBM) return NULL; log_end = log->buffer + ext_log_length; p = ext_log->vendor_log; while (p < log_end) { sect = (struct pseries_errorlog *)p; if (pseries_errorlog_id(sect) == section_id) return sect; p += pseries_errorlog_length(sect); } return NULL; } #ifdef CONFIG_PPC_RTAS_FILTER /* * The sys_rtas syscall, as originally designed, allows root to pass * arbitrary physical addresses to RTAS calls. A number of RTAS calls * can be abused to write to arbitrary memory and do other things that * are potentially harmful to system integrity, and thus should only * be used inside the kernel and not exposed to userspace. * * All known legitimate users of the sys_rtas syscall will only ever * pass addresses that fall within the RMO buffer, and use a known * subset of RTAS calls. * * Accordingly, we filter RTAS requests to check that the call is * permitted, and that provided pointers fall within the RMO buffer. * The rtas_filters list contains an entry for each permitted call, * with the indexes of the parameters which are expected to contain * addresses and sizes of buffers allocated inside the RMO buffer. */ struct rtas_filter { const char *name; int token; /* Indexes into the args buffer, -1 if not used */ int buf_idx1; int size_idx1; int buf_idx2; int size_idx2; int fixed_size; }; static struct rtas_filter rtas_filters[] __ro_after_init = { { "ibm,activate-firmware", -1, -1, -1, -1, -1 }, { "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 }, /* Special cased */ { "display-character", -1, -1, -1, -1, -1 }, { "ibm,display-message", -1, 0, -1, -1, -1 }, { "ibm,errinjct", -1, 2, -1, -1, -1, 1024 }, { "ibm,close-errinjct", -1, -1, -1, -1, -1 }, { "ibm,open-errinjct", -1, -1, -1, -1, -1 }, { "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 }, { "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 }, { "ibm,get-indices", -1, 2, 3, -1, -1 }, { "get-power-level", -1, -1, -1, -1, -1 }, { "get-sensor-state", -1, -1, -1, -1, -1 }, { "ibm,get-system-parameter", -1, 1, 2, -1, -1 }, { "get-time-of-day", -1, -1, -1, -1, -1 }, { "ibm,get-vpd", -1, 0, -1, 1, 2 }, { "ibm,lpar-perftools", -1, 2, 3, -1, -1 }, { "ibm,platform-dump", -1, 4, 5, -1, -1 }, /* Special cased */ { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 }, { "ibm,scan-log-dump", -1, 0, 1, -1, -1 }, { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 }, { "ibm,set-eeh-option", -1, -1, -1, -1, -1 }, { "set-indicator", -1, -1, -1, -1, -1 }, { "set-power-level", -1, -1, -1, -1, -1 }, { "set-time-for-power-on", -1, -1, -1, -1, -1 }, { "ibm,set-system-parameter", -1, 1, -1, -1, -1 }, { "set-time-of-day", -1, -1, -1, -1, -1 }, #ifdef CONFIG_CPU_BIG_ENDIAN { "ibm,suspend-me", -1, -1, -1, -1, -1 }, { "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 }, { "ibm,update-properties", -1, 0, -1, -1, -1, 4096 }, #endif { "ibm,physical-attestation", -1, 0, 1, -1, -1 }, }; static bool in_rmo_buf(u32 base, u32 end) { return base >= rtas_rmo_buf && base < (rtas_rmo_buf + RTAS_USER_REGION_SIZE) && base <= end && end >= rtas_rmo_buf && end < (rtas_rmo_buf + RTAS_USER_REGION_SIZE); } static bool block_rtas_call(int token, int nargs, struct rtas_args *args) { int i; for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) { struct rtas_filter *f = &rtas_filters[i]; u32 base, size, end; if (token != f->token) continue; if (f->buf_idx1 != -1) { base = be32_to_cpu(args->args[f->buf_idx1]); if (f->size_idx1 != -1) size = be32_to_cpu(args->args[f->size_idx1]); else if (f->fixed_size) size = f->fixed_size; else size = 1; end = base + size - 1; /* * Special case for ibm,platform-dump - NULL buffer * address is used to indicate end of dump processing */ if (!strcmp(f->name, "ibm,platform-dump") && base == 0) return false; if (!in_rmo_buf(base, end)) goto err; } if (f->buf_idx2 != -1) { base = be32_to_cpu(args->args[f->buf_idx2]); if (f->size_idx2 != -1) size = be32_to_cpu(args->args[f->size_idx2]); else if (f->fixed_size) size = f->fixed_size; else size = 1; end = base + size - 1; /* * Special case for ibm,configure-connector where the * address can be 0 */ if (!strcmp(f->name, "ibm,configure-connector") && base == 0) return false; if (!in_rmo_buf(base, end)) goto err; } return false; } err: pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n"); pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n", token, nargs, current->comm); return true; } static void __init rtas_syscall_filter_init(void) { unsigned int i; for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) rtas_filters[i].token = rtas_token(rtas_filters[i].name); } #else static bool block_rtas_call(int token, int nargs, struct rtas_args *args) { return false; } static void __init rtas_syscall_filter_init(void) { } #endif /* CONFIG_PPC_RTAS_FILTER */ /* We assume to be passed big endian arguments */ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) { struct rtas_args args; unsigned long flags; char *buff_copy, *errbuf = NULL; int nargs, nret, token; if (!capable(CAP_SYS_ADMIN)) return -EPERM; if (!rtas.entry) return -EINVAL; if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0) return -EFAULT; nargs = be32_to_cpu(args.nargs); nret = be32_to_cpu(args.nret); token = be32_to_cpu(args.token); if (nargs >= ARRAY_SIZE(args.args) || nret > ARRAY_SIZE(args.args) || nargs + nret > ARRAY_SIZE(args.args)) return -EINVAL; /* Copy in args. */ if (copy_from_user(args.args, uargs->args, nargs * sizeof(rtas_arg_t)) != 0) return -EFAULT; if (token == RTAS_UNKNOWN_SERVICE) return -EINVAL; args.rets = &args.args[nargs]; memset(args.rets, 0, nret * sizeof(rtas_arg_t)); if (block_rtas_call(token, nargs, &args)) return -EINVAL; /* Need to handle ibm,suspend_me call specially */ if (token == rtas_token("ibm,suspend-me")) { /* * rtas_ibm_suspend_me assumes the streamid handle is in cpu * endian, or at least the hcall within it requires it. */ int rc = 0; u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32) | be32_to_cpu(args.args[1]); rc = rtas_syscall_dispatch_ibm_suspend_me(handle); if (rc == -EAGAIN) args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE); else if (rc == -EIO) args.rets[0] = cpu_to_be32(-1); else if (rc) return rc; goto copy_return; } buff_copy = get_errorlog_buffer(); flags = lock_rtas(); rtas.args = args; do_enter_rtas(__pa(&rtas.args)); args = rtas.args; /* A -1 return code indicates that the last command couldn't be completed due to a hardware error. */ if (be32_to_cpu(args.rets[0]) == -1) errbuf = __fetch_rtas_last_error(buff_copy); unlock_rtas(flags); if (buff_copy) { if (errbuf) log_error(errbuf, ERR_TYPE_RTAS_LOG, 0); kfree(buff_copy); } copy_return: /* Copy out args. */ if (copy_to_user(uargs->args + nargs, args.args + nargs, nret * sizeof(rtas_arg_t)) != 0) return -EFAULT; return 0; } /* * Call early during boot, before mem init, to retrieve the RTAS * information from the device-tree and allocate the RMO buffer for userland * accesses. */ void __init rtas_initialize(void) { unsigned long rtas_region = RTAS_INSTANTIATE_MAX; u32 base, size, entry; int no_base, no_size, no_entry; /* Get RTAS dev node and fill up our "rtas" structure with infos * about it. */ rtas.dev = of_find_node_by_name(NULL, "rtas"); if (!rtas.dev) return; no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base); no_size = of_property_read_u32(rtas.dev, "rtas-size", &size); if (no_base || no_size) { of_node_put(rtas.dev); rtas.dev = NULL; return; } rtas.base = base; rtas.size = size; no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry); rtas.entry = no_entry ? rtas.base : entry; /* If RTAS was found, allocate the RMO buffer for it and look for * the stop-self token if any */ #ifdef CONFIG_PPC64 if (firmware_has_feature(FW_FEATURE_LPAR)) rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX); #endif rtas_rmo_buf = memblock_phys_alloc_range(RTAS_USER_REGION_SIZE, PAGE_SIZE, 0, rtas_region); if (!rtas_rmo_buf) panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n", PAGE_SIZE, &rtas_region); #ifdef CONFIG_RTAS_ERROR_LOGGING rtas_last_error_token = rtas_token("rtas-last-error"); #endif rtas_syscall_filter_init(); } int __init early_init_dt_scan_rtas(unsigned long node, const char *uname, int depth, void *data) { const u32 *basep, *entryp, *sizep; if (depth != 1 || strcmp(uname, "rtas") != 0) return 0; basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL); entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL); sizep = of_get_flat_dt_prop(node, "rtas-size", NULL); #ifdef CONFIG_PPC64 /* need this feature to decide the crashkernel offset */ if (of_get_flat_dt_prop(node, "ibm,hypertas-functions", NULL)) powerpc_firmware_features |= FW_FEATURE_LPAR; #endif if (basep && entryp && sizep) { rtas.base = *basep; rtas.entry = *entryp; rtas.size = *sizep; } #ifdef CONFIG_UDBG_RTAS_CONSOLE basep = of_get_flat_dt_prop(node, "put-term-char", NULL); if (basep) rtas_putchar_token = *basep; basep = of_get_flat_dt_prop(node, "get-term-char", NULL); if (basep) rtas_getchar_token = *basep; if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE && rtas_getchar_token != RTAS_UNKNOWN_SERVICE) udbg_init_rtas_console(); #endif /* break now */ return 1; } static arch_spinlock_t timebase_lock; static u64 timebase = 0; void rtas_give_timebase(void) { unsigned long flags; local_irq_save(flags); hard_irq_disable(); arch_spin_lock(&timebase_lock); rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); timebase = get_tb(); arch_spin_unlock(&timebase_lock); while (timebase) barrier(); rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); local_irq_restore(flags); } void rtas_take_timebase(void) { while (!timebase) barrier(); arch_spin_lock(&timebase_lock); set_tb(timebase >> 32, timebase & 0xffffffff); timebase = 0; arch_spin_unlock(&timebase_lock); }