// 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. */ #define pr_fmt(fmt) "rtas: " fmt #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 struct rtas_filter { /* Indexes into the args buffer, -1 if not used */ const int buf_idx1; const int size_idx1; const int buf_idx2; const int size_idx2; /* * Assumed buffer size per the spec if the function does not * have a size parameter, e.g. ibm,errinjct. 0 if unused. */ const int fixed_size; }; /** * struct rtas_function - Descriptor for RTAS functions. * * @token: Value of @name if it exists under the /rtas node. * @name: Function name. * @filter: If non-NULL, invoking this function via the rtas syscall is * generally allowed, and @filter describes constraints on the * arguments. See also @banned_for_syscall_on_le. * @banned_for_syscall_on_le: Set when call via sys_rtas is generally allowed * but specifically restricted on ppc64le. Such * functions are believed to have no users on * ppc64le, and we want to keep it that way. It does * not make sense for this to be set when @filter * is NULL. * @lock: Pointer to an optional dedicated per-function mutex. This * should be set for functions that require multiple calls in * sequence to complete a single operation, and such sequences * will disrupt each other if allowed to interleave. Users of * this function are required to hold the associated lock for * the duration of the call sequence. Add an explanatory * comment to the function table entry if setting this member. */ struct rtas_function { s32 token; const bool banned_for_syscall_on_le:1; const char * const name; const struct rtas_filter *filter; struct mutex *lock; }; /* * Per-function locks for sequence-based RTAS functions. */ static DEFINE_MUTEX(rtas_ibm_activate_firmware_lock); static DEFINE_MUTEX(rtas_ibm_get_dynamic_sensor_state_lock); static DEFINE_MUTEX(rtas_ibm_get_indices_lock); static DEFINE_MUTEX(rtas_ibm_lpar_perftools_lock); static DEFINE_MUTEX(rtas_ibm_physical_attestation_lock); static DEFINE_MUTEX(rtas_ibm_set_dynamic_indicator_lock); DEFINE_MUTEX(rtas_ibm_get_vpd_lock); static struct rtas_function rtas_function_table[] __ro_after_init = { [RTAS_FNIDX__CHECK_EXCEPTION] = { .name = "check-exception", }, [RTAS_FNIDX__DISPLAY_CHARACTER] = { .name = "display-character", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__EVENT_SCAN] = { .name = "event-scan", }, [RTAS_FNIDX__FREEZE_TIME_BASE] = { .name = "freeze-time-base", }, [RTAS_FNIDX__GET_POWER_LEVEL] = { .name = "get-power-level", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__GET_SENSOR_STATE] = { .name = "get-sensor-state", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__GET_TERM_CHAR] = { .name = "get-term-char", }, [RTAS_FNIDX__GET_TIME_OF_DAY] = { .name = "get-time-of-day", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_ACTIVATE_FIRMWARE] = { .name = "ibm,activate-firmware", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, /* * PAPR+ as of v2.13 doesn't explicitly impose any * restriction, but this typically requires multiple * calls before success, and there's no reason to * allow sequences to interleave. */ .lock = &rtas_ibm_activate_firmware_lock, }, [RTAS_FNIDX__IBM_CBE_START_PTCAL] = { .name = "ibm,cbe-start-ptcal", }, [RTAS_FNIDX__IBM_CBE_STOP_PTCAL] = { .name = "ibm,cbe-stop-ptcal", }, [RTAS_FNIDX__IBM_CHANGE_MSI] = { .name = "ibm,change-msi", }, [RTAS_FNIDX__IBM_CLOSE_ERRINJCT] = { .name = "ibm,close-errinjct", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_CONFIGURE_BRIDGE] = { .name = "ibm,configure-bridge", }, [RTAS_FNIDX__IBM_CONFIGURE_CONNECTOR] = { .name = "ibm,configure-connector", .filter = &(const struct rtas_filter) { .buf_idx1 = 0, .size_idx1 = -1, .buf_idx2 = 1, .size_idx2 = -1, .fixed_size = 4096, }, }, [RTAS_FNIDX__IBM_CONFIGURE_KERNEL_DUMP] = { .name = "ibm,configure-kernel-dump", }, [RTAS_FNIDX__IBM_CONFIGURE_PE] = { .name = "ibm,configure-pe", }, [RTAS_FNIDX__IBM_CREATE_PE_DMA_WINDOW] = { .name = "ibm,create-pe-dma-window", }, [RTAS_FNIDX__IBM_DISPLAY_MESSAGE] = { .name = "ibm,display-message", .filter = &(const struct rtas_filter) { .buf_idx1 = 0, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_ERRINJCT] = { .name = "ibm,errinjct", .filter = &(const struct rtas_filter) { .buf_idx1 = 2, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, .fixed_size = 1024, }, }, [RTAS_FNIDX__IBM_EXTI2C] = { .name = "ibm,exti2c", }, [RTAS_FNIDX__IBM_GET_CONFIG_ADDR_INFO] = { .name = "ibm,get-config-addr-info", }, [RTAS_FNIDX__IBM_GET_CONFIG_ADDR_INFO2] = { .name = "ibm,get-config-addr-info2", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_GET_DYNAMIC_SENSOR_STATE] = { .name = "ibm,get-dynamic-sensor-state", .filter = &(const struct rtas_filter) { .buf_idx1 = 1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, /* * PAPR+ v2.13 R1–7.3.19–3 is explicit that the OS * must not call ibm,get-dynamic-sensor-state with * different inputs until a non-retry status has been * returned. */ .lock = &rtas_ibm_get_dynamic_sensor_state_lock, }, [RTAS_FNIDX__IBM_GET_INDICES] = { .name = "ibm,get-indices", .filter = &(const struct rtas_filter) { .buf_idx1 = 2, .size_idx1 = 3, .buf_idx2 = -1, .size_idx2 = -1, }, /* * PAPR+ v2.13 R1–7.3.17–2 says that the OS must not * interleave ibm,get-indices call sequences with * different inputs. */ .lock = &rtas_ibm_get_indices_lock, }, [RTAS_FNIDX__IBM_GET_RIO_TOPOLOGY] = { .name = "ibm,get-rio-topology", }, [RTAS_FNIDX__IBM_GET_SYSTEM_PARAMETER] = { .name = "ibm,get-system-parameter", .filter = &(const struct rtas_filter) { .buf_idx1 = 1, .size_idx1 = 2, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_GET_VPD] = { .name = "ibm,get-vpd", .filter = &(const struct rtas_filter) { .buf_idx1 = 0, .size_idx1 = -1, .buf_idx2 = 1, .size_idx2 = 2, }, /* * PAPR+ v2.13 R1–7.3.20–4 indicates that sequences * should not be allowed to interleave. */ .lock = &rtas_ibm_get_vpd_lock, }, [RTAS_FNIDX__IBM_GET_XIVE] = { .name = "ibm,get-xive", }, [RTAS_FNIDX__IBM_INT_OFF] = { .name = "ibm,int-off", }, [RTAS_FNIDX__IBM_INT_ON] = { .name = "ibm,int-on", }, [RTAS_FNIDX__IBM_IO_QUIESCE_ACK] = { .name = "ibm,io-quiesce-ack", }, [RTAS_FNIDX__IBM_LPAR_PERFTOOLS] = { .name = "ibm,lpar-perftools", .filter = &(const struct rtas_filter) { .buf_idx1 = 2, .size_idx1 = 3, .buf_idx2 = -1, .size_idx2 = -1, }, /* * PAPR+ v2.13 R1–7.3.26–6 says the OS should allow * only one call sequence in progress at a time. */ .lock = &rtas_ibm_lpar_perftools_lock, }, [RTAS_FNIDX__IBM_MANAGE_FLASH_IMAGE] = { .name = "ibm,manage-flash-image", }, [RTAS_FNIDX__IBM_MANAGE_STORAGE_PRESERVATION] = { .name = "ibm,manage-storage-preservation", }, [RTAS_FNIDX__IBM_NMI_INTERLOCK] = { .name = "ibm,nmi-interlock", }, [RTAS_FNIDX__IBM_NMI_REGISTER] = { .name = "ibm,nmi-register", }, [RTAS_FNIDX__IBM_OPEN_ERRINJCT] = { .name = "ibm,open-errinjct", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_OPEN_SRIOV_ALLOW_UNFREEZE] = { .name = "ibm,open-sriov-allow-unfreeze", }, [RTAS_FNIDX__IBM_OPEN_SRIOV_MAP_PE_NUMBER] = { .name = "ibm,open-sriov-map-pe-number", }, [RTAS_FNIDX__IBM_OS_TERM] = { .name = "ibm,os-term", }, [RTAS_FNIDX__IBM_PARTNER_CONTROL] = { .name = "ibm,partner-control", }, [RTAS_FNIDX__IBM_PHYSICAL_ATTESTATION] = { .name = "ibm,physical-attestation", .filter = &(const struct rtas_filter) { .buf_idx1 = 0, .size_idx1 = 1, .buf_idx2 = -1, .size_idx2 = -1, }, /* * This follows a sequence-based pattern similar to * ibm,get-vpd et al. Since PAPR+ restricts * interleaving call sequences for other functions of * this style, assume the restriction applies here, * even though it's not explicit in the spec. */ .lock = &rtas_ibm_physical_attestation_lock, }, [RTAS_FNIDX__IBM_PLATFORM_DUMP] = { .name = "ibm,platform-dump", .filter = &(const struct rtas_filter) { .buf_idx1 = 4, .size_idx1 = 5, .buf_idx2 = -1, .size_idx2 = -1, }, /* * PAPR+ v2.13 7.3.3.4.1 indicates that concurrent * sequences of ibm,platform-dump are allowed if they * are operating on different dump tags. So leave the * lock pointer unset for now. This may need * reconsideration if kernel-internal users appear. */ }, [RTAS_FNIDX__IBM_POWER_OFF_UPS] = { .name = "ibm,power-off-ups", }, [RTAS_FNIDX__IBM_QUERY_INTERRUPT_SOURCE_NUMBER] = { .name = "ibm,query-interrupt-source-number", }, [RTAS_FNIDX__IBM_QUERY_PE_DMA_WINDOW] = { .name = "ibm,query-pe-dma-window", }, [RTAS_FNIDX__IBM_READ_PCI_CONFIG] = { .name = "ibm,read-pci-config", }, [RTAS_FNIDX__IBM_READ_SLOT_RESET_STATE] = { .name = "ibm,read-slot-reset-state", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_READ_SLOT_RESET_STATE2] = { .name = "ibm,read-slot-reset-state2", }, [RTAS_FNIDX__IBM_REMOVE_PE_DMA_WINDOW] = { .name = "ibm,remove-pe-dma-window", }, [RTAS_FNIDX__IBM_RESET_PE_DMA_WINDOW] = { /* * Note: PAPR+ v2.13 7.3.31.4.1 spells this as * "ibm,reset-pe-dma-windows" (plural), but RTAS * implementations use the singular form in practice. */ .name = "ibm,reset-pe-dma-window", }, [RTAS_FNIDX__IBM_SCAN_LOG_DUMP] = { .name = "ibm,scan-log-dump", .filter = &(const struct rtas_filter) { .buf_idx1 = 0, .size_idx1 = 1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_SET_DYNAMIC_INDICATOR] = { .name = "ibm,set-dynamic-indicator", .filter = &(const struct rtas_filter) { .buf_idx1 = 2, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, /* * PAPR+ v2.13 R1–7.3.18–3 says the OS must not call * this function with different inputs until a * non-retry status has been returned. */ .lock = &rtas_ibm_set_dynamic_indicator_lock, }, [RTAS_FNIDX__IBM_SET_EEH_OPTION] = { .name = "ibm,set-eeh-option", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_SET_SLOT_RESET] = { .name = "ibm,set-slot-reset", }, [RTAS_FNIDX__IBM_SET_SYSTEM_PARAMETER] = { .name = "ibm,set-system-parameter", .filter = &(const struct rtas_filter) { .buf_idx1 = 1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_SET_XIVE] = { .name = "ibm,set-xive", }, [RTAS_FNIDX__IBM_SLOT_ERROR_DETAIL] = { .name = "ibm,slot-error-detail", }, [RTAS_FNIDX__IBM_SUSPEND_ME] = { .name = "ibm,suspend-me", .banned_for_syscall_on_le = true, .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__IBM_TUNE_DMA_PARMS] = { .name = "ibm,tune-dma-parms", }, [RTAS_FNIDX__IBM_UPDATE_FLASH_64_AND_REBOOT] = { .name = "ibm,update-flash-64-and-reboot", }, [RTAS_FNIDX__IBM_UPDATE_NODES] = { .name = "ibm,update-nodes", .banned_for_syscall_on_le = true, .filter = &(const struct rtas_filter) { .buf_idx1 = 0, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, .fixed_size = 4096, }, }, [RTAS_FNIDX__IBM_UPDATE_PROPERTIES] = { .name = "ibm,update-properties", .banned_for_syscall_on_le = true, .filter = &(const struct rtas_filter) { .buf_idx1 = 0, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, .fixed_size = 4096, }, }, [RTAS_FNIDX__IBM_VALIDATE_FLASH_IMAGE] = { .name = "ibm,validate-flash-image", }, [RTAS_FNIDX__IBM_WRITE_PCI_CONFIG] = { .name = "ibm,write-pci-config", }, [RTAS_FNIDX__NVRAM_FETCH] = { .name = "nvram-fetch", }, [RTAS_FNIDX__NVRAM_STORE] = { .name = "nvram-store", }, [RTAS_FNIDX__POWER_OFF] = { .name = "power-off", }, [RTAS_FNIDX__PUT_TERM_CHAR] = { .name = "put-term-char", }, [RTAS_FNIDX__QUERY_CPU_STOPPED_STATE] = { .name = "query-cpu-stopped-state", }, [RTAS_FNIDX__READ_PCI_CONFIG] = { .name = "read-pci-config", }, [RTAS_FNIDX__RTAS_LAST_ERROR] = { .name = "rtas-last-error", }, [RTAS_FNIDX__SET_INDICATOR] = { .name = "set-indicator", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__SET_POWER_LEVEL] = { .name = "set-power-level", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__SET_TIME_FOR_POWER_ON] = { .name = "set-time-for-power-on", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__SET_TIME_OF_DAY] = { .name = "set-time-of-day", .filter = &(const struct rtas_filter) { .buf_idx1 = -1, .size_idx1 = -1, .buf_idx2 = -1, .size_idx2 = -1, }, }, [RTAS_FNIDX__START_CPU] = { .name = "start-cpu", }, [RTAS_FNIDX__STOP_SELF] = { .name = "stop-self", }, [RTAS_FNIDX__SYSTEM_REBOOT] = { .name = "system-reboot", }, [RTAS_FNIDX__THAW_TIME_BASE] = { .name = "thaw-time-base", }, [RTAS_FNIDX__WRITE_PCI_CONFIG] = { .name = "write-pci-config", }, }; #define for_each_rtas_function(funcp) \ for (funcp = &rtas_function_table[0]; \ funcp < &rtas_function_table[ARRAY_SIZE(rtas_function_table)]; \ ++funcp) /* * Nearly all RTAS calls need to be serialized. All uses of the * default rtas_args block must hold rtas_lock. * * Exceptions to the RTAS serialization requirement (e.g. stop-self) * must use a separate rtas_args structure. */ static DEFINE_RAW_SPINLOCK(rtas_lock); static struct rtas_args rtas_args; /** * rtas_function_token() - RTAS function token lookup. * @handle: Function handle, e.g. RTAS_FN_EVENT_SCAN. * * Context: Any context. * Return: the token value for the function if implemented by this platform, * otherwise RTAS_UNKNOWN_SERVICE. */ s32 rtas_function_token(const rtas_fn_handle_t handle) { const size_t index = handle.index; const bool out_of_bounds = index >= ARRAY_SIZE(rtas_function_table); if (WARN_ONCE(out_of_bounds, "invalid function index %zu", index)) return RTAS_UNKNOWN_SERVICE; /* * Various drivers attempt token lookups on non-RTAS * platforms. */ if (!rtas.dev) return RTAS_UNKNOWN_SERVICE; return rtas_function_table[index].token; } EXPORT_SYMBOL_GPL(rtas_function_token); static int rtas_function_cmp(const void *a, const void *b) { const struct rtas_function *f1 = a; const struct rtas_function *f2 = b; return strcmp(f1->name, f2->name); } /* * Boot-time initialization of the function table needs the lookup to * return a non-const-qualified object. Use rtas_name_to_function() * in all other contexts. */ static struct rtas_function *__rtas_name_to_function(const char *name) { const struct rtas_function key = { .name = name, }; struct rtas_function *found; found = bsearch(&key, rtas_function_table, ARRAY_SIZE(rtas_function_table), sizeof(rtas_function_table[0]), rtas_function_cmp); return found; } static const struct rtas_function *rtas_name_to_function(const char *name) { return __rtas_name_to_function(name); } static DEFINE_XARRAY(rtas_token_to_function_xarray); static int __init rtas_token_to_function_xarray_init(void) { const struct rtas_function *func; int err = 0; for_each_rtas_function(func) { const s32 token = func->token; if (token == RTAS_UNKNOWN_SERVICE) continue; err = xa_err(xa_store(&rtas_token_to_function_xarray, token, (void *)func, GFP_KERNEL)); if (err) break; } return err; } arch_initcall(rtas_token_to_function_xarray_init); /* * For use by sys_rtas(), where the token value is provided by user * space and we don't want to warn on failed lookups. */ static const struct rtas_function *rtas_token_to_function_untrusted(s32 token) { return xa_load(&rtas_token_to_function_xarray, token); } /* * Reverse lookup for deriving the function descriptor from a * known-good token value in contexts where the former is not already * available. @token must be valid, e.g. derived from the result of a * prior lookup against the function table. */ static const struct rtas_function *rtas_token_to_function(s32 token) { const struct rtas_function *func; if (WARN_ONCE(token < 0, "invalid token %d", token)) return NULL; func = rtas_token_to_function_untrusted(token); if (func) return func; /* * Fall back to linear scan in case the reverse mapping hasn't * been initialized yet. */ if (xa_empty(&rtas_token_to_function_xarray)) { for_each_rtas_function(func) { if (func->token == token) return func; } } WARN_ONCE(true, "unexpected failed lookup for token %d", token); return NULL; } /* This is here deliberately so it's only used in this file */ void enter_rtas(unsigned long); static void __do_enter_rtas(struct rtas_args *args) { enter_rtas(__pa(args)); srr_regs_clobbered(); /* rtas uses SRRs, invalidate */ } static void __do_enter_rtas_trace(struct rtas_args *args) { const struct rtas_function *func = rtas_token_to_function(be32_to_cpu(args->token)); /* * If there is a per-function lock, it must be held by the * caller. */ if (func->lock) lockdep_assert_held(func->lock); if (args == &rtas_args) lockdep_assert_held(&rtas_lock); trace_rtas_input(args, func->name); trace_rtas_ll_entry(args); __do_enter_rtas(args); trace_rtas_ll_exit(args); trace_rtas_output(args, func->name); } static void do_enter_rtas(struct rtas_args *args) { const unsigned long msr = mfmsr(); /* * Situations where we want to skip any active tracepoints for * safety reasons: * * 1. The last code executed on an offline CPU as it stops, * i.e. we're about to call stop-self. The tracepoints' * function name lookup uses xarray, which uses RCU, which * isn't valid to call on an offline CPU. Any events * emitted on an offline CPU will be discarded anyway. * * 2. In real mode, as when invoking ibm,nmi-interlock from * the pseries MCE handler. We cannot count on trace * buffers or the entries in rtas_token_to_function_xarray * to be contained in the RMO. */ const unsigned long mask = MSR_IR | MSR_DR; const bool can_trace = likely(cpu_online(raw_smp_processor_id()) && (msr & mask) == mask); /* * Make sure MSR[RI] is currently enabled as it will be forced later * in enter_rtas. */ BUG_ON(!(msr & MSR_RI)); BUG_ON(!irqs_disabled()); hard_irq_disable(); /* Ensure MSR[EE] is disabled on PPC64 */ if (can_trace) __do_enter_rtas_trace(args); else __do_enter_rtas(args); } struct rtas_t rtas; DEFINE_SPINLOCK(rtas_data_buf_lock); EXPORT_SYMBOL_GPL(rtas_data_buf_lock); char rtas_data_buf[RTAS_DATA_BUF_SIZE] __aligned(SZ_4K); EXPORT_SYMBOL_GPL(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_GPL(rtas_flash_term_hook); /* * 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 flags; if (!rtas.base) return; raw_spin_lock_irqsave(&rtas_lock, flags); rtas_call_unlocked(&rtas_args, 10, 1, 1, NULL, c); raw_spin_unlock_irqrestore(&rtas_lock, flags); } 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_function_token(RTAS_FN_DISPLAY_CHARACTER); set_indicator = rtas_function_token(RTAS_FN_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_GPL(rtas_progress); /* needed by rtas_flash module */ int rtas_token(const char *service) { const struct rtas_function *func; const __be32 *tokp; if (rtas.dev == NULL) return RTAS_UNKNOWN_SERVICE; func = rtas_name_to_function(service); if (func) return func->token; /* * The caller is looking up a name that is not known to be an * RTAS function. Either it's a function that needs to be * added to the table, or they're misusing rtas_token() to * access non-function properties of the /rtas node. Warn and * fall back to the legacy behavior. */ WARN_ONCE(1, "unknown function `%s`, should it be added to rtas_function_table?\n", service); tokp = of_get_property(rtas.dev, service, NULL); return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE; } EXPORT_SYMBOL_GPL(rtas_token); #ifdef CONFIG_RTAS_ERROR_LOGGING static u32 rtas_error_log_max __ro_after_init = RTAS_ERROR_LOG_MAX; /* * 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) { return rtas_error_log_max; } static void __init init_error_log_max(void) { static const char propname[] __initconst = "rtas-error-log-max"; u32 max; if (of_property_read_u32(rtas.dev, propname, &max)) { pr_warn("%s not found, using default of %u\n", propname, RTAS_ERROR_LOG_MAX); max = RTAS_ERROR_LOG_MAX; } if (max > RTAS_ERROR_LOG_MAX) { pr_warn("%s = %u, clamping max error log size to %u\n", propname, max, RTAS_ERROR_LOG_MAX); max = RTAS_ERROR_LOG_MAX; } rtas_error_log_max = max; } static char rtas_err_buf[RTAS_ERROR_LOG_MAX]; /** 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) { const s32 token = rtas_function_token(RTAS_FN_RTAS_LAST_ERROR); struct rtas_args err_args, save_args; u32 bufsz; char *buf = NULL; lockdep_assert_held(&rtas_lock); if (token == -1) return NULL; bufsz = rtas_get_error_log_max(); err_args.token = cpu_to_be32(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(&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) memmove(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 static void __init init_error_log_max(void) {} #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(args); } /** * rtas_call_unlocked() - Invoke an RTAS firmware function without synchronization. * @args: RTAS parameter block to be used for the call, must obey RTAS addressing * constraints. * @token: Identifies the function being invoked. * @nargs: Number of input parameters. Does not include token. * @nret: Number of output parameters, including the call status. * @....: List of @nargs input parameters. * * Invokes the RTAS function indicated by @token, which the caller * should obtain via rtas_function_token(). * * This function is similar to rtas_call(), but must be used with a * limited set of RTAS calls specifically exempted from the general * requirement that only one RTAS call may be in progress at any * time. Examples include stop-self and ibm,nmi-interlock. */ 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); } static bool token_is_restricted_errinjct(s32 token) { return token == rtas_function_token(RTAS_FN_IBM_OPEN_ERRINJCT) || token == rtas_function_token(RTAS_FN_IBM_ERRINJCT); } /** * rtas_call() - Invoke an RTAS firmware function. * @token: Identifies the function being invoked. * @nargs: Number of input parameters. Does not include token. * @nret: Number of output parameters, including the call status. * @outputs: Array of @nret output words. * @....: List of @nargs input parameters. * * Invokes the RTAS function indicated by @token, which the caller * should obtain via rtas_function_token(). * * The @nargs and @nret arguments must match the number of input and * output parameters specified for the RTAS function. * * rtas_call() returns RTAS status codes, not conventional Linux errno * values. Callers must translate any failure to an appropriate errno * in syscall context. Most callers of RTAS functions that can return * -2 or 990x should use rtas_busy_delay() to correctly handle those * statuses before calling again. * * The return value descriptions are adapted from 7.2.8 [RTAS] Return * Codes of the PAPR and CHRP specifications. * * Context: Process context preferably, interrupt context if * necessary. Acquires an internal spinlock and may perform * GFP_ATOMIC slab allocation in error path. Unsafe for NMI * context. * Return: * * 0 - RTAS function call succeeded. * * -1 - RTAS function encountered a hardware or * platform error, or the token is invalid, * or the function is restricted by kernel policy. * * -2 - Specs say "A necessary hardware device was busy, * and the requested function could not be * performed. The operation should be retried at * a later time." This is misleading, at least with * respect to current RTAS implementations. What it * usually means in practice is that the function * could not be completed while meeting RTAS's * deadline for returning control to the OS (250us * for PAPR/PowerVM, typically), but the call may be * immediately reattempted to resume work on it. * * -3 - Parameter error. * * -7 - Unexpected state change. * * 9000...9899 - Vendor-specific success codes. * * 9900...9905 - Advisory extended delay. Caller should try * again after ~10^x ms has elapsed, where x is * the last digit of the status [0-5]. Again going * beyond the PAPR text, 990x on PowerVM indicates * contention for RTAS-internal resources. Other * RTAS call sequences in progress should be * allowed to complete before reattempting the * call. * * -9000 - Multi-level isolation error. * * -9999...-9004 - Vendor-specific error codes. * * Additional negative values - Function-specific error. * * Additional positive values - Function-specific success. */ int rtas_call(int token, int nargs, int nret, int *outputs, ...) { struct pin_cookie cookie; va_list list; int i; unsigned long flags; struct rtas_args *args; char *buff_copy = NULL; int ret; if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) return -1; if (token_is_restricted_errinjct(token)) { /* * It would be nicer to not discard the error value * from security_locked_down(), but callers expect an * RTAS status, not an errno. */ if (security_locked_down(LOCKDOWN_RTAS_ERROR_INJECTION)) return -1; } if ((mfmsr() & (MSR_IR|MSR_DR)) != (MSR_IR|MSR_DR)) { WARN_ON_ONCE(1); return -1; } raw_spin_lock_irqsave(&rtas_lock, flags); cookie = lockdep_pin_lock(&rtas_lock); /* We use the global rtas args buffer */ args = &rtas_args; va_start(list, outputs); va_rtas_call_unlocked(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(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(args->rets[i + 1]); ret = (nret > 0) ? be32_to_cpu(args->rets[0]) : 0; lockdep_unpin_lock(&rtas_lock, cookie); raw_spin_unlock_irqrestore(&rtas_lock, flags); if (buff_copy) { log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0); if (slab_is_available()) kfree(buff_copy); } return ret; } EXPORT_SYMBOL_GPL(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; } /* * Early boot fallback for rtas_busy_delay(). */ static bool __init rtas_busy_delay_early(int status) { static size_t successive_ext_delays __initdata; bool retry; switch (status) { case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX: /* * In the unlikely case that we receive an extended * delay status in early boot, the OS is probably not * the cause, and there's nothing we can do to clear * the condition. Best we can do is delay for a bit * and hope it's transient. Lie to the caller if it * seems like we're stuck in a retry loop. */ mdelay(1); retry = true; successive_ext_delays += 1; if (successive_ext_delays > 1000) { pr_err("too many extended delays, giving up\n"); dump_stack(); retry = false; successive_ext_delays = 0; } break; case RTAS_BUSY: retry = true; successive_ext_delays = 0; break; default: retry = false; successive_ext_delays = 0; break; } return retry; } /** * 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 __ref rtas_busy_delay(int status) { unsigned int ms; bool ret; /* * Can't do timed sleeps before timekeeping is up. */ if (system_state < SYSTEM_SCHEDULING) return rtas_busy_delay_early(status); 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. To make sure pause time will * not be way longer than requested independent of HZ * configuration, use fsleep(). See fsleep() for details of * used sleeping functions. */ fsleep(ms * 1000); 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_GPL(rtas_busy_delay); int rtas_error_rc(int rtas_rc) { int rc; switch (rtas_rc) { case RTAS_HARDWARE_ERROR: /* Hardware Error */ rc = -EIO; break; case RTAS_INVALID_PARAMETER: /* 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: pr_err("%s: unexpected error %d\n", __func__, rtas_rc); rc = -ERANGE; break; } return rc; } EXPORT_SYMBOL_GPL(rtas_error_rc); int rtas_get_power_level(int powerdomain, int *level) { int token = rtas_function_token(RTAS_FN_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_GPL(rtas_get_power_level); int rtas_set_power_level(int powerdomain, int level, int *setlevel) { int token = rtas_function_token(RTAS_FN_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_GPL(rtas_set_power_level); int rtas_get_sensor(int sensor, int index, int *state) { int token = rtas_function_token(RTAS_FN_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_GPL(rtas_get_sensor); int rtas_get_sensor_fast(int sensor, int index, int *state) { int token = rtas_function_token(RTAS_FN_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; } int rtas_set_indicator(int indicator, int index, int new_value) { int token = rtas_function_token(RTAS_FN_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_GPL(rtas_set_indicator); /* * Ignoring RTAS extended delay */ int rtas_set_indicator_fast(int indicator, int index, int new_value) { int token = rtas_function_token(RTAS_FN_SET_INDICATOR); int rc; 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 token = rtas_function_token(RTAS_FN_IBM_SUSPEND_ME); int fwrc; int ret; fwrc = rtas_call(token, 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); pr_emerg("system-reboot returned %d\n", rtas_call(rtas_function_token(RTAS_FN_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 */ pr_emerg("power-off returned %d\n", rtas_call(rtas_function_token(RTAS_FN_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 */ pr_emerg("power-off returned %d\n", rtas_call(rtas_function_token(RTAS_FN_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]; static bool ibm_extended_os_term; void rtas_os_term(char *str) { s32 token = rtas_function_token(RTAS_FN_IBM_OS_TERM); static struct rtas_args args; 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 (token == RTAS_UNKNOWN_SERVICE || !ibm_extended_os_term) return; snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str); /* * Keep calling as long as RTAS returns a "try again" status, * but don't use rtas_busy_delay(), which potentially * schedules. */ do { rtas_call_unlocked(&args, token, 1, 1, NULL, __pa(rtas_os_term_buf)); status = be32_to_cpu(args.rets[0]); } while (rtas_busy_delay_time(status)); if (status != 0) pr_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 = rtas_function_token(RTAS_FN_IBM_ACTIVATE_FIRMWARE); int fwrc; if (token == RTAS_UNKNOWN_SERVICE) { pr_notice("ibm,activate-firmware method unavailable\n"); return; } mutex_lock(&rtas_ibm_activate_firmware_lock); do { fwrc = rtas_call(token, 0, 1, NULL); } while (rtas_busy_delay(fwrc)); mutex_unlock(&rtas_ibm_activate_firmware_lock); if (fwrc) pr_err("ibm,activate-firmware failed (%i)\n", fwrc); } /** * 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; } /* * 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. * If a function is allowed to be invoked via the syscall, then its * entry in the rtas_functions table points to a rtas_filter that * describes its constraints, with the indexes of the parameters which * are expected to contain addresses and sizes of buffers allocated * inside the RMO buffer. */ 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(const struct rtas_function *func, int nargs, struct rtas_args *args) { const struct rtas_filter *f; const bool is_platform_dump = func == &rtas_function_table[RTAS_FNIDX__IBM_PLATFORM_DUMP]; const bool is_config_conn = func == &rtas_function_table[RTAS_FNIDX__IBM_CONFIGURE_CONNECTOR]; u32 base, size, end; /* * Only functions with filters attached are allowed. */ f = func->filter; if (!f) goto err; /* * And some functions aren't allowed on LE. */ if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) && func->banned_for_syscall_on_le) goto err; 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 (is_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 (is_config_conn && 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: %s nargs=%d (called by %s)\n", func->name, nargs, current->comm); return true; } /* We assume to be passed big endian arguments */ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) { const struct rtas_function *func; struct pin_cookie cookie; 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; nargs = array_index_nospec(nargs, ARRAY_SIZE(args.args)); nret = array_index_nospec(nret, ARRAY_SIZE(args.args) - nargs); /* Copy in args. */ if (copy_from_user(args.args, uargs->args, nargs * sizeof(rtas_arg_t)) != 0) return -EFAULT; /* * If this token doesn't correspond to a function the kernel * understands, you're not allowed to call it. */ func = rtas_token_to_function_untrusted(token); if (!func) return -EINVAL; args.rets = &args.args[nargs]; memset(args.rets, 0, nret * sizeof(rtas_arg_t)); if (block_rtas_call(func, nargs, &args)) return -EINVAL; if (token_is_restricted_errinjct(token)) { int err; err = security_locked_down(LOCKDOWN_RTAS_ERROR_INJECTION); if (err) return err; } /* Need to handle ibm,suspend_me call specially */ if (token == rtas_function_token(RTAS_FN_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(); /* * If this function has a mutex assigned to it, we must * acquire it to avoid interleaving with any kernel-based uses * of the same function. Kernel-based sequences acquire the * appropriate mutex explicitly. */ if (func->lock) mutex_lock(func->lock); raw_spin_lock_irqsave(&rtas_lock, flags); cookie = lockdep_pin_lock(&rtas_lock); rtas_args = args; do_enter_rtas(&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); lockdep_unpin_lock(&rtas_lock, cookie); raw_spin_unlock_irqrestore(&rtas_lock, flags); if (func->lock) mutex_unlock(func->lock); 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; } static void __init rtas_function_table_init(void) { struct property *prop; for (size_t i = 0; i < ARRAY_SIZE(rtas_function_table); ++i) { struct rtas_function *curr = &rtas_function_table[i]; struct rtas_function *prior; int cmp; curr->token = RTAS_UNKNOWN_SERVICE; if (i == 0) continue; /* * Ensure table is sorted correctly for binary search * on function names. */ prior = &rtas_function_table[i - 1]; cmp = strcmp(prior->name, curr->name); if (cmp < 0) continue; if (cmp == 0) { pr_err("'%s' has duplicate function table entries\n", curr->name); } else { pr_err("function table unsorted: '%s' wrongly precedes '%s'\n", prior->name, curr->name); } } for_each_property_of_node(rtas.dev, prop) { struct rtas_function *func; if (prop->length != sizeof(u32)) continue; func = __rtas_name_to_function(prop->name); if (!func) continue; func->token = be32_to_cpup((__be32 *)prop->value); pr_debug("function %s has token %u\n", func->name, func->token); } } /* * 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; init_error_log_max(); /* Must be called before any function token lookups */ rtas_function_table_init(); /* * Discover this now to avoid a device tree lookup in the * panic path. */ ibm_extended_os_term = of_property_read_bool(rtas.dev, "ibm,extended-os-term"); /* 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); rtas_work_area_reserve_arena(rtas_region); } 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 DEFINE_RAW_SPINLOCK(timebase_lock); static u64 timebase = 0; void rtas_give_timebase(void) { unsigned long flags; raw_spin_lock_irqsave(&timebase_lock, flags); hard_irq_disable(); rtas_call(rtas_function_token(RTAS_FN_FREEZE_TIME_BASE), 0, 1, NULL); timebase = get_tb(); raw_spin_unlock(&timebase_lock); while (timebase) barrier(); rtas_call(rtas_function_token(RTAS_FN_THAW_TIME_BASE), 0, 1, NULL); local_irq_restore(flags); } void rtas_take_timebase(void) { while (!timebase) barrier(); raw_spin_lock(&timebase_lock); set_tb(timebase >> 32, timebase & 0xffffffff); timebase = 0; raw_spin_unlock(&timebase_lock); }