| // 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 <linux/bsearch.h> |
| #include <linux/capability.h> |
| #include <linux/delay.h> |
| #include <linux/export.h> |
| #include <linux/init.h> |
| #include <linux/kconfig.h> |
| #include <linux/kernel.h> |
| #include <linux/memblock.h> |
| #include <linux/of.h> |
| #include <linux/of_fdt.h> |
| #include <linux/reboot.h> |
| #include <linux/sched.h> |
| #include <linux/security.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <linux/stdarg.h> |
| #include <linux/syscalls.h> |
| #include <linux/types.h> |
| #include <linux/uaccess.h> |
| #include <linux/xarray.h> |
| |
| #include <asm/delay.h> |
| #include <asm/firmware.h> |
| #include <asm/interrupt.h> |
| #include <asm/machdep.h> |
| #include <asm/mmu.h> |
| #include <asm/page.h> |
| #include <asm/rtas-work-area.h> |
| #include <asm/rtas.h> |
| #include <asm/time.h> |
| #include <asm/trace.h> |
| #include <asm/udbg.h> |
| |
| 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 false. |
| */ |
| struct rtas_function { |
| s32 token; |
| const bool banned_for_syscall_on_le:1; |
| const char * const name; |
| const struct rtas_filter *filter; |
| }; |
| |
| 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, |
| }, |
| }, |
| [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, |
| }, |
| }, |
| [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, |
| }, |
| }, |
| [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, |
| }, |
| }, |
| [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, |
| }, |
| }, |
| [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, |
| }, |
| }, |
| [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, |
| }, |
| }, |
| [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_WINDOWS] = { |
| .name = "ibm,reset-pe-dma-windows", |
| }, |
| [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, |
| }, |
| }, |
| [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", |
| }, |
| }; |
| |
| /** |
| * 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) |
| { |
| int err = 0; |
| |
| for (size_t i = 0; i < ARRAY_SIZE(rtas_function_table); ++i) { |
| const struct rtas_function *func = &rtas_function_table[i]; |
| 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); |
| |
| 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 = xa_load(&rtas_token_to_function_xarray, token); |
| |
| if (WARN_ONCE(!func, "unexpected failed lookup for token %d", token)) |
| return NULL; |
| |
| return func; |
| } |
| |
| /* 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 char *name = NULL; |
| /* |
| * If the tracepoints that consume the function name aren't |
| * active, avoid the lookup. |
| */ |
| if ((trace_rtas_input_enabled() || trace_rtas_output_enabled())) { |
| const s32 token = be32_to_cpu(args->token); |
| const struct rtas_function *func = rtas_token_to_function(token); |
| |
| name = func->name; |
| } |
| |
| trace_rtas_input(args, name); |
| trace_rtas_ll_entry(args); |
| |
| __do_enter_rtas(args); |
| |
| trace_rtas_ll_exit(args); |
| trace_rtas_output(args, 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; |
| |
| /* |
| * 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; |
| |
| 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); |
| |
| int rtas_service_present(const char *service) |
| { |
| return rtas_token(service) != RTAS_UNKNOWN_SERVICE; |
| } |
| |
| #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; |
| |
| 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) |
| 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 |
| 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); |
| } |
| |
| 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, ...) |
| { |
| 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); |
| /* 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; |
| |
| 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. 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_GPL(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: |
| pr_err("%s: unexpected error %d\n", __func__, rtas_rc); |
| rc = -ERANGE; |
| break; |
| } |
| return 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); |
| 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 { |
| status = rtas_call(token, 1, 1, NULL, __pa(rtas_os_term_buf)); |
| } 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; |
| } |
| |
| do { |
| fwrc = rtas_call(token, 0, 1, NULL); |
| } while (rtas_busy_delay(fwrc)); |
| |
| 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(int token, int nargs, |
| struct rtas_args *args) |
| { |
| const struct rtas_function *func; |
| const struct rtas_filter *f; |
| const bool is_platform_dump = token == rtas_function_token(RTAS_FN_IBM_PLATFORM_DUMP); |
| const bool is_config_conn = token == rtas_function_token(RTAS_FN_IBM_CONFIGURE_CONNECTOR); |
| u32 base, size, end; |
| |
| /* |
| * If this token doesn't correspond to a function the kernel |
| * understands, you're not allowed to call it. |
| */ |
| func = rtas_token_to_function(token); |
| if (!func) |
| goto err; |
| /* |
| * And 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: token=0x%x, nargs=%d (called by %s)\n", |
| token, nargs, current->comm); |
| return true; |
| } |
| |
| /* 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; |
| |
| 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(); |
| |
| raw_spin_lock_irqsave(&rtas_lock, flags); |
| |
| 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); |
| |
| raw_spin_unlock_irqrestore(&rtas_lock, 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; |
| } |
| |
| 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); |
| } |