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author | 2023-02-10 12:42:08 -0600 | |
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committer | 2023-02-13 22:35:03 +1100 | |
commit | 08273c9f619cb32fb041935724f576e607101f3b (patch) | |
tree | 49017ed6ba9e8a9dec74342d86a4fe425d6a3303 /arch/powerpc/kernel/rtas.c | |
parent | powerpc/rtas: introduce rtas_function_token() API (diff) | |
download | linux-08273c9f619cb32fb041935724f576e607101f3b.tar.gz linux-08273c9f619cb32fb041935724f576e607101f3b.tar.bz2 linux-08273c9f619cb32fb041935724f576e607101f3b.zip |
powerpc/rtas: arch-wide function token lookup conversions
With the tokens for all implemented RTAS functions now available via
rtas_function_token(), which is optimal and safe for arbitrary
contexts, there is no need to use rtas_token() or cache its result.
Most conversions are trivial, but a few are worth describing in more
detail:
* Error injection token comparisons for lockdown purposes are
consolidated into a simple predicate: token_is_restricted_errinjct().
* A couple of special cases in block_rtas_call() do not use
rtas_token() but perform string comparisons against names in the
function table. These are converted to compare against token values
instead, which is logically equivalent but less expensive.
* The lookup for the ibm,os-term token can be deferred until needed,
instead of caching it at boot to avoid device tree traversal during
panic.
* Since rtas_function_token() accesses a read-only data structure
without taking any locks, xmon's lookup of set-indicator can be
performed as needed instead of cached at startup.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-20-26929c8cce78@linux.ibm.com
Diffstat (limited to 'arch/powerpc/kernel/rtas.c')
-rw-r--r-- | arch/powerpc/kernel/rtas.c | 79 |
1 files changed, 38 insertions, 41 deletions
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index bb6f5370c279..31175b34856a 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -782,8 +782,8 @@ void rtas_progress(char *s, unsigned short hex) "ibm,display-truncation-length", NULL); of_node_put(root); } - display_character = rtas_token("display-character"); - set_indicator = rtas_token("set-indicator"); + display_character = rtas_function_token(RTAS_FN_DISPLAY_CHARACTER); + set_indicator = rtas_function_token(RTAS_FN_SET_INDICATOR); } if (display_character == RTAS_UNKNOWN_SERVICE) { @@ -937,7 +937,6 @@ static void __init init_error_log_max(void) static char rtas_err_buf[RTAS_ERROR_LOG_MAX]; -static int rtas_last_error_token; /** Return a copy of the detailed error text associated with the * most recent failed call to rtas. Because the error text @@ -947,16 +946,17 @@ static int rtas_last_error_token; */ 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 (rtas_last_error_token == -1) + if (token == -1) return NULL; bufsz = rtas_get_error_log_max(); - err_args.token = cpu_to_be32(rtas_last_error_token); + 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)); @@ -1025,8 +1025,11 @@ void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, va_end(list); } -static int ibm_open_errinjct_token; -static int ibm_errinjct_token; +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. @@ -1098,7 +1101,7 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...) if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) return -1; - if (token == ibm_open_errinjct_token || token == ibm_errinjct_token) { + if (token_is_restricted_errinjct(token)) { /* * It would be nicer to not discard the error value * from security_locked_down(), but callers expect an @@ -1330,7 +1333,7 @@ static int rtas_error_rc(int rtas_rc) int rtas_get_power_level(int powerdomain, int *level) { - int token = rtas_token("get-power-level"); + int token = rtas_function_token(RTAS_FN_GET_POWER_LEVEL); int rc; if (token == RTAS_UNKNOWN_SERVICE) @@ -1347,7 +1350,7 @@ EXPORT_SYMBOL_GPL(rtas_get_power_level); int rtas_set_power_level(int powerdomain, int level, int *setlevel) { - int token = rtas_token("set-power-level"); + int token = rtas_function_token(RTAS_FN_SET_POWER_LEVEL); int rc; if (token == RTAS_UNKNOWN_SERVICE) @@ -1365,7 +1368,7 @@ EXPORT_SYMBOL_GPL(rtas_set_power_level); int rtas_get_sensor(int sensor, int index, int *state) { - int token = rtas_token("get-sensor-state"); + int token = rtas_function_token(RTAS_FN_GET_SENSOR_STATE); int rc; if (token == RTAS_UNKNOWN_SERVICE) @@ -1383,7 +1386,7 @@ EXPORT_SYMBOL_GPL(rtas_get_sensor); int rtas_get_sensor_fast(int sensor, int index, int *state) { - int token = rtas_token("get-sensor-state"); + int token = rtas_function_token(RTAS_FN_GET_SENSOR_STATE); int rc; if (token == RTAS_UNKNOWN_SERVICE) @@ -1425,7 +1428,7 @@ bool rtas_indicator_present(int token, int *maxindex) int rtas_set_indicator(int indicator, int index, int new_value) { - int token = rtas_token("set-indicator"); + int token = rtas_function_token(RTAS_FN_SET_INDICATOR); int rc; if (token == RTAS_UNKNOWN_SERVICE) @@ -1446,8 +1449,8 @@ EXPORT_SYMBOL_GPL(rtas_set_indicator); */ int rtas_set_indicator_fast(int indicator, int index, int new_value) { + int token = rtas_function_token(RTAS_FN_SET_INDICATOR); int rc; - int token = rtas_token("set-indicator"); if (token == RTAS_UNKNOWN_SERVICE) return -ENOENT; @@ -1489,10 +1492,11 @@ int rtas_set_indicator_fast(int indicator, int index, int new_value) */ 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(rtas_token("ibm,suspend-me"), 0, 1, NULL); + fwrc = rtas_call(token, 0, 1, NULL); switch (fwrc) { case 0: @@ -1525,7 +1529,7 @@ 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_token("system-reboot"), 0, 1, NULL)); + rtas_call(rtas_function_token(RTAS_FN_SYSTEM_REBOOT), 0, 1, NULL)); for (;;); } @@ -1535,7 +1539,7 @@ void rtas_power_off(void) 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_token("power-off"), 2, 1, NULL, -1, -1)); + rtas_call(rtas_function_token(RTAS_FN_POWER_OFF), 2, 1, NULL, -1, -1)); for (;;); } @@ -1545,16 +1549,17 @@ void __noreturn rtas_halt(void) rtas_flash_term_hook(SYS_HALT); /* allow power on only with power button press */ pr_emerg("power-off returned %d\n", - rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); + 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 s32 ibm_os_term_token = RTAS_UNKNOWN_SERVICE; +static bool ibm_extended_os_term; void rtas_os_term(char *str) { + s32 token = rtas_function_token(RTAS_FN_IBM_OS_TERM); int status; /* @@ -1563,7 +1568,8 @@ void rtas_os_term(char *str) * this property may terminate the partition which we want to avoid * since it interferes with panic_timeout. */ - if (ibm_os_term_token == RTAS_UNKNOWN_SERVICE) + + if (token == RTAS_UNKNOWN_SERVICE || !ibm_extended_os_term) return; snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str); @@ -1574,8 +1580,7 @@ void rtas_os_term(char *str) * schedules. */ do { - status = rtas_call(ibm_os_term_token, 1, 1, NULL, - __pa(rtas_os_term_buf)); + status = rtas_call(token, 1, 1, NULL, __pa(rtas_os_term_buf)); } while (rtas_busy_delay_time(status)); if (status != 0) @@ -1595,10 +1600,9 @@ void rtas_os_term(char *str) */ void rtas_activate_firmware(void) { - int token; + int token = rtas_function_token(RTAS_FN_IBM_ACTIVATE_FIRMWARE); int fwrc; - token = rtas_token("ibm,activate-firmware"); if (token == RTAS_UNKNOWN_SERVICE) { pr_notice("ibm,activate-firmware method unavailable\n"); return; @@ -1684,6 +1688,8 @@ static bool block_rtas_call(int token, int nargs, { 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; /* @@ -1720,8 +1726,7 @@ static bool block_rtas_call(int token, int nargs, * Special case for ibm,platform-dump - NULL buffer * address is used to indicate end of dump processing */ - if (!strcmp(func->name, "ibm,platform-dump") && - base == 0) + if (is_platform_dump && base == 0) return false; if (!in_rmo_buf(base, end)) @@ -1742,8 +1747,7 @@ static bool block_rtas_call(int token, int nargs, * Special case for ibm,configure-connector where the * address can be 0 */ - if (!strcmp(func->name, "ibm,configure-connector") && - base == 0) + if (is_config_conn && base == 0) return false; if (!in_rmo_buf(base, end)) @@ -1798,7 +1802,7 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) if (block_rtas_call(token, nargs, &args)) return -EINVAL; - if (token == ibm_open_errinjct_token || token == ibm_errinjct_token) { + if (token_is_restricted_errinjct(token)) { int err; err = security_locked_down(LOCKDOWN_RTAS_ERROR_INJECTION); @@ -1807,7 +1811,7 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) } /* Need to handle ibm,suspend_me call specially */ - if (token == rtas_token("ibm,suspend-me")) { + if (token == rtas_function_token(RTAS_FN_IBM_SUSPEND_ME)) { /* * rtas_ibm_suspend_me assumes the streamid handle is in cpu @@ -1942,11 +1946,10 @@ void __init rtas_initialize(void) rtas_function_table_init(); /* - * Discover these now to avoid device tree lookups in the + * Discover this now to avoid a device tree lookup in the * panic path. */ - if (of_property_read_bool(rtas.dev, "ibm,extended-os-term")) - ibm_os_term_token = rtas_token("ibm,os-term"); + 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 @@ -1961,12 +1964,6 @@ void __init rtas_initialize(void) panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n", PAGE_SIZE, &rtas_region); -#ifdef CONFIG_RTAS_ERROR_LOGGING - rtas_last_error_token = rtas_token("rtas-last-error"); -#endif - ibm_open_errinjct_token = rtas_token("ibm,open-errinjct"); - ibm_errinjct_token = rtas_token("ibm,errinjct"); - rtas_work_area_reserve_arena(rtas_region); } @@ -2022,13 +2019,13 @@ void rtas_give_timebase(void) raw_spin_lock_irqsave(&timebase_lock, flags); hard_irq_disable(); - rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); + 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_token("thaw-time-base"), 0, 1, NULL); + rtas_call(rtas_function_token(RTAS_FN_THAW_TIME_BASE), 0, 1, NULL); local_irq_restore(flags); } |