diff options
Diffstat (limited to 'arch/powerpc/kernel/rtas.c')
| -rw-r--r-- | arch/powerpc/kernel/rtas.c | 192 |
1 files changed, 126 insertions, 66 deletions
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index e847f9b1c5b9..deded51a7978 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -7,43 +7,35 @@ * Copyright (C) 2001 IBM. */ -#include <linux/stdarg.h> -#include <linux/kernel.h> -#include <linux/types.h> -#include <linux/spinlock.h> -#include <linux/export.h> -#include <linux/init.h> +#define pr_fmt(fmt) "rtas: " fmt + #include <linux/capability.h> #include <linux/delay.h> -#include <linux/cpu.h> -#include <linux/sched.h> -#include <linux/smp.h> -#include <linux/completion.h> -#include <linux/cpumask.h> +#include <linux/export.h> +#include <linux/init.h> +#include <linux/kernel.h> #include <linux/memblock.h> -#include <linux/slab.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/of.h> -#include <linux/of_fdt.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <asm/delay.h> +#include <asm/firmware.h> #include <asm/interrupt.h> -#include <asm/rtas.h> -#include <asm/hvcall.h> #include <asm/machdep.h> -#include <asm/firmware.h> +#include <asm/mmu.h> #include <asm/page.h> -#include <asm/param.h> -#include <asm/delay.h> -#include <linux/uaccess.h> -#include <asm/udbg.h> -#include <asm/syscalls.h> -#include <asm/smp.h> -#include <linux/atomic.h> +#include <asm/rtas.h> #include <asm/time.h> -#include <asm/mmu.h> -#include <asm/topology.h> +#include <asm/udbg.h> /* This is here deliberately so it's only used in this file */ void enter_rtas(unsigned long); @@ -353,6 +345,9 @@ int rtas_service_present(const char *service) EXPORT_SYMBOL(rtas_service_present); #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. @@ -360,21 +355,30 @@ EXPORT_SYMBOL(rtas_service_present); */ int rtas_get_error_log_max(void) { - static int rtas_error_log_max; - if (rtas_error_log_max) - return rtas_error_log_max; - - rtas_error_log_max = rtas_token ("rtas-error-log-max"); - if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) || - (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) { - printk (KERN_WARNING "RTAS: bad log buffer size %d\n", - rtas_error_log_max); - rtas_error_log_max = RTAS_ERROR_LOG_MAX; - } return rtas_error_log_max; } EXPORT_SYMBOL(rtas_get_error_log_max); +static 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]; static int rtas_last_error_token; @@ -432,6 +436,7 @@ static char *__fetch_rtas_last_error(char *altbuf) #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 @@ -467,6 +472,64 @@ void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, static int ibm_open_errinjct_token; static int ibm_errinjct_token; +/** + * 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_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; @@ -657,8 +720,7 @@ static int rtas_error_rc(int rtas_rc) rc = -ENODEV; break; default: - printk(KERN_ERR "%s: unexpected RTAS error %d\n", - __func__, rtas_rc); + pr_err("%s: unexpected error %d\n", __func__, rtas_rc); rc = -ERANGE; break; } @@ -862,8 +924,8 @@ void __noreturn rtas_restart(char *cmd) { if (rtas_flash_term_hook) rtas_flash_term_hook(SYS_RESTART); - printk("RTAS system-reboot returned %d\n", - rtas_call(rtas_token("system-reboot"), 0, 1, NULL)); + pr_emerg("system-reboot returned %d\n", + rtas_call(rtas_token("system-reboot"), 0, 1, NULL)); for (;;); } @@ -872,8 +934,8 @@ void rtas_power_off(void) if (rtas_flash_term_hook) rtas_flash_term_hook(SYS_POWER_OFF); /* allow power on only with power button press */ - printk("RTAS power-off returned %d\n", - rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); + pr_emerg("power-off returned %d\n", + rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); for (;;); } @@ -882,13 +944,14 @@ void __noreturn rtas_halt(void) if (rtas_flash_term_hook) rtas_flash_term_hook(SYS_HALT); /* allow power on only with power button press */ - printk("RTAS power-off returned %d\n", - rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); + pr_emerg("power-off returned %d\n", + rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); for (;;); } /* Must be in the RMO region, so we place it here */ static char rtas_os_term_buf[2048]; +static s32 ibm_os_term_token = RTAS_UNKNOWN_SERVICE; void rtas_os_term(char *str) { @@ -900,19 +963,23 @@ void rtas_os_term(char *str) * this property may terminate the partition which we want to avoid * since it interferes with panic_timeout. */ - if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") || - RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term")) + if (ibm_os_term_token == RTAS_UNKNOWN_SERVICE) 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(rtas_token("ibm,os-term"), 1, 1, NULL, + status = rtas_call(ibm_os_term_token, 1, 1, NULL, __pa(rtas_os_term_buf)); - } while (rtas_busy_delay(status)); + } while (rtas_busy_delay_time(status)); if (status != 0) - printk(KERN_EMERG "ibm,os-term call failed %d\n", status); + pr_emerg("ibm,os-term call failed %d\n", status); } /** @@ -983,8 +1050,6 @@ noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log return NULL; } -#ifdef CONFIG_PPC_RTAS_FILTER - /* * The sys_rtas syscall, as originally designed, allows root to pass * arbitrary physical addresses to RTAS calls. A number of RTAS calls @@ -1133,20 +1198,6 @@ static void __init rtas_syscall_filter_init(void) rtas_filters[i].token = rtas_token(rtas_filters[i].name); } -#else - -static bool block_rtas_call(int token, int nargs, - struct rtas_args *args) -{ - return false; -} - -static void __init rtas_syscall_filter_init(void) -{ -} - -#endif /* CONFIG_PPC_RTAS_FILTER */ - /* We assume to be passed big endian arguments */ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) { @@ -1277,6 +1328,15 @@ void __init rtas_initialize(void) no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry); rtas.entry = no_entry ? rtas.base : entry; + init_error_log_max(); + + /* + * Discover these now to avoid device tree lookups in the + * panic path. + */ + if (of_property_read_bool(rtas.dev, "ibm,extended-os-term")) + ibm_os_term_token = rtas_token("ibm,os-term"); + /* If RTAS was found, allocate the RMO buffer for it and look for * the stop-self token if any */ |