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Diffstat (limited to 'arch/powerpc/kernel/rtas.c')
| -rw-r--r-- | arch/powerpc/kernel/rtas.c | 1384 |
1 files changed, 1384 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c new file mode 100644 index 000000000..f8d3caad4 --- /dev/null +++ b/arch/powerpc/kernel/rtas.c @@ -0,0 +1,1384 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * + * Procedures for interfacing to the RTAS on CHRP machines. + * + * Peter Bergner, IBM March 2001. + * Copyright (C) 2001 IBM. + */ + +#include <linux/stdarg.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/spinlock.h> +#include <linux/export.h> +#include <linux/init.h> +#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/memblock.h> +#include <linux/slab.h> +#include <linux/reboot.h> +#include <linux/security.h> +#include <linux/syscalls.h> +#include <linux/of.h> +#include <linux/of_fdt.h> + +#include <asm/interrupt.h> +#include <asm/rtas.h> +#include <asm/hvcall.h> +#include <asm/machdep.h> +#include <asm/firmware.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/time.h> +#include <asm/mmu.h> +#include <asm/topology.h> + +/* This is here deliberately so it's only used in this file */ +void enter_rtas(unsigned long); + +static inline void do_enter_rtas(unsigned long args) +{ + unsigned long msr; + + /* + * Make sure MSR[RI] is currently enabled as it will be forced later + * in enter_rtas. + */ + msr = mfmsr(); + BUG_ON(!(msr & MSR_RI)); + + BUG_ON(!irqs_disabled()); + + hard_irq_disable(); /* Ensure MSR[EE] is disabled on PPC64 */ + + enter_rtas(args); + + srr_regs_clobbered(); /* rtas uses SRRs, invalidate */ +} + +struct rtas_t rtas = { + .lock = __ARCH_SPIN_LOCK_UNLOCKED +}; +EXPORT_SYMBOL(rtas); + +DEFINE_SPINLOCK(rtas_data_buf_lock); +EXPORT_SYMBOL(rtas_data_buf_lock); + +char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned; +EXPORT_SYMBOL(rtas_data_buf); + +unsigned long rtas_rmo_buf; + +/* + * If non-NULL, this gets called when the kernel terminates. + * This is done like this so rtas_flash can be a module. + */ +void (*rtas_flash_term_hook)(int); +EXPORT_SYMBOL(rtas_flash_term_hook); + +/* RTAS use home made raw locking instead of spin_lock_irqsave + * because those can be called from within really nasty contexts + * such as having the timebase stopped which would lockup with + * normal locks and spinlock debugging enabled + */ +static unsigned long lock_rtas(void) +{ + unsigned long flags; + + local_irq_save(flags); + preempt_disable(); + arch_spin_lock(&rtas.lock); + return flags; +} + +static void unlock_rtas(unsigned long flags) +{ + arch_spin_unlock(&rtas.lock); + local_irq_restore(flags); + preempt_enable(); +} + +/* + * call_rtas_display_status and call_rtas_display_status_delay + * are designed only for very early low-level debugging, which + * is why the token is hard-coded to 10. + */ +static void call_rtas_display_status(unsigned char c) +{ + unsigned long s; + + if (!rtas.base) + return; + + s = lock_rtas(); + rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c); + unlock_rtas(s); +} + +static void call_rtas_display_status_delay(char c) +{ + static int pending_newline = 0; /* did last write end with unprinted newline? */ + static int width = 16; + + if (c == '\n') { + while (width-- > 0) + call_rtas_display_status(' '); + width = 16; + mdelay(500); + pending_newline = 1; + } else { + if (pending_newline) { + call_rtas_display_status('\r'); + call_rtas_display_status('\n'); + } + pending_newline = 0; + if (width--) { + call_rtas_display_status(c); + udelay(10000); + } + } +} + +void __init udbg_init_rtas_panel(void) +{ + udbg_putc = call_rtas_display_status_delay; +} + +#ifdef CONFIG_UDBG_RTAS_CONSOLE + +/* If you think you're dying before early_init_dt_scan_rtas() does its + * work, you can hard code the token values for your firmware here and + * hardcode rtas.base/entry etc. + */ +static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE; +static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE; + +static void udbg_rtascon_putc(char c) +{ + int tries; + + if (!rtas.base) + return; + + /* Add CRs before LFs */ + if (c == '\n') + udbg_rtascon_putc('\r'); + + /* if there is more than one character to be displayed, wait a bit */ + for (tries = 0; tries < 16; tries++) { + if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0) + break; + udelay(1000); + } +} + +static int udbg_rtascon_getc_poll(void) +{ + int c; + + if (!rtas.base) + return -1; + + if (rtas_call(rtas_getchar_token, 0, 2, &c)) + return -1; + + return c; +} + +static int udbg_rtascon_getc(void) +{ + int c; + + while ((c = udbg_rtascon_getc_poll()) == -1) + ; + + return c; +} + + +void __init udbg_init_rtas_console(void) +{ + udbg_putc = udbg_rtascon_putc; + udbg_getc = udbg_rtascon_getc; + udbg_getc_poll = udbg_rtascon_getc_poll; +} +#endif /* CONFIG_UDBG_RTAS_CONSOLE */ + +void rtas_progress(char *s, unsigned short hex) +{ + struct device_node *root; + int width; + const __be32 *p; + char *os; + static int display_character, set_indicator; + static int display_width, display_lines, form_feed; + static const int *row_width; + static DEFINE_SPINLOCK(progress_lock); + static int current_line; + static int pending_newline = 0; /* did last write end with unprinted newline? */ + + if (!rtas.base) + return; + + if (display_width == 0) { + display_width = 0x10; + if ((root = of_find_node_by_path("/rtas"))) { + if ((p = of_get_property(root, + "ibm,display-line-length", NULL))) + display_width = be32_to_cpu(*p); + if ((p = of_get_property(root, + "ibm,form-feed", NULL))) + form_feed = be32_to_cpu(*p); + if ((p = of_get_property(root, + "ibm,display-number-of-lines", NULL))) + display_lines = be32_to_cpu(*p); + row_width = of_get_property(root, + "ibm,display-truncation-length", NULL); + of_node_put(root); + } + display_character = rtas_token("display-character"); + set_indicator = rtas_token("set-indicator"); + } + + if (display_character == RTAS_UNKNOWN_SERVICE) { + /* use hex display if available */ + if (set_indicator != RTAS_UNKNOWN_SERVICE) + rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex); + return; + } + + spin_lock(&progress_lock); + + /* + * Last write ended with newline, but we didn't print it since + * it would just clear the bottom line of output. Print it now + * instead. + * + * If no newline is pending and form feed is supported, clear the + * display with a form feed; otherwise, print a CR to start output + * at the beginning of the line. + */ + if (pending_newline) { + rtas_call(display_character, 1, 1, NULL, '\r'); + rtas_call(display_character, 1, 1, NULL, '\n'); + pending_newline = 0; + } else { + current_line = 0; + if (form_feed) + rtas_call(display_character, 1, 1, NULL, + (char)form_feed); + else + rtas_call(display_character, 1, 1, NULL, '\r'); + } + + if (row_width) + width = row_width[current_line]; + else + width = display_width; + os = s; + while (*os) { + if (*os == '\n' || *os == '\r') { + /* If newline is the last character, save it + * until next call to avoid bumping up the + * display output. + */ + if (*os == '\n' && !os[1]) { + pending_newline = 1; + current_line++; + if (current_line > display_lines-1) + current_line = display_lines-1; + spin_unlock(&progress_lock); + return; + } + + /* RTAS wants CR-LF, not just LF */ + + if (*os == '\n') { + rtas_call(display_character, 1, 1, NULL, '\r'); + rtas_call(display_character, 1, 1, NULL, '\n'); + } else { + /* CR might be used to re-draw a line, so we'll + * leave it alone and not add LF. + */ + rtas_call(display_character, 1, 1, NULL, *os); + } + + if (row_width) + width = row_width[current_line]; + else + width = display_width; + } else { + width--; + rtas_call(display_character, 1, 1, NULL, *os); + } + + os++; + + /* if we overwrite the screen length */ + if (width <= 0) + while ((*os != 0) && (*os != '\n') && (*os != '\r')) + os++; + } + + spin_unlock(&progress_lock); +} +EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */ + +int rtas_token(const char *service) +{ + const __be32 *tokp; + if (rtas.dev == NULL) + return RTAS_UNKNOWN_SERVICE; + tokp = of_get_property(rtas.dev, service, NULL); + return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE; +} +EXPORT_SYMBOL(rtas_token); + +int rtas_service_present(const char *service) +{ + return rtas_token(service) != RTAS_UNKNOWN_SERVICE; +} +EXPORT_SYMBOL(rtas_service_present); + +#ifdef CONFIG_RTAS_ERROR_LOGGING +/* + * Return the firmware-specified size of the error log buffer + * for all rtas calls that require an error buffer argument. + * This includes 'check-exception' and 'rtas-last-error'. + */ +int rtas_get_error_log_max(void) +{ + static int rtas_error_log_max; + if (rtas_error_log_max) + return rtas_error_log_max; + + rtas_error_log_max = rtas_token ("rtas-error-log-max"); + if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) || + (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) { + printk (KERN_WARNING "RTAS: bad log buffer size %d\n", + rtas_error_log_max); + rtas_error_log_max = RTAS_ERROR_LOG_MAX; + } + return rtas_error_log_max; +} +EXPORT_SYMBOL(rtas_get_error_log_max); + + +static char rtas_err_buf[RTAS_ERROR_LOG_MAX]; +static int rtas_last_error_token; + +/** Return a copy of the detailed error text associated with the + * most recent failed call to rtas. Because the error text + * might go stale if there are any other intervening rtas calls, + * this routine must be called atomically with whatever produced + * the error (i.e. with rtas.lock still held from the previous call). + */ +static char *__fetch_rtas_last_error(char *altbuf) +{ + struct rtas_args err_args, save_args; + u32 bufsz; + char *buf = NULL; + + if (rtas_last_error_token == -1) + return NULL; + + bufsz = rtas_get_error_log_max(); + + err_args.token = cpu_to_be32(rtas_last_error_token); + err_args.nargs = cpu_to_be32(2); + err_args.nret = cpu_to_be32(1); + err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf)); + err_args.args[1] = cpu_to_be32(bufsz); + err_args.args[2] = 0; + + save_args = rtas.args; + rtas.args = err_args; + + do_enter_rtas(__pa(&rtas.args)); + + err_args = rtas.args; + rtas.args = save_args; + + /* Log the error in the unlikely case that there was one. */ + if (unlikely(err_args.args[2] == 0)) { + if (altbuf) { + buf = altbuf; + } else { + buf = rtas_err_buf; + if (slab_is_available()) + buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC); + } + if (buf) + 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 +#endif + + +static void +va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, + va_list list) +{ + int i; + + args->token = cpu_to_be32(token); + args->nargs = cpu_to_be32(nargs); + args->nret = cpu_to_be32(nret); + args->rets = &(args->args[nargs]); + + for (i = 0; i < nargs; ++i) + args->args[i] = cpu_to_be32(va_arg(list, __u32)); + + for (i = 0; i < nret; ++i) + args->rets[i] = 0; + + do_enter_rtas(__pa(args)); +} + +void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...) +{ + va_list list; + + va_start(list, nret); + va_rtas_call_unlocked(args, token, nargs, nret, list); + va_end(list); +} + +static int ibm_open_errinjct_token; +static int ibm_errinjct_token; + +int rtas_call(int token, int nargs, int nret, int *outputs, ...) +{ + va_list list; + int i; + unsigned long s; + struct rtas_args *rtas_args; + char *buff_copy = NULL; + int ret; + + if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) + return -1; + + if (token == ibm_open_errinjct_token || token == ibm_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; + } + + s = lock_rtas(); + + /* We use the global rtas args buffer */ + rtas_args = &rtas.args; + + va_start(list, outputs); + va_rtas_call_unlocked(rtas_args, token, nargs, nret, list); + va_end(list); + + /* A -1 return code indicates that the last command couldn't + be completed due to a hardware error. */ + if (be32_to_cpu(rtas_args->rets[0]) == -1) + buff_copy = __fetch_rtas_last_error(NULL); + + if (nret > 1 && outputs != NULL) + for (i = 0; i < nret-1; ++i) + outputs[i] = be32_to_cpu(rtas_args->rets[i+1]); + ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0; + + unlock_rtas(s); + + if (buff_copy) { + log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0); + if (slab_is_available()) + kfree(buff_copy); + } + return ret; +} +EXPORT_SYMBOL(rtas_call); + +/** + * rtas_busy_delay_time() - From an RTAS status value, calculate the + * suggested delay time in milliseconds. + * + * @status: a value returned from rtas_call() or similar APIs which return + * the status of a RTAS function call. + * + * Context: Any context. + * + * Return: + * * 100000 - If @status is 9905. + * * 10000 - If @status is 9904. + * * 1000 - If @status is 9903. + * * 100 - If @status is 9902. + * * 10 - If @status is 9901. + * * 1 - If @status is either 9900 or -2. This is "wrong" for -2, but + * some callers depend on this behavior, and the worst outcome + * is that they will delay for longer than necessary. + * * 0 - If @status is not a busy or extended delay value. + */ +unsigned int rtas_busy_delay_time(int status) +{ + int order; + unsigned int ms = 0; + + if (status == RTAS_BUSY) { + ms = 1; + } else if (status >= RTAS_EXTENDED_DELAY_MIN && + status <= RTAS_EXTENDED_DELAY_MAX) { + order = status - RTAS_EXTENDED_DELAY_MIN; + for (ms = 1; order > 0; order--) + ms *= 10; + } + + return ms; +} +EXPORT_SYMBOL(rtas_busy_delay_time); + +/** + * rtas_busy_delay() - helper for RTAS busy and extended delay statuses + * + * @status: a value returned from rtas_call() or similar APIs which return + * the status of a RTAS function call. + * + * Context: Process context. May sleep or schedule. + * + * Return: + * * true - @status is RTAS_BUSY or an extended delay hint. The + * caller may assume that the CPU has been yielded if necessary, + * and that an appropriate delay for @status has elapsed. + * Generally the caller should reattempt the RTAS call which + * yielded @status. + * + * * false - @status is not @RTAS_BUSY nor an extended delay hint. The + * caller is responsible for handling @status. + */ +bool rtas_busy_delay(int status) +{ + unsigned int ms; + bool ret; + + switch (status) { + case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX: + ret = true; + ms = rtas_busy_delay_time(status); + /* + * The extended delay hint can be as high as 100 seconds. + * Surely any function returning such a status is either + * buggy or isn't going to be significantly slowed by us + * polling at 1HZ. Clamp the sleep time to one second. + */ + ms = clamp(ms, 1U, 1000U); + /* + * The delay hint is an order-of-magnitude suggestion, not + * a minimum. It is fine, possibly even advantageous, for + * us to pause for less time than hinted. For small values, + * use usleep_range() to ensure we don't sleep much longer + * than actually needed. + * + * See Documentation/timers/timers-howto.rst for + * explanation of the threshold used here. In effect we use + * usleep_range() for 9900 and 9901, msleep() for + * 9902-9905. + */ + if (ms <= 20) + usleep_range(ms * 100, ms * 1000); + else + msleep(ms); + break; + case RTAS_BUSY: + ret = true; + /* + * We should call again immediately if there's no other + * work to do. + */ + cond_resched(); + break; + default: + ret = false; + /* + * Not a busy or extended delay status; the caller should + * handle @status itself. Ensure we warn on misuses in + * atomic context regardless. + */ + might_sleep(); + break; + } + + return ret; +} +EXPORT_SYMBOL(rtas_busy_delay); + +static int rtas_error_rc(int rtas_rc) +{ + int rc; + + switch (rtas_rc) { + case -1: /* Hardware Error */ + rc = -EIO; + break; + case -3: /* Bad indicator/domain/etc */ + rc = -EINVAL; + break; + case -9000: /* Isolation error */ + rc = -EFAULT; + break; + case -9001: /* Outstanding TCE/PTE */ + rc = -EEXIST; + break; + case -9002: /* No usable slot */ + rc = -ENODEV; + break; + default: + printk(KERN_ERR "%s: unexpected RTAS error %d\n", + __func__, rtas_rc); + rc = -ERANGE; + break; + } + return rc; +} + +int rtas_get_power_level(int powerdomain, int *level) +{ + int token = rtas_token("get-power-level"); + int rc; + + if (token == RTAS_UNKNOWN_SERVICE) + return -ENOENT; + + while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY) + udelay(1); + + if (rc < 0) + return rtas_error_rc(rc); + return rc; +} +EXPORT_SYMBOL(rtas_get_power_level); + +int rtas_set_power_level(int powerdomain, int level, int *setlevel) +{ + int token = rtas_token("set-power-level"); + int rc; + + if (token == RTAS_UNKNOWN_SERVICE) + return -ENOENT; + + do { + rc = rtas_call(token, 2, 2, setlevel, powerdomain, level); + } while (rtas_busy_delay(rc)); + + if (rc < 0) + return rtas_error_rc(rc); + return rc; +} +EXPORT_SYMBOL(rtas_set_power_level); + +int rtas_get_sensor(int sensor, int index, int *state) +{ + int token = rtas_token("get-sensor-state"); + int rc; + + if (token == RTAS_UNKNOWN_SERVICE) + return -ENOENT; + + do { + rc = rtas_call(token, 2, 2, state, sensor, index); + } while (rtas_busy_delay(rc)); + + if (rc < 0) + return rtas_error_rc(rc); + return rc; +} +EXPORT_SYMBOL(rtas_get_sensor); + +int rtas_get_sensor_fast(int sensor, int index, int *state) +{ + int token = rtas_token("get-sensor-state"); + int rc; + + if (token == RTAS_UNKNOWN_SERVICE) + return -ENOENT; + + rc = rtas_call(token, 2, 2, state, sensor, index); + WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN && + rc <= RTAS_EXTENDED_DELAY_MAX)); + + if (rc < 0) + return rtas_error_rc(rc); + return rc; +} + +bool rtas_indicator_present(int token, int *maxindex) +{ + int proplen, count, i; + const struct indicator_elem { + __be32 token; + __be32 maxindex; + } *indicators; + + indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen); + if (!indicators) + return false; + + count = proplen / sizeof(struct indicator_elem); + + for (i = 0; i < count; i++) { + if (__be32_to_cpu(indicators[i].token) != token) + continue; + if (maxindex) + *maxindex = __be32_to_cpu(indicators[i].maxindex); + return true; + } + + return false; +} +EXPORT_SYMBOL(rtas_indicator_present); + +int rtas_set_indicator(int indicator, int index, int new_value) +{ + int token = rtas_token("set-indicator"); + int rc; + + if (token == RTAS_UNKNOWN_SERVICE) + return -ENOENT; + + do { + rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); + } while (rtas_busy_delay(rc)); + + if (rc < 0) + return rtas_error_rc(rc); + return rc; +} +EXPORT_SYMBOL(rtas_set_indicator); + +/* + * Ignoring RTAS extended delay + */ +int rtas_set_indicator_fast(int indicator, int index, int new_value) +{ + int rc; + int token = rtas_token("set-indicator"); + + if (token == RTAS_UNKNOWN_SERVICE) + return -ENOENT; + + rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); + + WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN && + rc <= RTAS_EXTENDED_DELAY_MAX)); + + if (rc < 0) + return rtas_error_rc(rc); + + return rc; +} + +/** + * rtas_ibm_suspend_me() - Call ibm,suspend-me to suspend the LPAR. + * + * @fw_status: RTAS call status will be placed here if not NULL. + * + * rtas_ibm_suspend_me() should be called only on a CPU which has + * received H_CONTINUE from the H_JOIN hcall. All other active CPUs + * should be waiting to return from H_JOIN. + * + * rtas_ibm_suspend_me() may suspend execution of the OS + * indefinitely. Callers should take appropriate measures upon return, such as + * resetting watchdog facilities. + * + * Callers may choose to retry this call if @fw_status is + * %RTAS_THREADS_ACTIVE. + * + * Return: + * 0 - The partition has resumed from suspend, possibly after + * migration to a different host. + * -ECANCELED - The operation was aborted. + * -EAGAIN - There were other CPUs not in H_JOIN at the time of the call. + * -EBUSY - Some other condition prevented the suspend from succeeding. + * -EIO - Hardware/platform error. + */ +int rtas_ibm_suspend_me(int *fw_status) +{ + int fwrc; + int ret; + + fwrc = rtas_call(rtas_token("ibm,suspend-me"), 0, 1, NULL); + + switch (fwrc) { + case 0: + ret = 0; + break; + case RTAS_SUSPEND_ABORTED: + ret = -ECANCELED; + break; + case RTAS_THREADS_ACTIVE: + ret = -EAGAIN; + break; + case RTAS_NOT_SUSPENDABLE: + case RTAS_OUTSTANDING_COPROC: + ret = -EBUSY; + break; + case -1: + default: + ret = -EIO; + break; + } + + if (fw_status) + *fw_status = fwrc; + + return ret; +} + +void __noreturn rtas_restart(char *cmd) +{ + if (rtas_flash_term_hook) + rtas_flash_term_hook(SYS_RESTART); + printk("RTAS system-reboot returned %d\n", + rtas_call(rtas_token("system-reboot"), 0, 1, NULL)); + for (;;); +} + +void rtas_power_off(void) +{ + if (rtas_flash_term_hook) + rtas_flash_term_hook(SYS_POWER_OFF); + /* allow power on only with power button press */ + printk("RTAS power-off returned %d\n", + rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); + for (;;); +} + +void __noreturn rtas_halt(void) +{ + if (rtas_flash_term_hook) + rtas_flash_term_hook(SYS_HALT); + /* allow power on only with power button press */ + printk("RTAS power-off returned %d\n", + rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); + for (;;); +} + +/* Must be in the RMO region, so we place it here */ +static char rtas_os_term_buf[2048]; +static s32 ibm_os_term_token = RTAS_UNKNOWN_SERVICE; + +void rtas_os_term(char *str) +{ + int status; + + /* + * Firmware with the ibm,extended-os-term property is guaranteed + * to always return from an ibm,os-term call. Earlier versions without + * this property may terminate the partition which we want to avoid + * since it interferes with panic_timeout. + */ + if (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(ibm_os_term_token, 1, 1, NULL, + __pa(rtas_os_term_buf)); + } while (rtas_busy_delay_time(status)); + + if (status != 0) + printk(KERN_EMERG "ibm,os-term call failed %d\n", status); +} + +/** + * rtas_activate_firmware() - Activate a new version of firmware. + * + * Context: This function may sleep. + * + * Activate a new version of partition firmware. The OS must call this + * after resuming from a partition hibernation or migration in order + * to maintain the ability to perform live firmware updates. It's not + * catastrophic for this method to be absent or to fail; just log the + * condition in that case. + */ +void rtas_activate_firmware(void) +{ + int token; + int fwrc; + + token = rtas_token("ibm,activate-firmware"); + if (token == RTAS_UNKNOWN_SERVICE) { + pr_notice("ibm,activate-firmware method unavailable\n"); + return; + } + + do { + fwrc = rtas_call(token, 0, 1, NULL); + } while (rtas_busy_delay(fwrc)); + + if (fwrc) + pr_err("ibm,activate-firmware failed (%i)\n", fwrc); +} + +/** + * get_pseries_errorlog() - Find a specific pseries error log in an RTAS + * extended event log. + * @log: RTAS error/event log + * @section_id: two character section identifier + * + * Return: A pointer to the specified errorlog or NULL if not found. + */ +noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log, + uint16_t section_id) +{ + struct rtas_ext_event_log_v6 *ext_log = + (struct rtas_ext_event_log_v6 *)log->buffer; + struct pseries_errorlog *sect; + unsigned char *p, *log_end; + uint32_t ext_log_length = rtas_error_extended_log_length(log); + uint8_t log_format = rtas_ext_event_log_format(ext_log); + uint32_t company_id = rtas_ext_event_company_id(ext_log); + + /* Check that we understand the format */ + if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) || + log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG || + company_id != RTAS_V6EXT_COMPANY_ID_IBM) + return NULL; + + log_end = log->buffer + ext_log_length; + p = ext_log->vendor_log; + + while (p < log_end) { + sect = (struct pseries_errorlog *)p; + if (pseries_errorlog_id(sect) == section_id) + return sect; + p += pseries_errorlog_length(sect); + } + + return NULL; +} + +#ifdef CONFIG_PPC_RTAS_FILTER + +/* + * The sys_rtas syscall, as originally designed, allows root to pass + * arbitrary physical addresses to RTAS calls. A number of RTAS calls + * can be abused to write to arbitrary memory and do other things that + * are potentially harmful to system integrity, and thus should only + * be used inside the kernel and not exposed to userspace. + * + * All known legitimate users of the sys_rtas syscall will only ever + * pass addresses that fall within the RMO buffer, and use a known + * subset of RTAS calls. + * + * Accordingly, we filter RTAS requests to check that the call is + * permitted, and that provided pointers fall within the RMO buffer. + * The rtas_filters list contains an entry for each permitted call, + * with the indexes of the parameters which are expected to contain + * addresses and sizes of buffers allocated inside the RMO buffer. + */ +struct rtas_filter { + const char *name; + int token; + /* Indexes into the args buffer, -1 if not used */ + int buf_idx1; + int size_idx1; + int buf_idx2; + int size_idx2; + + int fixed_size; +}; + +static struct rtas_filter rtas_filters[] __ro_after_init = { + { "ibm,activate-firmware", -1, -1, -1, -1, -1 }, + { "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 }, /* Special cased */ + { "display-character", -1, -1, -1, -1, -1 }, + { "ibm,display-message", -1, 0, -1, -1, -1 }, + { "ibm,errinjct", -1, 2, -1, -1, -1, 1024 }, + { "ibm,close-errinjct", -1, -1, -1, -1, -1 }, + { "ibm,open-errinjct", -1, -1, -1, -1, -1 }, + { "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 }, + { "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 }, + { "ibm,get-indices", -1, 2, 3, -1, -1 }, + { "get-power-level", -1, -1, -1, -1, -1 }, + { "get-sensor-state", -1, -1, -1, -1, -1 }, + { "ibm,get-system-parameter", -1, 1, 2, -1, -1 }, + { "get-time-of-day", -1, -1, -1, -1, -1 }, + { "ibm,get-vpd", -1, 0, -1, 1, 2 }, + { "ibm,lpar-perftools", -1, 2, 3, -1, -1 }, + { "ibm,platform-dump", -1, 4, 5, -1, -1 }, /* Special cased */ + { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 }, + { "ibm,scan-log-dump", -1, 0, 1, -1, -1 }, + { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 }, + { "ibm,set-eeh-option", -1, -1, -1, -1, -1 }, + { "set-indicator", -1, -1, -1, -1, -1 }, + { "set-power-level", -1, -1, -1, -1, -1 }, + { "set-time-for-power-on", -1, -1, -1, -1, -1 }, + { "ibm,set-system-parameter", -1, 1, -1, -1, -1 }, + { "set-time-of-day", -1, -1, -1, -1, -1 }, +#ifdef CONFIG_CPU_BIG_ENDIAN + { "ibm,suspend-me", -1, -1, -1, -1, -1 }, + { "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 }, + { "ibm,update-properties", -1, 0, -1, -1, -1, 4096 }, +#endif + { "ibm,physical-attestation", -1, 0, 1, -1, -1 }, +}; + +static bool in_rmo_buf(u32 base, u32 end) +{ + return base >= rtas_rmo_buf && + base < (rtas_rmo_buf + RTAS_USER_REGION_SIZE) && + base <= end && + end >= rtas_rmo_buf && + end < (rtas_rmo_buf + RTAS_USER_REGION_SIZE); +} + +static bool block_rtas_call(int token, int nargs, + struct rtas_args *args) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) { + struct rtas_filter *f = &rtas_filters[i]; + u32 base, size, end; + + if (token != f->token) + continue; + + if (f->buf_idx1 != -1) { + base = be32_to_cpu(args->args[f->buf_idx1]); + if (f->size_idx1 != -1) + size = be32_to_cpu(args->args[f->size_idx1]); + else if (f->fixed_size) + size = f->fixed_size; + else + size = 1; + + end = base + size - 1; + + /* + * Special case for ibm,platform-dump - NULL buffer + * address is used to indicate end of dump processing + */ + if (!strcmp(f->name, "ibm,platform-dump") && + base == 0) + return false; + + if (!in_rmo_buf(base, end)) + goto err; + } + + if (f->buf_idx2 != -1) { + base = be32_to_cpu(args->args[f->buf_idx2]); + if (f->size_idx2 != -1) + size = be32_to_cpu(args->args[f->size_idx2]); + else if (f->fixed_size) + size = f->fixed_size; + else + size = 1; + end = base + size - 1; + + /* + * Special case for ibm,configure-connector where the + * address can be 0 + */ + if (!strcmp(f->name, "ibm,configure-connector") && + base == 0) + return false; + + if (!in_rmo_buf(base, end)) + goto err; + } + + return false; + } + +err: + pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n"); + pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n", + token, nargs, current->comm); + return true; +} + +static void __init rtas_syscall_filter_init(void) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) + rtas_filters[i].token = rtas_token(rtas_filters[i].name); +} + +#else + +static bool block_rtas_call(int token, int nargs, + struct rtas_args *args) +{ + return false; +} + +static void __init rtas_syscall_filter_init(void) +{ +} + +#endif /* CONFIG_PPC_RTAS_FILTER */ + +/* We assume to be passed big endian arguments */ +SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) +{ + struct rtas_args args; + unsigned long flags; + char *buff_copy, *errbuf = NULL; + int nargs, nret, token; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (!rtas.entry) + return -EINVAL; + + if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0) + return -EFAULT; + + nargs = be32_to_cpu(args.nargs); + nret = be32_to_cpu(args.nret); + token = be32_to_cpu(args.token); + + if (nargs >= ARRAY_SIZE(args.args) + || nret > ARRAY_SIZE(args.args) + || nargs + nret > ARRAY_SIZE(args.args)) + return -EINVAL; + + /* Copy in args. */ + if (copy_from_user(args.args, uargs->args, + nargs * sizeof(rtas_arg_t)) != 0) + return -EFAULT; + + if (token == RTAS_UNKNOWN_SERVICE) + return -EINVAL; + + args.rets = &args.args[nargs]; + memset(args.rets, 0, nret * sizeof(rtas_arg_t)); + + if (block_rtas_call(token, nargs, &args)) + return -EINVAL; + + if (token == ibm_open_errinjct_token || token == ibm_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_token("ibm,suspend-me")) { + + /* + * rtas_ibm_suspend_me assumes the streamid handle is in cpu + * endian, or at least the hcall within it requires it. + */ + int rc = 0; + u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32) + | be32_to_cpu(args.args[1]); + rc = rtas_syscall_dispatch_ibm_suspend_me(handle); + if (rc == -EAGAIN) + args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE); + else if (rc == -EIO) + args.rets[0] = cpu_to_be32(-1); + else if (rc) + return rc; + goto copy_return; + } + + buff_copy = get_errorlog_buffer(); + + flags = lock_rtas(); + + rtas.args = args; + do_enter_rtas(__pa(&rtas.args)); + args = rtas.args; + + /* A -1 return code indicates that the last command couldn't + be completed due to a hardware error. */ + if (be32_to_cpu(args.rets[0]) == -1) + errbuf = __fetch_rtas_last_error(buff_copy); + + unlock_rtas(flags); + + if (buff_copy) { + if (errbuf) + log_error(errbuf, ERR_TYPE_RTAS_LOG, 0); + kfree(buff_copy); + } + + copy_return: + /* Copy out args. */ + if (copy_to_user(uargs->args + nargs, + args.args + nargs, + nret * sizeof(rtas_arg_t)) != 0) + return -EFAULT; + + return 0; +} + +/* + * Call early during boot, before mem init, to retrieve the RTAS + * information from the device-tree and allocate the RMO buffer for userland + * accesses. + */ +void __init rtas_initialize(void) +{ + unsigned long rtas_region = RTAS_INSTANTIATE_MAX; + u32 base, size, entry; + int no_base, no_size, no_entry; + + /* Get RTAS dev node and fill up our "rtas" structure with infos + * about it. + */ + rtas.dev = of_find_node_by_name(NULL, "rtas"); + if (!rtas.dev) + return; + + no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base); + no_size = of_property_read_u32(rtas.dev, "rtas-size", &size); + if (no_base || no_size) { + of_node_put(rtas.dev); + rtas.dev = NULL; + return; + } + + rtas.base = base; + rtas.size = size; + no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry); + rtas.entry = no_entry ? rtas.base : entry; + + /* + * 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 + */ +#ifdef CONFIG_PPC64 + if (firmware_has_feature(FW_FEATURE_LPAR)) + rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX); +#endif + rtas_rmo_buf = memblock_phys_alloc_range(RTAS_USER_REGION_SIZE, PAGE_SIZE, + 0, rtas_region); + if (!rtas_rmo_buf) + panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n", + PAGE_SIZE, &rtas_region); + +#ifdef CONFIG_RTAS_ERROR_LOGGING + rtas_last_error_token = rtas_token("rtas-last-error"); +#endif + ibm_open_errinjct_token = rtas_token("ibm,open-errinjct"); + ibm_errinjct_token = rtas_token("ibm,errinjct"); + rtas_syscall_filter_init(); +} + +int __init early_init_dt_scan_rtas(unsigned long node, + const char *uname, int depth, void *data) +{ + const u32 *basep, *entryp, *sizep; + + if (depth != 1 || strcmp(uname, "rtas") != 0) + return 0; + + basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL); + entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL); + sizep = of_get_flat_dt_prop(node, "rtas-size", NULL); + +#ifdef CONFIG_PPC64 + /* need this feature to decide the crashkernel offset */ + if (of_get_flat_dt_prop(node, "ibm,hypertas-functions", NULL)) + powerpc_firmware_features |= FW_FEATURE_LPAR; +#endif + + if (basep && entryp && sizep) { + rtas.base = *basep; + rtas.entry = *entryp; + rtas.size = *sizep; + } + +#ifdef CONFIG_UDBG_RTAS_CONSOLE + basep = of_get_flat_dt_prop(node, "put-term-char", NULL); + if (basep) + rtas_putchar_token = *basep; + + basep = of_get_flat_dt_prop(node, "get-term-char", NULL); + if (basep) + rtas_getchar_token = *basep; + + if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE && + rtas_getchar_token != RTAS_UNKNOWN_SERVICE) + udbg_init_rtas_console(); + +#endif + + /* break now */ + return 1; +} + +static arch_spinlock_t timebase_lock; +static u64 timebase = 0; + +void rtas_give_timebase(void) +{ + unsigned long flags; + + local_irq_save(flags); + hard_irq_disable(); + arch_spin_lock(&timebase_lock); + rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); + timebase = get_tb(); + arch_spin_unlock(&timebase_lock); + + while (timebase) + barrier(); + rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); + local_irq_restore(flags); +} + +void rtas_take_timebase(void) +{ + while (!timebase) + barrier(); + arch_spin_lock(&timebase_lock); + set_tb(timebase >> 32, timebase & 0xffffffff); + timebase = 0; + arch_spin_unlock(&timebase_lock); +} |