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- // 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);
- }
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