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-rw-r--r--arch/powerpc/kernel/rtas.c1384
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);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-04 21:00:29 +0000