android_kernel_xiaomi_sm8350/arch/powerpc/kernel/rtas.c
Michael Ellerman 24da3dd534 [POWERPC] Make rtas_call() safe if RTAS hasn't been initialised
Currently it's unsafe to call rtas_call() prior to rtas_initialize(). This
is because the rtas.entry value hasn't been setup and so we don't know
where to enter, but we just try anyway.

We can't do anything intelligent without rtas.entry, so if it's not set, just
return. Code that calls rtas_call() early needs to be aware that the call
might fail.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-28 11:59:47 +10:00

805 lines
19 KiB
C

/*
*
* Procedures for interfacing to the RTAS on CHRP machines.
*
* Peter Bergner, IBM March 2001.
* Copyright (C) 2001 IBM.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <stdarg.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/capability.h>
#include <linux/delay.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/hvcall.h>
#include <asm/semaphore.h>
#include <asm/machdep.h>
#include <asm/firmware.h>
#include <asm/page.h>
#include <asm/param.h>
#include <asm/system.h>
#include <asm/delay.h>
#include <asm/uaccess.h>
#include <asm/lmb.h>
#include <asm/udbg.h>
#include <asm/syscalls.h>
struct rtas_t rtas = {
.lock = SPIN_LOCK_UNLOCKED
};
struct rtas_suspend_me_data {
long waiting;
struct rtas_args *args;
};
EXPORT_SYMBOL(rtas);
DEFINE_SPINLOCK(rtas_data_buf_lock);
char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
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);
/*
* 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(char c)
{
struct rtas_args *args = &rtas.args;
unsigned long s;
if (!rtas.base)
return;
spin_lock_irqsave(&rtas.lock, s);
args->token = 10;
args->nargs = 1;
args->nret = 1;
args->rets = (rtas_arg_t *)&(args->args[1]);
args->args[0] = (unsigned char)c;
enter_rtas(__pa(args));
spin_unlock_irqrestore(&rtas.lock, 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(void)
{
udbg_putc = call_rtas_display_status_delay;
}
void rtas_progress(char *s, unsigned short hex)
{
struct device_node *root;
int width, *p;
char *os;
static int display_character, set_indicator;
static int display_width, display_lines, *row_width, form_feed;
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 = find_path_device("/rtas"))) {
if ((p = (unsigned int *)get_property(root,
"ibm,display-line-length", NULL)))
display_width = *p;
if ((p = (unsigned int *)get_property(root,
"ibm,form-feed", NULL)))
form_feed = *p;
if ((p = (unsigned int *)get_property(root,
"ibm,display-number-of-lines", NULL)))
display_lines = *p;
row_width = (unsigned int *)get_property(root,
"ibm,display-truncation-length", NULL);
}
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)
{
int *tokp;
if (rtas.dev == NULL)
return RTAS_UNKNOWN_SERVICE;
tokp = (int *) get_property(rtas.dev, service, NULL);
return tokp ? *tokp : RTAS_UNKNOWN_SERVICE;
}
#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);
char rtas_err_buf[RTAS_ERROR_LOG_MAX];
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 = rtas_last_error_token;
err_args.nargs = 2;
err_args.nret = 1;
err_args.args[0] = (rtas_arg_t)__pa(rtas_err_buf);
err_args.args[1] = bufsz;
err_args.args[2] = 0;
save_args = rtas.args;
rtas.args = err_args;
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 (mem_init_done)
buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
}
if (buf)
memcpy(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
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;
/* Gotta do something different here, use global lock for now... */
spin_lock_irqsave(&rtas.lock, s);
rtas_args = &rtas.args;
rtas_args->token = token;
rtas_args->nargs = nargs;
rtas_args->nret = nret;
rtas_args->rets = (rtas_arg_t *)&(rtas_args->args[nargs]);
va_start(list, outputs);
for (i = 0; i < nargs; ++i)
rtas_args->args[i] = va_arg(list, rtas_arg_t);
va_end(list);
for (i = 0; i < nret; ++i)
rtas_args->rets[i] = 0;
enter_rtas(__pa(rtas_args));
/* A -1 return code indicates that the last command couldn't
be completed due to a hardware error. */
if (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] = rtas_args->rets[i+1];
ret = (nret > 0)? rtas_args->rets[0]: 0;
/* Gotta do something different here, use global lock for now... */
spin_unlock_irqrestore(&rtas.lock, s);
if (buff_copy) {
log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
if (mem_init_done)
kfree(buff_copy);
}
return ret;
}
/* For RTAS_BUSY (-2), delay for 1 millisecond. For an extended busy status
* code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
*/
unsigned int rtas_busy_delay_time(int status)
{
int order;
unsigned int ms = 0;
if (status == RTAS_BUSY) {
ms = 1;
} else if (status >= 9900 && status <= 9905) {
order = status - 9900;
for (ms = 1; order > 0; order--)
ms *= 10;
}
return ms;
}
/* For an RTAS busy status code, perform the hinted delay. */
unsigned int rtas_busy_delay(int status)
{
unsigned int ms;
might_sleep();
ms = rtas_busy_delay_time(status);
if (ms)
msleep(ms);
return ms;
}
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",
__FUNCTION__, 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;
}
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;
}
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;
}
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;
}
void 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 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];
void rtas_os_term(char *str)
{
int status;
if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term"))
return;
snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
do {
status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
__pa(rtas_os_term_buf));
} while (rtas_busy_delay(status));
if (status != 0)
printk(KERN_EMERG "ibm,os-term call failed %d\n",
status);
}
static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
#ifdef CONFIG_PPC_PSERIES
static void rtas_percpu_suspend_me(void *info)
{
int i;
long rc;
long flags;
struct rtas_suspend_me_data *data =
(struct rtas_suspend_me_data *)info;
/*
* We use "waiting" to indicate our state. As long
* as it is >0, we are still trying to all join up.
* If it goes to 0, we have successfully joined up and
* one thread got H_CONTINUE. If any error happens,
* we set it to <0.
*/
local_irq_save(flags);
do {
rc = plpar_hcall_norets(H_JOIN);
smp_rmb();
} while (rc == H_SUCCESS && data->waiting > 0);
if (rc == H_SUCCESS)
goto out;
if (rc == H_CONTINUE) {
data->waiting = 0;
data->args->args[data->args->nargs] =
rtas_call(ibm_suspend_me_token, 0, 1, NULL);
for_each_possible_cpu(i)
plpar_hcall_norets(H_PROD,i);
} else {
data->waiting = -EBUSY;
printk(KERN_ERR "Error on H_JOIN hypervisor call\n");
}
out:
local_irq_restore(flags);
return;
}
static int rtas_ibm_suspend_me(struct rtas_args *args)
{
int i;
long state;
long rc;
unsigned long dummy;
struct rtas_suspend_me_data data;
/* Make sure the state is valid */
rc = plpar_hcall(H_VASI_STATE,
((u64)args->args[0] << 32) | args->args[1],
0, 0, 0,
&state, &dummy, &dummy);
if (rc) {
printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
return rc;
} else if (state == H_VASI_ENABLED) {
args->args[args->nargs] = RTAS_NOT_SUSPENDABLE;
return 0;
} else if (state != H_VASI_SUSPENDING) {
printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
state);
args->args[args->nargs] = -1;
return 0;
}
data.waiting = 1;
data.args = args;
/* Call function on all CPUs. One of us will make the
* rtas call
*/
if (on_each_cpu(rtas_percpu_suspend_me, &data, 1, 0))
data.waiting = -EINVAL;
if (data.waiting != 0)
printk(KERN_ERR "Error doing global join\n");
/* Prod each CPU. This won't hurt, and will wake
* anyone we successfully put to sleep with H_JOIN.
*/
for_each_possible_cpu(i)
plpar_hcall_norets(H_PROD, i);
return data.waiting;
}
#else /* CONFIG_PPC_PSERIES */
static int rtas_ibm_suspend_me(struct rtas_args *args)
{
return -ENOSYS;
}
#endif
asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
{
struct rtas_args args;
unsigned long flags;
char *buff_copy, *errbuf = NULL;
int nargs;
int rc;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
return -EFAULT;
nargs = args.nargs;
if (nargs > ARRAY_SIZE(args.args)
|| args.nret > ARRAY_SIZE(args.args)
|| nargs + args.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 (args.token == RTAS_UNKNOWN_SERVICE)
return -EINVAL;
/* Need to handle ibm,suspend_me call specially */
if (args.token == ibm_suspend_me_token) {
rc = rtas_ibm_suspend_me(&args);
if (rc)
return rc;
goto copy_return;
}
buff_copy = get_errorlog_buffer();
spin_lock_irqsave(&rtas.lock, flags);
rtas.args = args;
enter_rtas(__pa(&rtas.args));
args = rtas.args;
args.rets = &args.args[nargs];
/* A -1 return code indicates that the last command couldn't
be completed due to a hardware error. */
if (args.rets[0] == -1)
errbuf = __fetch_rtas_last_error(buff_copy);
spin_unlock_irqrestore(&rtas.lock, 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,
args.nret * sizeof(rtas_arg_t)) != 0)
return -EFAULT;
return 0;
}
/* This version can't take the spinlock, because it never returns */
struct rtas_args rtas_stop_self_args = {
/* The token is initialized for real in setup_system() */
.token = RTAS_UNKNOWN_SERVICE,
.nargs = 0,
.nret = 1,
.rets = &rtas_stop_self_args.args[0],
};
void rtas_stop_self(void)
{
struct rtas_args *rtas_args = &rtas_stop_self_args;
local_irq_disable();
BUG_ON(rtas_args->token == RTAS_UNKNOWN_SERVICE);
printk("cpu %u (hwid %u) Ready to die...\n",
smp_processor_id(), hard_smp_processor_id());
enter_rtas(__pa(rtas_args));
panic("Alas, I survived.\n");
}
/*
* Call early during boot, before mem init or bootmem, to retrieve the RTAS
* informations from the device-tree and allocate the RMO buffer for userland
* accesses.
*/
void __init rtas_initialize(void)
{
unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
/* 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) {
u32 *basep, *entryp;
u32 *sizep;
basep = (u32 *)get_property(rtas.dev, "linux,rtas-base", NULL);
sizep = (u32 *)get_property(rtas.dev, "rtas-size", NULL);
if (basep != NULL && sizep != NULL) {
rtas.base = *basep;
rtas.size = *sizep;
entryp = (u32 *)get_property(rtas.dev, "linux,rtas-entry", NULL);
if (entryp == NULL) /* Ugh */
rtas.entry = rtas.base;
else
rtas.entry = *entryp;
} else
rtas.dev = NULL;
}
if (!rtas.dev)
return;
/* If RTAS was found, allocate the RMO buffer for it and look for
* the stop-self token if any
*/
#ifdef CONFIG_PPC64
if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR)) {
rtas_region = min(lmb.rmo_size, RTAS_INSTANTIATE_MAX);
ibm_suspend_me_token = rtas_token("ibm,suspend-me");
}
#endif
rtas_rmo_buf = lmb_alloc_base(RTAS_RMOBUF_MAX, PAGE_SIZE, rtas_region);
#ifdef CONFIG_HOTPLUG_CPU
rtas_stop_self_args.token = rtas_token("stop-self");
#endif /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_RTAS_ERROR_LOGGING
rtas_last_error_token = rtas_token("rtas-last-error");
#endif
}
EXPORT_SYMBOL(rtas_token);
EXPORT_SYMBOL(rtas_call);
EXPORT_SYMBOL(rtas_data_buf);
EXPORT_SYMBOL(rtas_data_buf_lock);
EXPORT_SYMBOL(rtas_busy_delay_time);
EXPORT_SYMBOL(rtas_busy_delay);
EXPORT_SYMBOL(rtas_get_sensor);
EXPORT_SYMBOL(rtas_get_power_level);
EXPORT_SYMBOL(rtas_set_power_level);
EXPORT_SYMBOL(rtas_set_indicator);