linux_dsm_epyc7002/arch/powerpc/kernel/rtas.c
Nathan Lynch a6717c01dd powerpc/rtas: use device model APIs and serialization during LPM
The LPAR migration implementation and userspace-initiated cpu hotplug
can interleave their executions like so:

1. Set cpu 7 offline via sysfs.

2. Begin a partition migration, whose implementation requires the OS
   to ensure all present cpus are online; cpu 7 is onlined:

     rtas_ibm_suspend_me -> rtas_online_cpus_mask -> cpu_up

   This sets cpu 7 online in all respects except for the cpu's
   corresponding struct device; dev->offline remains true.

3. Set cpu 7 online via sysfs. _cpu_up() determines that cpu 7 is
   already online and returns success. The driver core (device_online)
   sets dev->offline = false.

4. The migration completes and restores cpu 7 to offline state:

     rtas_ibm_suspend_me -> rtas_offline_cpus_mask -> cpu_down

This leaves cpu7 in a state where the driver core considers the cpu
device online, but in all other respects it is offline and
unused. Attempts to online the cpu via sysfs appear to succeed but the
driver core actually does not pass the request to the lower-level
cpuhp support code. This makes the cpu unusable until the cpu device
is manually set offline and then online again via sysfs.

Instead of directly calling cpu_up/cpu_down, the migration code should
use the higher-level device core APIs to maintain consistent state and
serialize operations.

Fixes: 120496ac2d ("powerpc: Bring all threads online prior to migration/hibernation")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802192926.19277-2-nathanl@linux.ibm.com
2019-08-20 21:22:27 +10:00

1264 lines
29 KiB
C

// 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 <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/smp.h>
#include <linux/completion.h>
#include <linux/cpumask.h>
#include <linux/memblock.h>
#include <linux/slab.h>
#include <linux/reboot.h>
#include <linux/syscalls.h>
#include <asm/prom.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);
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;
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)
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
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;
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);
}
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;
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);
/* 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 >= 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);
/* 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 && need_resched())
msleep(ms);
return ms;
}
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;
}
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];
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 (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") ||
RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-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 int __rtas_suspend_last_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
{
u16 slb_size = mmu_slb_size;
int rc = H_MULTI_THREADS_ACTIVE;
int cpu;
slb_set_size(SLB_MIN_SIZE);
printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n", smp_processor_id());
while (rc == H_MULTI_THREADS_ACTIVE && !atomic_read(&data->done) &&
!atomic_read(&data->error))
rc = rtas_call(data->token, 0, 1, NULL);
if (rc || atomic_read(&data->error)) {
printk(KERN_DEBUG "ibm,suspend-me returned %d\n", rc);
slb_set_size(slb_size);
}
if (atomic_read(&data->error))
rc = atomic_read(&data->error);
atomic_set(&data->error, rc);
pSeries_coalesce_init();
if (wake_when_done) {
atomic_set(&data->done, 1);
for_each_online_cpu(cpu)
plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
}
if (atomic_dec_return(&data->working) == 0)
complete(data->complete);
return rc;
}
int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data)
{
atomic_inc(&data->working);
return __rtas_suspend_last_cpu(data, 0);
}
static int __rtas_suspend_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
{
long rc = H_SUCCESS;
unsigned long msr_save;
int cpu;
atomic_inc(&data->working);
/* really need to ensure MSR.EE is off for H_JOIN */
msr_save = mfmsr();
mtmsr(msr_save & ~(MSR_EE));
while (rc == H_SUCCESS && !atomic_read(&data->done) && !atomic_read(&data->error))
rc = plpar_hcall_norets(H_JOIN);
mtmsr(msr_save);
if (rc == H_SUCCESS) {
/* This cpu was prodded and the suspend is complete. */
goto out;
} else if (rc == H_CONTINUE) {
/* All other cpus are in H_JOIN, this cpu does
* the suspend.
*/
return __rtas_suspend_last_cpu(data, wake_when_done);
} else {
printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n",
smp_processor_id(), rc);
atomic_set(&data->error, rc);
}
if (wake_when_done) {
atomic_set(&data->done, 1);
/* This cpu did the suspend or got an error; in either case,
* we need to prod all other other cpus out of join state.
* Extra prods are harmless.
*/
for_each_online_cpu(cpu)
plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
}
out:
if (atomic_dec_return(&data->working) == 0)
complete(data->complete);
return rc;
}
int rtas_suspend_cpu(struct rtas_suspend_me_data *data)
{
return __rtas_suspend_cpu(data, 0);
}
static void rtas_percpu_suspend_me(void *info)
{
__rtas_suspend_cpu((struct rtas_suspend_me_data *)info, 1);
}
enum rtas_cpu_state {
DOWN,
UP,
};
#ifndef CONFIG_SMP
static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
cpumask_var_t cpus)
{
if (!cpumask_empty(cpus)) {
cpumask_clear(cpus);
return -EINVAL;
} else
return 0;
}
#else
/* On return cpumask will be altered to indicate CPUs changed.
* CPUs with states changed will be set in the mask,
* CPUs with status unchanged will be unset in the mask. */
static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
cpumask_var_t cpus)
{
int cpu;
int cpuret = 0;
int ret = 0;
if (cpumask_empty(cpus))
return 0;
for_each_cpu(cpu, cpus) {
struct device *dev = get_cpu_device(cpu);
switch (state) {
case DOWN:
cpuret = device_offline(dev);
break;
case UP:
cpuret = device_online(dev);
break;
}
if (cpuret < 0) {
pr_debug("%s: cpu_%s for cpu#%d returned %d.\n",
__func__,
((state == UP) ? "up" : "down"),
cpu, cpuret);
if (!ret)
ret = cpuret;
if (state == UP) {
/* clear bits for unchanged cpus, return */
cpumask_shift_right(cpus, cpus, cpu);
cpumask_shift_left(cpus, cpus, cpu);
break;
} else {
/* clear bit for unchanged cpu, continue */
cpumask_clear_cpu(cpu, cpus);
}
}
}
return ret;
}
#endif
int rtas_online_cpus_mask(cpumask_var_t cpus)
{
int ret;
ret = rtas_cpu_state_change_mask(UP, cpus);
if (ret) {
cpumask_var_t tmp_mask;
if (!alloc_cpumask_var(&tmp_mask, GFP_KERNEL))
return ret;
/* Use tmp_mask to preserve cpus mask from first failure */
cpumask_copy(tmp_mask, cpus);
rtas_offline_cpus_mask(tmp_mask);
free_cpumask_var(tmp_mask);
}
return ret;
}
int rtas_offline_cpus_mask(cpumask_var_t cpus)
{
return rtas_cpu_state_change_mask(DOWN, cpus);
}
int rtas_ibm_suspend_me(u64 handle)
{
long state;
long rc;
unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
struct rtas_suspend_me_data data;
DECLARE_COMPLETION_ONSTACK(done);
cpumask_var_t offline_mask;
int cpuret;
if (!rtas_service_present("ibm,suspend-me"))
return -ENOSYS;
/* Make sure the state is valid */
rc = plpar_hcall(H_VASI_STATE, retbuf, handle);
state = retbuf[0];
if (rc) {
printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
return rc;
} else if (state == H_VASI_ENABLED) {
return -EAGAIN;
} else if (state != H_VASI_SUSPENDING) {
printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
state);
return -EIO;
}
if (!alloc_cpumask_var(&offline_mask, GFP_KERNEL))
return -ENOMEM;
atomic_set(&data.working, 0);
atomic_set(&data.done, 0);
atomic_set(&data.error, 0);
data.token = rtas_token("ibm,suspend-me");
data.complete = &done;
lock_device_hotplug();
/* All present CPUs must be online */
cpumask_andnot(offline_mask, cpu_present_mask, cpu_online_mask);
cpuret = rtas_online_cpus_mask(offline_mask);
if (cpuret) {
pr_err("%s: Could not bring present CPUs online.\n", __func__);
atomic_set(&data.error, cpuret);
goto out;
}
cpu_hotplug_disable();
/* Check if we raced with a CPU-Offline Operation */
if (!cpumask_equal(cpu_present_mask, cpu_online_mask)) {
pr_info("%s: Raced against a concurrent CPU-Offline\n", __func__);
atomic_set(&data.error, -EAGAIN);
goto out_hotplug_enable;
}
/* Call function on all CPUs. One of us will make the
* rtas call
*/
on_each_cpu(rtas_percpu_suspend_me, &data, 0);
wait_for_completion(&done);
if (atomic_read(&data.error) != 0)
printk(KERN_ERR "Error doing global join\n");
out_hotplug_enable:
cpu_hotplug_enable();
/* Take down CPUs not online prior to suspend */
cpuret = rtas_offline_cpus_mask(offline_mask);
if (cpuret)
pr_warn("%s: Could not restore CPUs to offline state.\n",
__func__);
out:
unlock_device_hotplug();
free_cpumask_var(offline_mask);
return atomic_read(&data.error);
}
#else /* CONFIG_PPC_PSERIES */
int rtas_ibm_suspend_me(u64 handle)
{
return -ENOSYS;
}
#endif
/**
* Find a specific pseries error log in an RTAS extended event log.
* @log: RTAS error/event log
* @section_id: two character section identifier
*
* Returns a pointer to the specified errorlog or NULL if not found.
*/
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;
}
/* 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));
/* Need to handle ibm,suspend_me call specially */
if (token == ibm_suspend_me_token) {
/*
* 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_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;
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;
/* 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);
ibm_suspend_me_token = rtas_token("ibm,suspend-me");
}
#endif
rtas_rmo_buf = memblock_phys_alloc_range(RTAS_RMOBUF_MAX, 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
}
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);
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);
}