Commit 08273c9f authored by Nathan Lynch's avatar Nathan Lynch Committed by Michael Ellerman
Browse files

powerpc/rtas: arch-wide function token lookup conversions 



With the tokens for all implemented RTAS functions now available via
rtas_function_token(), which is optimal and safe for arbitrary
contexts, there is no need to use rtas_token() or cache its result.

Most conversions are trivial, but a few are worth describing in more
detail:

* Error injection token comparisons for lockdown purposes are
  consolidated into a simple predicate: token_is_restricted_errinjct().

* A couple of special cases in block_rtas_call() do not use
  rtas_token() but perform string comparisons against names in the
  function table. These are converted to compare against token values
  instead, which is logically equivalent but less expensive.

* The lookup for the ibm,os-term token can be deferred until needed,
  instead of caching it at boot to avoid device tree traversal during
  panic.

* Since rtas_function_token() accesses a read-only data structure
  without taking any locks, xmon's lookup of set-indicator can be
  performed as needed instead of cached at startup.

Signed-off-by: default avatarNathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-20-26929c8cce78@linux.ibm.com
parent 716bfc97

arch/powerpc/kernel/rtas-proc.c

+12 −12
Original line number Diff line number Diff line
@@ -287,7 +287,7 @@ static ssize_t ppc_rtas_poweron_write(struct file *file, 


	rtc_time64_to_tm(nowtime, &tm);



	error = rtas_call(rtas_token("set-time-for-power-on"), 7, 1, NULL, 

	error = rtas_call(rtas_function_token(RTAS_FN_SET_TIME_FOR_POWER_ON), 7, 1, NULL,

			  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,

			  tm.tm_hour, tm.tm_min, tm.tm_sec, 0 /* nano */);

	if (error)
@@ -350,7 +350,7 @@ static ssize_t ppc_rtas_clock_write(struct file *file, 
		return error;



	rtc_time64_to_tm(nowtime, &tm);

	error = rtas_call(rtas_token("set-time-of-day"), 7, 1, NULL, 

	error = rtas_call(rtas_function_token(RTAS_FN_SET_TIME_OF_DAY), 7, 1, NULL,

			  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,

			  tm.tm_hour, tm.tm_min, tm.tm_sec, 0);

	if (error)
@@ -362,7 +362,7 @@ static ssize_t ppc_rtas_clock_write(struct file *file, 
static int ppc_rtas_clock_show(struct seq_file *m, void *v)

{

	int ret[8];

	int error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);

	int error = rtas_call(rtas_function_token(RTAS_FN_GET_TIME_OF_DAY), 0, 8, ret);



	if (error) {

		printk(KERN_WARNING "error: reading the clock returned: %s\n",
@@ -385,7 +385,7 @@ static int ppc_rtas_sensors_show(struct seq_file *m, void *v) 
{

	int i,j;

	int state, error;

	int get_sensor_state = rtas_token("get-sensor-state");

	int get_sensor_state = rtas_function_token(RTAS_FN_GET_SENSOR_STATE);



	seq_printf(m, "RTAS (RunTime Abstraction Services) Sensor Information\n");

	seq_printf(m, "Sensor\t\tValue\t\tCondition\tLocation\n");
@@ -708,7 +708,7 @@ static ssize_t ppc_rtas_tone_freq_write(struct file *file, 
		return error;



	rtas_tone_frequency = freq; /* save it for later */

	error = rtas_call(rtas_token("set-indicator"), 3, 1, NULL,

	error = rtas_call(rtas_function_token(RTAS_FN_SET_INDICATOR), 3, 1, NULL,

			  TONE_FREQUENCY, 0, freq);

	if (error)

		printk(KERN_WARNING "error: setting tone frequency returned: %s\n",
@@ -736,7 +736,7 @@ static ssize_t ppc_rtas_tone_volume_write(struct file *file, 
		volume = 100;

	

        rtas_tone_volume = volume; /* save it for later */

	error = rtas_call(rtas_token("set-indicator"), 3, 1, NULL,

	error = rtas_call(rtas_function_token(RTAS_FN_SET_INDICATOR), 3, 1, NULL,

			  TONE_VOLUME, 0, volume);

	if (error)

		printk(KERN_WARNING "error: setting tone volume returned: %s\n",

arch/powerpc/kernel/rtas-rtc.c

+3 −3
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ time64_t __init rtas_get_boot_time(void) 


	max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;

	do {

		error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);

		error = rtas_call(rtas_function_token(RTAS_FN_GET_TIME_OF_DAY), 0, 8, ret);



		wait_time = rtas_busy_delay_time(error);

		if (wait_time) {
@@ -53,7 +53,7 @@ void rtas_get_rtc_time(struct rtc_time *rtc_tm) 


	max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;

	do {

		error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);

		error = rtas_call(rtas_function_token(RTAS_FN_GET_TIME_OF_DAY), 0, 8, ret);



		wait_time = rtas_busy_delay_time(error);

		if (wait_time) {
@@ -90,7 +90,7 @@ int rtas_set_rtc_time(struct rtc_time *tm) 


	max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;

	do {

	        error = rtas_call(rtas_token("set-time-of-day"), 7, 1, NULL,

		error = rtas_call(rtas_function_token(RTAS_FN_SET_TIME_OF_DAY), 7, 1, NULL,

				  tm->tm_year + 1900, tm->tm_mon + 1,

				  tm->tm_mday, tm->tm_hour, tm->tm_min,

				  tm->tm_sec, 0);

arch/powerpc/kernel/rtas.c

+38 −41
Original line number Diff line number Diff line
@@ -782,8 +782,8 @@ void rtas_progress(char *s, unsigned short hex) 
					"ibm,display-truncation-length", NULL);

			of_node_put(root);

		}

		display_character = rtas_token("display-character");

		set_indicator = rtas_token("set-indicator");

		display_character = rtas_function_token(RTAS_FN_DISPLAY_CHARACTER);

		set_indicator = rtas_function_token(RTAS_FN_SET_INDICATOR);

	}



	if (display_character == RTAS_UNKNOWN_SERVICE) {
@@ -937,7 +937,6 @@ static void __init init_error_log_max(void) 




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
@@ -947,16 +946,17 @@ static int rtas_last_error_token; 
 */

static char *__fetch_rtas_last_error(char *altbuf)

{

	const s32 token = rtas_function_token(RTAS_FN_RTAS_LAST_ERROR);

	struct rtas_args err_args, save_args;

	u32 bufsz;

	char *buf = NULL;



	if (rtas_last_error_token == -1)

	if (token == -1)

		return NULL;



	bufsz = rtas_get_error_log_max();



	err_args.token = cpu_to_be32(rtas_last_error_token);

	err_args.token = cpu_to_be32(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));
@@ -1025,8 +1025,11 @@ void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, 
	va_end(list);

}



static int ibm_open_errinjct_token;

static int ibm_errinjct_token;

static bool token_is_restricted_errinjct(s32 token)

{

	return token == rtas_function_token(RTAS_FN_IBM_OPEN_ERRINJCT) ||

	       token == rtas_function_token(RTAS_FN_IBM_ERRINJCT);

}



/**

 * rtas_call() - Invoke an RTAS firmware function.
@@ -1098,7 +1101,7 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...) 
	if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)

		return -1;



	if (token == ibm_open_errinjct_token || token == ibm_errinjct_token) {

	if (token_is_restricted_errinjct(token)) {

		/*

		 * It would be nicer to not discard the error value

		 * from security_locked_down(), but callers expect an
@@ -1330,7 +1333,7 @@ static int rtas_error_rc(int rtas_rc) 


int rtas_get_power_level(int powerdomain, int *level)

{

	int token = rtas_token("get-power-level");

	int token = rtas_function_token(RTAS_FN_GET_POWER_LEVEL);

	int rc;



	if (token == RTAS_UNKNOWN_SERVICE)
@@ -1347,7 +1350,7 @@ EXPORT_SYMBOL_GPL(rtas_get_power_level); 


int rtas_set_power_level(int powerdomain, int level, int *setlevel)

{

	int token = rtas_token("set-power-level");

	int token = rtas_function_token(RTAS_FN_SET_POWER_LEVEL);

	int rc;



	if (token == RTAS_UNKNOWN_SERVICE)
@@ -1365,7 +1368,7 @@ EXPORT_SYMBOL_GPL(rtas_set_power_level); 


int rtas_get_sensor(int sensor, int index, int *state)

{

	int token = rtas_token("get-sensor-state");

	int token = rtas_function_token(RTAS_FN_GET_SENSOR_STATE);

	int rc;



	if (token == RTAS_UNKNOWN_SERVICE)
@@ -1383,7 +1386,7 @@ EXPORT_SYMBOL_GPL(rtas_get_sensor); 


int rtas_get_sensor_fast(int sensor, int index, int *state)

{

	int token = rtas_token("get-sensor-state");

	int token = rtas_function_token(RTAS_FN_GET_SENSOR_STATE);

	int rc;



	if (token == RTAS_UNKNOWN_SERVICE)
@@ -1425,7 +1428,7 @@ bool rtas_indicator_present(int token, int *maxindex) 


int rtas_set_indicator(int indicator, int index, int new_value)

{

	int token = rtas_token("set-indicator");

	int token = rtas_function_token(RTAS_FN_SET_INDICATOR);

	int rc;



	if (token == RTAS_UNKNOWN_SERVICE)
@@ -1446,8 +1449,8 @@ EXPORT_SYMBOL_GPL(rtas_set_indicator); 
 */

int rtas_set_indicator_fast(int indicator, int index, int new_value)

{

	int token = rtas_function_token(RTAS_FN_SET_INDICATOR);

	int rc;

	int token = rtas_token("set-indicator");



	if (token == RTAS_UNKNOWN_SERVICE)

		return -ENOENT;
@@ -1489,10 +1492,11 @@ int rtas_set_indicator_fast(int indicator, int index, int new_value) 
 */

int rtas_ibm_suspend_me(int *fw_status)

{

	int token = rtas_function_token(RTAS_FN_IBM_SUSPEND_ME);

	int fwrc;

	int ret;



	fwrc = rtas_call(rtas_token("ibm,suspend-me"), 0, 1, NULL);

	fwrc = rtas_call(token, 0, 1, NULL);



	switch (fwrc) {

	case 0:
@@ -1525,7 +1529,7 @@ void __noreturn rtas_restart(char *cmd) 
	if (rtas_flash_term_hook)

		rtas_flash_term_hook(SYS_RESTART);

	pr_emerg("system-reboot returned %d\n",

		 rtas_call(rtas_token("system-reboot"), 0, 1, NULL));

		 rtas_call(rtas_function_token(RTAS_FN_SYSTEM_REBOOT), 0, 1, NULL));

	for (;;);

}
@@ -1535,7 +1539,7 @@ void rtas_power_off(void) 
		rtas_flash_term_hook(SYS_POWER_OFF);

	/* allow power on only with power button press */

	pr_emerg("power-off returned %d\n",

		 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));

		 rtas_call(rtas_function_token(RTAS_FN_POWER_OFF), 2, 1, NULL, -1, -1));

	for (;;);

}
@@ -1545,16 +1549,17 @@ void __noreturn rtas_halt(void) 
		rtas_flash_term_hook(SYS_HALT);

	/* allow power on only with power button press */

	pr_emerg("power-off returned %d\n",

		 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));

		 rtas_call(rtas_function_token(RTAS_FN_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;

static bool ibm_extended_os_term;



void rtas_os_term(char *str)

{

	s32 token = rtas_function_token(RTAS_FN_IBM_OS_TERM);

	int status;



	/*
@@ -1563,7 +1568,8 @@ void rtas_os_term(char *str) 
	 * 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)



	if (token == RTAS_UNKNOWN_SERVICE || !ibm_extended_os_term)

		return;



	snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
@@ -1574,8 +1580,7 @@ void rtas_os_term(char *str) 
	 * schedules.

	 */

	do {

		status = rtas_call(ibm_os_term_token, 1, 1, NULL,

				   __pa(rtas_os_term_buf));

		status = rtas_call(token, 1, 1, NULL, __pa(rtas_os_term_buf));

	} while (rtas_busy_delay_time(status));



	if (status != 0)
@@ -1595,10 +1600,9 @@ void rtas_os_term(char *str) 
 */

void rtas_activate_firmware(void)

{

	int token;

	int token = rtas_function_token(RTAS_FN_IBM_ACTIVATE_FIRMWARE);

	int fwrc;



	token = rtas_token("ibm,activate-firmware");

	if (token == RTAS_UNKNOWN_SERVICE) {

		pr_notice("ibm,activate-firmware method unavailable\n");

		return;
@@ -1684,6 +1688,8 @@ static bool block_rtas_call(int token, int nargs, 
{

	const struct rtas_function *func;

	const struct rtas_filter *f;

	const bool is_platform_dump = token == rtas_function_token(RTAS_FN_IBM_PLATFORM_DUMP);

	const bool is_config_conn = token == rtas_function_token(RTAS_FN_IBM_CONFIGURE_CONNECTOR);

	u32 base, size, end;



	/*
@@ -1720,8 +1726,7 @@ static bool block_rtas_call(int token, int nargs, 
		 * Special case for ibm,platform-dump - NULL buffer

		 * address is used to indicate end of dump processing

		 */

		if (!strcmp(func->name, "ibm,platform-dump") &&

		    base == 0)

		if (is_platform_dump && base == 0)

			return false;



		if (!in_rmo_buf(base, end))
@@ -1742,8 +1747,7 @@ static bool block_rtas_call(int token, int nargs, 
		 * Special case for ibm,configure-connector where the

		 * address can be 0

		 */

		if (!strcmp(func->name, "ibm,configure-connector") &&

		    base == 0)

		if (is_config_conn && base == 0)

			return false;



		if (!in_rmo_buf(base, end))
@@ -1798,7 +1802,7 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) 
	if (block_rtas_call(token, nargs, &args))

		return -EINVAL;



	if (token == ibm_open_errinjct_token || token == ibm_errinjct_token) {

	if (token_is_restricted_errinjct(token)) {

		int err;



		err = security_locked_down(LOCKDOWN_RTAS_ERROR_INJECTION);
@@ -1807,7 +1811,7 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) 
	}



	/* Need to handle ibm,suspend_me call specially */

	if (token == rtas_token("ibm,suspend-me")) {

	if (token == rtas_function_token(RTAS_FN_IBM_SUSPEND_ME)) {



		/*

		 * rtas_ibm_suspend_me assumes the streamid handle is in cpu
@@ -1942,11 +1946,10 @@ void __init rtas_initialize(void) 
	rtas_function_table_init();



	/*

	 * Discover these now to avoid device tree lookups in the

	 * Discover this now to avoid a device tree lookup in the

	 * panic path.

	 */

	if (of_property_read_bool(rtas.dev, "ibm,extended-os-term"))

		ibm_os_term_token = rtas_token("ibm,os-term");

	ibm_extended_os_term = of_property_read_bool(rtas.dev, "ibm,extended-os-term");



	/* If RTAS was found, allocate the RMO buffer for it and look for

	 * the stop-self token if any
@@ -1961,12 +1964,6 @@ void __init rtas_initialize(void) 
		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_work_area_reserve_arena(rtas_region);

}
@@ -2022,13 +2019,13 @@ void rtas_give_timebase(void) 


	raw_spin_lock_irqsave(&timebase_lock, flags);

	hard_irq_disable();

	rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);

	rtas_call(rtas_function_token(RTAS_FN_FREEZE_TIME_BASE), 0, 1, NULL);

	timebase = get_tb();

	raw_spin_unlock(&timebase_lock);



	while (timebase)

		barrier();

	rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);

	rtas_call(rtas_function_token(RTAS_FN_THAW_TIME_BASE), 0, 1, NULL);

	local_irq_restore(flags);

}

arch/powerpc/kernel/rtas_flash.c

+10 −11
Original line number Diff line number Diff line
@@ -376,7 +376,7 @@ static void manage_flash(struct rtas_manage_flash_t *args_buf, unsigned int op) 
	s32 rc;



	do {

		rc = rtas_call(rtas_token("ibm,manage-flash-image"), 1, 1,

		rc = rtas_call(rtas_function_token(RTAS_FN_IBM_MANAGE_FLASH_IMAGE), 1, 1,

			       NULL, op);

	} while (rtas_busy_delay(rc));
@@ -444,7 +444,7 @@ static ssize_t manage_flash_write(struct file *file, const char __user *buf, 
 */

static void validate_flash(struct rtas_validate_flash_t *args_buf)

{

	int token = rtas_token("ibm,validate-flash-image");

	int token = rtas_function_token(RTAS_FN_IBM_VALIDATE_FLASH_IMAGE);

	int update_results;

	s32 rc;
@@ -570,7 +570,7 @@ static void rtas_flash_firmware(int reboot_type) 
		return;

	}



	update_token = rtas_token("ibm,update-flash-64-and-reboot");

	update_token = rtas_function_token(RTAS_FN_IBM_UPDATE_FLASH_64_AND_REBOOT);

	if (update_token == RTAS_UNKNOWN_SERVICE) {

		printk(KERN_ALERT "FLASH: ibm,update-flash-64-and-reboot "

		       "is not available -- not a service partition?\n");
@@ -653,7 +653,7 @@ static void rtas_flash_firmware(int reboot_type) 
 */

struct rtas_flash_file {

	const char *filename;

	const char *rtas_call_name;

	const rtas_fn_handle_t handle;

	int *status;

	const struct proc_ops ops;

};
@@ -661,7 +661,7 @@ struct rtas_flash_file { 
static const struct rtas_flash_file rtas_flash_files[] = {

	{

		.filename	= "powerpc/rtas/" FIRMWARE_FLASH_NAME,

		.rtas_call_name	= "ibm,update-flash-64-and-reboot",

		.handle		= RTAS_FN_IBM_UPDATE_FLASH_64_AND_REBOOT,

		.status		= &rtas_update_flash_data.status,

		.ops.proc_read	= rtas_flash_read_msg,

		.ops.proc_write	= rtas_flash_write,
@@ -670,7 +670,7 @@ static const struct rtas_flash_file rtas_flash_files[] = { 
	},

	{

		.filename	= "powerpc/rtas/" FIRMWARE_UPDATE_NAME,

		.rtas_call_name	= "ibm,update-flash-64-and-reboot",

		.handle		= RTAS_FN_IBM_UPDATE_FLASH_64_AND_REBOOT,

		.status		= &rtas_update_flash_data.status,

		.ops.proc_read	= rtas_flash_read_num,

		.ops.proc_write	= rtas_flash_write,
@@ -679,7 +679,7 @@ static const struct rtas_flash_file rtas_flash_files[] = { 
	},

	{

		.filename	= "powerpc/rtas/" VALIDATE_FLASH_NAME,

		.rtas_call_name	= "ibm,validate-flash-image",

		.handle		= RTAS_FN_IBM_VALIDATE_FLASH_IMAGE,

		.status		= &rtas_validate_flash_data.status,

		.ops.proc_read	= validate_flash_read,

		.ops.proc_write	= validate_flash_write,
@@ -688,7 +688,7 @@ static const struct rtas_flash_file rtas_flash_files[] = { 
	},

	{

		.filename	= "powerpc/rtas/" MANAGE_FLASH_NAME,

		.rtas_call_name	= "ibm,manage-flash-image",

		.handle		= RTAS_FN_IBM_MANAGE_FLASH_IMAGE,

		.status		= &rtas_manage_flash_data.status,

		.ops.proc_read	= manage_flash_read,

		.ops.proc_write	= manage_flash_write,
@@ -700,8 +700,7 @@ static int __init rtas_flash_init(void) 
{

	int i;



	if (rtas_token("ibm,update-flash-64-and-reboot") ==

		       RTAS_UNKNOWN_SERVICE) {

	if (rtas_function_token(RTAS_FN_IBM_UPDATE_FLASH_64_AND_REBOOT) == RTAS_UNKNOWN_SERVICE) {

		pr_info("rtas_flash: no firmware flash support\n");

		return -EINVAL;

	}
@@ -730,7 +729,7 @@ static int __init rtas_flash_init(void) 
		 * This code assumes that the status int is the first member of the

		 * struct

		 */

		token = rtas_token(f->rtas_call_name);

		token = rtas_function_token(f->handle);

		if (token == RTAS_UNKNOWN_SERVICE)

			*f->status = FLASH_AUTH;

		else

arch/powerpc/kernel/rtas_pci.c

+4 −4
Original line number Diff line number Diff line
@@ -191,10 +191,10 @@ static void python_countermeasures(struct device_node *dev) 


void __init init_pci_config_tokens(void)

{

	read_pci_config = rtas_token("read-pci-config");

	write_pci_config = rtas_token("write-pci-config");

	ibm_read_pci_config = rtas_token("ibm,read-pci-config");

	ibm_write_pci_config = rtas_token("ibm,write-pci-config");

	read_pci_config = rtas_function_token(RTAS_FN_READ_PCI_CONFIG);

	write_pci_config = rtas_function_token(RTAS_FN_WRITE_PCI_CONFIG);

	ibm_read_pci_config = rtas_function_token(RTAS_FN_IBM_READ_PCI_CONFIG);

	ibm_write_pci_config = rtas_function_token(RTAS_FN_IBM_WRITE_PCI_CONFIG);

}



unsigned long get_phb_buid(struct device_node *phb)