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Revision bd8733738c5af6114dd15d340b3f8713e9b624c2 authored by Boris Brezillon on 08 February 2015, 18:23:42 UTC, committed by Linus Walleij on 18 March 2015, 01:01:36 UTC 
pinctrl: at91: move lock/unlock_as_irq calls into request/release
 
The gpiochip_lock_as_irq call can fail and return an error,
while the irq_startup is not expected to fail (returns an
unsigned int which is not checked by irq core code).

irq_request/release_resources functions have been created
to address this problem.

Move gpiochip_lock/unlock_as_irq calls into
irq_request/release_resources functions to prevent using a
gpio as an irq if the gpiochip_lock_as_irq call failed.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
1 parent 549e783
Raw File
disable-tsc-test.c 
/*
 * Tests for prctl(PR_GET_TSC, ...) / prctl(PR_SET_TSC, ...)
 *
 * Basic test to test behaviour of PR_GET_TSC and PR_SET_TSC
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <inttypes.h>


#include <sys/prctl.h>
#include <linux/prctl.h>

/* Get/set the process' ability to use the timestamp counter instruction */
#ifndef PR_GET_TSC
#define PR_GET_TSC 25
#define PR_SET_TSC 26
# define PR_TSC_ENABLE		1   /* allow the use of the timestamp counter */
# define PR_TSC_SIGSEGV		2   /* throw a SIGSEGV instead of reading the TSC */
#endif

const char *tsc_names[] =
{
	[0] = "[not set]",
	[PR_TSC_ENABLE] = "PR_TSC_ENABLE",
	[PR_TSC_SIGSEGV] = "PR_TSC_SIGSEGV",
};

static uint64_t rdtsc(void)
{
uint32_t lo, hi;
/* We cannot use "=A", since this would use %rax on x86_64 */
__asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
return (uint64_t)hi << 32 | lo;
}

static void sigsegv_cb(int sig)
{
	int tsc_val = 0;

	printf("[ SIG_SEGV ]\n");
	printf("prctl(PR_GET_TSC, &tsc_val); ");
	fflush(stdout);

	if ( prctl(PR_GET_TSC, &tsc_val) == -1)
		perror("prctl");

	printf("tsc_val == %s\n", tsc_names[tsc_val]);
	printf("prctl(PR_SET_TSC, PR_TSC_ENABLE)\n");
	fflush(stdout);
	if ( prctl(PR_SET_TSC, PR_TSC_ENABLE) == -1)
		perror("prctl");

	printf("rdtsc() == ");
}

int main(int argc, char **argv)
{
	int tsc_val = 0;

	signal(SIGSEGV, sigsegv_cb);

	printf("rdtsc() == %llu\n", (unsigned long long)rdtsc());
	printf("prctl(PR_GET_TSC, &tsc_val); ");
	fflush(stdout);

	if ( prctl(PR_GET_TSC, &tsc_val) == -1)
		perror("prctl");

	printf("tsc_val == %s\n", tsc_names[tsc_val]);
	printf("rdtsc() == %llu\n", (unsigned long long)rdtsc());
	printf("prctl(PR_SET_TSC, PR_TSC_ENABLE)\n");
	fflush(stdout);

	if ( prctl(PR_SET_TSC, PR_TSC_ENABLE) == -1)
		perror("prctl");

	printf("rdtsc() == %llu\n", (unsigned long long)rdtsc());
	printf("prctl(PR_SET_TSC, PR_TSC_SIGSEGV)\n");
	fflush(stdout);

	if ( prctl(PR_SET_TSC, PR_TSC_SIGSEGV) == -1)
		perror("prctl");

	printf("rdtsc() == ");
	fflush(stdout);
	printf("%llu\n", (unsigned long long)rdtsc());
	fflush(stdout);

	exit(EXIT_SUCCESS);
}
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