* Re: [PATCH] time: Rename udelay_test.c to test_udelay.c
2014-08-04 18:35 ` [PATCH] time: Rename udelay_test.c to test_udelay.c John Stultz
@ 2014-08-04 19:35 ` Kees Cook
2014-08-06 16:31 ` David Riley
1 sibling, 0 replies; 8+ messages in thread
From: Kees Cook @ 2014-08-04 19:35 UTC (permalink / raw)
To: John Stultz
Cc: LKML, Greg KH, Stephen Rothwell, Thomas Gleixner, Ingo Molnar,
Linux-Next, David Riley
On Mon, Aug 4, 2014 at 11:35 AM, John Stultz <john.stultz@linaro•org> wrote:
> Kees requested that this test module be renamed for consistency sake,
> so this patch renames the udelay_test.c file (recently added to
> tip/timers/core for 3.17) to test_udelay.c
>
> Cc: Kees Cook <keescook@chromium•org>
> Cc: Greg KH <greg@kroah•com>
> Cc: Stephen Rothwell <sfr@canb•auug.org.au>
> Cc: Thomas Gleixner <tglx@linutronix•de>
> Cc: Ingo Molnar <mingo@elte•hu>
> Cc: Linux-Next <linux-next@vger•kernel.org>
> Cc: David Riley <davidriley@chromium•org>
> Signed-off-by: John Stultz <john.stultz@linaro•org>
Thank you! :)
Acked-by: Kees Cook <keescook@chromium•org>
-Kees
> ---
> kernel/time/Makefile | 2 +-
> kernel/time/test_udelay.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++
> kernel/time/udelay_test.c | 168 ----------------------------------------------
> 3 files changed, 169 insertions(+), 169 deletions(-)
> create mode 100644 kernel/time/test_udelay.c
> delete mode 100644 kernel/time/udelay_test.c
>
> diff --git a/kernel/time/Makefile b/kernel/time/Makefile
> index 7347426..f622cf2 100644
> --- a/kernel/time/Makefile
> +++ b/kernel/time/Makefile
> @@ -13,7 +13,7 @@ obj-$(CONFIG_TICK_ONESHOT) += tick-oneshot.o
> obj-$(CONFIG_TICK_ONESHOT) += tick-sched.o
> obj-$(CONFIG_TIMER_STATS) += timer_stats.o
> obj-$(CONFIG_DEBUG_FS) += timekeeping_debug.o
> -obj-$(CONFIG_TEST_UDELAY) += udelay_test.o
> +obj-$(CONFIG_TEST_UDELAY) += test_udelay.o
>
> $(obj)/time.o: $(obj)/timeconst.h
>
> diff --git a/kernel/time/test_udelay.c b/kernel/time/test_udelay.c
> new file mode 100644
> index 0000000..e622ba3
> --- /dev/null
> +++ b/kernel/time/test_udelay.c
> @@ -0,0 +1,168 @@
> +/*
> + * udelay() test kernel module
> + *
> + * Test is executed by writing and reading to /sys/kernel/debug/udelay_test
> + * Tests are configured by writing: USECS ITERATIONS
> + * Tests are executed by reading from the same file.
> + * Specifying usecs of 0 or negative values will run multiples tests.
> + *
> + * Copyright (C) 2014 Google, Inc.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/debugfs.h>
> +#include <linux/delay.h>
> +#include <linux/ktime.h>
> +#include <linux/module.h>
> +#include <linux/uaccess.h>
> +
> +#define DEFAULT_ITERATIONS 100
> +
> +#define DEBUGFS_FILENAME "udelay_test"
> +
> +static DEFINE_MUTEX(udelay_test_lock);
> +static struct dentry *udelay_test_debugfs_file;
> +static int udelay_test_usecs;
> +static int udelay_test_iterations = DEFAULT_ITERATIONS;
> +
> +static int udelay_test_single(struct seq_file *s, int usecs, uint32_t iters)
> +{
> + int min = 0, max = 0, fail_count = 0;
> + uint64_t sum = 0;
> + uint64_t avg;
> + int i;
> + /* Allow udelay to be up to 0.5% fast */
> + int allowed_error_ns = usecs * 5;
> +
> + for (i = 0; i < iters; ++i) {
> + struct timespec ts1, ts2;
> + int time_passed;
> +
> + ktime_get_ts(&ts1);
> + udelay(usecs);
> + ktime_get_ts(&ts2);
> + time_passed = timespec_to_ns(&ts2) - timespec_to_ns(&ts1);
> +
> + if (i == 0 || time_passed < min)
> + min = time_passed;
> + if (i == 0 || time_passed > max)
> + max = time_passed;
> + if ((time_passed + allowed_error_ns) / 1000 < usecs)
> + ++fail_count;
> + WARN_ON(time_passed < 0);
> + sum += time_passed;
> + }
> +
> + avg = sum;
> + do_div(avg, iters);
> + seq_printf(s, "%d usecs x %d: exp=%d allowed=%d min=%d avg=%lld max=%d",
> + usecs, iters, usecs * 1000,
> + (usecs * 1000) - allowed_error_ns, min, avg, max);
> + if (fail_count)
> + seq_printf(s, " FAIL=%d", fail_count);
> + seq_puts(s, "\n");
> +
> + return 0;
> +}
> +
> +static int udelay_test_show(struct seq_file *s, void *v)
> +{
> + int usecs;
> + int iters;
> + int ret = 0;
> +
> + mutex_lock(&udelay_test_lock);
> + usecs = udelay_test_usecs;
> + iters = udelay_test_iterations;
> + mutex_unlock(&udelay_test_lock);
> +
> + if (usecs > 0 && iters > 0) {
> + return udelay_test_single(s, usecs, iters);
> + } else if (usecs == 0) {
> + struct timespec ts;
> +
> + ktime_get_ts(&ts);
> + seq_printf(s, "udelay() test (lpj=%ld kt=%ld.%09ld)\n",
> + loops_per_jiffy, ts.tv_sec, ts.tv_nsec);
> + seq_puts(s, "usage:\n");
> + seq_puts(s, "echo USECS [ITERS] > " DEBUGFS_FILENAME "\n");
> + seq_puts(s, "cat " DEBUGFS_FILENAME "\n");
> + }
> +
> + return ret;
> +}
> +
> +static int udelay_test_open(struct inode *inode, struct file *file)
> +{
> + return single_open(file, udelay_test_show, inode->i_private);
> +}
> +
> +static ssize_t udelay_test_write(struct file *file, const char __user *buf,
> + size_t count, loff_t *pos)
> +{
> + char lbuf[32];
> + int ret;
> + int usecs;
> + int iters;
> +
> + if (count >= sizeof(lbuf))
> + return -EINVAL;
> +
> + if (copy_from_user(lbuf, buf, count))
> + return -EFAULT;
> + lbuf[count] = '\0';
> +
> + ret = sscanf(lbuf, "%d %d", &usecs, &iters);
> + if (ret < 1)
> + return -EINVAL;
> + else if (ret < 2)
> + iters = DEFAULT_ITERATIONS;
> +
> + mutex_lock(&udelay_test_lock);
> + udelay_test_usecs = usecs;
> + udelay_test_iterations = iters;
> + mutex_unlock(&udelay_test_lock);
> +
> + return count;
> +}
> +
> +static const struct file_operations udelay_test_debugfs_ops = {
> + .owner = THIS_MODULE,
> + .open = udelay_test_open,
> + .read = seq_read,
> + .write = udelay_test_write,
> + .llseek = seq_lseek,
> + .release = single_release,
> +};
> +
> +static int __init udelay_test_init(void)
> +{
> + mutex_lock(&udelay_test_lock);
> + udelay_test_debugfs_file = debugfs_create_file(DEBUGFS_FILENAME,
> + S_IRUSR, NULL, NULL, &udelay_test_debugfs_ops);
> + mutex_unlock(&udelay_test_lock);
> +
> + return 0;
> +}
> +
> +module_init(udelay_test_init);
> +
> +static void __exit udelay_test_exit(void)
> +{
> + mutex_lock(&udelay_test_lock);
> + debugfs_remove(udelay_test_debugfs_file);
> + mutex_unlock(&udelay_test_lock);
> +}
> +
> +module_exit(udelay_test_exit);
> +
> +MODULE_AUTHOR("David Riley <davidriley@chromium•org>");
> +MODULE_LICENSE("GPL");
> diff --git a/kernel/time/udelay_test.c b/kernel/time/udelay_test.c
> deleted file mode 100644
> index e622ba3..0000000
> --- a/kernel/time/udelay_test.c
> +++ /dev/null
> @@ -1,168 +0,0 @@
> -/*
> - * udelay() test kernel module
> - *
> - * Test is executed by writing and reading to /sys/kernel/debug/udelay_test
> - * Tests are configured by writing: USECS ITERATIONS
> - * Tests are executed by reading from the same file.
> - * Specifying usecs of 0 or negative values will run multiples tests.
> - *
> - * Copyright (C) 2014 Google, Inc.
> - *
> - * This software is licensed under the terms of the GNU General Public
> - * License version 2, as published by the Free Software Foundation, and
> - * may be copied, distributed, and modified under those terms.
> - *
> - * This program is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> - * GNU General Public License for more details.
> - */
> -
> -#include <linux/debugfs.h>
> -#include <linux/delay.h>
> -#include <linux/ktime.h>
> -#include <linux/module.h>
> -#include <linux/uaccess.h>
> -
> -#define DEFAULT_ITERATIONS 100
> -
> -#define DEBUGFS_FILENAME "udelay_test"
> -
> -static DEFINE_MUTEX(udelay_test_lock);
> -static struct dentry *udelay_test_debugfs_file;
> -static int udelay_test_usecs;
> -static int udelay_test_iterations = DEFAULT_ITERATIONS;
> -
> -static int udelay_test_single(struct seq_file *s, int usecs, uint32_t iters)
> -{
> - int min = 0, max = 0, fail_count = 0;
> - uint64_t sum = 0;
> - uint64_t avg;
> - int i;
> - /* Allow udelay to be up to 0.5% fast */
> - int allowed_error_ns = usecs * 5;
> -
> - for (i = 0; i < iters; ++i) {
> - struct timespec ts1, ts2;
> - int time_passed;
> -
> - ktime_get_ts(&ts1);
> - udelay(usecs);
> - ktime_get_ts(&ts2);
> - time_passed = timespec_to_ns(&ts2) - timespec_to_ns(&ts1);
> -
> - if (i == 0 || time_passed < min)
> - min = time_passed;
> - if (i == 0 || time_passed > max)
> - max = time_passed;
> - if ((time_passed + allowed_error_ns) / 1000 < usecs)
> - ++fail_count;
> - WARN_ON(time_passed < 0);
> - sum += time_passed;
> - }
> -
> - avg = sum;
> - do_div(avg, iters);
> - seq_printf(s, "%d usecs x %d: exp=%d allowed=%d min=%d avg=%lld max=%d",
> - usecs, iters, usecs * 1000,
> - (usecs * 1000) - allowed_error_ns, min, avg, max);
> - if (fail_count)
> - seq_printf(s, " FAIL=%d", fail_count);
> - seq_puts(s, "\n");
> -
> - return 0;
> -}
> -
> -static int udelay_test_show(struct seq_file *s, void *v)
> -{
> - int usecs;
> - int iters;
> - int ret = 0;
> -
> - mutex_lock(&udelay_test_lock);
> - usecs = udelay_test_usecs;
> - iters = udelay_test_iterations;
> - mutex_unlock(&udelay_test_lock);
> -
> - if (usecs > 0 && iters > 0) {
> - return udelay_test_single(s, usecs, iters);
> - } else if (usecs == 0) {
> - struct timespec ts;
> -
> - ktime_get_ts(&ts);
> - seq_printf(s, "udelay() test (lpj=%ld kt=%ld.%09ld)\n",
> - loops_per_jiffy, ts.tv_sec, ts.tv_nsec);
> - seq_puts(s, "usage:\n");
> - seq_puts(s, "echo USECS [ITERS] > " DEBUGFS_FILENAME "\n");
> - seq_puts(s, "cat " DEBUGFS_FILENAME "\n");
> - }
> -
> - return ret;
> -}
> -
> -static int udelay_test_open(struct inode *inode, struct file *file)
> -{
> - return single_open(file, udelay_test_show, inode->i_private);
> -}
> -
> -static ssize_t udelay_test_write(struct file *file, const char __user *buf,
> - size_t count, loff_t *pos)
> -{
> - char lbuf[32];
> - int ret;
> - int usecs;
> - int iters;
> -
> - if (count >= sizeof(lbuf))
> - return -EINVAL;
> -
> - if (copy_from_user(lbuf, buf, count))
> - return -EFAULT;
> - lbuf[count] = '\0';
> -
> - ret = sscanf(lbuf, "%d %d", &usecs, &iters);
> - if (ret < 1)
> - return -EINVAL;
> - else if (ret < 2)
> - iters = DEFAULT_ITERATIONS;
> -
> - mutex_lock(&udelay_test_lock);
> - udelay_test_usecs = usecs;
> - udelay_test_iterations = iters;
> - mutex_unlock(&udelay_test_lock);
> -
> - return count;
> -}
> -
> -static const struct file_operations udelay_test_debugfs_ops = {
> - .owner = THIS_MODULE,
> - .open = udelay_test_open,
> - .read = seq_read,
> - .write = udelay_test_write,
> - .llseek = seq_lseek,
> - .release = single_release,
> -};
> -
> -static int __init udelay_test_init(void)
> -{
> - mutex_lock(&udelay_test_lock);
> - udelay_test_debugfs_file = debugfs_create_file(DEBUGFS_FILENAME,
> - S_IRUSR, NULL, NULL, &udelay_test_debugfs_ops);
> - mutex_unlock(&udelay_test_lock);
> -
> - return 0;
> -}
> -
> -module_init(udelay_test_init);
> -
> -static void __exit udelay_test_exit(void)
> -{
> - mutex_lock(&udelay_test_lock);
> - debugfs_remove(udelay_test_debugfs_file);
> - mutex_unlock(&udelay_test_lock);
> -}
> -
> -module_exit(udelay_test_exit);
> -
> -MODULE_AUTHOR("David Riley <davidriley@chromium•org>");
> -MODULE_LICENSE("GPL");
> --
> 1.9.1
>
--
Kees Cook
Chrome OS Security
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] time: Rename udelay_test.c to test_udelay.c
2014-08-04 18:35 ` [PATCH] time: Rename udelay_test.c to test_udelay.c John Stultz
2014-08-04 19:35 ` Kees Cook
@ 2014-08-06 16:31 ` David Riley
1 sibling, 0 replies; 8+ messages in thread
From: David Riley @ 2014-08-06 16:31 UTC (permalink / raw)
To: John Stultz
Cc: LKML, Kees Cook, Greg KH, Stephen Rothwell, Thomas Gleixner,
Ingo Molnar, Linux-Next
On Mon, Aug 4, 2014 at 11:35 AM, John Stultz <john.stultz@linaro•org> wrote:
> Kees requested that this test module be renamed for consistency sake,
> so this patch renames the udelay_test.c file (recently added to
> tip/timers/core for 3.17) to test_udelay.c
>
> Cc: Kees Cook <keescook@chromium•org>
> Cc: Greg KH <greg@kroah•com>
> Cc: Stephen Rothwell <sfr@canb•auug.org.au>
> Cc: Thomas Gleixner <tglx@linutronix•de>
> Cc: Ingo Molnar <mingo@elte•hu>
> Cc: Linux-Next <linux-next@vger•kernel.org>
> Cc: David Riley <davidriley@chromium•org>
> Signed-off-by: John Stultz <john.stultz@linaro•org>
Acked-by: David Riley <davidriley@chromium•org>
> ---
> kernel/time/Makefile | 2 +-
> kernel/time/test_udelay.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++
> kernel/time/udelay_test.c | 168 ----------------------------------------------
> 3 files changed, 169 insertions(+), 169 deletions(-)
> create mode 100644 kernel/time/test_udelay.c
> delete mode 100644 kernel/time/udelay_test.c
>
> diff --git a/kernel/time/Makefile b/kernel/time/Makefile
> index 7347426..f622cf2 100644
> --- a/kernel/time/Makefile
> +++ b/kernel/time/Makefile
> @@ -13,7 +13,7 @@ obj-$(CONFIG_TICK_ONESHOT) += tick-oneshot.o
> obj-$(CONFIG_TICK_ONESHOT) += tick-sched.o
> obj-$(CONFIG_TIMER_STATS) += timer_stats.o
> obj-$(CONFIG_DEBUG_FS) += timekeeping_debug.o
> -obj-$(CONFIG_TEST_UDELAY) += udelay_test.o
> +obj-$(CONFIG_TEST_UDELAY) += test_udelay.o
>
> $(obj)/time.o: $(obj)/timeconst.h
>
> diff --git a/kernel/time/test_udelay.c b/kernel/time/test_udelay.c
> new file mode 100644
> index 0000000..e622ba3
> --- /dev/null
> +++ b/kernel/time/test_udelay.c
> @@ -0,0 +1,168 @@
> +/*
> + * udelay() test kernel module
> + *
> + * Test is executed by writing and reading to /sys/kernel/debug/udelay_test
> + * Tests are configured by writing: USECS ITERATIONS
> + * Tests are executed by reading from the same file.
> + * Specifying usecs of 0 or negative values will run multiples tests.
> + *
> + * Copyright (C) 2014 Google, Inc.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/debugfs.h>
> +#include <linux/delay.h>
> +#include <linux/ktime.h>
> +#include <linux/module.h>
> +#include <linux/uaccess.h>
> +
> +#define DEFAULT_ITERATIONS 100
> +
> +#define DEBUGFS_FILENAME "udelay_test"
> +
> +static DEFINE_MUTEX(udelay_test_lock);
> +static struct dentry *udelay_test_debugfs_file;
> +static int udelay_test_usecs;
> +static int udelay_test_iterations = DEFAULT_ITERATIONS;
> +
> +static int udelay_test_single(struct seq_file *s, int usecs, uint32_t iters)
> +{
> + int min = 0, max = 0, fail_count = 0;
> + uint64_t sum = 0;
> + uint64_t avg;
> + int i;
> + /* Allow udelay to be up to 0.5% fast */
> + int allowed_error_ns = usecs * 5;
> +
> + for (i = 0; i < iters; ++i) {
> + struct timespec ts1, ts2;
> + int time_passed;
> +
> + ktime_get_ts(&ts1);
> + udelay(usecs);
> + ktime_get_ts(&ts2);
> + time_passed = timespec_to_ns(&ts2) - timespec_to_ns(&ts1);
> +
> + if (i == 0 || time_passed < min)
> + min = time_passed;
> + if (i == 0 || time_passed > max)
> + max = time_passed;
> + if ((time_passed + allowed_error_ns) / 1000 < usecs)
> + ++fail_count;
> + WARN_ON(time_passed < 0);
> + sum += time_passed;
> + }
> +
> + avg = sum;
> + do_div(avg, iters);
> + seq_printf(s, "%d usecs x %d: exp=%d allowed=%d min=%d avg=%lld max=%d",
> + usecs, iters, usecs * 1000,
> + (usecs * 1000) - allowed_error_ns, min, avg, max);
> + if (fail_count)
> + seq_printf(s, " FAIL=%d", fail_count);
> + seq_puts(s, "\n");
> +
> + return 0;
> +}
> +
> +static int udelay_test_show(struct seq_file *s, void *v)
> +{
> + int usecs;
> + int iters;
> + int ret = 0;
> +
> + mutex_lock(&udelay_test_lock);
> + usecs = udelay_test_usecs;
> + iters = udelay_test_iterations;
> + mutex_unlock(&udelay_test_lock);
> +
> + if (usecs > 0 && iters > 0) {
> + return udelay_test_single(s, usecs, iters);
> + } else if (usecs == 0) {
> + struct timespec ts;
> +
> + ktime_get_ts(&ts);
> + seq_printf(s, "udelay() test (lpj=%ld kt=%ld.%09ld)\n",
> + loops_per_jiffy, ts.tv_sec, ts.tv_nsec);
> + seq_puts(s, "usage:\n");
> + seq_puts(s, "echo USECS [ITERS] > " DEBUGFS_FILENAME "\n");
> + seq_puts(s, "cat " DEBUGFS_FILENAME "\n");
> + }
> +
> + return ret;
> +}
> +
> +static int udelay_test_open(struct inode *inode, struct file *file)
> +{
> + return single_open(file, udelay_test_show, inode->i_private);
> +}
> +
> +static ssize_t udelay_test_write(struct file *file, const char __user *buf,
> + size_t count, loff_t *pos)
> +{
> + char lbuf[32];
> + int ret;
> + int usecs;
> + int iters;
> +
> + if (count >= sizeof(lbuf))
> + return -EINVAL;
> +
> + if (copy_from_user(lbuf, buf, count))
> + return -EFAULT;
> + lbuf[count] = '\0';
> +
> + ret = sscanf(lbuf, "%d %d", &usecs, &iters);
> + if (ret < 1)
> + return -EINVAL;
> + else if (ret < 2)
> + iters = DEFAULT_ITERATIONS;
> +
> + mutex_lock(&udelay_test_lock);
> + udelay_test_usecs = usecs;
> + udelay_test_iterations = iters;
> + mutex_unlock(&udelay_test_lock);
> +
> + return count;
> +}
> +
> +static const struct file_operations udelay_test_debugfs_ops = {
> + .owner = THIS_MODULE,
> + .open = udelay_test_open,
> + .read = seq_read,
> + .write = udelay_test_write,
> + .llseek = seq_lseek,
> + .release = single_release,
> +};
> +
> +static int __init udelay_test_init(void)
> +{
> + mutex_lock(&udelay_test_lock);
> + udelay_test_debugfs_file = debugfs_create_file(DEBUGFS_FILENAME,
> + S_IRUSR, NULL, NULL, &udelay_test_debugfs_ops);
> + mutex_unlock(&udelay_test_lock);
> +
> + return 0;
> +}
> +
> +module_init(udelay_test_init);
> +
> +static void __exit udelay_test_exit(void)
> +{
> + mutex_lock(&udelay_test_lock);
> + debugfs_remove(udelay_test_debugfs_file);
> + mutex_unlock(&udelay_test_lock);
> +}
> +
> +module_exit(udelay_test_exit);
> +
> +MODULE_AUTHOR("David Riley <davidriley@chromium•org>");
> +MODULE_LICENSE("GPL");
> diff --git a/kernel/time/udelay_test.c b/kernel/time/udelay_test.c
> deleted file mode 100644
> index e622ba3..0000000
> --- a/kernel/time/udelay_test.c
> +++ /dev/null
> @@ -1,168 +0,0 @@
> -/*
> - * udelay() test kernel module
> - *
> - * Test is executed by writing and reading to /sys/kernel/debug/udelay_test
> - * Tests are configured by writing: USECS ITERATIONS
> - * Tests are executed by reading from the same file.
> - * Specifying usecs of 0 or negative values will run multiples tests.
> - *
> - * Copyright (C) 2014 Google, Inc.
> - *
> - * This software is licensed under the terms of the GNU General Public
> - * License version 2, as published by the Free Software Foundation, and
> - * may be copied, distributed, and modified under those terms.
> - *
> - * This program is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> - * GNU General Public License for more details.
> - */
> -
> -#include <linux/debugfs.h>
> -#include <linux/delay.h>
> -#include <linux/ktime.h>
> -#include <linux/module.h>
> -#include <linux/uaccess.h>
> -
> -#define DEFAULT_ITERATIONS 100
> -
> -#define DEBUGFS_FILENAME "udelay_test"
> -
> -static DEFINE_MUTEX(udelay_test_lock);
> -static struct dentry *udelay_test_debugfs_file;
> -static int udelay_test_usecs;
> -static int udelay_test_iterations = DEFAULT_ITERATIONS;
> -
> -static int udelay_test_single(struct seq_file *s, int usecs, uint32_t iters)
> -{
> - int min = 0, max = 0, fail_count = 0;
> - uint64_t sum = 0;
> - uint64_t avg;
> - int i;
> - /* Allow udelay to be up to 0.5% fast */
> - int allowed_error_ns = usecs * 5;
> -
> - for (i = 0; i < iters; ++i) {
> - struct timespec ts1, ts2;
> - int time_passed;
> -
> - ktime_get_ts(&ts1);
> - udelay(usecs);
> - ktime_get_ts(&ts2);
> - time_passed = timespec_to_ns(&ts2) - timespec_to_ns(&ts1);
> -
> - if (i == 0 || time_passed < min)
> - min = time_passed;
> - if (i == 0 || time_passed > max)
> - max = time_passed;
> - if ((time_passed + allowed_error_ns) / 1000 < usecs)
> - ++fail_count;
> - WARN_ON(time_passed < 0);
> - sum += time_passed;
> - }
> -
> - avg = sum;
> - do_div(avg, iters);
> - seq_printf(s, "%d usecs x %d: exp=%d allowed=%d min=%d avg=%lld max=%d",
> - usecs, iters, usecs * 1000,
> - (usecs * 1000) - allowed_error_ns, min, avg, max);
> - if (fail_count)
> - seq_printf(s, " FAIL=%d", fail_count);
> - seq_puts(s, "\n");
> -
> - return 0;
> -}
> -
> -static int udelay_test_show(struct seq_file *s, void *v)
> -{
> - int usecs;
> - int iters;
> - int ret = 0;
> -
> - mutex_lock(&udelay_test_lock);
> - usecs = udelay_test_usecs;
> - iters = udelay_test_iterations;
> - mutex_unlock(&udelay_test_lock);
> -
> - if (usecs > 0 && iters > 0) {
> - return udelay_test_single(s, usecs, iters);
> - } else if (usecs == 0) {
> - struct timespec ts;
> -
> - ktime_get_ts(&ts);
> - seq_printf(s, "udelay() test (lpj=%ld kt=%ld.%09ld)\n",
> - loops_per_jiffy, ts.tv_sec, ts.tv_nsec);
> - seq_puts(s, "usage:\n");
> - seq_puts(s, "echo USECS [ITERS] > " DEBUGFS_FILENAME "\n");
> - seq_puts(s, "cat " DEBUGFS_FILENAME "\n");
> - }
> -
> - return ret;
> -}
> -
> -static int udelay_test_open(struct inode *inode, struct file *file)
> -{
> - return single_open(file, udelay_test_show, inode->i_private);
> -}
> -
> -static ssize_t udelay_test_write(struct file *file, const char __user *buf,
> - size_t count, loff_t *pos)
> -{
> - char lbuf[32];
> - int ret;
> - int usecs;
> - int iters;
> -
> - if (count >= sizeof(lbuf))
> - return -EINVAL;
> -
> - if (copy_from_user(lbuf, buf, count))
> - return -EFAULT;
> - lbuf[count] = '\0';
> -
> - ret = sscanf(lbuf, "%d %d", &usecs, &iters);
> - if (ret < 1)
> - return -EINVAL;
> - else if (ret < 2)
> - iters = DEFAULT_ITERATIONS;
> -
> - mutex_lock(&udelay_test_lock);
> - udelay_test_usecs = usecs;
> - udelay_test_iterations = iters;
> - mutex_unlock(&udelay_test_lock);
> -
> - return count;
> -}
> -
> -static const struct file_operations udelay_test_debugfs_ops = {
> - .owner = THIS_MODULE,
> - .open = udelay_test_open,
> - .read = seq_read,
> - .write = udelay_test_write,
> - .llseek = seq_lseek,
> - .release = single_release,
> -};
> -
> -static int __init udelay_test_init(void)
> -{
> - mutex_lock(&udelay_test_lock);
> - udelay_test_debugfs_file = debugfs_create_file(DEBUGFS_FILENAME,
> - S_IRUSR, NULL, NULL, &udelay_test_debugfs_ops);
> - mutex_unlock(&udelay_test_lock);
> -
> - return 0;
> -}
> -
> -module_init(udelay_test_init);
> -
> -static void __exit udelay_test_exit(void)
> -{
> - mutex_lock(&udelay_test_lock);
> - debugfs_remove(udelay_test_debugfs_file);
> - mutex_unlock(&udelay_test_lock);
> -}
> -
> -module_exit(udelay_test_exit);
> -
> -MODULE_AUTHOR("David Riley <davidriley@chromium•org>");
> -MODULE_LICENSE("GPL");
> --
> 1.9.1
>
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