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/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/sort.h>
#include <linux/random.h>
#include <asm/cpufeature.h>
#include <asm/processor.h>
#include <asm/fpu/api.h>
#include <asm/simd.h>
static unsigned long stamp = 0;
module_param(stamp, ulong, 0);
#define declare_it(name) bool mix_ ##name(void *input, size_t len);
#define do_it(name, input, len) do { \
u32 eax = 0, ebx = 0, ecx = 0, edx = 0; \
for (i = 0; i < WARMUP; ++i) \
ret |= mix_ ##name(input, len); \
asm volatile("cpuid" : "+a" (eax), "=b" (ebx), "=d" (edx), "+c" (ecx)); \
for (i = 0; i <= TRIALS; ++i) { \
trial_times[i] = get_cycles(); \
ret |= mix_ ##name(input, len); \
} \
for (i = 0; i < TRIALS; ++i) \
trial_times[i] = trial_times[i + 1] - trial_times[i]; \
sort(trial_times, TRIALS + 1, sizeof(cycles_t), compare_cycles, NULL); \
median_ ## name = trial_times[TRIALS / 2]; \
} while (0)
#define report_it(name) do { \
pr_err("%lu: %12s: %6llu cycles per call\n", stamp, #name, median_ ## name); \
} while (0)
declare_it(original)
declare_it(crc32loop)
declare_it(tinylfsr)
declare_it(widelfsr)
declare_it(blake2s)
declare_it(dblblake2s)
declare_it(k12f800)
declare_it(k12f1600)
static int compare_cycles(const void *a, const void *b)
{
return *((cycles_t *)a) - *((cycles_t *)b);
}
static int __init mod_init(void)
{
enum { WARMUP = 6000, TRIALS = 10000, IDLE = 1 * 1000, LEN = 4096 };
static u8 buffer[LEN];
int ret = 0, i;
cycles_t *trial_times;
cycles_t median_original = 0;
cycles_t median_crc32loop = 0;
cycles_t median_tinylfsr = 0;
cycles_t median_widelfsr = 0;
cycles_t median_blake2s = 0;
cycles_t median_dblblake2s = 0;
cycles_t median_k12f800 = 0;
cycles_t median_k12f1600 = 0;
unsigned long flags;
DEFINE_SPINLOCK(lock);
get_random_bytes(buffer, sizeof(buffer));
trial_times = kcalloc(TRIALS + 1, sizeof(cycles_t), GFP_KERNEL);
if (!trial_times)
return -ENOMEM;
msleep(IDLE);
spin_lock_irqsave(&lock, flags);
do_it(original, buffer, sizeof(buffer));
do_it(crc32loop, buffer, sizeof(buffer));
do_it(tinylfsr, buffer, sizeof(buffer));
do_it(widelfsr, buffer, sizeof(buffer));
do_it(blake2s, buffer, sizeof(buffer));
do_it(dblblake2s, buffer, sizeof(buffer));
do_it(k12f800, buffer, sizeof(buffer));
do_it(k12f1600, buffer, sizeof(buffer));
spin_unlock_irqrestore(&lock, flags);
report_it(original);
report_it(crc32loop);
report_it(tinylfsr);
report_it(widelfsr);
report_it(blake2s);
report_it(dblblake2s);
report_it(k12f800);
report_it(k12f1600);
kfree(trial_times);
/* We should never actually agree to insert the module. Choosing
* -0x1000 here is an amazing hack. It causes the kernel to not
* actually load the module, while the standard userspace tools
* don't return an error, because it's too big. */
return -0x1000;
}
module_init(mod_init);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("kBench9000 Cycle Counter");
MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
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