[mirror_ubuntu-hirsute-kernel.git] / mm / gup_benchmark.c

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/ktime.h>
#include <linux/debugfs.h>

#define GUP_FAST_BENCHMARK	_IOWR('g', 1, struct gup_benchmark)
#define GUP_BENCHMARK		_IOWR('g', 2, struct gup_benchmark)
#define PIN_FAST_BENCHMARK	_IOWR('g', 3, struct gup_benchmark)
#define PIN_BENCHMARK		_IOWR('g', 4, struct gup_benchmark)
#define PIN_LONGTERM_BENCHMARK	_IOWR('g', 5, struct gup_benchmark)

struct gup_benchmark {
	__u64 get_delta_usec;
	__u64 put_delta_usec;
	__u64 addr;
	__u64 size;
	__u32 nr_pages_per_call;
	__u32 flags;
	__u64 expansion[10];	/* For future use */
};

static void put_back_pages(unsigned int cmd, struct page **pages,
			   unsigned long nr_pages)
{
	unsigned long i;

	switch (cmd) {
	case GUP_FAST_BENCHMARK:
	case GUP_BENCHMARK:
		for (i = 0; i < nr_pages; i++)
			put_page(pages[i]);
		break;

	case PIN_FAST_BENCHMARK:
	case PIN_BENCHMARK:
	case PIN_LONGTERM_BENCHMARK:
		unpin_user_pages(pages, nr_pages);
		break;
	}
}

static void verify_dma_pinned(unsigned int cmd, struct page **pages,
			      unsigned long nr_pages)
{
	unsigned long i;
	struct page *page;

	switch (cmd) {
	case PIN_FAST_BENCHMARK:
	case PIN_BENCHMARK:
	case PIN_LONGTERM_BENCHMARK:
		for (i = 0; i < nr_pages; i++) {
			page = pages[i];
			if (WARN(!page_maybe_dma_pinned(page),
				 "pages[%lu] is NOT dma-pinned\n", i)) {

				dump_page(page, "gup_benchmark failure");
				break;
			}
		}
		break;
	}
}

static int __gup_benchmark_ioctl(unsigned int cmd,
		struct gup_benchmark *gup)
{
	ktime_t start_time, end_time;
	unsigned long i, nr_pages, addr, next;
	int nr;
	struct page **pages;
	int ret = 0;
	bool needs_mmap_lock =
		cmd != GUP_FAST_BENCHMARK && cmd != PIN_FAST_BENCHMARK;

	if (gup->size > ULONG_MAX)
		return -EINVAL;

	nr_pages = gup->size / PAGE_SIZE;
	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
	if (!pages)
		return -ENOMEM;

	if (needs_mmap_lock && mmap_read_lock_killable(current->mm)) {
		ret = -EINTR;
		goto free_pages;
	}

	i = 0;
	nr = gup->nr_pages_per_call;
	start_time = ktime_get();
	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
		if (nr != gup->nr_pages_per_call)
			break;

		next = addr + nr * PAGE_SIZE;
		if (next > gup->addr + gup->size) {
			next = gup->addr + gup->size;
			nr = (next - addr) / PAGE_SIZE;
		}

		/* Filter out most gup flags: only allow a tiny subset here: */
		gup->flags &= FOLL_WRITE;

		switch (cmd) {
		case GUP_FAST_BENCHMARK:
			nr = get_user_pages_fast(addr, nr, gup->flags,
						 pages + i);
			break;
		case GUP_BENCHMARK:
			nr = get_user_pages(addr, nr, gup->flags, pages + i,
					    NULL);
			break;
		case PIN_FAST_BENCHMARK:
			nr = pin_user_pages_fast(addr, nr, gup->flags,
						 pages + i);
			break;
		case PIN_BENCHMARK:
			nr = pin_user_pages(addr, nr, gup->flags, pages + i,
					    NULL);
			break;
		case PIN_LONGTERM_BENCHMARK:
			nr = pin_user_pages(addr, nr,
					    gup->flags | FOLL_LONGTERM,
					    pages + i, NULL);
			break;
		default:
			ret = -EINVAL;
			goto unlock;
		}

		if (nr <= 0)
			break;
		i += nr;
	}
	end_time = ktime_get();

	/* Shifting the meaning of nr_pages: now it is actual number pinned: */
	nr_pages = i;

	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
	gup->size = addr - gup->addr;

	/*
	 * Take an un-benchmark-timed moment to verify DMA pinned
	 * state: print a warning if any non-dma-pinned pages are found:
	 */
	verify_dma_pinned(cmd, pages, nr_pages);

	start_time = ktime_get();

	put_back_pages(cmd, pages, nr_pages);

	end_time = ktime_get();
	gup->put_delta_usec = ktime_us_delta(end_time, start_time);

unlock:
	if (needs_mmap_lock)
		mmap_read_unlock(current->mm);
free_pages:
	kvfree(pages);
	return ret;
}

static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
		unsigned long arg)
{
	struct gup_benchmark gup;
	int ret;

	switch (cmd) {
	case GUP_FAST_BENCHMARK:
	case GUP_BENCHMARK:
	case PIN_FAST_BENCHMARK:
	case PIN_BENCHMARK:
	case PIN_LONGTERM_BENCHMARK:
		break;
	default:
		return -EINVAL;
	}

	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
		return -EFAULT;

	ret = __gup_benchmark_ioctl(cmd, &gup);
	if (ret)
		return ret;

	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
		return -EFAULT;

	return 0;
}

static const struct file_operations gup_benchmark_fops = {
	.open = nonseekable_open,
	.unlocked_ioctl = gup_benchmark_ioctl,
};

static int gup_benchmark_init(void)
{
	debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
				   &gup_benchmark_fops);

	return 0;
}

late_initcall(gup_benchmark_init);
Commit	Line	Data
64c349f4 KS	1	#include <linux/kernel.h>
	2	#include <linux/mm.h>
	3	#include <linux/slab.h>
	4	#include <linux/uaccess.h>
	5	#include <linux/ktime.h>
	6	#include <linux/debugfs.h>
	7
	8	#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark)
657d4f79 BS	9	#define GUP_BENCHMARK _IOWR('g', 2, struct gup_benchmark)
	10	#define PIN_FAST_BENCHMARK _IOWR('g', 3, struct gup_benchmark)
	11	#define PIN_BENCHMARK _IOWR('g', 4, struct gup_benchmark)
	12	#define PIN_LONGTERM_BENCHMARK _IOWR('g', 5, struct gup_benchmark)
64c349f4 KS	13
64c349f4 KS	14	struct gup_benchmark {
26db3d09 KB	15	__u64 get_delta_usec;
26db3d09 KB	16	__u64 put_delta_usec;
64c349f4 KS	17	__u64 addr;
	18	__u64 size;
	19	__u32 nr_pages_per_call;
	20	__u32 flags;
26db3d09	21	__u64 expansion[10]; /* For future use */
64c349f4 KS	22	};
64c349f4 KS	23
41c45d37 JH	24	static void put_back_pages(unsigned int cmd, struct page **pages,
	25	unsigned long nr_pages)
	26	{
	27	unsigned long i;
	28
	29	switch (cmd) {
	30	case GUP_FAST_BENCHMARK:
41c45d37 JH	31	case GUP_BENCHMARK:
	32	for (i = 0; i < nr_pages; i++)
	33	put_page(pages[i]);
	34	break;
	35
	36	case PIN_FAST_BENCHMARK:
	37	case PIN_BENCHMARK:
657d4f79	38	case PIN_LONGTERM_BENCHMARK:
41c45d37 JH	39	unpin_user_pages(pages, nr_pages);
	40	break;
	41	}
	42	}
	43
	44	static void verify_dma_pinned(unsigned int cmd, struct page **pages,
	45	unsigned long nr_pages)
	46	{
	47	unsigned long i;
	48	struct page *page;
	49
	50	switch (cmd) {
	51	case PIN_FAST_BENCHMARK:
	52	case PIN_BENCHMARK:
657d4f79	53	case PIN_LONGTERM_BENCHMARK:
41c45d37 JH	54	for (i = 0; i < nr_pages; i++) {
	55	page = pages[i];
	56	if (WARN(!page_maybe_dma_pinned(page),
	57	"pages[%lu] is NOT dma-pinned\n", i)) {
	58
	59	dump_page(page, "gup_benchmark failure");
	60	break;
	61	}
	62	}
	63	break;
	64	}
	65	}
	66
64c349f4 KS	67	static int __gup_benchmark_ioctl(unsigned int cmd,
	68	struct gup_benchmark *gup)
	69	{
	70	ktime_t start_time, end_time;
51896864 Y	71	unsigned long i, nr_pages, addr, next;
51896864 Y	72	int nr;
64c349f4	73	struct page **pages;
a7c46c0c	74	int ret = 0;
f3964599 JH	75	bool needs_mmap_lock =
f3964599 JH	76	cmd != GUP_FAST_BENCHMARK && cmd != PIN_FAST_BENCHMARK;
64c349f4	77
4b408c74 DC	78	if (gup->size > ULONG_MAX)
	79	return -EINVAL;
	80
64c349f4	81	nr_pages = gup->size / PAGE_SIZE;
778e1cdd	82	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
64c349f4 KS	83	if (!pages)
	84	return -ENOMEM;
	85
f3964599 JH	86	if (needs_mmap_lock && mmap_read_lock_killable(current->mm)) {
	87	ret = -EINTR;
	88	goto free_pages;
	89	}
	90
64c349f4 KS	91	i = 0;
	92	nr = gup->nr_pages_per_call;
	93	start_time = ktime_get();
	94	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
	95	if (nr != gup->nr_pages_per_call)
	96	break;
	97
	98	next = addr + nr * PAGE_SIZE;
	99	if (next > gup->addr + gup->size) {
	100	next = gup->addr + gup->size;
	101	nr = (next - addr) / PAGE_SIZE;
	102	}
	103
bdffe23e JH	104	/* Filter out most gup flags: only allow a tiny subset here: */
	105	gup->flags &= FOLL_WRITE;
	106
714a3a1e KB	107	switch (cmd) {
714a3a1e KB	108	case GUP_FAST_BENCHMARK:
bdffe23e	109	nr = get_user_pages_fast(addr, nr, gup->flags,
714a3a1e KB	110	pages + i);
714a3a1e KB	111	break;
714a3a1e	112	case GUP_BENCHMARK:
bdffe23e	113	nr = get_user_pages(addr, nr, gup->flags, pages + i,
714a3a1e KB	114	NULL);
714a3a1e KB	115	break;
41c45d37 JH	116	case PIN_FAST_BENCHMARK:
	117	nr = pin_user_pages_fast(addr, nr, gup->flags,
	118	pages + i);
	119	break;
	120	case PIN_BENCHMARK:
	121	nr = pin_user_pages(addr, nr, gup->flags, pages + i,
	122	NULL);
	123	break;
657d4f79 BS	124	case PIN_LONGTERM_BENCHMARK:
	125	nr = pin_user_pages(addr, nr,
	126	gup->flags \| FOLL_LONGTERM,
	127	pages + i, NULL);
	128	break;
714a3a1e	129	default:
a7c46c0c	130	ret = -EINVAL;
f3964599	131	goto unlock;
714a3a1e KB	132	}
714a3a1e KB	133
09e35a4a MT	134	if (nr <= 0)
09e35a4a MT	135	break;
64c349f4 KS	136	i += nr;
	137	}
	138	end_time = ktime_get();
	139
41c45d37 JH	140	/* Shifting the meaning of nr_pages: now it is actual number pinned: */
	141	nr_pages = i;
	142
26db3d09	143	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
64c349f4 KS	144	gup->size = addr - gup->addr;
64c349f4 KS	145
41c45d37 JH	146	/*
	147	* Take an un-benchmark-timed moment to verify DMA pinned
	148	* state: print a warning if any non-dma-pinned pages are found:
	149	*/
	150	verify_dma_pinned(cmd, pages, nr_pages);
	151
26db3d09	152	start_time = ktime_get();
41c45d37 JH	153
	154	put_back_pages(cmd, pages, nr_pages);
	155
26db3d09 KB	156	end_time = ktime_get();
26db3d09 KB	157	gup->put_delta_usec = ktime_us_delta(end_time, start_time);
64c349f4	158
f3964599 JH	159	unlock:
	160	if (needs_mmap_lock)
	161	mmap_read_unlock(current->mm);
	162	free_pages:
64c349f4	163	kvfree(pages);
a7c46c0c	164	return ret;
64c349f4 KS	165	}
	166
	167	static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
	168	unsigned long arg)
	169	{
	170	struct gup_benchmark gup;
	171	int ret;
	172
714a3a1e KB	173	switch (cmd) {
714a3a1e KB	174	case GUP_FAST_BENCHMARK:
714a3a1e	175	case GUP_BENCHMARK:
41c45d37 JH	176	case PIN_FAST_BENCHMARK:
41c45d37 JH	177	case PIN_BENCHMARK:
657d4f79	178	case PIN_LONGTERM_BENCHMARK:
714a3a1e KB	179	break;
714a3a1e KB	180	default:
64c349f4	181	return -EINVAL;
714a3a1e	182	}
64c349f4 KS	183
	184	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
	185	return -EFAULT;
	186
	187	ret = __gup_benchmark_ioctl(cmd, &gup);
	188	if (ret)
	189	return ret;
	190
	191	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
	192	return -EFAULT;
	193
	194	return 0;
	195	}
	196
	197	static const struct file_operations gup_benchmark_fops = {
	198	.open = nonseekable_open,
	199	.unlocked_ioctl = gup_benchmark_ioctl,
	200	};
	201
	202	static int gup_benchmark_init(void)
	203	{
d9f7979c GKH	204	debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
d9f7979c GKH	205	&gup_benchmark_fops);
64c349f4 KS	206
	207	return 0;
	208	}
	209
	210	late_initcall(gup_benchmark_init);