gup_test.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>
#include <linux/highmem.h>
#include "gup_test.h"
static void put_back_pages(unsigned int cmd, struct page **pages,
unsigned long nr_pages, unsigned int gup_test_flags)
{
unsigned long i;
switch (cmd) {
case GUP_FAST_BENCHMARK:
case GUP_BASIC_TEST:
for (i = 0; i < nr_pages; i++)
put_page(pages[i]);
break;
case PIN_FAST_BENCHMARK:
case PIN_BASIC_TEST:
case PIN_LONGTERM_BENCHMARK:
unpin_user_pages(pages, nr_pages);
break;
case DUMP_USER_PAGES_TEST:
if (gup_test_flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN) {
unpin_user_pages(pages, nr_pages);
} else {
for (i = 0; i < nr_pages; i++)
put_page(pages[i]);
}
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_BASIC_TEST:
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_test failure");
break;
} else if (cmd == PIN_LONGTERM_BENCHMARK &&
WARN(!is_longterm_pinnable_page(page),
"pages[%lu] is NOT pinnable but pinned\n",
i)) {
dump_page(page, "gup_test failure");
break;
}
}
break;
}
}
static void dump_pages_test(struct gup_test *gup, struct page **pages,
unsigned long nr_pages)
{
unsigned int index_to_dump;
unsigned int i;
/*
* Zero out any user-supplied page index that is out of range. Remember:
* .which_pages[] contains a 1-based set of page indices.
*/
for (i = 0; i < GUP_TEST_MAX_PAGES_TO_DUMP; i++) {
if (gup->which_pages[i] > nr_pages) {
pr_warn("ZEROING due to out of range: .which_pages[%u]: %u\n",
i, gup->which_pages[i]);
gup->which_pages[i] = 0;
}
}
for (i = 0; i < GUP_TEST_MAX_PAGES_TO_DUMP; i++) {
index_to_dump = gup->which_pages[i];
if (index_to_dump) {
index_to_dump--; // Decode from 1-based, to 0-based
pr_info("---- page #%u, starting from user virt addr: 0x%llx\n",
index_to_dump, gup->addr);
dump_page(pages[index_to_dump],
"gup_test: dump_pages() test");
}
}
}
static int __gup_test_ioctl(unsigned int cmd,
struct gup_test *gup)
{
ktime_t start_time, end_time;
unsigned long i, nr_pages, addr, next;
long 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;
}
switch (cmd) {
case GUP_FAST_BENCHMARK:
nr = get_user_pages_fast(addr, nr, gup->gup_flags,
pages + i);
break;
case GUP_BASIC_TEST:
nr = get_user_pages(addr, nr, gup->gup_flags, pages + i,
NULL);
break;
case PIN_FAST_BENCHMARK:
nr = pin_user_pages_fast(addr, nr, gup->gup_flags,
pages + i);
break;
case PIN_BASIC_TEST:
nr = pin_user_pages(addr, nr, gup->gup_flags, pages + i,
NULL);
break;
case PIN_LONGTERM_BENCHMARK:
nr = pin_user_pages(addr, nr,
gup->gup_flags | FOLL_LONGTERM,
pages + i, NULL);
break;
case DUMP_USER_PAGES_TEST:
if (gup->test_flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN)
nr = pin_user_pages(addr, nr, gup->gup_flags,
pages + i, NULL);
else
nr = get_user_pages(addr, nr, gup->gup_flags,
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);
if (cmd == DUMP_USER_PAGES_TEST)
dump_pages_test(gup, pages, nr_pages);
start_time = ktime_get();
put_back_pages(cmd, pages, nr_pages, gup->test_flags);
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 DEFINE_MUTEX(pin_longterm_test_mutex);
static struct page **pin_longterm_test_pages;
static unsigned long pin_longterm_test_nr_pages;
static inline void pin_longterm_test_stop(void)
{
if (pin_longterm_test_pages) {
if (pin_longterm_test_nr_pages)
unpin_user_pages(pin_longterm_test_pages,
pin_longterm_test_nr_pages);
kvfree(pin_longterm_test_pages);
pin_longterm_test_pages = NULL;
pin_longterm_test_nr_pages = 0;
}
}
static inline int pin_longterm_test_start(unsigned long arg)
{
long nr_pages, cur_pages, addr, remaining_pages;
int gup_flags = FOLL_LONGTERM;
struct pin_longterm_test args;
struct page **pages;
int ret = 0;
bool fast;
if (pin_longterm_test_pages)
return -EINVAL;
if (copy_from_user(&args, (void __user *)arg, sizeof(args)))
return -EFAULT;
if (args.flags &
~(PIN_LONGTERM_TEST_FLAG_USE_WRITE|PIN_LONGTERM_TEST_FLAG_USE_FAST))
return -EINVAL;
if (!IS_ALIGNED(args.addr | args.size, PAGE_SIZE))
return -EINVAL;
if (args.size > LONG_MAX)
return -EINVAL;
nr_pages = args.size / PAGE_SIZE;
if (!nr_pages)
return -EINVAL;
pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
if (!pages)
return -ENOMEM;
if (args.flags & PIN_LONGTERM_TEST_FLAG_USE_WRITE)
gup_flags |= FOLL_WRITE;
fast = !!(args.flags & PIN_LONGTERM_TEST_FLAG_USE_FAST);
if (!fast && mmap_read_lock_killable(current->mm)) {
kvfree(pages);
return -EINTR;
}
pin_longterm_test_pages = pages;
pin_longterm_test_nr_pages = 0;
while (nr_pages - pin_longterm_test_nr_pages) {
remaining_pages = nr_pages - pin_longterm_test_nr_pages;
addr = args.addr + pin_longterm_test_nr_pages * PAGE_SIZE;
if (fast)
cur_pages = pin_user_pages_fast(addr, remaining_pages,
gup_flags, pages);
else
cur_pages = pin_user_pages(addr, remaining_pages,
gup_flags, pages, NULL);
if (cur_pages < 0) {
pin_longterm_test_stop();
ret = cur_pages;
break;
}
pin_longterm_test_nr_pages += cur_pages;
pages += cur_pages;
}
if (!fast)
mmap_read_unlock(current->mm);
return ret;
}
static inline int pin_longterm_test_read(unsigned long arg)
{
__u64 user_addr;
unsigned long i;
if (!pin_longterm_test_pages)
return -EINVAL;
if (copy_from_user(&user_addr, (void __user *)arg, sizeof(user_addr)))
return -EFAULT;
for (i = 0; i < pin_longterm_test_nr_pages; i++) {
void *addr = kmap_local_page(pin_longterm_test_pages[i]);
unsigned long ret;
ret = copy_to_user((void __user *)(unsigned long)user_addr, addr,
PAGE_SIZE);
kunmap_local(addr);
if (ret)
return -EFAULT;
user_addr += PAGE_SIZE;
}
return 0;
}
static long pin_longterm_test_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
int ret = -EINVAL;
if (mutex_lock_killable(&pin_longterm_test_mutex))
return -EINTR;
switch (cmd) {
case PIN_LONGTERM_TEST_START:
ret = pin_longterm_test_start(arg);
break;
case PIN_LONGTERM_TEST_STOP:
pin_longterm_test_stop();
ret = 0;
break;
case PIN_LONGTERM_TEST_READ:
ret = pin_longterm_test_read(arg);
break;
}
mutex_unlock(&pin_longterm_test_mutex);
return ret;
}
static long gup_test_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
struct gup_test gup;
int ret;
switch (cmd) {
case GUP_FAST_BENCHMARK:
case PIN_FAST_BENCHMARK:
case PIN_LONGTERM_BENCHMARK:
case GUP_BASIC_TEST:
case PIN_BASIC_TEST:
case DUMP_USER_PAGES_TEST:
break;
case PIN_LONGTERM_TEST_START:
case PIN_LONGTERM_TEST_STOP:
case PIN_LONGTERM_TEST_READ:
return pin_longterm_test_ioctl(filep, cmd, arg);
default:
return -EINVAL;
}
if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
return -EFAULT;
ret = __gup_test_ioctl(cmd, &gup);
if (ret)
return ret;
if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
return -EFAULT;
return 0;
}
static int gup_test_release(struct inode *inode, struct file *file)
{
pin_longterm_test_stop();
return 0;
}
static const struct file_operations gup_test_fops = {
.open = nonseekable_open,
.unlocked_ioctl = gup_test_ioctl,
.release = gup_test_release,
};
static int __init gup_test_init(void)
{
debugfs_create_file_unsafe("gup_test", 0600, NULL, NULL,
&gup_test_fops);
return 0;
}
late_initcall(gup_test_init);