123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210 |
- #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);
|