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210 lines
4.5 KiB
210 lines
4.5 KiB
#include <linux/kernel.h> |
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#include <linux/mm.h> |
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#include <linux/slab.h> |
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#include <linux/uaccess.h> |
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#include <linux/ktime.h> |
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#include <linux/debugfs.h> |
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#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark) |
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#define GUP_BENCHMARK _IOWR('g', 2, struct gup_benchmark) |
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#define PIN_FAST_BENCHMARK _IOWR('g', 3, struct gup_benchmark) |
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#define PIN_BENCHMARK _IOWR('g', 4, struct gup_benchmark) |
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#define PIN_LONGTERM_BENCHMARK _IOWR('g', 5, struct gup_benchmark) |
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struct gup_benchmark { |
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__u64 get_delta_usec; |
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__u64 put_delta_usec; |
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__u64 addr; |
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__u64 size; |
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__u32 nr_pages_per_call; |
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__u32 flags; |
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__u64 expansion[10]; /* For future use */ |
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}; |
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static void put_back_pages(unsigned int cmd, struct page **pages, |
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unsigned long nr_pages) |
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{ |
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unsigned long i; |
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switch (cmd) { |
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case GUP_FAST_BENCHMARK: |
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case GUP_BENCHMARK: |
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for (i = 0; i < nr_pages; i++) |
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put_page(pages[i]); |
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break; |
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case PIN_FAST_BENCHMARK: |
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case PIN_BENCHMARK: |
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case PIN_LONGTERM_BENCHMARK: |
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unpin_user_pages(pages, nr_pages); |
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break; |
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} |
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} |
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static void verify_dma_pinned(unsigned int cmd, struct page **pages, |
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unsigned long nr_pages) |
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{ |
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unsigned long i; |
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struct page *page; |
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switch (cmd) { |
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case PIN_FAST_BENCHMARK: |
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case PIN_BENCHMARK: |
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case PIN_LONGTERM_BENCHMARK: |
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for (i = 0; i < nr_pages; i++) { |
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page = pages[i]; |
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if (WARN(!page_maybe_dma_pinned(page), |
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"pages[%lu] is NOT dma-pinned\n", i)) { |
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dump_page(page, "gup_benchmark failure"); |
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break; |
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} |
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} |
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break; |
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} |
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} |
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static int __gup_benchmark_ioctl(unsigned int cmd, |
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struct gup_benchmark *gup) |
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{ |
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ktime_t start_time, end_time; |
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unsigned long i, nr_pages, addr, next; |
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int nr; |
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struct page **pages; |
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int ret = 0; |
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bool needs_mmap_lock = |
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cmd != GUP_FAST_BENCHMARK && cmd != PIN_FAST_BENCHMARK; |
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if (gup->size > ULONG_MAX) |
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return -EINVAL; |
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nr_pages = gup->size / PAGE_SIZE; |
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pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL); |
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if (!pages) |
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return -ENOMEM; |
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if (needs_mmap_lock && mmap_read_lock_killable(current->mm)) { |
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ret = -EINTR; |
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goto free_pages; |
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} |
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i = 0; |
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nr = gup->nr_pages_per_call; |
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start_time = ktime_get(); |
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for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) { |
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if (nr != gup->nr_pages_per_call) |
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break; |
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next = addr + nr * PAGE_SIZE; |
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if (next > gup->addr + gup->size) { |
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next = gup->addr + gup->size; |
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nr = (next - addr) / PAGE_SIZE; |
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} |
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/* Filter out most gup flags: only allow a tiny subset here: */ |
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gup->flags &= FOLL_WRITE; |
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switch (cmd) { |
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case GUP_FAST_BENCHMARK: |
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nr = get_user_pages_fast(addr, nr, gup->flags, |
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pages + i); |
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break; |
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case GUP_BENCHMARK: |
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nr = get_user_pages(addr, nr, gup->flags, pages + i, |
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NULL); |
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break; |
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case PIN_FAST_BENCHMARK: |
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nr = pin_user_pages_fast(addr, nr, gup->flags, |
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pages + i); |
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break; |
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case PIN_BENCHMARK: |
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nr = pin_user_pages(addr, nr, gup->flags, pages + i, |
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NULL); |
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break; |
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case PIN_LONGTERM_BENCHMARK: |
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nr = pin_user_pages(addr, nr, |
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gup->flags | FOLL_LONGTERM, |
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pages + i, NULL); |
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break; |
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default: |
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ret = -EINVAL; |
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goto unlock; |
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} |
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if (nr <= 0) |
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break; |
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i += nr; |
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} |
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end_time = ktime_get(); |
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/* Shifting the meaning of nr_pages: now it is actual number pinned: */ |
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nr_pages = i; |
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gup->get_delta_usec = ktime_us_delta(end_time, start_time); |
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gup->size = addr - gup->addr; |
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/* |
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* Take an un-benchmark-timed moment to verify DMA pinned |
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* state: print a warning if any non-dma-pinned pages are found: |
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*/ |
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verify_dma_pinned(cmd, pages, nr_pages); |
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start_time = ktime_get(); |
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put_back_pages(cmd, pages, nr_pages); |
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end_time = ktime_get(); |
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gup->put_delta_usec = ktime_us_delta(end_time, start_time); |
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unlock: |
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if (needs_mmap_lock) |
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mmap_read_unlock(current->mm); |
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free_pages: |
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kvfree(pages); |
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return ret; |
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} |
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static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd, |
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unsigned long arg) |
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{ |
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struct gup_benchmark gup; |
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int ret; |
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switch (cmd) { |
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case GUP_FAST_BENCHMARK: |
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case GUP_BENCHMARK: |
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case PIN_FAST_BENCHMARK: |
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case PIN_BENCHMARK: |
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case PIN_LONGTERM_BENCHMARK: |
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break; |
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default: |
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return -EINVAL; |
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} |
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if (copy_from_user(&gup, (void __user *)arg, sizeof(gup))) |
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return -EFAULT; |
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ret = __gup_benchmark_ioctl(cmd, &gup); |
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if (ret) |
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return ret; |
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if (copy_to_user((void __user *)arg, &gup, sizeof(gup))) |
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return -EFAULT; |
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return 0; |
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} |
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static const struct file_operations gup_benchmark_fops = { |
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.open = nonseekable_open, |
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.unlocked_ioctl = gup_benchmark_ioctl, |
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}; |
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static int gup_benchmark_init(void) |
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{ |
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debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL, |
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&gup_benchmark_fops); |
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return 0; |
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} |
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late_initcall(gup_benchmark_init);
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