#include <linux/vmalloc.h>
#include <linux/hugetlb.h>
#include <linux/interval_tree.h>
+#include <linux/hmm.h>
#include <linux/pagemap.h>
#include <rdma/ib_verbs.h>
size_t page_size = 1UL << umem_odp->page_shift;
unsigned long start;
unsigned long end;
- size_t pages;
+ size_t ndmas, npfns;
start = ALIGN_DOWN(umem_odp->umem.address, page_size);
if (check_add_overflow(umem_odp->umem.address,
if (unlikely(end < page_size))
return -EOVERFLOW;
- pages = (end - start) >> umem_odp->page_shift;
- if (!pages)
+ ndmas = (end - start) >> umem_odp->page_shift;
+ if (!ndmas)
return -EINVAL;
- umem_odp->page_list = kvcalloc(
- pages, sizeof(*umem_odp->page_list), GFP_KERNEL);
- if (!umem_odp->page_list)
+ npfns = (end - start) >> PAGE_SHIFT;
+ umem_odp->pfn_list = kvcalloc(
+ npfns, sizeof(*umem_odp->pfn_list), GFP_KERNEL);
+ if (!umem_odp->pfn_list)
return -ENOMEM;
umem_odp->dma_list = kvcalloc(
- pages, sizeof(*umem_odp->dma_list), GFP_KERNEL);
+ ndmas, sizeof(*umem_odp->dma_list), GFP_KERNEL);
if (!umem_odp->dma_list) {
ret = -ENOMEM;
- goto out_page_list;
+ goto out_pfn_list;
}
ret = mmu_interval_notifier_insert(&umem_odp->notifier,
out_dma_list:
kvfree(umem_odp->dma_list);
-out_page_list:
- kvfree(umem_odp->page_list);
+out_pfn_list:
+ kvfree(umem_odp->pfn_list);
return ret;
}
mutex_unlock(&umem_odp->umem_mutex);
mmu_interval_notifier_remove(&umem_odp->notifier);
kvfree(umem_odp->dma_list);
- kvfree(umem_odp->page_list);
+ kvfree(umem_odp->pfn_list);
}
put_pid(umem_odp->tgid);
kfree(umem_odp);
* Map for DMA and insert a single page into the on-demand paging page tables.
*
* @umem: the umem to insert the page to.
- * @page_index: index in the umem to add the page to.
+ * @dma_index: index in the umem to add the dma to.
* @page: the page struct to map and add.
* @access_mask: access permissions needed for this page.
- * @current_seq: sequence number for synchronization with invalidations.
- * the sequence number is taken from
- * umem_odp->notifiers_seq.
*
- * The function returns -EFAULT if the DMA mapping operation fails. It returns
- * -EAGAIN if a concurrent invalidation prevents us from updating the page.
+ * The function returns -EFAULT if the DMA mapping operation fails.
*
- * The page is released via put_page even if the operation failed. For on-demand
- * pinning, the page is released whenever it isn't stored in the umem.
*/
static int ib_umem_odp_map_dma_single_page(
struct ib_umem_odp *umem_odp,
- unsigned int page_index,
+ unsigned int dma_index,
struct page *page,
- u64 access_mask,
- unsigned long current_seq)
+ u64 access_mask)
{
struct ib_device *dev = umem_odp->umem.ibdev;
- dma_addr_t dma_addr;
- int ret = 0;
+ dma_addr_t *dma_addr = &umem_odp->dma_list[dma_index];
- if (mmu_interval_check_retry(&umem_odp->notifier, current_seq)) {
- ret = -EAGAIN;
- goto out;
- }
- if (!(umem_odp->dma_list[page_index])) {
- dma_addr =
- ib_dma_map_page(dev, page, 0, BIT(umem_odp->page_shift),
- DMA_BIDIRECTIONAL);
- if (ib_dma_mapping_error(dev, dma_addr)) {
- ret = -EFAULT;
- goto out;
- }
- umem_odp->dma_list[page_index] = dma_addr | access_mask;
- umem_odp->page_list[page_index] = page;
- umem_odp->npages++;
- } else if (umem_odp->page_list[page_index] == page) {
- umem_odp->dma_list[page_index] |= access_mask;
- } else {
+ if (*dma_addr) {
/*
- * This is a race here where we could have done:
- *
- * CPU0 CPU1
- * get_user_pages()
- * invalidate()
- * page_fault()
- * mutex_lock(umem_mutex)
- * page from GUP != page in ODP
- *
- * It should be prevented by the retry test above as reading
- * the seq number should be reliable under the
- * umem_mutex. Thus something is really not working right if
- * things get here.
+ * If the page is already dma mapped it means it went through
+ * a non-invalidating trasition, like read-only to writable.
+ * Resync the flags.
*/
- WARN(true,
- "Got different pages in IB device and from get_user_pages. IB device page: %p, gup page: %p\n",
- umem_odp->page_list[page_index], page);
- ret = -EAGAIN;
+ *dma_addr = (*dma_addr & ODP_DMA_ADDR_MASK) | access_mask;
+ return 0;
}
-out:
- put_page(page);
- return ret;
+ *dma_addr = ib_dma_map_page(dev, page, 0, 1 << umem_odp->page_shift,
+ DMA_BIDIRECTIONAL);
+ if (ib_dma_mapping_error(dev, *dma_addr)) {
+ *dma_addr = 0;
+ return -EFAULT;
+ }
+ umem_odp->npages++;
+ *dma_addr |= access_mask;
+ return 0;
}
/**
- * ib_umem_odp_map_dma_pages - Pin and DMA map userspace memory in an ODP MR.
+ * ib_umem_odp_map_dma_and_lock - DMA map userspace memory in an ODP MR and lock it.
*
- * Pins the range of pages passed in the argument, and maps them to
- * DMA addresses. The DMA addresses of the mapped pages is updated in
- * umem_odp->dma_list.
+ * Maps the range passed in the argument to DMA addresses.
+ * The DMA addresses of the mapped pages is updated in umem_odp->dma_list.
+ * Upon success the ODP MR will be locked to let caller complete its device
+ * page table update.
*
* Returns the number of pages mapped in success, negative error code
* for failure.
- * An -EAGAIN error code is returned when a concurrent mmu notifier prevents
- * the function from completing its task.
- * An -ENOENT error code indicates that userspace process is being terminated
- * and mm was already destroyed.
* @umem_odp: the umem to map and pin
* @user_virt: the address from which we need to map.
* @bcnt: the minimal number of bytes to pin and map. The mapping might be
* the return value.
* @access_mask: bit mask of the requested access permissions for the given
* range.
- * @current_seq: the MMU notifiers sequance value for synchronization with
- * invalidations. the sequance number is read from
- * umem_odp->notifiers_seq before calling this function
+ * @fault: is faulting required for the given range
*/
-int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt,
- u64 bcnt, u64 access_mask,
- unsigned long current_seq)
+int ib_umem_odp_map_dma_and_lock(struct ib_umem_odp *umem_odp, u64 user_virt,
+ u64 bcnt, u64 access_mask, bool fault)
+ __acquires(&umem_odp->umem_mutex)
{
struct task_struct *owning_process = NULL;
struct mm_struct *owning_mm = umem_odp->umem.owning_mm;
- struct page **local_page_list = NULL;
- u64 page_mask, off;
- int j, k, ret = 0, start_idx, npages = 0;
- unsigned int flags = 0, page_shift;
- phys_addr_t p = 0;
+ int pfn_index, dma_index, ret = 0, start_idx;
+ unsigned int page_shift, hmm_order, pfn_start_idx;
+ unsigned long num_pfns, current_seq;
+ struct hmm_range range = {};
+ unsigned long timeout;
if (access_mask == 0)
return -EINVAL;
user_virt + bcnt > ib_umem_end(umem_odp))
return -EFAULT;
- local_page_list = (struct page **)__get_free_page(GFP_KERNEL);
- if (!local_page_list)
- return -ENOMEM;
-
page_shift = umem_odp->page_shift;
- page_mask = ~(BIT(page_shift) - 1);
- off = user_virt & (~page_mask);
- user_virt = user_virt & page_mask;
- bcnt += off; /* Charge for the first page offset as well. */
/*
* owning_process is allowed to be NULL, this means somehow the mm is
goto out_put_task;
}
- if (access_mask & ODP_WRITE_ALLOWED_BIT)
- flags |= FOLL_WRITE;
+ range.notifier = &umem_odp->notifier;
+ range.start = ALIGN_DOWN(user_virt, 1UL << page_shift);
+ range.end = ALIGN(user_virt + bcnt, 1UL << page_shift);
+ pfn_start_idx = (range.start - ib_umem_start(umem_odp)) >> PAGE_SHIFT;
+ num_pfns = (range.end - range.start) >> PAGE_SHIFT;
+ if (fault) {
+ range.default_flags = HMM_PFN_REQ_FAULT;
- start_idx = (user_virt - ib_umem_start(umem_odp)) >> page_shift;
- k = start_idx;
+ if (access_mask & ODP_WRITE_ALLOWED_BIT)
+ range.default_flags |= HMM_PFN_REQ_WRITE;
+ }
- while (bcnt > 0) {
- const size_t gup_num_pages = min_t(size_t,
- ALIGN(bcnt, PAGE_SIZE) / PAGE_SIZE,
- PAGE_SIZE / sizeof(struct page *));
+ range.hmm_pfns = &(umem_odp->pfn_list[pfn_start_idx]);
+ timeout = jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
- mmap_read_lock(owning_mm);
- /*
- * Note: this might result in redundent page getting. We can
- * avoid this by checking dma_list to be 0 before calling
- * get_user_pages. However, this make the code much more
- * complex (and doesn't gain us much performance in most use
- * cases).
- */
- npages = get_user_pages_remote(owning_mm,
- user_virt, gup_num_pages,
- flags, local_page_list, NULL, NULL);
- mmap_read_unlock(owning_mm);
-
- if (npages < 0) {
- if (npages != -EAGAIN)
- pr_warn("fail to get %zu user pages with error %d\n", gup_num_pages, npages);
- else
- pr_debug("fail to get %zu user pages with error %d\n", gup_num_pages, npages);
- break;
- }
+retry:
+ current_seq = range.notifier_seq =
+ mmu_interval_read_begin(&umem_odp->notifier);
- bcnt -= min_t(size_t, npages << PAGE_SHIFT, bcnt);
- mutex_lock(&umem_odp->umem_mutex);
- for (j = 0; j < npages; j++, user_virt += PAGE_SIZE) {
- if (user_virt & ~page_mask) {
- p += PAGE_SIZE;
- if (page_to_phys(local_page_list[j]) != p) {
- ret = -EFAULT;
- break;
- }
- put_page(local_page_list[j]);
- continue;
- }
+ mmap_read_lock(owning_mm);
+ ret = hmm_range_fault(&range);
+ mmap_read_unlock(owning_mm);
+ if (unlikely(ret)) {
+ if (ret == -EBUSY && !time_after(jiffies, timeout))
+ goto retry;
+ goto out_put_mm;
+ }
- ret = ib_umem_odp_map_dma_single_page(
- umem_odp, k, local_page_list[j],
- access_mask, current_seq);
- if (ret < 0) {
- if (ret != -EAGAIN)
- pr_warn("ib_umem_odp_map_dma_single_page failed with error %d\n", ret);
- else
- pr_debug("ib_umem_odp_map_dma_single_page failed with error %d\n", ret);
- break;
- }
+ start_idx = (range.start - ib_umem_start(umem_odp)) >> page_shift;
+ dma_index = start_idx;
- p = page_to_phys(local_page_list[j]);
- k++;
- }
+ mutex_lock(&umem_odp->umem_mutex);
+ if (mmu_interval_read_retry(&umem_odp->notifier, current_seq)) {
mutex_unlock(&umem_odp->umem_mutex);
+ goto retry;
+ }
- if (ret < 0) {
+ for (pfn_index = 0; pfn_index < num_pfns;
+ pfn_index += 1 << (page_shift - PAGE_SHIFT), dma_index++) {
+
+ if (fault) {
/*
- * Release pages, remembering that the first page
- * to hit an error was already released by
- * ib_umem_odp_map_dma_single_page().
+ * Since we asked for hmm_range_fault() to populate
+ * pages it shouldn't return an error entry on success.
*/
- if (npages - (j + 1) > 0)
- release_pages(&local_page_list[j+1],
- npages - (j + 1));
+ WARN_ON(range.hmm_pfns[pfn_index] & HMM_PFN_ERROR);
+ WARN_ON(!(range.hmm_pfns[pfn_index] & HMM_PFN_VALID));
+ } else {
+ if (!(range.hmm_pfns[pfn_index] & HMM_PFN_VALID)) {
+ WARN_ON(umem_odp->dma_list[dma_index]);
+ continue;
+ }
+ access_mask = ODP_READ_ALLOWED_BIT;
+ if (range.hmm_pfns[pfn_index] & HMM_PFN_WRITE)
+ access_mask |= ODP_WRITE_ALLOWED_BIT;
+ }
+
+ hmm_order = hmm_pfn_to_map_order(range.hmm_pfns[pfn_index]);
+ /* If a hugepage was detected and ODP wasn't set for, the umem
+ * page_shift will be used, the opposite case is an error.
+ */
+ if (hmm_order + PAGE_SHIFT < page_shift) {
+ ret = -EINVAL;
+ ibdev_dbg(umem_odp->umem.ibdev,
+ "%s: un-expected hmm_order %u, page_shift %u\n",
+ __func__, hmm_order, page_shift);
break;
}
- }
- if (ret >= 0) {
- if (npages < 0 && k == start_idx)
- ret = npages;
- else
- ret = k - start_idx;
+ ret = ib_umem_odp_map_dma_single_page(
+ umem_odp, dma_index, hmm_pfn_to_page(range.hmm_pfns[pfn_index]),
+ access_mask);
+ if (ret < 0) {
+ ibdev_dbg(umem_odp->umem.ibdev,
+ "ib_umem_odp_map_dma_single_page failed with error %d\n", ret);
+ break;
+ }
}
+ /* upon sucesss lock should stay on hold for the callee */
+ if (!ret)
+ ret = dma_index - start_idx;
+ else
+ mutex_unlock(&umem_odp->umem_mutex);
+out_put_mm:
mmput(owning_mm);
out_put_task:
if (owning_process)
put_task_struct(owning_process);
- free_page((unsigned long)local_page_list);
return ret;
}
-EXPORT_SYMBOL(ib_umem_odp_map_dma_pages);
+EXPORT_SYMBOL(ib_umem_odp_map_dma_and_lock);
void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 virt,
u64 bound)
{
+ dma_addr_t dma_addr;
+ dma_addr_t dma;
int idx;
u64 addr;
struct ib_device *dev = umem_odp->umem.ibdev;
virt = max_t(u64, virt, ib_umem_start(umem_odp));
bound = min_t(u64, bound, ib_umem_end(umem_odp));
- /* Note that during the run of this function, the
- * notifiers_count of the MR is > 0, preventing any racing
- * faults from completion. We might be racing with other
- * invalidations, so we must make sure we free each page only
- * once. */
for (addr = virt; addr < bound; addr += BIT(umem_odp->page_shift)) {
idx = (addr - ib_umem_start(umem_odp)) >> umem_odp->page_shift;
- if (umem_odp->page_list[idx]) {
- struct page *page = umem_odp->page_list[idx];
- dma_addr_t dma = umem_odp->dma_list[idx];
- dma_addr_t dma_addr = dma & ODP_DMA_ADDR_MASK;
+ dma = umem_odp->dma_list[idx];
- WARN_ON(!dma_addr);
+ /* The access flags guaranteed a valid DMA address in case was NULL */
+ if (dma) {
+ unsigned long pfn_idx = (addr - ib_umem_start(umem_odp)) >> PAGE_SHIFT;
+ struct page *page = hmm_pfn_to_page(umem_odp->pfn_list[pfn_idx]);
+ dma_addr = dma & ODP_DMA_ADDR_MASK;
ib_dma_unmap_page(dev, dma_addr,
BIT(umem_odp->page_shift),
DMA_BIDIRECTIONAL);
*/
set_page_dirty(head_page);
}
- umem_odp->page_list[idx] = NULL;
umem_odp->dma_list[idx] = 0;
umem_odp->npages--;
}
projects / linux-2.6-microblaze.git / blobdiff