IB/umem: Add hugetlb flag to struct ib_umem

During ib_umem_get(), determine whether all pages from the memory
region are hugetlb pages and report this in the "hugetlb" member.
Low-level drivers can use this information if they need it.

Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 19 insertions, 1 deletions

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 664d2faa9e74..2f54e29dc7a6 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -37,6 +37,7 @@
 #include <linux/mm.h>
 #include <linux/dma-mapping.h>
 #include <linux/sched.h>
+#include <linux/hugetlb.h>
 
 #include "uverbs.h"
 
@@ -75,6 +76,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
 {
         struct ib_umem *umem;
         struct page **page_list;
+        struct vm_area_struct **vma_list;
         struct ib_umem_chunk *chunk;
         unsigned long locked;
         unsigned long lock_limit;
@@ -104,6 +106,9 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
          */
         umem->writable  = !!(access & ~IB_ACCESS_REMOTE_READ);
 
+        /* We assume the memory is from hugetlb until proved otherwise */
+        umem->hugetlb   = 1;
+
         INIT_LIST_HEAD(&umem->chunk_list);
 
         page_list = (struct page **) __get_free_page(GFP_KERNEL);
@@ -112,6 +117,14 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
                 return ERR_PTR(-ENOMEM);
         }
 
+        /*
+         * if we can't alloc the vma_list, it's not so bad;
+         * just assume the memory is not hugetlb memory
+         */
+        vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL);
+        if (!vma_list)
+                umem->hugetlb = 0;
+
         npages = PAGE_ALIGN(size + umem->offset) >> PAGE_SHIFT;
 
         down_write(&current->mm->mmap_sem);
@@ -131,7 +144,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
                 ret = get_user_pages(current, current->mm, cur_base,
                                      min_t(int, npages,
                                            PAGE_SIZE / sizeof (struct page *)),
-                                     1, !umem->writable, page_list, NULL);
+                                     1, !umem->writable, page_list, vma_list);
 
                 if (ret < 0)
                         goto out;
@@ -152,6 +165,9 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
 
                         chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
                         for (i = 0; i < chunk->nents; ++i) {
+                                if (vma_list &&
+                                    !is_vm_hugetlb_page(vma_list[i + off]))
+                                        umem->hugetlb = 0;
                                 chunk->page_list[i].page   = page_list[i + off];
                                 chunk->page_list[i].offset = 0;
                                 chunk->page_list[i].length = PAGE_SIZE;
@@ -186,6 +202,8 @@ out:
                 current->mm->locked_vm = locked;
 
         up_write(&current->mm->mmap_sem);
+        if (vma_list)
+                free_page((unsigned long) vma_list);
         free_page((unsigned long) page_list);
 
         return ret < 0 ? ERR_PTR(ret) : umem;