io_uring/zcrx: separate niov number from pages

A preparation patch that separates the number of pages / folios from
the number of niovs. They will not match in the future to support huge
pages, improved dma mapping and/or larger chunk sizes.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0780ac966ee84200385737f45bb0f2ada052392b.1743848231.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index 80d4a6f71d2931223c2a932e34d38a37a1df8efe..0f46e0404c0454177a92e5313a8ed19a227d5d67 100644 (file)
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -181,7 +181,7 @@ static void io_zcrx_free_area(struct io_zcrx_area *area)
        kvfree(area->nia.niovs);
        kvfree(area->user_refs);
        if (area->pages) {
-               unpin_user_pages(area->pages, area->nia.num_niovs);
+               unpin_user_pages(area->pages, area->nr_folios);
                kvfree(area->pages);
        }
        kfree(area);
@@ -192,7 +192,7 @@ static int io_zcrx_create_area(struct io_zcrx_ifq *ifq,
                               struct io_uring_zcrx_area_reg *area_reg)
 {
        struct io_zcrx_area *area;
-       int i, ret, nr_pages;
+       int i, ret, nr_pages, nr_iovs;
        struct iovec iov;
 
        if (area_reg->flags || area_reg->rq_area_token)
@@ -220,27 +220,28 @@ static int io_zcrx_create_area(struct io_zcrx_ifq *ifq,
                area->pages = NULL;
                goto err;
        }
-       area->nia.num_niovs = nr_pages;
+       area->nr_folios = nr_iovs = nr_pages;
+       area->nia.num_niovs = nr_iovs;
 
-       area->nia.niovs = kvmalloc_array(nr_pages, sizeof(area->nia.niovs[0]),
+       area->nia.niovs = kvmalloc_array(nr_iovs, sizeof(area->nia.niovs[0]),
                                         GFP_KERNEL | __GFP_ZERO);
        if (!area->nia.niovs)
                goto err;
 
-       area->freelist = kvmalloc_array(nr_pages, sizeof(area->freelist[0]),
+       area->freelist = kvmalloc_array(nr_iovs, sizeof(area->freelist[0]),
                                        GFP_KERNEL | __GFP_ZERO);
        if (!area->freelist)
                goto err;
 
-       for (i = 0; i < nr_pages; i++)
+       for (i = 0; i < nr_iovs; i++)
                area->freelist[i] = i;
 
-       area->user_refs = kvmalloc_array(nr_pages, sizeof(area->user_refs[0]),
+       area->user_refs = kvmalloc_array(nr_iovs, sizeof(area->user_refs[0]),
                                        GFP_KERNEL | __GFP_ZERO);
        if (!area->user_refs)
                goto err;
 
-       for (i = 0; i < nr_pages; i++) {
+       for (i = 0; i < nr_iovs; i++) {
                struct net_iov *niov = &area->nia.niovs[i];
 
                niov->owner = &area->nia;
@@ -248,7 +249,7 @@ static int io_zcrx_create_area(struct io_zcrx_ifq *ifq,
                atomic_set(&area->user_refs[i], 0);
        }
 
-       area->free_count = nr_pages;
+       area->free_count = nr_iovs;
        area->ifq = ifq;
        /* we're only supporting one area per ifq for now */
        area->area_id = 0;

diff --git a/io_uring/zcrx.h b/io_uring/zcrx.h
index b59c560d5d84a6951b4d34b470c6a4b96c71c5ed..47f1c0e8c197ca7c362352c81912d0693e9f0cba 100644 (file)
--- a/io_uring/zcrx.h
+++ b/io_uring/zcrx.h
@@ -15,6 +15,7 @@ struct io_zcrx_area {
        bool                    is_mapped;
        u16                     area_id;
        struct page             **pages;
+       unsigned long           nr_folios;
 
        /* freelist */
        spinlock_t              freelist_lock ____cacheline_aligned_in_smp;