infiniband: Fix alignment of mmap cookies to support VIPT caching

When vmalloc_user is used to create memory that is supposed to be mmap'd
to user space, it is necessary for the mmap cookie (eg the offset) to be
aligned to SHMLBA.

This creates a situation where all virtual mappings of the same physical
page share the same virtual cache index and guarantees VIPT coherence.
Otherwise the cache is non-coherent and the kernel will not see writes
by userspace when reading the shared page (or vice-versa).

Reported-by: Josh Beavers <josh.beavers@gmail.com>
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/sw/rdmavt/mmap.c b/drivers/infiniband/sw/rdmavt/mmap.c
index e202b8142759f58e0c06317ce1e4f3d798c54f37..6b712eecbd37d9ca5a0bf312028dc7b23c1c2fd8 100644 (file)
--- a/drivers/infiniband/sw/rdmavt/mmap.c
+++ b/drivers/infiniband/sw/rdmavt/mmap.c
@@ -170,9 +170,9 @@ struct rvt_mmap_info *rvt_create_mmap_info(struct rvt_dev_info *rdi,
 
        spin_lock_irq(&rdi->mmap_offset_lock);
        if (rdi->mmap_offset == 0)
-               rdi->mmap_offset = PAGE_SIZE;
+               rdi->mmap_offset = ALIGN(PAGE_SIZE, SHMLBA);
        ip->offset = rdi->mmap_offset;
-       rdi->mmap_offset += size;
+       rdi->mmap_offset += ALIGN(size, SHMLBA);
        spin_unlock_irq(&rdi->mmap_offset_lock);
 
        INIT_LIST_HEAD(&ip->pending_mmaps);

diff --git a/drivers/infiniband/sw/rxe/rxe_mmap.c b/drivers/infiniband/sw/rxe/rxe_mmap.c
index c572a4c09359c9f91fcf7f55466fadff012fbc82..bd812e00988ed32f5517ce952a0e2186c4678f87 100644 (file)
--- a/drivers/infiniband/sw/rxe/rxe_mmap.c
+++ b/drivers/infiniband/sw/rxe/rxe_mmap.c
@@ -156,10 +156,10 @@ struct rxe_mmap_info *rxe_create_mmap_info(struct rxe_dev *rxe,
        spin_lock_bh(&rxe->mmap_offset_lock);
 
        if (rxe->mmap_offset == 0)
-               rxe->mmap_offset = PAGE_SIZE;
+               rxe->mmap_offset = ALIGN(PAGE_SIZE, SHMLBA);
 
        ip->info.offset = rxe->mmap_offset;
-       rxe->mmap_offset += size;
+       rxe->mmap_offset += ALIGN(size, SHMLBA);
 
        spin_unlock_bh(&rxe->mmap_offset_lock);