From cb8864559631754ac93d5734b165ccd0cad4728c Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Date: Fri, 10 Mar 2017 11:34:20 -0700 Subject: [PATCH] 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> --- drivers/infiniband/sw/rdmavt/mmap.c | 4 ++-- drivers/infiniband/sw/rxe/rxe_mmap.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/infiniband/sw/rdmavt/mmap.c b/drivers/infiniband/sw/rdmavt/mmap.c index e202b8142759f..6b712eecbd37d 100644 --- 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 c572a4c09359c..bd812e00988ed 100644 --- 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); -- GitLab