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authorEric Farman <farman@linux.ibm.com>2019-06-18 22:23:48 +0200
committerCornelia Huck <cohuck@redhat.com>2019-06-21 14:12:19 +0200
commit1d897e478da3db91593d86227854802102e2fcd3 (patch)
treefca71d80651b7f6a957737e09b1ed6649d248d18 /drivers/s390/cio/vfio_ccw_drv.c
parents390/cio: Combine direct and indirect CCW paths (diff)
downloadlinux-dev-1d897e478da3db91593d86227854802102e2fcd3.tar.xz
linux-dev-1d897e478da3db91593d86227854802102e2fcd3.zip
vfio-ccw: Move guest_cp storage into common struct
Rather than allocating/freeing a piece of memory every time we try to figure out how long a CCW chain is, let's use a piece of memory allocated for each device. The io_mutex added with commit 4f76617378ee9 ("vfio-ccw: protect the I/O region") is held for the duration of the VFIO_CCW_EVENT_IO_REQ event that accesses/uses this space, so there should be no race concerns with another CPU attempting an (unexpected) SSCH for the same device. Suggested-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190618202352.39702-2-farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to '')
-rw-r--r--drivers/s390/cio/vfio_ccw_drv.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 66a66ac1f3d1..34a9a5e3fd36 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -129,6 +129,11 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
if (!private)
return -ENOMEM;
+ private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1),
+ GFP_KERNEL);
+ if (!private->cp.guest_cp)
+ goto out_free;
+
private->io_region = kmem_cache_zalloc(vfio_ccw_io_region,
GFP_KERNEL | GFP_DMA);
if (!private->io_region)
@@ -169,6 +174,7 @@ out_free:
kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
if (private->io_region)
kmem_cache_free(vfio_ccw_io_region, private->io_region);
+ kfree(private->cp.guest_cp);
kfree(private);
return ret;
}
@@ -185,6 +191,7 @@ static int vfio_ccw_sch_remove(struct subchannel *sch)
kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
kmem_cache_free(vfio_ccw_io_region, private->io_region);
+ kfree(private->cp.guest_cp);
kfree(private);
return 0;