[Xen-changelog] [xen staging] xen/gnttab: Simplify gnttab_map_frame()

[p***@xen.org]

commit a2f6982a147821ce3fb129a161939557613a675d
Author: Andrew Cooper <***@citrix.com>
AuthorDate: Tue Oct 23 19:49:34 2018 +0100
Commit: Andrew Cooper <***@citrix.com>
CommitDate: Thu Nov 22 17:58:46 2018 +0000

xen/gnttab: Simplify gnttab_map_frame()

* Reflow some lines to remove unnecessary line breaks.
* Factor out the gnttab_get_frame_gfn() calculation. Neither x86 nor ARM
builds seem to be able to fold the two calls, and the resulting code is far
easier to follow.

Signed-off-by: Andrew Cooper <***@citrix.com>
Reviewed-by: Julien Grall <***@arm.com>
Reviewed-by: Jan Beulich <***@suse.com>
---
xen/common/grant_table.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index 9ddfee1da9..b67ae9e3f5 100644
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -3869,8 +3869,7 @@ static int gnttab_get_shared_frame_mfn(struct domain *d,
return 0;
}

-int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn,
- mfn_t *mfn)
+int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn, mfn_t *mfn)
{
int rc = 0;
struct grant_table *gt = d->grant_table;
@@ -3878,8 +3877,7 @@ int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn,

grant_write_lock(gt);

- if ( gt->gt_version == 2 &&
- (idx & XENMAPIDX_grant_table_status) )
+ if ( gt->gt_version == 2 && (idx & XENMAPIDX_grant_table_status) )
{
idx &= ~XENMAPIDX_grant_table_status;
status = true;
@@ -3889,10 +3887,13 @@ int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn,
else
rc = gnttab_get_shared_frame_mfn(d, idx, mfn);

- if ( !rc && paging_mode_translate(d) &&
- !gfn_eq(gnttab_get_frame_gfn(gt, status, idx), INVALID_GFN) )
- rc = guest_physmap_remove_page(d, gnttab_get_frame_gfn(gt, status, idx),
- *mfn, 0);
+ if ( !rc && paging_mode_translate(d) )
+ {
+ gfn_t gfn = gnttab_get_frame_gfn(gt, status, idx);
+
+ if ( !gfn_eq(gfn, INVALID_GFN) )
+ rc = guest_physmap_remove_page(d, gfn, *mfn, 0);
+ }

if ( !rc )
gnttab_set_frame_gfn(gt, status, idx, gfn);
--
generated by git-patchbot for /home/xen/git/xen.git#staging