[Xen-devel] [v2 12/16] xen/arm: p2m: Introduce p2m_tlb_flush_sync, export it and use it

[Julien Grall <julien.grall@xxxxxxxxxx>]

Multiple places in the code requires to flush the TLBs only when
p2m->need_flush is set.

Rather than open-coding it, introduce a new helper p2m_tlb_flush_sync to
do it.

Note that p2m_tlb_flush_sync is exported as it might be used by other
part of Xen.

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>

---
    Changes in v2:
        - Add Stefano's reviewed-by
        - Fix typo in the commit message
---
 xen/arch/arm/p2m.c        | 27 +++++++++++++--------------
 xen/include/asm-arm/p2m.h |  2 ++
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 95090874c3..15711a4c80 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -51,21 +51,15 @@ static const paddr_t level_masks[] =
 static const uint8_t level_orders[] =
     { ZEROETH_ORDER, FIRST_ORDER, SECOND_ORDER, THIRD_ORDER };
 
-static void p2m_tlb_flush(struct p2m_domain *p2m);
-
 /* Unlock the flush and do a P2M TLB flush if necessary */
 void p2m_write_unlock(struct p2m_domain *p2m)
 {
-    if ( p2m->need_flush )
-    {
-        p2m->need_flush = false;
-        /*
-         * The final flush is done with the P2M write lock taken to
-         * to avoid someone else modify the P2M before the TLB
-         * invalidation has completed.
-         */
-        p2m_tlb_flush(p2m);
-    }
+    /*
+     * The final flush is done with the P2M write lock taken to avoid
+     * someone else modifying the P2M wbefore the TLB invalidation has
+     * completed.
+     */
+    p2m_tlb_flush_sync(p2m);
 
     write_unlock(&p2m->lock);
 }
@@ -177,6 +171,12 @@ static void p2m_force_tlb_flush_sync(struct p2m_domain 
*p2m)
     p2m->need_flush = false;
 }
 
+void p2m_tlb_flush_sync(struct p2m_domain *p2m)
+{
+    if ( p2m->need_flush )
+        p2m_force_tlb_flush_sync(p2m);
+}
+
 /*
  * Find and map the root page table. The caller is responsible for
  * unmapping the table.
@@ -673,8 +673,7 @@ static void p2m_free_entry(struct p2m_domain *p2m,
      * XXX: Should we defer the free of the page table to avoid the
      * flush?
      */
-    if ( p2m->need_flush )
-        p2m_force_tlb_flush_sync(p2m);
+    p2m_tlb_flush_sync(p2m);
 
     mfn = _mfn(entry.p2m.base);
     ASSERT(mfn_valid(mfn));
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index faadcfe8fe..a0abc84ed8 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -204,6 +204,8 @@ static inline int p2m_is_write_locked(struct p2m_domain 
*p2m)
     return rw_is_write_locked(&p2m->lock);
 }
 
+void p2m_tlb_flush_sync(struct p2m_domain *p2m);
+
 /* Look up the MFN corresponding to a domain's GFN. */
 mfn_t p2m_lookup(struct domain *d, gfn_t gfn, p2m_type_t *t);
 
-- 
2.11.0


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel