[2/2] x86/mem-sharing: mov {get,put}_two_gfns()

Commit Message

Jan Beulich June 29, 2021, 12:54 p.m. UTC

There's no reason for every CU including p2m.h to have these two
functions compiled, when they're both mem-sharing specific right now and
for the foreseeable future.

Largely just code movement, with some style tweaks, the inline-s
dropped, and "put" being made consistent with "get" as to their NULL
checking of the passed in pointer to struct two_gfns.

Signed-off-by: Jan Beulich <[e-mail]>

Comments

Tamas K Lengyel July 6, 2021, 12:39 p.m. UTC | #1

On Tue, Jun 29, 2021 at 8:54 AM Jan Beulich <[e-mail]> wrote:
>
> There's no reason for every CU including p2m.h to have these two
> functions compiled, when they're both mem-sharing specific right now and
> for the foreseeable future.
>
> Largely just code movement, with some style tweaks, the inline-s
> dropped, and "put" being made consistent with "get" as to their NULL
> checking of the passed in pointer to struct two_gfns.
>
> Signed-off-by: Jan Beulich <[e-mail]>

Acked-by: Tamas K Lengyel <[e-mail]>

Patch

--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -432,6 +432,66 @@  static void mem_sharing_gfn_destroy(stru
     xfree(gfn_info);
 }
 
+/* Deadlock-avoidance scheme when calling get_gfn on different gfn's */
+struct two_gfns {
+    struct domain *first_domain, *second_domain;
+    gfn_t          first_gfn,     second_gfn;
+};
+
+/*
+ * Returns mfn, type and access for potential caller consumption, but any
+ * of those can be NULL.
+ */
+static void get_two_gfns(struct domain *rd, gfn_t rgfn, p2m_type_t *rt,
+                         p2m_access_t *ra, mfn_t *rmfn,
+                         struct domain *ld, gfn_t lgfn, p2m_type_t *lt,
+                         p2m_access_t *la, mfn_t *lmfn,
+                         p2m_query_t q, struct two_gfns *rval, bool lock)
+{
+    mfn_t        *first_mfn, *second_mfn, scratch_mfn;
+    p2m_access_t *first_a, *second_a, scratch_a;
+    p2m_type_t   *first_t, *second_t, scratch_t;
+
+    /* Sort by domain, if same domain by gfn */
+
+#define assign_pointers(dest, source)                   \
+do {                                                    \
+    rval-> dest ## _domain = source ## d;               \
+    rval-> dest ## _gfn = source ## gfn;                \
+    dest ## _mfn = (source ## mfn) ?: &scratch_mfn;     \
+    dest ## _a   = (source ## a)   ?: &scratch_a;       \
+    dest ## _t   = (source ## t)   ?: &scratch_t;       \
+} while ( false )
+
+    if ( (rd->domain_id < ld->domain_id) ||
+         ((rd == ld) && (gfn_x(rgfn) <= gfn_x(lgfn))) )
+    {
+        assign_pointers(first, r);
+        assign_pointers(second, l);
+    }
+    else
+    {
+        assign_pointers(first, l);
+        assign_pointers(second, r);
+    }
+
+#undef assign_pointers
+
+    /* Now do the gets. */
+    *first_mfn  = __get_gfn_type_access(p2m_get_hostp2m(rval->first_domain),
+                                        gfn_x(rval->first_gfn), first_t,
+                                        first_a, q, NULL, lock);
+    *second_mfn = __get_gfn_type_access(p2m_get_hostp2m(rval->second_domain),
+                                        gfn_x(rval->second_gfn), second_t,
+                                        second_a, q, NULL, lock);
+}
+
+static void put_two_gfns(const struct two_gfns *arg)
+{
+    put_gfn(arg->second_domain, gfn_x(arg->second_gfn));
+    put_gfn(arg->first_domain,  gfn_x(arg->first_gfn));
+}
+
 static struct page_info *mem_sharing_lookup(unsigned long mfn)
 {
     struct page_info *page;
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -559,62 +559,6 @@  int altp2m_get_effective_entry(struct p2
                                bool prepopulate);
 #endif
 
-/* Deadlock-avoidance scheme when calling get_gfn on different gfn's */
-struct two_gfns {
-    struct domain *first_domain, *second_domain;
-    gfn_t          first_gfn,     second_gfn;
-};
-
-/* Returns mfn, type and access for potential caller consumption, but any
- * of those can be NULL */
-static inline void get_two_gfns(struct domain *rd, gfn_t rgfn,
-        p2m_type_t *rt, p2m_access_t *ra, mfn_t *rmfn, struct domain *ld,
-        gfn_t lgfn, p2m_type_t *lt, p2m_access_t *la, mfn_t *lmfn,
-        p2m_query_t q, struct two_gfns *rval, bool lock)
-{
-    mfn_t           *first_mfn, *second_mfn, scratch_mfn;
-    p2m_access_t    *first_a, *second_a, scratch_a;
-    p2m_type_t      *first_t, *second_t, scratch_t;
-
-    /* Sort by domain, if same domain by gfn */
-
-#define assign_pointers(dest, source)                   \
-do {                                                    \
-    rval-> dest ## _domain = source ## d;               \
-    rval-> dest ## _gfn = source ## gfn;                \
-    dest ## _mfn = (source ## mfn) ?: &scratch_mfn;     \
-    dest ## _a   = (source ## a)   ?: &scratch_a;       \
-    dest ## _t   = (source ## t)   ?: &scratch_t;       \
-} while (0)
-
-    if ( (rd->domain_id < ld->domain_id) ||
-         ((rd == ld) && (gfn_x(rgfn) <= gfn_x(lgfn))) )
-    {
-        assign_pointers(first, r);
-        assign_pointers(second, l);
-    } else {
-        assign_pointers(first, l);
-        assign_pointers(second, r);
-    }
-
-#undef assign_pointers
-
-    /* Now do the gets */
-    *first_mfn  = __get_gfn_type_access(p2m_get_hostp2m(rval->first_domain),
-                                        gfn_x(rval->first_gfn), first_t, first_a, q, NULL, lock);
-    *second_mfn = __get_gfn_type_access(p2m_get_hostp2m(rval->second_domain),
-                                        gfn_x(rval->second_gfn), second_t, second_a, q, NULL, lock);
-}
-
-static inline void put_two_gfns(struct two_gfns *arg)
-{
-    if ( !arg )
-        return;
-
-    put_gfn(arg->second_domain, gfn_x(arg->second_gfn));
-    put_gfn(arg->first_domain,  gfn_x(arg->first_gfn));
-}
-
 /* Init the datastructures for later use by the p2m code */
 int p2m_init(struct domain *d);