[Xen-devel] [PATCH v2 04/16] xen/arm: p2m: Redefine mfn_to_page and page_to_mfn to use typesafe

[Julien Grall <julien.grall@xxxxxxx>]

The file xen/arch/arm/p2m.c is using typesafe MFN in most of the place.
This requires caller to mfn_to_page and page_to_mfn to use _mfn/mfn_x.

To avoid extra _mfn/mfn_x, re-define mfn_to_page and page_to_mfn within
xen/arch/arm/p2m.c to handle typesafe MFN.

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
---
    The idea behind redefining locally mfn_to_page and page_to_mfn is
    splitting the introduction of typesafe MFN in smaller series and
    between multiple people. We know the file is typesafe ready and if
    we decide to make the main helper typesafe, we would just need to
    drop the definition at the top of the file.
---
 xen/arch/arm/p2m.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 266d1c3bd6..6c1ac70044 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -38,6 +38,12 @@ static unsigned int __read_mostly max_vmid = MAX_VMID_8_BIT;
 
 #define P2M_ROOT_PAGES    (1<<P2M_ROOT_ORDER)
 
+/* Override macros from asm/mm.h to make them work with mfn_t */
+#undef mfn_to_page
+#define mfn_to_page(mfn) __mfn_to_page(mfn_x(mfn))
+#undef page_to_mfn
+#define page_to_mfn(pg) _mfn(__page_to_mfn(pg))
+
 unsigned int __read_mostly p2m_ipa_bits;
 
 /* Helpers to lookup the properties of each level */
@@ -115,7 +121,7 @@ void dump_p2m_lookup(struct domain *d, paddr_t addr)
     printk("dom%d IPA 0x%"PRIpaddr"\n", d->domain_id, addr);
 
     printk("P2M @ %p mfn:0x%lx\n",
-           p2m->root, page_to_mfn(p2m->root));
+           p2m->root, mfn_x(page_to_mfn(p2m->root)));
 
     dump_pt_walk(page_to_maddr(p2m->root), addr,
                  P2M_ROOT_LEVEL, P2M_ROOT_PAGES);
@@ -591,7 +597,7 @@ static int p2m_create_table(struct p2m_domain *p2m, lpae_t 
*entry)
      * The access value does not matter because the hardware will ignore
      * the permission fields for table entry.
      */
-    pte = mfn_to_p2m_entry(_mfn(page_to_mfn(page)), p2m_invalid,
+    pte = mfn_to_p2m_entry(page_to_mfn(page), p2m_invalid,
                            p2m->default_access);
 
     p2m_write_pte(entry, pte, p2m->clean_pte);
@@ -650,9 +656,9 @@ static void p2m_put_l3_page(const lpae_t pte)
      */
     if ( p2m_is_foreign(pte.p2m.type) )
     {
-        unsigned long mfn = pte.p2m.base;
+        mfn_t mfn = _mfn(pte.p2m.base);
 
-        ASSERT(mfn_valid(_mfn(mfn)));
+        ASSERT(mfn_valid(mfn));
         put_page(mfn_to_page(mfn));
     }
 }
@@ -702,7 +708,7 @@ static void p2m_free_entry(struct p2m_domain *p2m,
     mfn = _mfn(entry.p2m.base);
     ASSERT(mfn_valid(mfn));
 
-    pg = mfn_to_page(mfn_x(mfn));
+    pg = mfn_to_page(mfn);
 
     page_list_del(pg, &p2m->pages);
     free_domheap_page(pg);
@@ -780,7 +786,7 @@ static bool p2m_split_superpage(struct p2m_domain *p2m, 
lpae_t *entry,
 
     unmap_domain_page(table);
 
-    pte = mfn_to_p2m_entry(_mfn(page_to_mfn(page)), p2m_invalid,
+    pte = mfn_to_p2m_entry(page_to_mfn(page), p2m_invalid,
                            p2m->default_access);
 
     /*
@@ -1443,7 +1449,7 @@ struct page_info *get_page_from_gva(struct vcpu *v, 
vaddr_t va,
     if ( !mfn_valid(maddr_to_mfn(maddr)) )
         goto err;
 
-    page = mfn_to_page(mfn_x(maddr_to_mfn(maddr)));
+    page = mfn_to_page(maddr_to_mfn(maddr));
     ASSERT(page);
 
     if ( unlikely(!get_page(page, d)) )
-- 
2.11.0


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