[Xen-devel] [RFC PATCH 08/19] xen/arm: Add helper function to get domain page

[vijay.kilari@xxxxxxxxx]

From: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>

Given the physical address of the page, get
the maddr to map in Xen to access domain's memory.

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>
---
 xen/arch/arm/p2m.c        |   24 ++++++++++++++++++++++++
 xen/include/asm-arm/p2m.h |    3 +++
 2 files changed, 27 insertions(+)

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 8809f5a..b19c5e9 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -1152,6 +1152,30 @@ unsigned long gmfn_to_mfn(struct domain *d, unsigned 
long gpfn)
     return p >> PAGE_SHIFT;
 }
 
+struct page_info *get_page_from_paddr(struct domain *d, paddr_t paddr,
+                                      unsigned long flags)
+{
+    struct p2m_domain *p2m = &d->arch.p2m;
+    struct page_info *page = NULL;
+
+    ASSERT(d == current->domain);
+
+    spin_lock(&p2m->lock);
+
+    if ( !mfn_valid(paddr >> PAGE_SHIFT) )
+        goto err;
+
+    page = mfn_to_page(paddr >> PAGE_SHIFT);
+    ASSERT(page);
+
+    if ( unlikely(!get_page(page, d)) )
+        page = NULL;
+
+err:
+    spin_unlock(&p2m->lock);
+    return page;
+}
+
 struct page_info *get_page_from_gva(struct domain *d, vaddr_t va,
                                     unsigned long flags)
 {
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index da36504..7947e1b 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -147,6 +147,9 @@ void guest_physmap_remove_page(struct domain *d,
 
 unsigned long gmfn_to_mfn(struct domain *d, unsigned long gpfn);
 
+struct page_info *get_page_from_paddr(struct domain *d, paddr_t paddr,
+                                      unsigned long flags);
+
 /*
  * Populate-on-demand
  */
-- 
1.7.9.5


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