1 files changed, 38 insertions, 21 deletions

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index e0942630d47a..9deb6bab6c78 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -33,52 +33,69 @@ extern void xen_sysenter_target(void);
 extern void xen_syscall_target(void);
 extern void xen_syscall32_target(void);
 
-static unsigned long __init xen_release_chunk(phys_addr_t start_addr, phys_addr_t end_addr)
+static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
+                                              phys_addr_t end_addr)
 {
         struct xen_memory_reservation reservation = {
                 .address_bits = 0,
                 .extent_order = 0,
                 .domid        = DOMID_SELF
         };
-        unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list;
         unsigned long start, end;
-        unsigned long len;
+        unsigned long len = 0;
         unsigned long pfn;
         int ret;
 
         start = PFN_UP(start_addr);
-        end = PFN_UP(end_addr);
+        end = PFN_DOWN(end_addr);
 
         if (end <= start)
                 return 0;
 
-        len = end - start;
-
-        set_xen_guest_handle(reservation.extent_start, &mfn_list[start]);
-        reservation.nr_extents = len;
-
-        ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
-        WARN(ret != (end - start), "Failed to release memory %lx-%lx err=%d\n",
-             start, end, ret);
-
-        for(pfn = start; pfn < end; pfn++)
-                set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+        printk(KERN_INFO "xen_release_chunk: looking at area pfn %lx-%lx: ",
+               start, end);
+        for(pfn = start; pfn < end; pfn++) {
+                unsigned long mfn = pfn_to_mfn(pfn);
+
+                /* Make sure pfn exists to start with */
+                if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
+                        continue;
+
+                set_xen_guest_handle(reservation.extent_start, &mfn);
+                reservation.nr_extents = 1;
+
+                ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
+                                           &reservation);
+                WARN(ret != 1, "Failed to release memory %lx-%lx err=%d\n",
+                     start, end, ret);
+                if (ret == 1) {
+                        set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+                        len++;
+                }
+        }
+        printk(KERN_CONT "%ld pages freed\n", len);
 
         return len;
 }
 
-static unsigned long __init xen_return_unused_memory(const struct e820map *e820)
+static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
+                                                     const struct e820map *e820)
 {
-        unsigned long last_end = 0;
+        phys_addr_t max_addr = PFN_PHYS(max_pfn);
+        phys_addr_t last_end = 0;
         unsigned long released = 0;
         int i;
 
-        for (i = 0; i < e820->nr_map; i++) {
-                released += xen_release_chunk(last_end, e820->map[i].addr);
+        for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
+                phys_addr_t end = e820->map[i].addr;
+                end = min(max_addr, end);
+
+                released += xen_release_chunk(last_end, end);
                 last_end = e820->map[i].addr + e820->map[i].size;
         }
 
-        released += xen_release_chunk(last_end, PFN_PHYS(xen_start_info->nr_pages));
+        if (last_end < max_addr)
+                released += xen_release_chunk(last_end, max_addr);
 
         printk(KERN_INFO "released %ld pages of unused memory\n", released);
         return released;
@@ -118,7 +135,7 @@ char * __init xen_memory_setup(void)
 
         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 
-        xen_return_unused_memory(&e820);
+        xen_return_unused_memory(xen_start_info->nr_pages, &e820);
 
         return "Xen";
 }