4 files changed, 26 insertions, 35 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 02c710bebf7a..44dcad43989d 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1021,10 +1021,6 @@ static void xen_reboot(int reason)
 {
         struct sched_shutdown r = { .reason = reason };
 
-#ifdef CONFIG_SMP
-        stop_other_cpus();
-#endif
-
         if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
                 BUG();
 }
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 01afd8a94607..b5a7f928234b 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -181,24 +181,21 @@ char * __init xen_memory_setup(void)
         for (i = 0; i < memmap.nr_entries; i++) {
                 unsigned long long end = map[i].addr + map[i].size;
 
-                if (map[i].type == E820_RAM) {
-                        if (map[i].addr < mem_end && end > mem_end) {
-                                /* Truncate region to max_mem. */
-                                u64 delta = end - mem_end;
+                if (map[i].type == E820_RAM && end > mem_end) {
+                        /* RAM off the end - may be partially included */
+                        u64 delta = min(map[i].size, end - mem_end);
 
-                                map[i].size -= delta;
-                                extra_pages += PFN_DOWN(delta);
+                        map[i].size -= delta;
+                        end -= delta;
 
-                                end = mem_end;
-                        }
+                        extra_pages += PFN_DOWN(delta);
                 }
 
-                if (end > xen_extra_mem_start)
+                if (map[i].size > 0 && end > xen_extra_mem_start)
                         xen_extra_mem_start = end;
 
-                /* If region is non-RAM or below mem_end, add what remains */
-                if ((map[i].type != E820_RAM || map[i].addr < mem_end) &&
-                    map[i].size > 0)
+                /* Add region if any remains */
+                if (map[i].size > 0)
                         e820_add_region(map[i].addr, map[i].size, map[i].type);
         }
 
@@ -252,20 +249,6 @@ char * __init xen_memory_setup(void)
         return "Xen";
 }
 
-static void xen_idle(void)
-{
-        local_irq_disable();
-
-        if (need_resched())
-                local_irq_enable();
-        else {
-                current_thread_info()->status &= ~TS_POLLING;
-                smp_mb__after_clear_bit();
-                safe_halt();
-                current_thread_info()->status |= TS_POLLING;
-        }
-}
-
 /*
  * Set the bit indicating "nosegneg" library variants should be used.
  * We only need to bother in pure 32-bit mode; compat 32-bit processes
@@ -362,7 +345,11 @@ void __init xen_arch_setup(void)
                MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
                COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
 
-        pm_idle = xen_idle;
+        /* Set up idle, making sure it calls safe_halt() pvop */
+#ifdef CONFIG_X86_32
+        boot_cpu_data.hlt_works_ok = 1;
+#endif
+        pm_idle = default_idle;
 
         fiddle_vdso();
 }
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 2b17ad5b4b32..43f9f02c7db0 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -412,8 +412,16 @@ static int __init balloon_init(void)
 
         register_balloon(&balloon_sysdev);
 
-        /* Initialise the balloon with excess memory space. */
-        extra_pfn_end = min(e820_end_of_ram_pfn(),
+        /*
+         * Initialise the balloon with excess memory space.  We need
+         * to make sure we don't add memory which doesn't exist or
+         * logically exist.  The E820 map can be trimmed to be smaller
+         * than the amount of physical memory due to the mem= command
+         * line parameter.  And if this is a 32-bit non-HIGHMEM kernel
+         * on a system with memory which requires highmem to access,
+         * don't try to use it.
+         */
+        extra_pfn_end = min(min(max_pfn, e820_end_of_ram_pfn()),
                             (unsigned long)PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size));
         for (pfn = PFN_UP(xen_extra_mem_start);
              pfn < extra_pfn_end;
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 2811bb988ea0..0009e489272c 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -423,7 +423,7 @@ static int find_unbound_irq(void)
         if (irq == start)
                 goto no_irqs;
 
-        res = irq_alloc_desc_at(irq, 0);
+        res = irq_alloc_desc_at(irq, -1);
 
         if (WARN_ON(res != irq))
                 return -1;
@@ -630,7 +630,7 @@ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name)
         if (identity_mapped_irq(gsi) || (!xen_initial_domain() &&
                                 xen_pv_domain())) {
                 irq = gsi;
-                irq_alloc_desc_at(irq, 0);
+                irq_alloc_desc_at(irq, -1);
         } else
                 irq = find_unbound_irq();