[PATCH] x86/setup: call early_reserve_memory() earlier

[Juergen Gross <jgross@xxxxxxxx>]

Commit a799c2bd29d19c565 ("x86/setup: Consolidate early memory
reservations") introduced early_reserve_memory() to do all needed
initial memblock_reserve() calls in one function. Unfortunately the
call of early_reserve_memory() is done too late for Xen dom0, as in
some cases a Xen hook called by e820__memory_setup() will need those
memory reservations to have happened already.

Move the call of early_reserve_memory() to the beginning of
setup_arch() in order to avoid such problems.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: a799c2bd29d19c565 ("x86/setup: Consolidate early memory reservations")
Reported-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 arch/x86/kernel/setup.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 79f164141116..f369c51ec580 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -757,6 +757,18 @@ dump_kernel_offset(struct notifier_block *self, unsigned 
long v, void *p)
 
 void __init setup_arch(char **cmdline_p)
 {
+       /*
+        * Do some memory reservations *before* memory is added to
+        * memblock, so memblock allocations won't overwrite it.
+        * Do it after early param, so we could get (unlikely) panic from
+        * serial.
+        *
+        * After this point everything still needed from the boot loader or
+        * firmware or kernel text should be early reserved or marked not
+        * RAM in e820. All other memory is free game.
+        */
+       early_reserve_memory();
+
 #ifdef CONFIG_X86_32
        memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
 
@@ -876,18 +888,6 @@ void __init setup_arch(char **cmdline_p)
 
        parse_early_param();
 
-       /*
-        * Do some memory reservations *before* memory is added to
-        * memblock, so memblock allocations won't overwrite it.
-        * Do it after early param, so we could get (unlikely) panic from
-        * serial.
-        *
-        * After this point everything still needed from the boot loader or
-        * firmware or kernel text should be early reserved or marked not
-        * RAM in e820. All other memory is free game.
-        */
-       early_reserve_memory();
-
 #ifdef CONFIG_MEMORY_HOTPLUG
        /*
         * Memory used by the kernel cannot be hot-removed because Linux
-- 
2.26.2