kexec: add BSS to resource tree

Add the BSS to the resource tree just as kernel text and kernel data are in
the resource tree.  The main reason behind this is to avoid crashkernel
reservation in that area.

While it's not strictly necessary to have the BSS in the resource tree (the
actual collision detection is done in the reserve_bootmem() function before),
the usage of the BSS resource should be presented to the user in /proc/iomem
just as Kernel data and Kernel code.

Note: The patch currently is only implemented for x86 and ia64 (because
efi_initialize_iomem_resources() has the same signature on i386 and ia64).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 31322d42eaae..e7a9e36bd52d 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -58,6 +58,7 @@
 #include <asm/numa.h>
 #include <asm/sections.h>
 #include <asm/dmi.h>
+#include <asm/cacheflush.h>
 
 /*
  * Machine setup..
@@ -133,6 +134,12 @@ struct resource code_resource = {
         .end = 0,
         .flags = IORESOURCE_RAM,
 };
+struct resource bss_resource = {
+        .name = "Kernel bss",
+        .start = 0,
+        .end = 0,
+        .flags = IORESOURCE_RAM,
+};
 
 #ifdef CONFIG_PROC_VMCORE
 /* elfcorehdr= specifies the location of elf core header
@@ -276,6 +283,8 @@ void __init setup_arch(char **cmdline_p)
         code_resource.end = virt_to_phys(&_etext)-1;
         data_resource.start = virt_to_phys(&_etext);
         data_resource.end = virt_to_phys(&_edata)-1;
+        bss_resource.start = virt_to_phys(&__bss_start);
+        bss_resource.end = virt_to_phys(&__bss_stop)-1;
 
         early_identify_cpu(&boot_cpu_data);