kdump: arrange for paddr_vmcoreinfo_note() to return phys_addr_t

On PAE systems (eg, ARM LPAE) the vmcore note may be located above 4GB
physical on 32-bit architectures, so we need a wider type than "unsigned
long" here.  Arrange for paddr_vmcoreinfo_note() to return a
phys_addr_t, thereby allowing it to be located above 4GB.

This makes no difference for kexec-tools, as they already assume a
64-bit type when reading from this file.

Link: http://lkml.kernel.org/r/E1b8koK-0004HS-K9@rmk-PC.armlinux.org.uk
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: Pratyush Anand <panand@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Vitaly Andrianov <vitalya@ti.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Simon Horman <horms@verge.net.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/ia64/kernel/machine_kexec.c

@@ -163,7 +163,7 @@ void arch_crash_save_vmcoreinfo(void)
 #endif
 }
 
-unsigned long paddr_vmcoreinfo_note(void)
+phys_addr_t paddr_vmcoreinfo_note(void)
 {
 	return ia64_tpa((unsigned long)(char *)&vmcoreinfo_note);
 }

include/linux/kexec.h

@@ -233,7 +233,7 @@ void crash_save_vmcoreinfo(void);
 void arch_crash_save_vmcoreinfo(void);
 __printf(1, 2)
 void vmcoreinfo_append_str(const char *fmt, ...);
-unsigned long paddr_vmcoreinfo_note(void);
+phys_addr_t paddr_vmcoreinfo_note(void);
 
 #define VMCOREINFO_OSRELEASE(value) \
 	vmcoreinfo_append_str("OSRELEASE=%s\n", value)

kernel/kexec_core.c

@@ -1372,7 +1372,7 @@ void vmcoreinfo_append_str(const char *fmt, ...)
 void __weak arch_crash_save_vmcoreinfo(void)
 {}
 
-unsigned long __weak paddr_vmcoreinfo_note(void)
+phys_addr_t __weak paddr_vmcoreinfo_note(void)
 {
 	return __pa((unsigned long)(char *)&vmcoreinfo_note);
 }

kernel/ksysfs.c

@@ -128,8 +128,8 @@ KERNEL_ATTR_RW(kexec_crash_size);
 static ssize_t vmcoreinfo_show(struct kobject *kobj,
 			       struct kobj_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%lx %x\n",
-		       paddr_vmcoreinfo_note(),
+	phys_addr_t vmcore_base = paddr_vmcoreinfo_note();
+	return sprintf(buf, "%pa %x\n", &vmcore_base,
 		       (unsigned int)sizeof(vmcoreinfo_note));
 }
 KERNEL_ATTR_RO(vmcoreinfo);