mm, vmalloc: move get_vmalloc_info() to vmalloc.c

Now get_vmalloc_info() is in fs/proc/mmu.c.  There is no reason that this
code must be here and it's implementation needs vmlist_lock and it iterate
a vmlist which may be internal data structure for vmalloc.

It is preferable that vmlist_lock and vmlist is only used in vmalloc.c
for maintainability. So move the code to vmalloc.c

Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Dave Anderson <anderson@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/Makefile

@@ -5,7 +5,7 @@
 obj-y   += proc.o
 
 proc-y			:= nommu.o task_nommu.o
-proc-$(CONFIG_MMU)	:= mmu.o task_mmu.o
+proc-$(CONFIG_MMU)	:= task_mmu.o
 
 proc-y       += inode.o root.o base.o generic.o array.o \
 		fd.o

fs/proc/internal.h

@@ -30,24 +30,6 @@ extern int proc_net_init(void);
 static inline int proc_net_init(void) { return 0; }
 #endif
 
-struct vmalloc_info {
-	unsigned long	used;
-	unsigned long	largest_chunk;
-};
-
-#ifdef CONFIG_MMU
-#define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START)
-extern void get_vmalloc_info(struct vmalloc_info *vmi);
-#else
-
-#define VMALLOC_TOTAL 0UL
-#define get_vmalloc_info(vmi)			\
-do {						\
-	(vmi)->used = 0;			\
-	(vmi)->largest_chunk = 0;		\
-} while(0)
-#endif
-
 extern int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
 				struct pid *pid, struct task_struct *task);
 extern int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,

fs/proc/meminfo.c

@@ -11,6 +11,7 @@
 #include <linux/swap.h>
 #include <linux/vmstat.h>
 #include <linux/atomic.h>
+#include <linux/vmalloc.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include "internal.h"

include/linux/vmalloc.h

@@ -158,4 +158,22 @@ pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
 # endif
 #endif
 
+struct vmalloc_info {
+	unsigned long   used;
+	unsigned long   largest_chunk;
+};
+
+#ifdef CONFIG_MMU
+#define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START)
+extern void get_vmalloc_info(struct vmalloc_info *vmi);
+#else
+
+#define VMALLOC_TOTAL 0UL
+#define get_vmalloc_info(vmi)			\
+do {						\
+	(vmi)->used = 0;			\
+	(vmi)->largest_chunk = 0;		\
+} while (0)
+#endif
+
 #endif /* _LINUX_VMALLOC_H */

mm/vmalloc.c

@@ -2645,5 +2645,49 @@ static int __init proc_vmalloc_init(void)
 	return 0;
 }
 module_init(proc_vmalloc_init);
+
+void get_vmalloc_info(struct vmalloc_info *vmi)
+{
+	struct vm_struct *vma;
+	unsigned long free_area_size;
+	unsigned long prev_end;
+
+	vmi->used = 0;
+
+	if (!vmlist) {
+		vmi->largest_chunk = VMALLOC_TOTAL;
+	} else {
+		vmi->largest_chunk = 0;
+
+		prev_end = VMALLOC_START;
+
+		read_lock(&vmlist_lock);
+
+		for (vma = vmlist; vma; vma = vma->next) {
+			unsigned long addr = (unsigned long) vma->addr;
+
+			/*
+			 * Some archs keep another range for modules in vmlist
+			 */
+			if (addr < VMALLOC_START)
+				continue;
+			if (addr >= VMALLOC_END)
+				break;
+
+			vmi->used += vma->size;
+
+			free_area_size = addr - prev_end;
+			if (vmi->largest_chunk < free_area_size)
+				vmi->largest_chunk = free_area_size;
+
+			prev_end = vma->size + addr;
+		}
+
+		if (VMALLOC_END - prev_end > vmi->largest_chunk)
+			vmi->largest_chunk = VMALLOC_END - prev_end;
+
+		read_unlock(&vmlist_lock);
+	}
+}
 #endif