Detach sched.h from mm.h

First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
   getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
   they don't need sched.h
b) sched.h stops being dependency for significant number of files:
   on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
   after patch it's only 3744 (-8.3%).

Cross-compile tested on

	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
	alpha alpha-up
	arm
	i386 i386-up i386-defconfig i386-allnoconfig
	ia64 ia64-up
	m68k
	mips
	parisc parisc-up
	powerpc powerpc-up
	s390 s390-up
	sparc sparc-up
	sparc64 sparc64-up
	um-x86_64
	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/arm/mach-iop13xx/pci.c

@@ -19,10 +19,11 @@
 
 #include <linux/pci.h>
 #include <linux/delay.h>
-
+#include <linux/jiffies.h>
 #include <asm/irq.h>
 #include <asm/hardware.h>
 #include <asm/sizes.h>
+#include <asm/signal.h>
 #include <asm/mach/pci.h>
 #include <asm/arch/pci.h>
 

arch/arm/mm/mmap.c

@@ -5,7 +5,7 @@
 #include <linux/mm.h>
 #include <linux/mman.h>
 #include <linux/shm.h>
-
+#include <linux/sched.h>
 #include <asm/system.h>
 
 #define COLOUR_ALIGN(addr,pgoff)		\

arch/arm/plat-iop/pci.c

@@ -19,6 +19,7 @@
 #include <linux/ioport.h>
 #include <asm/io.h>
 #include <asm/irq.h>
+#include <asm/signal.h>
 #include <asm/system.h>
 #include <asm/hardware.h>
 #include <asm/mach/pci.h>

arch/i386/kernel/cpu/cpufreq/speedstep-ich.c

@@ -24,6 +24,7 @@
 #include <linux/cpufreq.h>
 #include <linux/pci.h>
 #include <linux/slab.h>
+#include <linux/sched.h>
 
 #include "speedstep-lib.h"
 

arch/i386/kernel/cpu/cyrix.c

@@ -7,6 +7,7 @@
 #include <asm/processor.h>
 #include <asm/timer.h>
 #include <asm/pci-direct.h>
+#include <asm/tsc.h>
 
 #include "cpu.h"
 

arch/i386/mm/mmap.c

@@ -27,6 +27,7 @@
 #include <linux/personality.h>
 #include <linux/mm.h>
 #include <linux/random.h>
+#include <linux/sched.h>
 
 /*
  * Top of mmap area (just below the process stack).

arch/mips/kernel/unaligned.c

@@ -76,7 +76,7 @@
 #include <linux/module.h>
 #include <linux/signal.h>
 #include <linux/smp.h>
-
+#include <linux/sched.h>
 #include <asm/asm.h>
 #include <asm/branch.h>
 #include <asm/byteorder.h>

arch/mips/mm/ioremap.c

@@ -9,7 +9,7 @@
 #include <linux/module.h>
 #include <asm/addrspace.h>
 #include <asm/byteorder.h>
-
+#include <linux/sched.h>
 #include <linux/vmalloc.h>
 #include <asm/cacheflush.h>
 #include <asm/io.h>

arch/parisc/kernel/cache.c

@@ -18,7 +18,7 @@
 #include <linux/module.h>
 #include <linux/seq_file.h>
 #include <linux/pagemap.h>
-
+#include <linux/sched.h>
 #include <asm/pdc.h>
 #include <asm/cache.h>
 #include <asm/cacheflush.h>

arch/parisc/kernel/processor.c

@@ -33,7 +33,7 @@
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/cpu.h>
-
+#include <asm/param.h>
 #include <asm/cache.h>
 #include <asm/hardware.h>	/* for register_parisc_driver() stuff */
 #include <asm/processor.h>

arch/powerpc/mm/mmap.c

@@ -24,6 +24,7 @@
 
 #include <linux/personality.h>
 #include <linux/mm.h>
+#include <linux/sched.h>
 
 /*
  * Top of mmap area (just below the process stack).

arch/x86_64/ia32/mmap32.c

@@ -29,6 +29,7 @@
 #include <linux/personality.h>
 #include <linux/mm.h>
 #include <linux/random.h>
+#include <linux/sched.h>
 
 /*
  * Top of mmap area (just below the process stack).

arch/x86_64/kernel/reboot.c

@@ -8,6 +8,7 @@
 #include <linux/string.h>
 #include <linux/pm.h>
 #include <linux/kdebug.h>
+#include <linux/sched.h>
 #include <asm/io.h>
 #include <asm/delay.h>
 #include <asm/hw_irq.h>

drivers/base/dmapool.c

@@ -8,6 +8,7 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/poison.h>
+#include <linux/sched.h>
 
 /*
  * Pool allocator ... wraps the dma_alloc_coherent page allocator, so

drivers/char/agp/frontend.c

@@ -37,6 +37,7 @@
 #include <linux/agpgart.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
+#include <linux/sched.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 #include "agp.h"

drivers/char/agp/generic.c

@@ -37,6 +37,7 @@
 #include <linux/vmalloc.h>
 #include <linux/dma-mapping.h>
 #include <linux/mm.h>
+#include <linux/sched.h>
 #include <asm/io.h>
 #include <asm/cacheflush.h>
 #include <asm/pgtable.h>

drivers/char/hangcheck-timer.c

@@ -48,7 +48,7 @@
 #include <linux/delay.h>
 #include <asm/uaccess.h>
 #include <linux/sysrq.h>
-
+#include <linux/timer.h>
 
 #define VERSION_STR "0.9.0"
 

drivers/infiniband/core/cache.c

@@ -38,6 +38,7 @@
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
+#include <linux/workqueue.h>
 
 #include <rdma/ib_cache.h>
 

drivers/infiniband/core/device.c

@@ -40,6 +40,7 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/mutex.h>
+#include <linux/workqueue.h>
 
 #include "core_priv.h"
 

drivers/infiniband/core/umem.c

@@ -36,6 +36,7 @@
 
 #include <linux/mm.h>
 #include <linux/dma-mapping.h>
+#include <linux/sched.h>
 
 #include "uverbs.h"