uml: header untangling

Untangle UML headers somewhat and add some includes where they were
needed explicitly, but gotten accidentally via some other header.

arch/um/include/um_uaccess.h loses asm/fixmap.h because it uses no
fixmap stuff and gains elf.h, because it needs FIXADDR_USER_*, and
archsetjmp.h, because it needs jmp_buf.

pmd_alloc_one is uninlined because it needs mm_struct, and that's
inconvenient to provide in asm-um/pgtable-3level.h.

elf_core_copy_fpregs is also uninlined from elf-i386.h and
elf-x86_64.h, which duplicated the code anyway, to
arch/um/kernel/process.c, so that the reference to current_thread
doesn't pull sched.h or anything related into asm/elf.h.

arch/um/sys-i386/ldt.c, arch/um/kernel/tlb.c and
arch/um/kernel/skas/uaccess.c got sched.h because they dereference
task_structs.  Its includes of linux and asm headers got turned from
"" to <>.

arch/um/sys-i386/bug.c gets asm/errno.h because it needs errno
constants.

asm/elf-i386 gets asm/user.h because it needs user_regs_struct.

asm/fixmap.h gets page.h because it needs PAGE_SIZE and PAGE_MASK and
system.h for BUG_ON.

asm/pgtable doesn't need sched.h.

asm/processor-generic.h defined mm_segment_t, but didn't use it.  So,
that definition is moved to uaccess.h, which defines a bunch of
mm_segment_t-related stuff.  thread_info.h uses mm_segment_t, and
includes uaccess.h, which causes a recursion.  So, the definition is
placed above the include of thread_info. in uaccess.h.  thread_info.h
also gets page.h because it needs PAGE_SIZE.

ObCheckpatchViolationJustification - I'm not adding a typedef; I'm
moving mm_segment_t from one place to another.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/um/kernel/mem.c

@@ -152,7 +152,7 @@ pgprot_t kmap_prot;
 
 #define kmap_get_fixmap_pte(vaddr)					\
 	pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
- 			  (vaddr)), (vaddr))
+				     (vaddr)), (vaddr))
 
 static void __init kmap_init(void)
 {
@@ -278,7 +278,8 @@ struct page *arch_validate(struct page *page, gfp_t mask, int order)
 	goto again;
 }
 
-/* This can't do anything because nothing in the kernel image can be freed
+/*
+ * This can't do anything because nothing in the kernel image can be freed
  * since it's not in kernel physical memory.
  */
 
@@ -331,9 +332,7 @@ void show_mem(void)
 	printk("%d pages swap cached\n", cached);
 }
 
-/*
- * Allocate and free page tables.
- */
+/* Allocate and free page tables. */
 
 pgd_t *pgd_alloc(struct mm_struct *mm)
 {
@@ -368,3 +367,15 @@ struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
 	pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 	return pte;
 }
+
+#ifdef CONFIG_3_LEVEL_PGTABLES
+pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+	pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
+
+	if (pmd)
+		memset(pmd, 0, PAGE_SIZE);
+
+	return pmd;
+}
+#endif

arch/um/kernel/process.c

@@ -446,3 +446,11 @@ unsigned long get_wchan(struct task_struct *p)
 
 	return 0;
 }
+
+int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
+{
+	int cpu = current_thread_info()->cpu;
+
+	return save_fp_registers(userspace_pid[cpu], (unsigned long *) fpu);
+}
+

arch/um/kernel/skas/uaccess.c

@@ -3,12 +3,13 @@
  * Licensed under the GPL
  */
 
-#include "linux/err.h"
-#include "linux/highmem.h"
-#include "linux/mm.h"
-#include "asm/current.h"
-#include "asm/page.h"
-#include "asm/pgtable.h"
+#include <linux/err.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <asm/current.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
 #include "kern_util.h"
 #include "os.h"
 

arch/um/kernel/tlb.c

@@ -3,9 +3,10 @@
  * Licensed under the GPL
  */
 
-#include "linux/mm.h"
-#include "asm/pgtable.h"
-#include "asm/tlbflush.h"
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
 #include "as-layout.h"
 #include "mem_user.h"
 #include "os.h"