[RFC PATCH 2/9] um: decouple MMU specific code from the common part

[Johannes Berg]

From: Hajime Tazaki <thehajime at gmail.com>

This splits the memory, process related code with common and MMU
specific parts in order to avoid ifdefs in .c file and duplication
between MMU and !MMU.

Signed-off-by: Hajime Tazaki <thehajime at gmail.com>
Link: https://patch.msgid.link/e789a6ce3204b7697adba6d70e52e1ec3b61a451.1770170302.git.thehajime@gmail.com
[drop many unnecessary changes]
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
---
 arch/um/kernel/Makefile      |  3 +-
 arch/um/kernel/mem-pgtable.c | 55 ++++++++++++++++++++++++++++++++++++
 arch/um/kernel/mem.c         | 35 -----------------------
 3 files changed, 57 insertions(+), 36 deletions(-)
 create mode 100644 arch/um/kernel/mem-pgtable.c

diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index be60bc451b3f..d56fe6d829cc 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -16,9 +16,10 @@ always-$(KBUILD_BUILTIN) := vmlinux.lds
 
 obj-y = config.o exec.o exitcode.o irq.o ksyms.o mem.o \
 	physmem.o process.o ptrace.o reboot.o sigio.o \
-	signal.o sysrq.o time.o tlb.o trap.o \
+	signal.o sysrq.o time.o trap.o \
 	um_arch.o umid.o kmsg_dump.o capflags.o skas/
 obj-y += load_file.o
+obj-$(CONFIG_MMU) += mem-pgtable.o tlb.o
 
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
 obj-$(CONFIG_GPROF)	+= gprof_syms.o
diff --git a/arch/um/kernel/mem-pgtable.c b/arch/um/kernel/mem-pgtable.c
new file mode 100644
index 000000000000..549da1d3bff0
--- /dev/null
+++ b/arch/um/kernel/mem-pgtable.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/stddef.h>
+#include <linux/module.h>
+#include <linux/memblock.h>
+#include <linux/swap.h>
+#include <linux/slab.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <as-layout.h>
+#include <init.h>
+#include <kern.h>
+#include <kern_util.h>
+#include <mem_user.h>
+#include <os.h>
+#include <um_malloc.h>
+
+
+/* Allocate and free page tables. */
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+	pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
+
+	if (pgd) {
+		memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
+		memcpy(pgd + USER_PTRS_PER_PGD,
+		       swapper_pg_dir + USER_PTRS_PER_PGD,
+		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+	}
+	return pgd;
+}
+
+static const pgprot_t protection_map[16] = {
+	[VM_NONE]					= PAGE_NONE,
+	[VM_READ]					= PAGE_READONLY,
+	[VM_WRITE]					= PAGE_COPY,
+	[VM_WRITE | VM_READ]				= PAGE_COPY,
+	[VM_EXEC]					= PAGE_READONLY,
+	[VM_EXEC | VM_READ]				= PAGE_READONLY,
+	[VM_EXEC | VM_WRITE]				= PAGE_COPY,
+	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_COPY,
+	[VM_SHARED]					= PAGE_NONE,
+	[VM_SHARED | VM_READ]				= PAGE_READONLY,
+	[VM_SHARED | VM_WRITE]				= PAGE_SHARED,
+	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
+	[VM_SHARED | VM_EXEC]				= PAGE_READONLY,
+	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_READONLY,
+	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_SHARED,
+	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_SHARED
+};
+DECLARE_VM_GET_PAGE_PROT
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 1eef0e42ef5d..4b84760b5e55 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -6,7 +6,6 @@
 #include <linux/stddef.h>
 #include <linux/module.h>
 #include <linux/memblock.h>
-#include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/slab.h>
 #include <linux/init.h>
@@ -91,45 +90,11 @@ void free_initmem(void)
 {
 }
 
-/* Allocate and free page tables. */
-
-pgd_t *pgd_alloc(struct mm_struct *mm)
-{
-	pgd_t *pgd = __pgd_alloc(mm, 0);
-
-	if (pgd)
-		memcpy(pgd + USER_PTRS_PER_PGD,
-		       swapper_pg_dir + USER_PTRS_PER_PGD,
-		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
-
-	return pgd;
-}
-
 void *uml_kmalloc(int size, int flags)
 {
 	return kmalloc(size, flags);
 }
 
-static const pgprot_t protection_map[16] = {
-	[VM_NONE]					= PAGE_NONE,
-	[VM_READ]					= PAGE_READONLY,
-	[VM_WRITE]					= PAGE_COPY,
-	[VM_WRITE | VM_READ]				= PAGE_COPY,
-	[VM_EXEC]					= PAGE_READONLY,
-	[VM_EXEC | VM_READ]				= PAGE_READONLY,
-	[VM_EXEC | VM_WRITE]				= PAGE_COPY,
-	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_COPY,
-	[VM_SHARED]					= PAGE_NONE,
-	[VM_SHARED | VM_READ]				= PAGE_READONLY,
-	[VM_SHARED | VM_WRITE]				= PAGE_SHARED,
-	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
-	[VM_SHARED | VM_EXEC]				= PAGE_READONLY,
-	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_READONLY,
-	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_SHARED,
-	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_SHARED
-};
-DECLARE_VM_GET_PAGE_PROT
-
 void mark_rodata_ro(void)
 {
 	unsigned long rodata_start = PFN_ALIGN(__start_rodata);
-- 
2.53.0