um: switch to NO_BOOTMEM

Replace bootmem initialization with memblock_add and memblock_reserve calls
and explicit initialization of {min,max}_low_pfn.

Link: http://lkml.kernel.org/r/1533326330-31677-7-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/um/Kconfig

@@ -12,6 +12,8 @@ config UML
 	select HAVE_UID16
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_DEBUG_KMEMLEAK
+	select HAVE_MEMBLOCK
+	select NO_BOOTMEM
 	select GENERIC_IRQ_SHOW
 	select GENERIC_CPU_DEVICES
 	select GENERIC_CLOCKEVENTS

arch/um/kernel/physmem.c

@@ -5,6 +5,7 @@
 
 #include <linux/module.h>
 #include <linux/bootmem.h>
+#include <linux/memblock.h>
 #include <linux/mm.h>
 #include <linux/pfn.h>
 #include <asm/page.h>
@@ -80,23 +81,18 @@ void __init setup_physmem(unsigned long start, unsigned long reserve_end,
 			  unsigned long len, unsigned long long highmem)
 {
 	unsigned long reserve = reserve_end - start;
-	unsigned long pfn = PFN_UP(__pa(reserve_end));
-	unsigned long delta = (len - reserve) >> PAGE_SHIFT;
-	unsigned long offset, bootmap_size;
-	long map_size;
+	long map_size = len - reserve;
 	int err;
 
-	offset = reserve_end - start;
-	map_size = len - offset;
 	if(map_size <= 0) {
 		os_warn("Too few physical memory! Needed=%lu, given=%lu\n",
-			offset, len);
+			reserve, len);
 		exit(1);
 	}
 
 	physmem_fd = create_mem_file(len + highmem);
 
-	err = os_map_memory((void *) reserve_end, physmem_fd, offset,
+	err = os_map_memory((void *) reserve_end, physmem_fd, reserve,
 			    map_size, 1, 1, 1);
 	if (err < 0) {
 		os_warn("setup_physmem - mapping %ld bytes of memory at 0x%p "
@@ -113,9 +109,11 @@ void __init setup_physmem(unsigned long start, unsigned long reserve_end,
 	os_write_file(physmem_fd, __syscall_stub_start, PAGE_SIZE);
 	os_fsync_file(physmem_fd);
 
-	bootmap_size = init_bootmem(pfn, pfn + delta);
-	free_bootmem(__pa(reserve_end) + bootmap_size,
-		     len - bootmap_size - reserve);
+	memblock_add(__pa(start), len + highmem);
+	memblock_reserve(__pa(start), reserve);
+
+	min_low_pfn = PFN_UP(__pa(reserve_end));
+	max_low_pfn = min_low_pfn + (map_size >> PAGE_SHIFT);
 }
 
 int phys_mapping(unsigned long phys, unsigned long long *offset_out)