core: Move early_res from arch/x86 to kernel/

This makes the range reservation feature available to other
architectures.

-v2: add get_max_mapped, max_pfn_mapped only defined in x86...
     to fix PPC compiling
-v3: according to hpa, add CONFIG_HAVE_EARLY_RES
-v4: fix typo about EARLY_RES in config

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B7B5723.4070009@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/Kconfig

@@ -183,6 +183,9 @@ config ARCH_SUPPORTS_OPTIMIZED_INLINING
 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 	def_bool y
 
+config HAVE_EARLY_RES
+	def_bool y
+
 config HAVE_INTEL_TXT
 	def_bool y
 	depends on EXPERIMENTAL && DMAR && ACPI

arch/x86/include/asm/e820.h

@@ -112,7 +112,7 @@ extern unsigned long end_user_pfn;
 extern u64 find_e820_area(u64 start, u64 end, u64 size, u64 align);
 extern u64 find_e820_area_size(u64 start, u64 *sizep, u64 align);
 extern u64 early_reserve_e820(u64 startt, u64 sizet, u64 align);
-#include <asm/early_res.h>
+#include <linux/early_res.h>
 
 extern unsigned long e820_end_of_ram_pfn(void);
 extern unsigned long e820_end_of_low_ram_pfn(void);

arch/x86/kernel/Makefile

@@ -38,7 +38,7 @@ obj-$(CONFIG_X86_32)	+= probe_roms_32.o
 obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o
 obj-$(CONFIG_X86_64)	+= sys_x86_64.o x8664_ksyms_64.o
 obj-$(CONFIG_X86_64)	+= syscall_64.o vsyscall_64.o
-obj-y			+= bootflag.o e820.o early_res.o
+obj-y			+= bootflag.o e820.o
 obj-y			+= pci-dma.o quirks.o i8237.o topology.o kdebugfs.o
 obj-y			+= alternative.o i8253.o pci-nommu.o hw_breakpoint.o
 obj-y			+= tsc.o io_delay.o rtc.o

arch/x86/kernel/e820.c

@@ -17,7 +17,6 @@
 #include <linux/firmware-map.h>
 
 #include <asm/e820.h>
-#include <asm/early_res.h>
 #include <asm/proto.h>
 #include <asm/setup.h>
 
@@ -752,6 +751,15 @@ u64 __init find_fw_memmap_area(u64 start, u64 end, u64 size, u64 align)
 {
 	return find_e820_area(start, end, size, align);
 }
+
+u64 __init get_max_mapped(void)
+{
+	u64 end = max_pfn_mapped;
+
+	end <<= PAGE_SHIFT;
+
+	return end;
+}
 /*
  * Find next free range after *start
  */

include/linux/early_res.h

@@ -1,5 +1,5 @@
-#ifndef _ASM_X86_EARLY_RES_H
-#define _ASM_X86_EARLY_RES_H
+#ifndef _LINUX_EARLY_RES_H
+#define _LINUX_EARLY_RES_H
 #ifdef __KERNEL__
 
 extern void reserve_early(u64 start, u64 end, char *name);
@@ -13,9 +13,10 @@ u64 find_early_area(u64 ei_start, u64 ei_last, u64 start, u64 end,
 u64 find_early_area_size(u64 ei_start, u64 ei_last, u64 start,
 			 u64 *sizep, u64 align);
 u64 find_fw_memmap_area(u64 start, u64 end, u64 size, u64 align);
+u64 get_max_mapped(void);
 #include <linux/range.h>
 int get_free_all_memory_range(struct range **rangep, int nodeid);
 
 #endif /* __KERNEL__ */
 
-#endif /* _ASM_X86_EARLY_RES_H */
+#endif /* _LINUX_EARLY_RES_H */

kernel/Makefile

@@ -11,6 +11,7 @@ obj-y     = sched.o fork.o exec_domain.o panic.o printk.o \
 	    hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
 	    notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o \
 	    async.o range.o
+obj-$(CONFIG_HAVE_EARLY_RES) += early_res.o
 obj-y += groups.o
 
 ifdef CONFIG_FUNCTION_TRACER

kernel/early_res.c

@@ -6,8 +6,7 @@
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/mm.h>
-
-#include <asm/early_res.h>
+#include <linux/early_res.h>
 
 /*
  * Early reserved memory areas.
@@ -178,13 +177,6 @@ void __init reserve_early_overlap_ok(u64 start, u64 end, char *name)
 	__reserve_early(start, end, name, 1);
 }
 
-u64 __init __weak find_fw_memmap_area(u64 start, u64 end, u64 size, u64 align)
-{
-	panic("should have find_fw_memmap_area defined with arch");
-
-	return -1ULL;
-}
-
 static void __init __check_and_double_early_res(u64 ex_start, u64 ex_end)
 {
 	u64 start, end, size, mem;
@@ -207,7 +199,7 @@ static void __init __check_and_double_early_res(u64 ex_start, u64 ex_end)
 					 sizeof(struct early_res));
 	if (mem == -1ULL) {
 		start = ex_end;
-		end = max_pfn_mapped << PAGE_SHIFT;
+		end = get_max_mapped();
 		if (start + size < end)
 			mem = find_fw_memmap_area(start, end, size,
 						 sizeof(struct early_res));
@@ -343,11 +335,11 @@ int __init get_free_all_memory_range(struct range **rangep, int nodeid)
 	count *= 2;
 
 	size = sizeof(struct range) * count;
+	end = get_max_mapped();
 #ifdef MAX_DMA32_PFN
-	if (max_pfn_mapped > MAX_DMA32_PFN)
+	if (end > (MAX_DMA32_PFN << PAGE_SHIFT))
 		start = MAX_DMA32_PFN << PAGE_SHIFT;
 #endif
-	end = max_pfn_mapped << PAGE_SHIFT;
 	mem = find_fw_memmap_area(start, end, size, sizeof(struct range));
 	if (mem == -1ULL)
 		panic("can not find more space for range free");