[PATCH] x86: cleanup using max_low_pfn for 32 bit

From: Yinghai Lu
Date: Mon Jun 23 2008 - 06:05:20 EST



for max_low_pfn is not changed after it is set.
so we can move that early and out of initmem_init.

could call find_low_pfn_range just after max_pfn is set.

also could move reserve_initrd out of setup_bootmem_allocator

so 32bit is more like 64bit.

Signed-off-by: Yinghai Lu <yhlu.kernel@xxxxxxxxx>

---
arch/x86/kernel/setup_32.c | 16 ++++++++++------
arch/x86/kernel/setup_64.c | 2 +-
arch/x86/mm/discontig_32.c | 22 +++++++---------------
arch/x86/mm/init_32.c | 25 +++++++++----------------
include/asm-x86/page_32.h | 3 ++-
include/asm-x86/setup.h | 2 --
6 files changed, 29 insertions(+), 41 deletions(-)

Index: linux-2.6/arch/x86/kernel/setup_32.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup_32.c
+++ linux-2.6/arch/x86/kernel/setup_32.c
@@ -189,13 +189,14 @@ static inline void copy_edd(void)

static bool do_relocate_initrd = false;

-void __init reserve_initrd(void)
+static void __init reserve_initrd(void)
{
u64 ramdisk_image = boot_params.hdr.ramdisk_image;
u64 ramdisk_size = boot_params.hdr.ramdisk_size;
u64 ramdisk_end = ramdisk_image + ramdisk_size;
u64 end_of_lowmem = max_low_pfn << PAGE_SHIFT;
u64 ramdisk_here;
+ u64 ramdisk_target;

if (!boot_params.hdr.type_of_loader ||
!ramdisk_image || !ramdisk_size)
@@ -203,7 +204,7 @@ void __init reserve_initrd(void)

initrd_start = 0;

- if (ramdisk_size >= end_of_lowmem/2) {
+ if (ramdisk_size >= (end_of_lowmem>>1)) {
free_early(ramdisk_image, ramdisk_end);
printk(KERN_ERR "initrd too large to handle, "
"disabling initrd\n");
@@ -226,7 +227,8 @@ void __init reserve_initrd(void)
}

/* We need to move the initrd down into lowmem */
- ramdisk_here = find_e820_area(min_low_pfn<<PAGE_SHIFT,
+ ramdisk_target = max_pfn_mapped<<PAGE_SHIFT;
+ ramdisk_here = find_e820_area(min(ramdisk_target, end_of_lowmem>>1),
end_of_lowmem, ramdisk_size,
PAGE_SIZE);

@@ -347,8 +349,6 @@ static void set_mca_bus(int x) { }
*/
void __init setup_arch(char **cmdline_p)
{
- unsigned long max_low_pfn;
-
memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
pre_setup_arch_hook();
early_cpu_init();
@@ -456,6 +456,10 @@ void __init setup_arch(char **cmdline_p)
max_pfn = e820_end_of_ram();
}

+ find_low_pfn_range();
+
+ reserve_initrd();
+
dmi_scan_machine();

io_delay_init();
@@ -472,7 +476,7 @@ void __init setup_arch(char **cmdline_p)
acpi_numa_init();
#endif

- max_low_pfn = initmem_init(0, max_pfn);
+ initmem_init(0, max_pfn);

#ifdef CONFIG_ACPI_SLEEP
/*
Index: linux-2.6/arch/x86/kernel/setup_64.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup_64.c
+++ linux-2.6/arch/x86/kernel/setup_64.c
@@ -154,7 +154,7 @@ static inline void copy_edd(void)
}
#endif

-void __init reserve_initrd(void)
+static void __init reserve_initrd(void)
{
#ifdef CONFIG_BLK_DEV_INITRD
if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
Index: linux-2.6/arch/x86/mm/discontig_32.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/discontig_32.c
+++ linux-2.6/arch/x86/mm/discontig_32.c
@@ -309,11 +309,10 @@ static void init_remap_allocator(int nid
(ulong) node_remap_end_vaddr[nid]);
}

-unsigned long __init initmem_init(unsigned long start_pfn,
+void __init initmem_init(unsigned long start_pfn,
unsigned long end_pfn)
{
int nid;
- unsigned long system_start_pfn, system_max_low_pfn;
long kva_target_pfn;

/*
@@ -324,17 +323,11 @@ unsigned long __init initmem_init(unsign
* and ZONE_HIGHMEM.
*/

- /* call find_max_low_pfn at first, it could update max_pfn */
- system_max_low_pfn = max_low_pfn = find_max_low_pfn();
-
remove_all_active_ranges();
get_memcfg_numa();

kva_pages = round_up(calculate_numa_remap_pages(), PTRS_PER_PTE);

- /* partially used pages are not usable - thus round upwards */
- system_start_pfn = min_low_pfn = PFN_UP(init_pg_tables_end);
-
kva_target_pfn = round_down(max_low_pfn - kva_pages, PTRS_PER_PTE);
do {
kva_start_pfn = find_e820_area(kva_target_pfn<<PAGE_SHIFT,
@@ -357,19 +350,19 @@ unsigned long __init initmem_init(unsign
"KVA PG");
#ifdef CONFIG_HIGHMEM
highstart_pfn = highend_pfn = max_pfn;
- if (max_pfn > system_max_low_pfn)
- highstart_pfn = system_max_low_pfn;
+ if (max_pfn > max_low_pfn)
+ highstart_pfn = max_low_pfn;
printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
pages_to_mb(highend_pfn - highstart_pfn));
num_physpages = highend_pfn;
high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
#else
- num_physpages = system_max_low_pfn;
- high_memory = (void *) __va(system_max_low_pfn * PAGE_SIZE - 1) + 1;
+ num_physpages = max_low_pfn;
+ high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
#endif
printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
- pages_to_mb(system_max_low_pfn));
- printk("min_low_pfn = %ld, max_low_pfn = %ld, highstart_pfn = %ld\n",
+ pages_to_mb(max_low_pfn));
+ printk("min_low_pfn = %ld, max_low_pfn = %ld, highstart_pfn = %ld\n",
min_low_pfn, max_low_pfn, highstart_pfn);

printk("Low memory ends at vaddr %08lx\n",
@@ -387,7 +380,6 @@ unsigned long __init initmem_init(unsign
memset(NODE_DATA(0), 0, sizeof(struct pglist_data));
NODE_DATA(0)->bdata = &node0_bdata;
setup_bootmem_allocator();
- return max_low_pfn;
}

void __init zone_sizes_init(void)
Index: linux-2.6/arch/x86/mm/init_32.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/init_32.c
+++ linux-2.6/arch/x86/mm/init_32.c
@@ -561,9 +561,15 @@ early_param("highmem", parse_highmem);
/*
* Determine low and high memory ranges:
*/
-unsigned long __init find_max_low_pfn(void)
+void __init find_low_pfn_range(void)
{
- unsigned long max_low_pfn;
+ /* it could update max_pfn */
+
+ /*
+ * partially used pages are not usable - thus
+ * we are rounding upwards:
+ */
+ min_low_pfn = PFN_UP(init_pg_tables_end);

max_low_pfn = max_pfn;
if (max_low_pfn > MAXMEM_PFN) {
@@ -625,21 +631,12 @@ unsigned long __init find_max_low_pfn(vo
" kernel!\n");
#endif
}
- return max_low_pfn;
}

#ifndef CONFIG_NEED_MULTIPLE_NODES
-unsigned long __init initmem_init(unsigned long start_pfn,
+void __init initmem_init(unsigned long start_pfn,
unsigned long end_pfn)
{
- /*
- * partially used pages are not usable - thus
- * we are rounding upwards:
- */
- min_low_pfn = PFN_UP(init_pg_tables_end);
-
- max_low_pfn = find_max_low_pfn();
-
#ifdef CONFIG_HIGHMEM
highstart_pfn = highend_pfn = max_pfn;
if (max_pfn > max_low_pfn)
@@ -661,8 +658,6 @@ unsigned long __init initmem_init(unsign
pages_to_mb(max_low_pfn));

setup_bootmem_allocator();
-
- return max_low_pfn;
}

void __init zone_sizes_init(void)
@@ -699,8 +694,6 @@ void __init setup_bootmem_allocator(void
panic("Cannot find bootmem map of size %ld\n", bootmap_size);
reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP");

- reserve_initrd();
-
bootmap_size = init_bootmem(bootmap >> PAGE_SHIFT, max_low_pfn);
printk(KERN_INFO " mapped low ram: 0 - %08lx\n",
max_pfn_mapped<<PAGE_SHIFT);
Index: linux-2.6/include/asm-x86/page_32.h
===================================================================
--- linux-2.6.orig/include/asm-x86/page_32.h
+++ linux-2.6/include/asm-x86/page_32.h
@@ -97,7 +97,8 @@ extern int sysctl_legacy_va_layout;
#define VMALLOC_RESERVE ((unsigned long)__VMALLOC_RESERVE)
#define MAXMEM (-__PAGE_OFFSET - __VMALLOC_RESERVE)

-extern unsigned long initmem_init(unsigned long, unsigned long);
+extern void find_low_pfn_range(void);
+extern void initmem_init(unsigned long, unsigned long);
extern void zone_sizes_init(void);
extern void setup_bootmem_allocator(void);

Index: linux-2.6/include/asm-x86/setup.h
===================================================================
--- linux-2.6.orig/include/asm-x86/setup.h
+++ linux-2.6/include/asm-x86/setup.h
@@ -39,8 +39,6 @@ void reserve_crashkernel(void);
#include <asm/bootparam.h>

void reserve_standard_io_resources(void);
-void reserve_initrd(void);
-

#ifndef _SETUP

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