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linux/arch/i386/kernel/setup.c
john stultz 6bb74df481 [PATCH] clocksource init adjustments (fix bug #7426) 
This patch resolves the issue found here:
http://bugme.osdl.org/show_bug.cgi?id=7426

The basic summary is:
Currently we register most of i386/x86_64 clocksources at module_init
time. Then we enable clocksource selection at late_initcall time. This
causes some problems for drivers that use gettimeofday for init
calibration routines (specifically the es1968 driver in this case),
where durring module_init, the only clocksource available is the low-res
jiffies clocksource. This may cause slight calibration errors, due to
the small sampling time used.

It should be noted that drivers that require fine grained time may not
function on architectures that do not have better then jiffies
resolution timekeeping (there are a few). However, this does not
discount the reasonable need for such fine-grained timekeeping at init
time.

Thus the solution here is to register clocksources earlier (ideally when
the hardware is being initialized), and then we enable clocksource
selection at fs_initcall (before device_initcall).

This patch should probably get some testing time in -mm, since
clocksource selection is one of the most important issues for correct
timekeeping, and I've only been able to test this on a few of my own
boxes.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 07:57:53 -08:00

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/*
* linux/arch/i386/kernel/setup.c
*
* Copyright (C) 1995 Linus Torvalds
*
* Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
*
* Memory region support
* David Parsons <orc@pell.chi.il.us>, July-August 1999
*
* Added E820 sanitization routine (removes overlapping memory regions);
* Brian Moyle <bmoyle@mvista.com>, February 2001
*
* Moved CPU detection code to cpu/${cpu}.c
* Patrick Mochel <mochel@osdl.org>, March 2002
*
* Provisions for empty E820 memory regions (reported by certain BIOSes).
* Alex Achenbach <xela@slit.de>, December 2002.
*
*/
/*
* This file handles the architecture-dependent parts of initialization
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/screen_info.h>
#include <linux/ioport.h>
#include <linux/acpi.h>
#include <linux/apm_bios.h>
#include <linux/initrd.h>
#include <linux/bootmem.h>
#include <linux/seq_file.h>
#include <linux/console.h>
#include <linux/mca.h>
#include <linux/root_dev.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/efi.h>
#include <linux/init.h>
#include <linux/edd.h>
#include <linux/nodemask.h>
#include <linux/kexec.h>
#include <linux/crash_dump.h>
#include <linux/dmi.h>
#include <linux/pfn.h>
#include <video/edid.h>
#include <asm/apic.h>
#include <asm/e820.h>
#include <asm/mpspec.h>
#include <asm/mmzone.h>
#include <asm/setup.h>
#include <asm/arch_hooks.h>
#include <asm/sections.h>
#include <asm/io_apic.h>
#include <asm/ist.h>
#include <asm/io.h>
#include <asm/vmi.h>
#include <setup_arch.h>
#include <bios_ebda.h>
/* This value is set up by the early boot code to point to the value
immediately after the boot time page tables. It contains a *physical*
address, and must not be in the .bss segment! */
unsigned long init_pg_tables_end __initdata = ~0UL;
int disable_pse __devinitdata = 0;
/*
* Machine setup..
*/
extern struct resource code_resource;
extern struct resource data_resource;
/* cpu data as detected by the assembly code in head.S */
struct cpuinfo_x86 new_cpu_data __cpuinitdata = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };
/* common cpu data for all cpus */
struct cpuinfo_x86 boot_cpu_data __read_mostly = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };
EXPORT_SYMBOL(boot_cpu_data);
unsigned long mmu_cr4_features;
/* for MCA, but anyone else can use it if they want */
unsigned int machine_id;
#ifdef CONFIG_MCA
EXPORT_SYMBOL(machine_id);
#endif
unsigned int machine_submodel_id;
unsigned int BIOS_revision;
unsigned int mca_pentium_flag;
/* Boot loader ID as an integer, for the benefit of proc_dointvec */
int bootloader_type;
/* user-defined highmem size */
static unsigned int highmem_pages = -1;
/*
* Setup options
*/
struct drive_info_struct { char dummy[32]; } drive_info;
#if defined(CONFIG_BLK_DEV_IDE) || defined(CONFIG_BLK_DEV_HD) || \
defined(CONFIG_BLK_DEV_IDE_MODULE) || defined(CONFIG_BLK_DEV_HD_MODULE)
EXPORT_SYMBOL(drive_info);
#endif
struct screen_info screen_info;
EXPORT_SYMBOL(screen_info);
struct apm_info apm_info;
EXPORT_SYMBOL(apm_info);
struct sys_desc_table_struct {
unsigned short length;
unsigned char table[0];
};
struct edid_info edid_info;
EXPORT_SYMBOL_GPL(edid_info);
struct ist_info ist_info;
#if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
EXPORT_SYMBOL(ist_info);
#endif
extern void early_cpu_init(void);
extern int root_mountflags;
unsigned long saved_videomode;
#define RAMDISK_IMAGE_START_MASK 0x07FF
#define RAMDISK_PROMPT_FLAG 0x8000
#define RAMDISK_LOAD_FLAG 0x4000
static char __initdata command_line[COMMAND_LINE_SIZE];
unsigned char __initdata boot_params[PARAM_SIZE];
#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
struct edd edd;
#ifdef CONFIG_EDD_MODULE
EXPORT_SYMBOL(edd);
#endif
/**
* copy_edd() - Copy the BIOS EDD information
* from boot_params into a safe place.
*
*/
static inline void copy_edd(void)
{
memcpy(edd.mbr_signature, EDD_MBR_SIGNATURE, sizeof(edd.mbr_signature));
memcpy(edd.edd_info, EDD_BUF, sizeof(edd.edd_info));
edd.mbr_signature_nr = EDD_MBR_SIG_NR;
edd.edd_info_nr = EDD_NR;
}
#else
static inline void copy_edd(void)
{
}
#endif
int __initdata user_defined_memmap = 0;
/*
* "mem=nopentium" disables the 4MB page tables.
* "mem=XXX[kKmM]" defines a memory region from HIGH_MEM
* to <mem>, overriding the bios size.
* "memmap=XXX[KkmM]@XXX[KkmM]" defines a memory region from
* <start> to <start>+<mem>, overriding the bios size.
*
* HPA tells me bootloaders need to parse mem=, so no new
* option should be mem= [also see Documentation/i386/boot.txt]
*/
static int __init parse_mem(char *arg)
{
if (!arg)
return -EINVAL;
if (strcmp(arg, "nopentium") == 0) {
clear_bit(X86_FEATURE_PSE, boot_cpu_data.x86_capability);
disable_pse = 1;
} else {
/* If the user specifies memory size, we
* limit the BIOS-provided memory map to
* that size. exactmap can be used to specify
* the exact map. mem=number can be used to
* trim the existing memory map.
*/
unsigned long long mem_size;
mem_size = memparse(arg, &arg);
limit_regions(mem_size);
user_defined_memmap = 1;
}
return 0;
}
early_param("mem", parse_mem);
#ifdef CONFIG_PROC_VMCORE
/* elfcorehdr= specifies the location of elf core header
* stored by the crashed kernel.
*/
static int __init parse_elfcorehdr(char *arg)
{
if (!arg)
return -EINVAL;
elfcorehdr_addr = memparse(arg, &arg);
return 0;
}
early_param("elfcorehdr", parse_elfcorehdr);
#endif /* CONFIG_PROC_VMCORE */
/*
* highmem=size forces highmem to be exactly 'size' bytes.
* This works even on boxes that have no highmem otherwise.
* This also works to reduce highmem size on bigger boxes.
*/
static int __init parse_highmem(char *arg)
{
if (!arg)
return -EINVAL;
highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
return 0;
}
early_param("highmem", parse_highmem);
/*
* vmalloc=size forces the vmalloc area to be exactly 'size'
* bytes. This can be used to increase (or decrease) the
* vmalloc area - the default is 128m.
*/
static int __init parse_vmalloc(char *arg)
{
if (!arg)
return -EINVAL;
__VMALLOC_RESERVE = memparse(arg, &arg);
return 0;
}
early_param("vmalloc", parse_vmalloc);
/*
* reservetop=size reserves a hole at the top of the kernel address space which
* a hypervisor can load into later. Needed for dynamically loaded hypervisors,
* so relocating the fixmap can be done before paging initialization.
*/
static int __init parse_reservetop(char *arg)
{
unsigned long address;
if (!arg)
return -EINVAL;
address = memparse(arg, &arg);
reserve_top_address(address);
return 0;
}
early_param("reservetop", parse_reservetop);
/*
* Determine low and high memory ranges:
*/
unsigned long __init find_max_low_pfn(void)
{
unsigned long max_low_pfn;
max_low_pfn = max_pfn;
if (max_low_pfn > MAXMEM_PFN) {
if (highmem_pages == -1)
highmem_pages = max_pfn - MAXMEM_PFN;
if (highmem_pages + MAXMEM_PFN < max_pfn)
max_pfn = MAXMEM_PFN + highmem_pages;
if (highmem_pages + MAXMEM_PFN > max_pfn) {
printk("only %luMB highmem pages available, ignoring highmem size of %uMB.\n", pages_to_mb(max_pfn - MAXMEM_PFN), pages_to_mb(highmem_pages));
highmem_pages = 0;
}
max_low_pfn = MAXMEM_PFN;
#ifndef CONFIG_HIGHMEM
/* Maximum memory usable is what is directly addressable */
printk(KERN_WARNING "Warning only %ldMB will be used.\n",
MAXMEM>>20);
if (max_pfn > MAX_NONPAE_PFN)
printk(KERN_WARNING "Use a PAE enabled kernel.\n");
else
printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
max_pfn = MAXMEM_PFN;
#else /* !CONFIG_HIGHMEM */
#ifndef CONFIG_X86_PAE
if (max_pfn > MAX_NONPAE_PFN) {
max_pfn = MAX_NONPAE_PFN;
printk(KERN_WARNING "Warning only 4GB will be used.\n");
printk(KERN_WARNING "Use a PAE enabled kernel.\n");
}
#endif /* !CONFIG_X86_PAE */
#endif /* !CONFIG_HIGHMEM */
} else {
if (highmem_pages == -1)
highmem_pages = 0;
#ifdef CONFIG_HIGHMEM
if (highmem_pages >= max_pfn) {
printk(KERN_ERR "highmem size specified (%uMB) is bigger than pages available (%luMB)!.\n", pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
highmem_pages = 0;
}
if (highmem_pages) {
if (max_low_pfn-highmem_pages < 64*1024*1024/PAGE_SIZE){
printk(KERN_ERR "highmem size %uMB results in smaller than 64MB lowmem, ignoring it.\n", pages_to_mb(highmem_pages));
highmem_pages = 0;
}
max_low_pfn -= highmem_pages;
}
#else
if (highmem_pages)
printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
#endif
}
return max_low_pfn;
}
/*
* workaround for Dell systems that neglect to reserve EBDA
*/
static void __init reserve_ebda_region(void)
{
unsigned int addr;
addr = get_bios_ebda();
if (addr)
reserve_bootmem(addr, PAGE_SIZE);
}
#ifndef CONFIG_NEED_MULTIPLE_NODES
void __init setup_bootmem_allocator(void);
static unsigned long __init setup_memory(void)
{
/*
* partially used pages are not usable - thus
* we are rounding upwards:
*/
min_low_pfn = PFN_UP(init_pg_tables_end);
find_max_pfn();
max_low_pfn = find_max_low_pfn();
#ifdef CONFIG_HIGHMEM
highstart_pfn = highend_pfn = max_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 = max_low_pfn;
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
#endif
#ifdef CONFIG_FLATMEM
max_mapnr = num_physpages;
#endif
printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
pages_to_mb(max_low_pfn));
setup_bootmem_allocator();
return max_low_pfn;
}
void __init zone_sizes_init(void)
{
unsigned long max_zone_pfns[MAX_NR_ZONES];
memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
max_zone_pfns[ZONE_DMA] =
virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM
max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
add_active_range(0, 0, highend_pfn);
#else
add_active_range(0, 0, max_low_pfn);
#endif
free_area_init_nodes(max_zone_pfns);
}
#else
extern unsigned long __init setup_memory(void);
extern void zone_sizes_init(void);
#endif /* !CONFIG_NEED_MULTIPLE_NODES */
void __init setup_bootmem_allocator(void)
{
unsigned long bootmap_size;
/*
* Initialize the boot-time allocator (with low memory only):
*/
bootmap_size = init_bootmem(min_low_pfn, max_low_pfn);
register_bootmem_low_pages(max_low_pfn);
/*
* Reserve the bootmem bitmap itself as well. We do this in two
* steps (first step was init_bootmem()) because this catches
* the (very unlikely) case of us accidentally initializing the
* bootmem allocator with an invalid RAM area.
*/
reserve_bootmem(__pa_symbol(_text), (PFN_PHYS(min_low_pfn) +
bootmap_size + PAGE_SIZE-1) - __pa_symbol(_text));
/*
* reserve physical page 0 - it's a special BIOS page on many boxes,
* enabling clean reboots, SMP operation, laptop functions.
*/
reserve_bootmem(0, PAGE_SIZE);
/* reserve EBDA region, it's a 4K region */
reserve_ebda_region();
/* could be an AMD 768MPX chipset. Reserve a page before VGA to prevent
PCI prefetch into it (errata #56). Usually the page is reserved anyways,
unless you have no PS/2 mouse plugged in. */
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
boot_cpu_data.x86 == 6)
reserve_bootmem(0xa0000 - 4096, 4096);
#ifdef CONFIG_SMP
/*
* But first pinch a few for the stack/trampoline stuff
* FIXME: Don't need the extra page at 4K, but need to fix
* trampoline before removing it. (see the GDT stuff)
*/
reserve_bootmem(PAGE_SIZE, PAGE_SIZE);
#endif
#ifdef CONFIG_ACPI_SLEEP
/*
* Reserve low memory region for sleep support.
*/
acpi_reserve_bootmem();
#endif
#ifdef CONFIG_X86_FIND_SMP_CONFIG
/*
* Find and reserve possible boot-time SMP configuration:
*/
find_smp_config();
#endif
numa_kva_reserve();
#ifdef CONFIG_BLK_DEV_INITRD
if (LOADER_TYPE && INITRD_START) {
if (INITRD_START + INITRD_SIZE <= (max_low_pfn << PAGE_SHIFT)) {
reserve_bootmem(INITRD_START, INITRD_SIZE);
initrd_start = INITRD_START + PAGE_OFFSET;
initrd_end = initrd_start+INITRD_SIZE;
}
else {
printk(KERN_ERR "initrd extends beyond end of memory "
"(0x%08lx > 0x%08lx)\ndisabling initrd\n",
INITRD_START + INITRD_SIZE,
max_low_pfn << PAGE_SHIFT);
initrd_start = 0;
}
}
#endif
#ifdef CONFIG_KEXEC
if (crashk_res.start != crashk_res.end)
reserve_bootmem(crashk_res.start,
crashk_res.end - crashk_res.start + 1);
#endif
}
/*
* The node 0 pgdat is initialized before all of these because
* it's needed for bootmem. node>0 pgdats have their virtual
* space allocated before the pagetables are in place to access
* them, so they can't be cleared then.
*
* This should all compile down to nothing when NUMA is off.
*/
void __init remapped_pgdat_init(void)
{
int nid;
for_each_online_node(nid) {
if (nid != 0)
memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));
}
}
#ifdef CONFIG_MCA
static void set_mca_bus(int x)
{
MCA_bus = x;
}
#else
static void set_mca_bus(int x) { }
#endif
/* Overridden in paravirt.c if CONFIG_PARAVIRT */
char * __init __attribute__((weak)) memory_setup(void)
{
return machine_specific_memory_setup();
}
/*
* Determine if we were loaded by an EFI loader. If so, then we have also been
* passed the efi memmap, systab, etc., so we should use these data structures
* for initialization. Note, the efi init code path is determined by the
* global efi_enabled. This allows the same kernel image to be used on existing
* systems (with a traditional BIOS) as well as on EFI systems.
*/
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();
/*
* FIXME: This isn't an official loader_type right
* now but does currently work with elilo.
* If we were configured as an EFI kernel, check to make
* sure that we were loaded correctly from elilo and that
* the system table is valid. If not, then initialize normally.
*/
#ifdef CONFIG_EFI
if ((LOADER_TYPE == 0x50) && EFI_SYSTAB)
efi_enabled = 1;
#endif
ROOT_DEV = old_decode_dev(ORIG_ROOT_DEV);
drive_info = DRIVE_INFO;
screen_info = SCREEN_INFO;
edid_info = EDID_INFO;
apm_info.bios = APM_BIOS_INFO;
ist_info = IST_INFO;
saved_videomode = VIDEO_MODE;
if( SYS_DESC_TABLE.length != 0 ) {
set_mca_bus(SYS_DESC_TABLE.table[3] & 0x2);
machine_id = SYS_DESC_TABLE.table[0];
machine_submodel_id = SYS_DESC_TABLE.table[1];
BIOS_revision = SYS_DESC_TABLE.table[2];
}
bootloader_type = LOADER_TYPE;
#ifdef CONFIG_BLK_DEV_RAM
rd_image_start = RAMDISK_FLAGS & RAMDISK_IMAGE_START_MASK;
rd_prompt = ((RAMDISK_FLAGS & RAMDISK_PROMPT_FLAG) != 0);
rd_doload = ((RAMDISK_FLAGS & RAMDISK_LOAD_FLAG) != 0);
#endif
ARCH_SETUP
if (efi_enabled)
efi_init();
else {
printk(KERN_INFO "BIOS-provided physical RAM map:\n");
print_memory_map(memory_setup());
}
copy_edd();
if (!MOUNT_ROOT_RDONLY)
root_mountflags &= ~MS_RDONLY;
init_mm.start_code = (unsigned long) _text;
init_mm.end_code = (unsigned long) _etext;
init_mm.end_data = (unsigned long) _edata;
init_mm.brk = init_pg_tables_end + PAGE_OFFSET;
code_resource.start = virt_to_phys(_text);
code_resource.end = virt_to_phys(_etext)-1;
data_resource.start = virt_to_phys(_etext);
data_resource.end = virt_to_phys(_edata)-1;
parse_early_param();
if (user_defined_memmap) {
printk(KERN_INFO "user-defined physical RAM map:\n");
print_memory_map("user");
}
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
max_low_pfn = setup_memory();
#ifdef CONFIG_VMI
/*
* Must be after max_low_pfn is determined, and before kernel
* pagetables are setup.
*/
vmi_init();
#endif
/*
* NOTE: before this point _nobody_ is allowed to allocate
* any memory using the bootmem allocator. Although the
* alloctor is now initialised only the first 8Mb of the kernel
* virtual address space has been mapped. All allocations before
* paging_init() has completed must use the alloc_bootmem_low_pages()
* variant (which allocates DMA'able memory) and care must be taken
* not to exceed the 8Mb limit.
*/
#ifdef CONFIG_SMP
smp_alloc_memory(); /* AP processor realmode stacks in low memory*/
#endif
paging_init();
remapped_pgdat_init();
sparse_init();
zone_sizes_init();
/*
* NOTE: at this point the bootmem allocator is fully available.
*/
dmi_scan_machine();
#ifdef CONFIG_X86_GENERICARCH
generic_apic_probe();
#endif
if (efi_enabled)
efi_map_memmap();
#ifdef CONFIG_ACPI
/*
* Parse the ACPI tables for possible boot-time SMP configuration.
*/
acpi_boot_table_init();
#endif
#ifdef CONFIG_PCI
#ifdef CONFIG_X86_IO_APIC
check_acpi_pci(); /* Checks more than just ACPI actually */
#endif
#endif
#ifdef CONFIG_ACPI
acpi_boot_init();
#if defined(CONFIG_SMP) && defined(CONFIG_X86_PC)
if (def_to_bigsmp)
printk(KERN_WARNING "More than 8 CPUs detected and "
"CONFIG_X86_PC cannot handle it.\nUse "
"CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.\n");
#endif
#endif
#ifdef CONFIG_X86_LOCAL_APIC
if (smp_found_config)
get_smp_config();
#endif
e820_register_memory();
#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)
if (!efi_enabled || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
conswitchp = &vga_con;
#elif defined(CONFIG_DUMMY_CONSOLE)
conswitchp = &dummy_con;
#endif
#endif
}
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