linux/include/asm-generic
Jiang Liu 1622d1abdf vmlinux.lds: add comments for global variables and clean up useless declarations
The original goal of this patchset is to fix the bug reported by
https://bugzilla.kernel.org/show_bug.cgi?id=53501 Now it has also been
expanded to reduce common code used by memory initializion.

Patch 1-7:
	1) add comments for global variables exported by vmlinux.lds
	2) normalize global variables exported by vmlinux.lds
Patch 8:
	Introduce helper functions mem_init_print_info() and
	get_num_physpages()
Patch 9:
	Avoid using global variable num_physpages at runtime
Patch 10:
	Don't update num_physpages in memory_hotplug.c
Patch 11-40:
	Modify arch mm initialization code to:
	1) Simplify mem_init() by using mem_init_print_info()
	2) Prepare for killing global variable num_physpages
Patch 41:
	Kill the global variable num_physpages

With all patches applied, mem_init(), free_initmem(), free_initrd_mem()
could be as simple as below.  This patch series has reduced about 1.2K
lines of code in total.

#ifndef CONFIG_DISCONTIGMEM
void __init
mem_init(void)
{
	max_mapnr = max_low_pfn;
	free_all_bootmem();
	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);

	mem_init_print_info(NULL);
}
#endif /* CONFIG_DISCONTIGMEM */

void
free_initmem(void)
{
	free_initmem_default(-1);
}

#ifdef CONFIG_BLK_DEV_INITRD
void
free_initrd_mem(unsigned long start, unsigned long end)
{
	free_reserved_area(start, end, -1, "initrd");
}
#endif

Due to hardware resource limitations, I have only tested this on x86_64.
And the messages reported on an x86_64 system are:

Log message before applying patches:
Memory: 7745676k/8910848k available (6934k kernel code, 836024k absent, 329148k reserved, 6343k data, 1012k init)

Log message after applying patches:
Memory: 7744624K/8074824K available (6969K kernel code, 1011K data, 2828K rodata, 1016K init, 9640K bss, 330200K reserved)

Great thanks to Vineet Gupta for testing on ARC.

This patch:

Document global variables exported from vmlinux.lds.

1) Add comments about usage guidelines for global variables exported
   from vmlinux.lds.S.
2) Remove unused __initdata_begin[] and __initdata_end[].

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:34 -07:00
..
bitops Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
4level-fixup.h
atomic64.h
atomic-long.h
atomic.h asm-generic: move cmpxchg*_local defs to cmpxchg.h 2013-03-13 06:11:05 +01:00
audit_change_attr.h
audit_dir_write.h
audit_read.h
audit_signal.h
audit_write.h
barrier.h Create asm-generic/barrier.h 2012-03-28 18:30:03 +01:00
bitops.h
bitsperlong.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
bug.h bug.h: Fix up CONFIG_BUG=n implicit function declarations. 2012-06-25 10:32:49 -07:00
bugs.h
cache.h
cacheflush.h
checksum.h asm-generic headers: Allow yet more arch overrides in checksum.h 2013-02-11 20:00:33 +05:30
clkdev.h asm-generic: Add default clkdev.h 2012-10-03 21:33:53 +02:00
cmpxchg-local.h generic: Use raw local irq variant for generic cmpxchg 2013-02-19 08:43:37 +01:00
cmpxchg.h asm-generic: move cmpxchg*_local defs to cmpxchg.h 2013-03-13 06:11:05 +01:00
cputime_jiffies.h cputime: Move default nsecs_to_cputime() to jiffies based cputime file 2013-01-27 19:23:25 +01:00
cputime_nsecs.h cputime_nsecs: use math64.h for nsec resolution conversion helpers 2013-04-26 18:58:12 +02:00
cputime.h cputime: Generic on-demand virtual cputime accounting 2013-01-27 19:23:27 +01:00
current.h
delay.h
device.h
div64.h
dma-coherent.h common: dma-mapping: add support for generic dma_mmap_* calls 2012-07-30 12:25:46 +02:00
dma-contiguous.h mm: cma: fix condition check when setting global cma area 2012-07-06 12:02:04 +02:00
dma-mapping-broken.h asm-generic/dma-mapping-broken.h: Provide dma_alloc_attrs()/dma_free_attrs() 2012-12-25 20:14:54 +01:00
dma-mapping-common.h common: dma-mapping: introduce dma_get_sgtable() function 2012-07-30 12:25:46 +02:00
dma.h
emergency-restart.h
exec.h Split arch_align_stack() out from asm-generic/system.h 2012-03-28 18:30:03 +01:00
fb.h
ftrace.h
futex.h
getorder.h bitops: Add missing parentheses to new get_order macro 2012-02-24 10:39:27 -08:00
gpio.h gpiolib: let gpio_chip reference its descriptors 2013-02-11 22:21:28 +00:00
hardirq.h
hugetlb.h mm/hugetlb: add more arch-defined huge_pte functions 2013-04-29 15:54:33 -07:00
hw_irq.h
ide_iops.h
int-l64.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
int-ll64.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
io-64-nonatomic-hi-lo.h asm-generic: architecture independent readq/writeq for 32bit environment 2012-02-21 16:47:28 -08:00
io-64-nonatomic-lo-hi.h asm-generic: architecture independent readq/writeq for 32bit environment 2012-02-21 16:47:28 -08:00
io.h kernel: Fix s390 absolute memory access for /dev/mem 2013-05-22 09:45:57 +02:00
ioctl.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
iomap.h [PARISC] fix compile break caused by iomap: make IOPORT/PCI mapping functions conditional 2012-02-27 09:43:30 -06:00
irq_regs.h
irq.h
irqflags.h
Kbuild.asm UAPI: Set up uapi/asm/Kbuild.asm 2012-10-02 18:01:56 +01:00
kdebug.h
kmap_types.h asm-generic: remove km_type definitions 2012-07-24 15:27:30 +08:00
kvm_para.h KVM: add kvm_para_available to asm-generic/kvm_para.h 2013-06-05 13:21:29 +03:00
libata-portmap.h
linkage.h
local64.h atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
local.h atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
memory_model.h mm: fix __page_to_pfn for a const struct page argument 2011-08-17 13:00:20 -07:00
mm_hooks.h
mmu_context.h
mmu.h asm-generic/mmu.h: Add support for FDPIC 2012-12-09 23:14:14 +01:00
module.h Make most arch asm/module.h files use asm-generic/module.h 2012-09-28 14:31:03 +09:30
mutex-dec.h arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not 2013-06-26 12:10:55 +02:00
mutex-null.h arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not 2013-06-26 12:10:55 +02:00
mutex-xchg.h arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not 2013-06-26 12:10:55 +02:00
mutex.h
page.h The following changes since commit 3ee72ca992 2012-01-10 17:39:40 -08:00
param.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
parport.h include: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
pci_iomap.h [PARISC] fix compile break caused by iomap: make IOPORT/PCI mapping functions conditional 2012-02-27 09:43:30 -06:00
pci-bridge.h PCI: work around Stratus ftServer broken PCIe hierarchy 2012-04-30 15:21:02 -06:00
pci-dma-compat.h
pci.h PCI: collapse pcibios_resource_to_bus 2012-02-23 20:19:04 -07:00
percpu.h
pgalloc.h
pgtable-nopmd.h
pgtable-nopud.h
pgtable.h mm: soft-dirty bits for user memory changes tracking 2013-07-03 16:07:26 -07:00
ptrace.h
resource.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
rtc.h
rwsem.h Hexagon: Add locking types and functions 2011-11-01 07:34:20 -07:00
scatterlist.h
sections.h vmlinux.lds: add comments for global variables and clean up useless declarations 2013-07-03 16:07:34 -07:00
segment.h
serial.h
siginfo.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
signal.h unify default ptrace_signal_deliver 2012-11-29 00:01:23 -05:00
sizes.h ARM: 7430/1: sizes.h: move from asm-generic to <linux/sizes.h> 2012-06-28 17:14:34 +01:00
spinlock.h
statfs.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
string.h
switch_to.h Split the switch_to() wrapper out of asm-generic/system.h 2012-03-28 18:30:03 +01:00
syscall.h asm/syscall.h: add syscall_get_arch 2012-04-14 11:13:19 +10:00
syscalls.h burying unused conditionals 2013-02-14 09:21:15 -05:00
termios-base.h
termios.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
timex.h
tlb.h arch, mm: Remove tlb_fast_mode() 2013-06-06 10:07:26 +09:00
tlbflush.h BUG: headers with BUG/BUG_ON etc. need linux/bug.h 2012-03-04 17:54:34 -05:00
topology.h
trace_clock.h tracing,x86: Add a TSC trace_clock 2012-11-13 15:48:27 -05:00
uaccess-unaligned.h
uaccess.h asm-generic: uaccess s/might_sleep/might_fault/ 2013-05-28 09:41:05 +02:00
unaligned.h
unistd.h We get rid of the general module prefix confusion with a binary config option, 2013-05-05 10:58:06 -07:00
user.h
vga.h
vmlinux.lds.h Finally eradicate CONFIG_HOTPLUG 2013-06-03 14:20:18 -07:00
word-at-a-time.h word-at-a-time: make the interfaces truly generic 2012-05-26 11:33:40 -07:00
xor.h asm-generic: xor: mark static functions as __maybe_unused 2012-10-03 21:21:06 +02:00