linux-toradex.git/arch/x86/kernel/head64.c, branch v3.2.36

x86: Cleanup highmap after brk is concluded

2011-03-19T18:58:19+00:00

Now cleanup_highmap actually is in two steps: one is early in head64.c
and only clears above _end; a second one is in init_memory_mapping() and
tries to clean from _brk_end to _end.
It should check if those boundaries are PMD_SIZE aligned but currently
does not.
Also init_memory_mapping() is called several times for numa or memory
hotplug, so we really should not handle initial kernel mappings there.

This patch moves cleanup_highmap() down after _brk_end is settled so
we can do everything in one step.
Also we honor max_pfn_mapped in the implementation of cleanup_highmap.

Signed-off-by: Yinghai Lu 
Signed-off-by: Stefano Stabellini 
LKML-Reference: 
Signed-off-by: H. Peter Anvin

x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S

2010-10-14T07:06:49+00:00

head_64.S maps up to 512 MiB, but that is not necessarity true for
other entry paths, such as Xen.

Thus, co-locate the setting of max_pfn_mapped with the code to
actually set up the page tables in head_64.S.  The 32-bit code is
already so co-located.  (The Xen code already sets max_pfn_mapped
correctly for its own use case.)

-v2:

 Yinghai fixed the following bug in this patch:

 |
 | max_pfn_mapped is in .bss section, so we need to set that
 | after bss get cleared. Without that we crash on bootup.
 |
 | That is safe because Xen does not call x86_64_start_kernel().
 |

Signed-off-by: Jeremy Fitzhardinge 
Fixed-by: Yinghai Lu 
Signed-off-by: H. Peter Anvin 
LKML-Reference: <4CB6AB24.9020504@kernel.org>
Signed-off-by: Ingo Molnar

x86, memblock: Replace e820_/_early string with memblock_

2010-08-27T18:13:47+00:00

1.include linux/memblock.h directly. so later could reduce e820.h reference.
2 this patch is done by sed scripts mainly

-v2: use MEMBLOCK_ERROR instead of -1ULL or -1UL

Signed-off-by: Yinghai Lu 
Signed-off-by: H. Peter Anvin

x86: Use memblock to replace early_res

2010-08-27T18:12:29+00:00

1. replace find_e820_area with memblock_find_in_range
2. replace reserve_early with memblock_x86_reserve_range
3. replace free_early with memblock_x86_free_range.
4. NO_BOOTMEM will switch to use memblock too.
5. use _e820, _early wrap in the patch, in following patch, will
   replace them all
6. because memblock_x86_free_range support partial free, we can remove some special care
7. Need to make sure that memblock_find_in_range() is called after memblock_x86_fill()
   so adjust some calling later in setup.c::setup_arch()
   -- corruption_check and mptable_update

-v2: Move reserve_brk() early
    Before fill_memblock_area, to avoid overlap between brk and memblock_find_in_range()
    that could happen We have more then 128 RAM entry in E820 tables, and
    memblock_x86_fill() could use memblock_find_in_range() to find a new place for
    memblock.memory.region array.
    and We don't need to use extend_brk() after fill_memblock_area()
    So move reserve_brk() early before fill_memblock_area().
-v3: Move find_smp_config early
    To make sure memblock_find_in_range not find wrong place, if BIOS doesn't put mptable
    in right place.
-v4: Treat RESERVED_KERN as RAM in memblock.memory. and they are already in
    memblock.reserved already..
    use __NOT_KEEP_MEMBLOCK to make sure memblock related code could be freed later.
-v5: Generic version __memblock_find_in_range() is going from high to low, and for 32bit
    active_region for 32bit does include high pages
    need to replace the limit with memblock.default_alloc_limit, aka get_max_mapped()
-v6: Use current_limit instead
-v7: check with MEMBLOCK_ERROR instead of -1ULL or -1L
-v8: Set memblock_can_resize early to handle EFI with more RAM entries
-v9: update after kmemleak changes in mainline

Suggested-by: David S. Miller 
Suggested-by: Benjamin Herrenschmidt 
Suggested-by: Thomas Gleixner 
Signed-off-by: Yinghai Lu 
Signed-off-by: H. Peter Anvin

x86: Make sure free_init_pages() frees pages on page boundary

2010-03-29T16:55:33+00:00

When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or
in a more compact fashion.

Example:

 Allocated new RAMDISK: 00ec2000 - 0248ce57
 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56

The new RAMDISK's end is not page aligned.
Last page could be shared with other users.

When free_init_pages are called for initrd or .init, the page
could be freed and we could corrupt other data.

code segment in free_init_pages():

 |        for (; addr < end; addr += PAGE_SIZE) {
 |                ClearPageReserved(virt_to_page(addr));
 |                init_page_count(virt_to_page(addr));
 |                memset((void *)(addr & ~(PAGE_SIZE-1)),
 |                        POISON_FREE_INITMEM, PAGE_SIZE);
 |                free_page(addr);
 |                totalram_pages++;
 |        }

last half page could be used as one whole free page.

So page align the boundaries.

-v2: make the original initramdisk to be aligned, according to
     Johannes, otherwise we have the chance to lose one page.
     we still need to keep initrd_end not aligned, otherwise it could
     confuse decompressor.
-v3: change to WARN_ON instead, suggested by Johannes.
-v4: use PAGE_ALIGN, suggested by Johannes.
     We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN
     Add comments about assuming ramdisk start is aligned
     in relocate_initrd(), change to re get ramdisk_image instead of save it
     to make diff smaller. Add warning for wrong range, suggested by Johannes.
-v6: remove one WARN()
     We need to align beginning in free_init_pages()
     do not copy more than ramdisk_size, noticed by Johannes

Reported-by: Stanislaw Gruszka 
Tested-by: Stanislaw Gruszka 
Signed-off-by: Yinghai Lu 
Acked-by: Johannes Weiner 
Cc: David Miller 
Cc: Benjamin Herrenschmidt 
Cc: Linus Torvalds 
LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org>
Signed-off-by: Ingo Molnar

x86: Use find_e820() instead of hard coded trampoline address

2009-12-11T08:28:22+00:00

Jens found the following crash/regression:

[    0.000000] found SMP MP-table at [ffff8800000fdd80] fdd80
[    0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 0-fff BIOS data page

and

[    0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 6000-7fff TRAMPOLINE

and bisected it to b24c2a9 ("x86: Move find_smp_config()
earlier and avoid bootmem usage").

It turns out the BIOS is using the first 64k for mptable,
without reserving it.

So try to find good range for the real-mode trampoline instead of
hard coding it, in case some bios tries to use that range for sth.

Reported-by: Jens Axboe 
Signed-off-by: Yinghai Lu 
Tested-by: Jens Axboe 
Cc: Randy Dunlap 
LKML-Reference: <4B21630A.6000308@kernel.org>
Signed-off-by: Ingo Molnar

x86: Add early platform detection

2009-08-31T09:09:40+00:00

Platforms like Moorestown require early setup and want to avoid the
call to reserve_ebda_region. The x86_init override is too late when
the MRST detection happens in setup_arch. Move the default i386
x86_init overrides and the call to reserve_ebda_region into a separate
function which is called as the default of a switch case depending on
the hardware_subarch id in boot params. This allows us to add a case
for MRST and let MRST have its own early setup function.

Signed-off-by: Thomas Gleixner

x86: Add reserve_ebda_region to x86_init_ops

2009-08-27T15:12:52+00:00

reserve_ebda_region needs to be called befor start_kernel. Moorestown
needs to override it. Make it a x86_init_ops function and initialize
it with the default reserve_ebda_region.

Signed-off-by: Thomas Gleixner

x86: add brk allocation for very, very early allocations

2009-03-14T22:37:14+00:00

Impact: new interface

Add a brk()-like allocator which effectively extends the bss in order
to allow very early code to do dynamic allocations.  This is better than
using statically allocated arrays for data in subsystems which may never
get used.

The space for brk allocations is in the bss ELF segment, so that the
space is mapped properly by the code which maps the kernel, and so
that bootloaders keep the space free rather than putting a ramdisk or
something into it.

The bss itself, delimited by __bss_stop, ends before the brk area
(__brk_base to __brk_limit).  The kernel text, data and bss is reserved
up to __bss_stop.

Any brk-allocated data is reserved separately just before the kernel
pagetable is built, as that code allocates from unreserved spaces
in the e820 map, potentially allocating from any unused brk memory.
Ultimately any unused memory in the brk area is used in the general
kernel memory pool.

Initially the brk space is set to 1MB, which is probably much larger
than any user needs (the largest current user is i386 head_32.S's code
to build the pagetables to map the kernel, which can get fairly large
with a big kernel image and no PSE support).  So long as the system
has sufficient memory for the bootloader to reserve the kernel+1MB brk,
there are no bad effects resulting from an over-large brk.

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: H. Peter Anvin

x86: remove pda_init()

2009-01-20T03:29:19+00:00

Impact: cleanup

Copy the code to cpu_init() to satisfy the requirement that the cpu
be reinitialized.  Remove all other calls, since the segments are
already initialized in head_64.S.

Signed-off-by: Brian Gerst 
Signed-off-by: Tejun Heo