Skip to content

R
raspberrypi-kernel

openeuler / raspberrypi-kernel

通知 13
Star 1
Fork 0
R
raspberrypi-kernel
切换分支/标签
  1. 07 6月, 2013 1 次提交
  3. 13 2月, 2013 4 次提交
  5. 01 2月, 2013 1 次提交
  7. 20 1月, 2013 1 次提交
    • H
      x86-32: Start out cr0 clean, disable paging before modifying cr3/4 · 021ef050
      由 H. Peter Anvin 提交于 
      Patch

  5a5a51db x86-32: Start out eflags and cr4 clean

... made x86-32 match x86-64 in that we initialize %eflags and %cr4
from scratch.  This broke OLPC XO-1.5, because the XO enters the
kernel with paging enabled, which the kernel doesn't expect.

Since we no longer support 386 (the source of most of the variability
in %cr0 configuration), we can simply match further x86-64 and
initialize %cr0 to a fixed value -- the one variable part remaining in
%cr0 is for FPU control, but all that is handled later on in
initialization; in particular, configuring %cr0 as if the FPU is
present until proven otherwise is correct and necessary for the probe
to work.

To deal with the XO case sanely, explicitly disable paging in %cr0
before we muck with %cr3, %cr4 or EFER -- those operations are
inherently unsafe with paging enabled.

NOTE: There is still a lot of 386-related junk in head_32.S which we
can and should get rid of, however, this is intended as a minimal fix
whereas the cleanup can be deferred to the next merge window.
Reported-by: NAndres Salomon <dilinger@queued.net>
Tested-by: NDaniel Drake <dsd@laptop.org>
Link: http://lkml.kernel.org/r/50FA0661.2060400@linux.intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      021ef050
  9. 28 11月, 2012 1 次提交
    • H
      x86-32: Unbreak booting on some 486 clones · 6662c34f
      由 H. Peter Anvin 提交于 
      There appear to have been some 486 clones, including the "enhanced"
version of Am486, which have CPUID but not CR4.  These 486 clones had
only the FPU flag, if any, unlike the Intel 486s with CPUID, which
also had VME and therefore needed CR4.

Therefore, look at the basic CPUID flags and require at least one bit
other than bit 0 before we modify CR4.

Thanks to Christian Ludloff of sandpile.org for confirming this as a
problem.
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      6662c34f
  11. 15 11月, 2012 1 次提交
  13. 27 9月, 2012 1 次提交
  15. 09 5月, 2012 1 次提交
  17. 20 4月, 2012 1 次提交
    • H
      x86-32: Handle exception table entries during early boot · 4c5023a3
      由 H. Peter Anvin 提交于 
      If we get an exception during early boot, walk the exception table to
see if we should intercept it.  The main use case for this is to allow
rdmsr_safe()/wrmsr_safe() during CPU initialization.

Since the exception table is currently sorted at runtime, and fairly
late in startup, this code walks the exception table linearly.  We
obviously don't need to worry about modules, however: none have been
loaded at this point.

This patch changes the early IDT setup to look a lot more like x86-64:
we now install handlers for all 32 exception vectors.  The output of
the early exception handler has changed somewhat as it directly
reflects the stack frame of the exception handler, and the stack frame
has been somewhat restructured.

Finally, centralize the code that can and should be run only once.

[ v2: Use early_fixup_exception() instead of linear search ]
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1334794610-5546-6-git-send-email-hpa@zytor.com
      4c5023a3
  19. 26 2月, 2011 1 次提交
  21. 23 2月, 2011 1 次提交
  23. 05 2月, 2011 1 次提交
  25. 04 1月, 2011 1 次提交
  27. 17 12月, 2010 1 次提交
  29. 16 12月, 2010 1 次提交
    • R
      lguest: populate initial_page_table · da32dac1
      由 Rusty Russell 提交于 
      Two x86 patches broke lguest:
1) v2.6.35-492-g72d7c3b3, which changed x86 to use the memblock allocator.

In lguest, the host places linear page tables at the top of mem, which
used to be enough to get us up to the swapper_pg_dir page tables.  With
the first patch, the direct mapping tables used that memory:

Before: kernel direct mapping tables up to 4000000 @ 7000-1a000
After: kernel direct mapping tables up to 4000000 @ 3fed000-4000000

I initially fixed this by lying about the amount of memory we had, so
the kernel wouldn't blatt the lguest boot pagetables (yuk!), but then...

2) v2.6.36-rc8-54-gb40827fa, which made x86 boot use initial_page_table.

This was initialized in a part of head_32.S which isn't executed by
lguest; it is then copied into swapper_pg_dir.  So we have to initialize
it; and anyway we switch to it before we blatt the old tables, so that
fixes the previous damage as well.

For the moment, I cut & pasted the code into lguest's boot code, but
next merge window I will merge them.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: x86@kernel.org
      da32dac1
  31. 11 11月, 2010 1 次提交
  33. 02 11月, 2010 1 次提交
  35. 21 10月, 2010 1 次提交
  37. 19 8月, 2010 1 次提交
    • J
      x86-32: Separate 1:1 pagetables from swapper_pg_dir · fd89a137
      由 Joerg Roedel 提交于 
      This patch fixes machine crashes which occur when heavily exercising the
CPU hotplug codepaths on a 32-bit kernel. These crashes are caused by
AMD Erratum 383 and result in a fatal machine check exception. Here's
the scenario:

1. On 32-bit, the swapper_pg_dir page table is used as the initial page
table for booting a secondary CPU.

2. To make this work, swapper_pg_dir needs a direct mapping of physical
memory in it (the low mappings). By adding those low, large page (2M)
mappings (PAE kernel), we create the necessary conditions for Erratum
383 to occur.

3. Other CPUs which do not participate in the off- and onlining game may
use swapper_pg_dir while the low mappings are present (when leave_mm is
called). For all steps below, the CPU referred to is a CPU that is using
swapper_pg_dir, and not the CPU which is being onlined.

4. The presence of the low mappings in swapper_pg_dir can result
in TLB entries for addresses below __PAGE_OFFSET to be established
speculatively. These TLB entries are marked global and large.

5. When the CPU with such TLB entry switches to another page table, this
TLB entry remains because it is global.

6. The process then generates an access to an address covered by the
above TLB entry but there is a permission mismatch - the TLB entry
covers a large global page not accessible to userspace.

7. Due to this permission mismatch a new 4kb, user TLB entry gets
established. Further, Erratum 383 provides for a small window of time
where both TLB entries are present. This results in an uncorrectable
machine check exception signalling a TLB multimatch which panics the
machine.

There are two ways to fix this issue:

        1. Always do a global TLB flush when a new cr3 is loaded and the
        old page table was swapper_pg_dir. I consider this a hack hard
        to understand and with performance implications

        2. Do not use swapper_pg_dir to boot secondary CPUs like 64-bit
        does.

This patch implements solution 2. It introduces a trampoline_pg_dir
which has the same layout as swapper_pg_dir with low_mappings. This page
table is used as the initial page table of the booting CPU. Later in the
bringup process, it switches to swapper_pg_dir and does a global TLB
flush. This fixes the crashes in our test cases.

-v2: switch to swapper_pg_dir right after entering start_secondary() so
that we are able to access percpu data which might not be mapped in the
trampoline page table.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <20100816123833.GB28147@aftab>
Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      fd89a137
  39. 19 6月, 2010 1 次提交
    • A
      x86, olpc: Add support for calling into OpenFirmware · fd699c76
      由 Andres Salomon 提交于 
      Add support for saving OFW's cif, and later calling into it to run OFW
commands.  OFW remains resident in memory, living within virtual range
0xff800000 - 0xffc00000.  A single page directory entry points to the
pgdir that OFW actually uses, so rather than saving the entire page
table, we grab and install that one entry permanently in the kernel's
page table.

This is currently only used by the OLPC XO.  Note that this particular
calling convention breaks PAE and PAT, and so cannot be used on newer
x86 hardware.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
LKML-Reference: <20100618174653.7755a39a@dev.queued.net>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      fd699c76
  41. 17 11月, 2009 1 次提交
  43. 29 10月, 2009 1 次提交
  45. 21 9月, 2009 2 次提交
  47. 19 9月, 2009 1 次提交
    • T
      x86: convert to use __HEAD and HEAD_TEXT macros. · 4ae59b91
      由 Tim Abbott 提交于 
      This has the consequence of changing the section name use for head
code from ".text.head" to ".head.text".  It also eliminates the
".text.head" output section (instead placing head code at the start of
the .text output section), which should be harmless.

This patch only changes the sections in the actual kernel, not those
in the compressed boot loader.
Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      4ae59b91
  49. 04 9月, 2009 1 次提交
    • J
      x86/i386: Make sure stack-protector segment base is cache aligned · 1ea0d14e
      由 Jeremy Fitzhardinge 提交于 
      The Intel Optimization Reference Guide says:

	In Intel Atom microarchitecture, the address generation unit
	assumes that the segment base will be 0 by default. Non-zero
	segment base will cause load and store operations to experience
	a delay.
		- If the segment base isn't aligned to a cache line
		  boundary, the max throughput of memory operations is
		  reduced to one [e]very 9 cycles.
	[...]
	Assembly/Compiler Coding Rule 15. (H impact, ML generality)
	For Intel Atom processors, use segments with base set to 0
	whenever possible; avoid non-zero segment base address that is
	not aligned to cache line boundary at all cost.

We can't avoid having a non-zero base for the stack-protector
segment, but we can make it cache-aligned.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: <stable@kernel.org>
LKML-Reference: <4AA01893.6000507@goop.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1ea0d14e
  51. 31 8月, 2009 1 次提交
  53. 18 8月, 2009 1 次提交
    • J
      i386: Fix section mismatches for init code with !HOTPLUG_CPU · 78b89ecd
      由 Jan Beulich 提交于 
      Commit 0e83815b changed the
section the initial_code variable gets allocated in, in an
attempt to address a section conflict warning. This, however
created a new section conflict when building without
HOTPLUG_CPU. The apparently only (reasonable) way to address
this is to always use __REFDATA.

Once at it, also fix a second section mismatch when not using
HOTPLUG_CPU.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <4A8AE7CD020000780001054B@vpn.id2.novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      78b89ecd
  55. 28 7月, 2009 1 次提交
    • R
      x86: fix section mismatch for i386 init code · 0e83815b
      由 Robert Richter 提交于 
      Startup code for i386 in arch/x86/kernel/head_32.S is using the
reference variable initial_code that is located in the .cpuinit.data
section. If CONFIG_HOTPLUG_CPU is enabled, startup code is not in an
init section and can be called later too. In this case the reference
initial_code must be kept too. This patch fixes this. See below for
the section mismatch warning.

 WARNING: vmlinux.o(.cpuinit.data+0x0): Section mismatch in reference
 from the variable initial_code to the function
 .init.text:i386_start_kernel()
 The variable __cpuinitdata initial_code references
 a function __init i386_start_kernel().
 If i386_start_kernel is only used by initial_code then
 annotate i386_start_kernel with a matching annotation.
Signed-off-by: NRobert Richter <robert.richter@amd.com>
LKML-Reference: <1248716632-26844-1-git-send-email-robert.richter@amd.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      0e83815b
  57. 18 6月, 2009 1 次提交
  59. 29 4月, 2009 1 次提交
    • S
      x86, vmlinux.lds: unify .text output sections · dfc20895
      由 Sam Ravnborg 提交于 
      32 bit x86 had a dedicated .text.head output section,
whereas 64 bit had it all in a single output section.

In the unified version the dedicated .text.head output section
was kept to have full control over the head code.

32 bit:

- Moved definition of _stext to the linker script.
  The definition is located _after_ .text.page_aligned as this
  is what 32 bit did before.

The ALIGN(8) was introduced so we hit the exact same address
(on the tested config) before and after the move.

I assume that it is a bug that _stext did not cover the
.text.page_aligned section - if this is true it can be fixed
in a follow-up patch (and the ugly ALIGN() can be dropped).

[ Impact: 64-bit: cleanup, 32-bit: use the 64-bit linker script ]
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Tim Abbott <tabbott@MIT.EDU>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1240991249-27117-5-git-send-email-sam@ravnborg.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      dfc20895
  61. 18 3月, 2009 3 次提交
  63. 15 3月, 2009 3 次提交
    • Y
      x86: put initial_pg_tables into .bss · 2bd2753f
      由 Yinghai Lu 提交于 
      Impact: makes vmlinux section information more useful

Don't use ram after _end blindly for pagetables. aka init pages is before _end
put those pg table into .bss

[Adapted to use brk segment - Jeremy]

v2: keep initial page table up to 512M only.
v4: put initial page tables just before _end
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      2bd2753f
    • J
      x86: allow extend_brk users to reserve brk space · 796216a5
      由 Jeremy Fitzhardinge 提交于 
      Impact: new interface; remove hard-coded limit

Add RESERVE_BRK(name, size) macro to reserve space in the brk
area.  This should be a conservative (ie, larger) estimate of
how much space might possibly be required from the brk area.
Any unused space will be freed, so there's no real downside
on making the reservation too large (within limits).

The name should be unique within a given file, and somewhat
descriptive.

The C definition of RESERVE_BRK() ends up being more complex than
one would expect to work around a cluster of gcc infelicities:

  The first attempt was to simply try putting __section(.brk_reservation)
  on a variable.  This doesn't work because it ends up making it a
  @progbits section, which gets actual space allocated in the vmlinux
  executable.

  The second attempt was to emit the space into a section using asm,
  but gcc doesn't allow arguments to be passed to file-level asm()
  statements, making it hard to pass in the size.

  The final attempt is to wrap the asm() in a function to allow
  it to have arguments, and put the function itself into the
  .discard section, which vmlinux*.lds drops entirely from the
  emitted vmlinux.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      796216a5
    • Y
      x86-32: compute initial mapping size more accurately · 7543c1de
      由 Yinghai Lu 提交于 
      Impact: simplification

We only need to map the kernel in head_32.S, not the whole of
lowmem.  We use 512MB as a reasonable (but arbitrary) limit on
the maximum size of the kernel image.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      7543c1de