linux.git/include/asm-x86, branch v2.6.25

Add commentary about the new "asmlinkage_protect()" macro

2008-04-11T00:35:23+00:00

It's really a pretty ugly thing to need, and some day it will hopefully
be obviated by teaching gcc about the magic calling conventions for the
low-level system call code, but in the meantime we can at least add big
honking comments about why we need these insane and strange macros.

I took my comments from my version of the macro, but I ended up deciding
to just pick Roland's version of the actual code instead (with his
prettier syntax that uses vararg macros).  Thus the previous two commits
that actually implement it.

Signed-off-by: Linus Torvalds

asmlinkage_protect replaces prevent_tail_call

2008-04-11T00:28:26+00:00

The prevent_tail_call() macro works around the problem of the compiler
clobbering argument words on the stack, which for asmlinkage functions
is the caller's (user's) struct pt_regs.  The tail/sibling-call
optimization is not the only way that the compiler can decide to use
stack argument words as scratch space, which we have to prevent.
Other optimizations can do it too.

Until we have new compiler support to make "asmlinkage" binding on the
compiler's own use of the stack argument frame, we have work around all
the manifestations of this issue that crop up.

More cases seem to be prevented by also keeping the incoming argument
variables live at the end of the function.  This makes their original
stack slots attractive places to leave those variables, so the compiler
tends not clobber them for something else.  It's still no guarantee, but
it handles some observed cases that prevent_tail_call() did not.

Signed-off-by: Roland McGrath 
Signed-off-by: Linus Torvalds

x86: fix 64-bit asm NOPS for CONFIG_GENERIC_CPU

2008-04-07T19:09:14+00:00

ASM_NOP's for 64-bit kernel with CONFIG_GENERIC_CPU is broken
with the recent x86 nops merge. They were using GENERIC_NOPS
which will truncate the upper 32bits of %rsi, because of the missing
64bit rex prefix.

For now, fall back ASM NOPS for generic cpu to K8 NOPS, similar
to the code before the wrong x86 nop merge.

This should resolve the crash seen by Ingo on a test-system:

BUG: unable to handle kernel paging request at 00000000d80d8ee8
IP: [] save_i387_ia32+0x61/0xd8
PGD b8e0067 PUD 51490067 PMD 0
Oops: 0000 [1] SMP
CPU 2
Modules linked in:
Pid: 3871, comm: distcc Not tainted 2.6.25-rc7-sched-devel.git-x86-latest.git #359
RIP: 0010:[]  [] save_i387_ia32+0x61/0xd8
RSP: 0000:ffff81003abd3cb8  EFLAGS: 00010246
RAX: ffff810082e93400 RBX: 00000000ffc37f84 RCX: ffff8100d80d8ee0
RDX: 0000000000000000 RSI: 00000000d80d8ee0 RDI: ffff810082e93400
RBP: 00000000ffc37fdc R08: 00000000ffc37f88 R09: 0000000000000008
R10: ffff81003abd2000 R11: 0000000000000000 R12: ffff810082e93400
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff81011fb12dc0(0063) knlGS:00000000f7f1a6c0
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000d80d8ee8 CR3: 0000000076922000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process distcc (pid: 3871, threadinfo ffff81003abd2000, task ffff8100d80d8ee0)
Stack:  ffff8100bb670380 ffffffff8026de50 0000000000000118 0000000000000002
 0000000000000002 ffff81003abd3e68 ffff81003abd3ed8 ffff81003abd3de8
 ffff81003abd3d18 ffffffff80229785 ffff8100d80d8ee0 ffff810001041280
Call Trace:
 [] ? __generic_file_aio_write_nolock+0x343/0x377
 [] ? update_curr+0x54/0x64
 [] ? ia32_setup_sigcontext+0x125/0x1d2
 [] ? ia32_setup_frame+0x73/0x1a5
 [] ? do_notify_resume+0x1aa/0x7db
 [] ? getnstimeofday+0x31/0x85
 [] ? ktime_get_ts+0x17/0x48
 [] ? ktime_get+0xc/0x41
 [] ? hrtimer_nanosleep+0x75/0xd5
 [] ? hrtimer_wakeup+0x0/0x21
 [] ? int_signal+0x12/0x17
 [] ? dummy_file_free_security+0x0/0x1

Code: a6 08 05 00 00 f6 40 14 01 74 34 4c 89 e7 48 0f ae 07 48 8b 86 08 05 00 00 80 78 02 00 79 02 db e2 90 8d b4 26 00 00 00 00 89 f6 <48> 8b 46 08 83 60 14 fe 0f 20 c0 48 83 c8 08 0f 22 c0 eb 07 c6 

Signed-off-by: Suresh Siddha 
Signed-off-by: Ingo Molnar

x86: fix breakage of vSMP irq operations

2008-04-04T16:36:46+00:00

25-rc* stopped working with CONFIG_X86_VSMP on vSMP machines.

Looks like the vsmp irq ops got accidentally removed during merge of x86_64
pvops in 2.6.25. -- commit 6abcd98ffafbff81f0bfd7ee1d129e634af13245 removed
vsmp irq ops.

Tested with both CONFIG_X86_VSMP and without CONFIG_X86_VSMP, on vSMP and non
vSMP x86_64 machines.

Please apply.

Signed-off-by: Ravikiran Thirumalai 
Signed-off-by: Ingo Molnar

lguest: comment documentation update.

2008-03-28T00:05:54+00:00

Took some cycles to re-read the Lguest Journey end-to-end, fix some
rot and tighten some phrases.

Only comments change.  No new jokes, but a couple of recycled old jokes.

Signed-off-by: Rusty Russell

rdc321x: GPIO routines bugfixes

2008-03-27T15:08:45+00:00

This patch fixes the use of GPIO routines which are in the PCI
configuration space of the RDC321x, therefore reading/writing
to this space without spinlock protection can be problematic.

We also now request and free GPIOs and support the MGB100
board, previous code was very AR525W-centric.

Signed-off-by: Volker Weiss 
Signed-off-by: Florian Fainelli 
Signed-off-by: Ingo Molnar

x86: fix performance drop for glx

2008-03-26T21:23:41+00:00

fix the 3D performance drop reported at:

   http://bugzilla.kernel.org/show_bug.cgi?id=10328

fb drivers are using ioremap()/ioremap_nocache(), followed by mtrr_add with
WC attribute. Recent changes in page attribute code made both
ioremap()/ioremap_nocache() mappings as UC (instead of previous UC-). This
breaks the graphics performance, as the effective memory type is UC instead
of expected WC.

The correct way to fix this is to add ioremap_wc() (which uses UC- in the
absence of PAT kernel support and WC with PAT) and change all the
fb drivers to use this new ioremap_wc() API.

We can take this correct and longer route for post 2.6.25. For now,
revert back to the UC- behavior for ioremap/ioremap_nocache.

Signed-off-by: Suresh Siddha 
Signed-off-by: Venkatesh Pallipadi 
Cc: Arjan van de Ven 
Signed-off-by: Ingo Molnar

x86-32: Pass the full resource data to ioremap()

2008-03-24T18:22:39+00:00

It appears that 64-bit PCI resources cannot possibly ever have worked on
x86-32 even when the RESOURCES_64BIT config option was set, because any
driver that tried to [pci_]ioremap() the resource would have been unable
to do so because the high 32 bits would have been silently dropped on
the floor by the ioremap() routines that only used "unsigned long".

Change them to use "resource_size_t" instead, which properly encodes the
whole 64-bit resource data if RESOURCES_64BIT is enabled.

Acked-by: H. Peter Anvin 
Acked-by: Stefan Richter 
Cc: Ivan Kokshaysky 
Signed-off-by: Linus Torvalds

x86: revert: reserve dma32 early for gart

2008-03-22T18:25:41+00:00

Revert

commit f62f1fc9ef94f74fda2b456d935ba2da69fa0a40
Author: Yinghai Lu 
Date:   Fri Mar 7 15:02:50 2008 -0800

    x86: reserve dma32 early for gart

The patch has a dependency on bootmem modifications which are not .25
material that late in the -rc cycle. The problem which is addressed by
the patch is limited to machines with 256G and more memory booted with
NUMA disabled. This is not a .25 regression and the audience which is
affected by this problem is very limited, so it's safer to do the
revert than pulling in intrusive bootmem changes right now.

Signed-off-by: Thomas Gleixner

sync_bitops: fix wrong comments [Bug 10247]

2008-03-21T16:06:15+00:00

Fix wrong function name and references to non-x86 architectures.

Signed-off-by: Matti Linnanvuori mattilinnanvuori@yahoo.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner