Jan Beulich [Thu, 13 Mar 2008 09:08:51 +0000 (09:08 +0000)]
x86: bitops asm constraint fixes
This (simplified) piece of code didn't behave as expected due to
incorrect constraints in some of the bitops functions, when
X86_FEATURE_xxx is referring to other than the first long:
int test(struct cpuinfo_x86 *c) {
if (cpu_has(c, X86_FEATURE_xxx))
clear_cpu_cap(c, X86_FEATURE_xxx);
return cpu_has(c, X86_FEATURE_xxx);
}
I'd really like understand, though, what the policy of (not) having a
"memory" clobber in these operations is - currently, this appears to
be totally inconsistent. Also, many comments of the non-atomic
functions say those may also be re-ordered - this contradicts the use
of "asm volatile" in there, which again I'd like to understand.
As much as all of these, using 'int' for the 'nr' parameter and
'void *' for the 'addr' one is in conflict with
Documentation/atomic_ops.txt, especially because bt{,c,r,s} indeed
take the bit index as signed (which hence would really need special
precaution) and access the full 32 bits (if 'unsigned long' was used
properly here, 64 bits for x86-64) pointed at, so invalid uses like
referencing a 'char' array cannot currently be caught.
Finally, the code with and without this patch relies heavily on the
-fno-strict-aliasing compiler switch and I'm not certain this really
is a good idea.
In the light of all of this I'm sending this as RFC, as fixing the
above might warrant a much bigger patch...
Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Andrew Morton [Wed, 19 Mar 2008 01:54:45 +0000 (18:54 -0700)]
i386: arch/x86/math-emu/reg_ld_str.c: fix warning
arch/x86/math-emu/reg_ld_str.c:380: warning: 'l[0]' may be used uninitialized in this function
arch/x86/math-emu/reg_ld_str.c:380: warning: 'l[1]' may be used uninitialized in this function
I can't actually spot the bug here. There's one obvious place, but fixing
that didn't shut the warning up.
Venki Pallipadi [Mon, 24 Mar 2008 21:39:55 +0000 (14:39 -0700)]
x86: PAT bug fix for attribute type check after reserve_memtype
Bug fixes for reserve_memtype() call in __ioremap and pci_mmap_page_range().
If reserve_memtype returns non-zero, then it is an error and subsequent free is
not required. Requested and returned prot value check should be done when
reserve_memtype returns success.
Adds debug prints at critical code. Adds enough info in dmesg to allow us to
do effective first round of analysis of any issues that may result due to PAT
patch series.
Add a set_memory_wc interface(), similar to set_memory_uc interface.
Callers has to call set_memory_uc, set_memory_wb and
set_memory_wc, set_memory_wb as pairs.
x86: PAT use reserve free memtype in pci_mmap_page_range
Add reserve_memtype and free_memtype wrapper for pci_mmap_page_range. Free
is called on unmap, but identity map continues to be mapped as per
pci_mmap_page_range request, until next request for the same region calls
ioremap_change_attr(), which will go through without conflict. This way of
mapping is identical to one used in ioremap/iounmap.
x86: PAT use reserve free memtype in set_memory_uc
Use reserve_memtype and free_memtype interfaces in set_memory_uc/set_memory_wb
interfaces to avoid aliasing.
Usage model of set_memory_uc and set_memory_wb is for RAM memory and users
will first call set_memory_uc and call set_memory_wb after use to reset the
attribute.
x86: PAT use reserve free memtype in ioremap and iounmap
Use reserve_memtype and free_memtype interfaces in ioremap/iounmap to avoid
aliasing.
If there is an existing alias for the region, inherit the memory type from
the alias. If there are conflicting aliases for the entire region, then fail
ioremap.
PAT MSR has following setting.
PAT
|PCD
||PWT
|||
000 WB _PAGE_CACHE_WB
001 WC _PAGE_CACHE_WC
010 UC- _PAGE_CACHE_UC_MINUS
011 UC _PAGE_CACHE_UC
We are effectively changing WT from boot time setting to WC.
UC_MINUS is used to provide backward compatibility to existing /dev/mem
users(X).
reserve_memtype and free_memtype are new interfaces for maintaining alias-free
mapping. It is currently implemented in a simple way with a linked list and
not optimized. reserve and free tracks the effective memory type, as a result
of PAT and MTRR setting rather than what is actually requested in PAT.
pat_init piggy backs on mtrr_init as the rules for setting both pat and mtrr
are same.
Yakov Lerner [Sun, 16 Mar 2008 08:21:21 +0000 (03:21 -0500)]
x86, kprobes: correct post-eip value in post_hander()
I was trying to get the address of instruction to be executed
next after the kprobed instruction. But regs->eip in post_handler()
contains value which is useless to the user. It's pre-corrected value.
This value is difficult to use without access to resume_execution(), which
is not exported anyway.
I moved the invocation of post_handler() to *after* resume_execution().
Now regs->eip contains meaningful value in post_handler().
I do not think this change breaks any backward-compatibility.
To make meaning of the old value, post_handler() would need access to
resume_execution() which is not exported. I have difficulty to believe
that previous, uncorrected, regs->eip can be meaningfully used in
post_handler().
Roland McGrath [Wed, 19 Mar 2008 01:23:50 +0000 (18:23 -0700)]
x86: ia32 ptrace vs -ENOSYS sysenter/syscall
The previous "x86_64 ia32 ptrace vs -ENOSYS" fix only covered
the int $0x80 system call entries. This does the same fix
for the sysenter and syscall instruction paths.
Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Roland McGrath [Mon, 17 Mar 2008 04:59:11 +0000 (21:59 -0700)]
x86: ptrace vs -ENOSYS
When we're stopped at syscall entry tracing, ptrace can change the %rax
value from -ENOSYS to something else. If no system call is actually made
because the syscall number (now in orig_rax) is bad, then we now always
reset %rax to -ENOSYS again.
This changes it to leave the return value alone after entry tracing.
That way, the %rax value set by ptrace is there to be seen in user mode
(or in syscall exit tracing). This is consistent with what the 32-bit
kernel does.
Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Roland McGrath [Mon, 17 Mar 2008 04:57:41 +0000 (21:57 -0700)]
x86: ia32 ptrace vs -ENOSYS
When we're stopped at syscall entry tracing, ptrace can change the %eax
value from -ENOSYS to something else. If no system call is actually made
because the syscall number (now in orig_eax) is bad, then the %eax value
set by ptrace should be returned to the user. But, instead it gets reset
to -ENOSYS again. This is a regression from the native 32-bit kernel.
This change fixes it by leaving the return value alone after entry tracing.
Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: fix build breakage when PCI is define and PARAVIRT is not
- Fix the the build breakage when PARAVIRT is defined
but PCI is not
This fixes problem reported at:
http://marc.info/?l=linux-kernel&m=120525966600698&w=2
- Make is_vsmp_box() available even when PARAVIRT is not defined.
This is needed to determine if tsc's are reliable as a time source
even when PARAVIRT is not defined.
- split vsmp_init to use is_vsmp_box() and set_vsmp_pv_ops()
set_vsmp_pv_ops will do nothing if PCI is not enabled in the config.
Remove the last leftovers from the files. Move the ones
that are still used to the files they belong, the others
that grep can't reach, simply throw away.
Merge comments ontop of file and that's it: smpboot integrated
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
With the previous changes, code for native_smp_prepare_cpus()
in i386 and x86_64 now look very similar. merge them into
smpboot.c. Minor differences are inside ifdef
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86_64 has two nr_ioapics = 0 statements. In 32-bit, it can be done
too. We do it through the smpboot_clear_io_apic() inline function,
to cope with subarchitectures (visws) that does not compile mpparse in
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
They are mostly inocuous. APIC_INTEGRATED will expand to 1,
check_phys_apicid_present is checking for the same thing it was before,
etc. But the code is identical to i386 now, and will allow us to
integrate it.
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: change x86_64 native_smp_prepare_cpus to match i386
An APIC test is moved, and code is replaced by the mach-default
already defined function (smpboot_setup_io_apic).
setup_portio_remap() is added, but it is a nop in mach-default.
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This is a very large patch, because it depends on a lot
of auxiliary static functions. But they all have been modified
to the point that they're sufficiently close now. So they're just
merged in smpboot.c
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
voyager would conflict with it, but the types are ultimately
compatible. So remove the extern definition from voyager_smp.c
in favour of the common one
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: include mach_apic.h in smpboot_64.c and smpboot.c
After the inclusion, a lot of files needs fixing for conflicts,
some of them in the headers themselves, to accomodate for both
i386 and x86_64 versions.
[ mingo@elte.hu: build fix ]
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
We do it to make it close to x86_64. The later needs it,
otherwise the nmi watchdog can get into the scene and kill us
with a hammer.
Enabling irqs here used to trigger a bug in i386. This is because
time irq handling relies upon structures that are only initialized
after smp initcalls (More precisely, it will find
per_cpu(hrtimer_bases, cpu)->cb_pending list not initialized and crash)
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
It splits setup_local_APIC in two, providing a function corresponding
to the ending part of it. As a side effect, smp_callin looks the same
between i386 and x86_64.
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use a new worker, with help of the create_idle struct
to fork the idle thread. We now have two workers, the first
of them triggered by __smp_prepare_cpu. But the later is
going away soon.
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: boot cpus from cpu_up, instead of prepare_cpus
After all the infrastructure work, we're now prepared
to boot the cpus from cpu_up, and not from prepare_cpus.
So the difference between cold boot and hotplug is effectively
over, and the functions are used to the purposes they're meant to.
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: do not zap_low_mappings in __smp_prepare_cpus
It was okay when cpus were cold booted before this point.
But with the new state machine, they will not have arrived to
the trampoline yet. zapping low mappings will have the bad effect
of breaking it completely after paging enablement
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
this patch allows x86_64 to use subarch mach_ headers
in practice, since x86_64 does not have any subarch, it
will use mach_default. But it will allow for substantially
less code duplication
Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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