Currently x86 (similar to x84-64) has a special per-cpu structure
called "i386_pda" which can be easily and efficiently referenced via
the %fs register. An ELF section is more flexible than a structure,
allowing any piece of code to use this area. Indeed, such a section
already exists: the per-cpu area.
So this patch:
(1) Removes the PDA and uses per-cpu variables for each current member.
(2) Replaces the __KERNEL_PDA segment with __KERNEL_PERCPU.
(3) Creates a per-cpu mirror of __per_cpu_offset called this_cpu_off, which
can be used to calculate addresses for this CPU's variables.
(4) Simplifies startup, because %fs doesn't need to be loaded with a
special segment at early boot; it can be deferred until the first
percpu area is allocated (or never for UP).
The result is less code and one less x86-specific concept.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Xen wants a dedicated page for the GDT. I believe VMI likes it too.
lguest, KVM and native don't care.
Simple transformation to page-aligned "struct gdt_page".
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
As a bug workaround bank 0 on K7s is normally disabled, but no need
to do that on other AMD CPUs.
Cc: davej@redhat.com
Signed-off-by: Andi Kleen <ak@suse.de>
It doesn't put the CPU into deeper sleep states, so it's better to use the standard
idle loop to save power. But allow to reenable it anyways for benchmarking.
I also removed the obsolete idle=halt on i386
Cc: andreas.herrmann@amd.com
Signed-off-by: Andi Kleen <ak@suse.de>
identify_cpu() is used to identify both the boot CPU and secondary
CPUs, but it performs some actions which only apply to the boot CPU.
Those functions are therefore really __init functions, but because
they're called by identify_cpu(), they must be marked __cpuinit.
This patch splits identify_cpu() into identify_boot_cpu() and
identify_secondary_cpu(), and calls the appropriate init functions
from each. Also, identify_boot_cpu() and all the functions it
dominates are marked __init.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Most of asm-i386/bugs.h is code which should be in a C file, so put it there.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Now we have an explicit per-cpu GDT variable, we don't need to keep the
descriptors around to use them to find the GDT: expose cpu_gdt directly.
We could go further and make load_gdt() pack the descriptor for us, or even
assume it means "load the current cpu's GDT" which is what it always does.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We now have cpu_init() and secondary_cpu_init() doing nothing but calling
_cpu_init() with the same arguments. Rename _cpu_init() to cpu_init() and use
it as a replcement for secondary_cpu_init().
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now we are no longer dynamically allocating the GDT, we don't need the
"cpu_gdt_table" at all: we can switch straight from "boot_gdt_table" to the
per-cpu GDT. This means initializing the cpu_gdt array in C.
The boot CPU uses the per-cpu var directly, then in smp_prepare_cpus() it
switches to the per-cpu copy just allocated. For secondary CPUs, the
early_gdt_descr is set to point directly to their per-cpu copy.
For UP the code is very simple: it keeps using the "per-cpu" GDT as per SMP,
but we never have to move.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Allocating PDA and GDT at boot is a pain. Using simple per-cpu variables adds
happiness (although we need the GDT page-aligned for Xen, which we do in a
followup patch).
[akpm@linux-foundation.org: build fix]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
remove the reporting of the constant_tsc flag from the "power management"
field in /proc/cpuinfo. The NULL value there was replaced by "" because
the former would result in a printout of [8] if the flag is set.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Change mark_tsc_unstable() so it takes a string argument, which holds the
reason the TSC was marked unstable.
This is then displayed the first time mark_tsc_unstable is called.
This should help us better debug why the TSC was marked unstable on certain
systems and allow us to make sure we're not being overly paranoid when
throwing out this troublesome clocksource.
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Eliminated the arch/i386/kernel/timers in 2.6.18, use clocksoures instead.
pit_latch_buggy was referred in timers/timer_tsc.c, and currently removed.
Therefore nobody refer it.
Until 2.6.17, MediaGX's TSC works correctly. after 2.6.18, warned "TSC
appears to be running slowly. Marking it as unstable". So marked unstable
TSC when CS55x0.
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Whether a region is below 1Mb is determined by its start rather than
its end.
This hunk got erroneously dropped from a previous patch.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Support for Longhaul ver. 2 broke driver for VIA C3 Eden 600MHz with
Samuel 2 core. Processor is not able to switch frequency anymore. I
don't know much about this issue at the moment, but until (if ever) I
will know why, this part should be reversed.
Signed-off-by: Rafal Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
AMD dual core laptops with C1E do not run the APIC timer correctly
when they go idle. Previously the code assumed this only happened
on C2 or deeper. But not all of these systems report support C2.
Use a AMD supplied snippet to detect C1E being enabled and then disable
local apic timer use.
This supercedes an earlier workaround using DMI detection of specific systems.
Thanks to Mark Langsdorf for the detection snippet.
Signed-off-by: Andi Kleen <ak@suse.de>
This reverts commit aeeddc1435, which was
half-baked and broken. It just resulted in compile errors, since
cpufreq_register_driver() still changes the 'driver_data' by setting
bits in the flags field. So claiming it is 'const' _really_ doesn't
work.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 2ff2d3d747.
Uwe Bugla reports that he cannot mount a floppy drive any more, and Jiri
Slaby bisected it down to this commit.
Benjamin LaHaise also points out that this is a big hot-path, and that
interrupt delivery while idle is very common and should not go through
all these expensive gyrations.
Fix up conflicts in arch/i386/kernel/apic.c and arch/i386/kernel/irq.c
due to other unrelated irq changes.
Cc: Stephane Eranian <eranian@hpl.hp.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Uwe Bugla <uwe.bugla@gmx.de>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Start using v2 version of Longhaul when available. It provides
voltage scaling and can use ACPI C3 state. That's curious. CPU
will not change frequency on ACPI C3 when v1 is in use, but it will
when v2 is used. Driver will return max frequency all the time if
this isn't true for all processors. There is strange thing with
mobile voltage. Looks like only Nehemiah (C3-M) supports it.
Earlier processors have different mobile VRM (in docs), but I can't
find any which is using it. Looks like all are using VRM 8.5. So
fail for non Nehemiah with mobile VRM.
Signed-off-by: Rafal Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
Solution for small, but nasty bug: access beyond end of f_table for C7 brand.
Signed-off-by: Rafal Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
The old Cyrix 5520 CPU detection code relied upon the PCI layer setup being
done earlier than the CPU setup, which is no longer true. Fortunately we
know that if the processor is a MediaGX we can do type 1 pci config
accesses to check the companion chip. We thus do those directly and from
this find the 5520 and implement the workarounds for the timer problem
Original report from takada@mbf.nifty.com, I sent a proposed patch which
Takara then corrected, tested and sent back to the list on 10th January.
Submitting for merging as it seems to have been missed
AK: Changed to use pci-direct.h and fix warning for !CONFIG_PCI (later
AK: originally from akpm)
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: <takada@mbf.nifty.com>
Cc: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fix bogus warning
linux/arch/i386/kernel/cpu/transmeta.c:12: warning: ‘cpu_freq’ may be used uninitialized in this function
Signed-off-by: Andi Kleen <ak@suse.de>
Just various new acronyms. The new popcnt bit is in the middle
of Intel space. This looks a little weird, but I've been assured
it's ok.
Also I fixed RDTSCP for i386 which was at the wrong place.
For i386 and x86-64.
Signed-off-by: Andi Kleen <ak@suse.de>
Original code doesn't write back to CCR4 register. This patch reflects a
value of a register.
Cc: Jordan Crouse <jordan.crouse@amd.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
I hope to support "classic" MediaGXm in kernel.
The DIR1 register of MediaGXm( or Geode) shows the following values for
identify CPU. For example, My MediaGXm shows 0x42.
We can read National Semiconductor's datasheet without any NDAs.
http://www.national.com/pf/GX/GXLV.html
from datasheets:
DIR1
0x30 - 0x33 GXm rev. 1.0 - 2.3
0x34 - 0x4f GXm rev. 2.4 - 3.x
0x5x GXm rev. 5.0 - 5.4
0x6x GXLV
0x7x (unknow)
0x8x Gx1
In nsc driver of X, accept 0x30 through 0x82. What will 0x7x mean?
Cc: Jordan Crouse <jordan.crouse@amd.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
All Transmeta CPUs ever produced have constant-rate TSCs.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mtrr: fix size_or_mask and size_and_mask
This fixes two bugs in /proc/mtrr interface:
o If physical address size crosses the 44 bit boundary
size_or_mask is evaluated wrong.
o size_and_mask limits width of physical base
address for an MTRR to be less than 44 bits.
TBD: later patch had one more change, but I think that was bogus.
TBD: need to double check
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Add a notifier mechanism to the low level idle loop. You can register a
callback function which gets invoked on entry and exit from the low level idle
loop. The low level idle loop is defined as the polling loop, low-power call,
or the mwait instruction. Interrupts processed by the idle thread are not
considered part of the low level loop.
The notifier can be used to measure precisely how much is spent in useless
execution (or low power mode). The perfmon subsystem uses it to turn on/off
monitoring.
Signed-off-by: stephane eranian <eranian@hpl.hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Every file should include the headers containing the prototypes for
it's global functions.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Convert the PDA code to use %fs rather than %gs as the segment for
per-processor data. This is because some processors show a small but
measurable performance gain for reloading a NULL segment selector (as %fs
generally is in user-space) versus a non-NULL one (as %gs generally is).
On modern processors the difference is very small, perhaps undetectable.
Some old AMD "K6 3D+" processors are noticably slower when %fs is used
rather than %gs; I have no idea why this might be, but I think they're
sufficiently rare that it doesn't matter much.
This patch also fixes the math emulator, which had not been adjusted to
match the changed struct pt_regs.
[frederik.deweerdt@gmail.com: fixit with gdb]
[mingo@elte.hu: Fix KVM too]
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Ian Campbell <Ian.Campbell@XenSource.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Zachary Amsden <zach@vmware.com>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
[akpm@osdl.org: sparc64 fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This change should make Longhaul more compatible with
both ver. 2 and Powersaver processors. Voltage transitions
will be done before or after frequency transition. That depends
on direction of change. I don't know how to force conservative
governor when voltage scaling is enabled, so there is only
a warning for user. Minimal voltage is calculated in different
way now because in this way more power is saved at lower
multipliers.
Signed-off-by: Rafal Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
This is driver for Enhanced Powersaver which is present in VIA C7
processors. Beta tested by Jorgen (jorgen (at) greven dot dk).
Thanks! Based on documentation provided by Dave Jones (Thanks!)
and C7 Eden datasheet available from www.via.com.tw. Looks like all
these C7 Eden CPU's don't have P-states in BIOS. I know that 2
p-states is low, but Jorgen finds it usefull anyway because board
is passive cooled.
There are 3 different types of C7 processors (called brands):
0. C7-M - these processors can set any maultiplier between min and
max, any voltage between min and max.
1. C7 - only min and max states are supported. Voltage is different
for min and max states.
2. Eden - only min and max states are supported. Looks like this
brand can only change multiplier. Voltage seems to be the same for
min and max frequency.
Signed-off-by: Rafal Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
I don't know why it is working and how, but it is working. On my
Epia transition time is by default set to 100us. I'm changing it to
200us. After that I can change frequency from min (x4.0) to max (x7.5)
without lockup. Many times.
There is a paranoid check at a beginning of a patch. Probably dead
code, but I don't have better ideas for CL10000 case at the moment.
Only way to to detect broken chip seems to be looking in log for
spurious interrupts.
Signed-off-by: Rafal Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
This is bug reported by John-Marc Chandonia:
> Detected 1002.292 MHz processor.
> longhaul: VIA C3 'Nehemiah B' [C5N] CPU detected. Powersaver supported.
> longhaul: Using throttling support.
> longhaul: Invalid (reserved) FSB!
FSB is correcly guessed for 999.554 MHz CPU.
To fix this error:
- ROUNDING should be range, not mask - at it's current value it is +7 -8,
- more precise calculations inside guess_fsb - 7.5x133MHz is 1000MHz now.
Signed-off-by: Rafal Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
Now there is no need to depend on -1 in Nehemiah tables. After
previous change code is eliminating multipliers lower then 5.0
by minmult for Nehemiah A and B.
Signed-off-by: Rafa³ Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
Looks like some time ago I introduced a bug to Longhaul.
I had report that 9x133Mhz CPU is seen as 5x133MHz. So I
changed multipliers table. That was a mistake. According to
documentation table was correct. So only way to avoid 5 or 9
dilema is not use MaxMHzBR for PowerSaver 1.0. One code that
works on all processors. To do it I need also separate flag for
Nehemiah C (min = x4.0) and Nehemiah (min = x5.0).
Signed-off-by: Rafa³ Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
This fixes the cpuinfo_cur_freq value by using the correct
find_khz_freq_from_fiddid() when the CPU uses hardware p-states.
Signed-off-by: Joachim Deguara <joachim.deguara@amd.com>
Acked-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
There is no need to have this option in Longhaul anymore.
It was for laptop with CLE266 chipset in times, when only
ACPI C3 was used to switch frequency. Now we have native
support not only for CLE266, but CN400 too. Would be good
to have support for PN266, but I can't find datasheet for it.
Looks like BIOS for CPU's faster then 1GHz don't support
ACPI C2 nor C3.
Signed-off-by: Rafa³ Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
