This patch consolidates macros used to generate assembly for
compatibility across different CPUs or configs. A new header,
asm-powerpc/asm-compat.h contains the main compatibility macros. It
uses some preprocessor magic to make the macros suitable both for use
in .S files, and in inline asm in .c files. Headers (bitops.h,
uaccess.h, atomic.h, bug.h) which had their own such compatibility
macros are changed to use asm-compat.h.
ppc_asm.h is now for use in .S files *only*, and a #error enforces
that. As such, we're a lot more careless about namespace pollution
here than in asm-compat.h.
While we're at it, this patch adds a call to the PPC405_ERR77 macro in
futex.h which should have had it already, but didn't.
Built and booted on pSeries, Maple and iSeries (ARCH=powerpc). Built
for 32-bit powermac (ARCH=powerpc) and Walnut (ARCH=ppc).
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
confusion, and make their semantics rigid. Improves efficiency of
resched_task and some cpu_idle routines.
* In resched_task:
- TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
and as we hold it during resched_task, then there is no need for an
atomic test and set there. The only other time this should be set is
when the task's quantum expires, in the timer interrupt - this is
protected against because the rq lock is irq-safe.
- If TIF_NEED_RESCHED is set, then we don't need to do anything. It
won't get unset until the task get's schedule()d off.
- If we are running on the same CPU as the task we resched, then set
TIF_NEED_RESCHED and no further action is required.
- If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
after TIF_NEED_RESCHED has been set, then we need to send an IPI.
Using these rules, we are able to remove the test and set operation in
resched_task, and make clear the previously vague semantics of
POLLING_NRFLAG.
* In idle routines:
- Enter cpu_idle with preempt disabled. When the need_resched() condition
becomes true, explicitly call schedule(). This makes things a bit clearer
(IMO), but haven't updated all architectures yet.
- Many do a test and clear of TIF_NEED_RESCHED for some reason. According
to the resched_task rules, this isn't needed (and actually breaks the
assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
held). So remove that. Generally one less locked memory op when switching
to the idle thread.
- Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
most polling idle loops. The above resched_task semantics allow it to be
set until before the last time need_resched() is checked before going into
a halt requiring interrupt wakeup.
Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
can be always left set, completely eliminating resched IPIs when rescheduling
the idle task.
POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Run idle threads with preempt disabled.
Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?
Might fix the CPU hotplugging hang which Nigel Cunningham noted.
We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.
After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep. The CPU will continue executing
previous idle and have no chance to call play_dead.
By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.
From: alexs <ashepard@u.washington.edu>
PPC build fix
From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
MIPS build fix
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use __do_IRQ instead. The only difference is that every controller
is now assumed to have an end() routine (only xics_8259 did not).
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
The ancient ppcdebug/PPCDBG mechanism is now only used in two places.
First, in the hash setup code, one of the bits allows the size of the
hash table to be reduced by a factor of 8 - which would be better
accomplished with a command line option for that purpose. The other
was a bunch of bus walking related messages in the iSeries code, which
would seem to be insufficient reason to keep the mechanism.
This patch removes the last traces of this mechanism.
Built and booted on iSeries and pSeries POWER5 LPAR (ARCH=powerpc).
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Adds a new CONFIG_PPC_64K_PAGES which, when enabled, changes the kernel
base page size to 64K. The resulting kernel still boots on any
hardware. On current machines with 4K pages support only, the kernel
will maintain 16 "subpages" for each 64K page transparently.
Note that while real 64K capable HW has been tested, the current patch
will not enable it yet as such hardware is not released yet, and I'm
still verifying with the firmware architects the proper to get the
information from the newer hypervisors.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
These days, the NACA only exists on iSeries. Therefore, this patch
moves naca.h from include/asm-ppc64 to arch/powerpc/platforms/iseries.
There was one file including naca.h outside of platforms/iseries -
arch/ppc64/kernel/udbg_scc.c. However, that's obviously a hangover
from older days. The include is not necessary, so this patch simply
removes it.
Built and booted on iSeries, built for G5 (which uses udbg_scc.o).
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
By parsing the command line earlier, we can add the mem= value to the
flattened device tree and let the generic code sort out the memory limit
for us.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
We had a static memory_limit in prom.c, and then another one defined
in setup_64.c and used in numa.c, which resulted in the kernel crashing
when mem=xxx was given on the command line. This puts the declaration
in system.h and the definition in mem.c. This also moves the
definition of tce_alloc_start/end out of setup_64.c.
Signed-off-by: Paul Mackerras <paulus@samba.org>
A comment in lpevents.c refers to code that's actually in HvCallEvent.h.
The code in HvCallEvent.h is pretty obvious, so just remove the comment
altogether.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
A few things change for consistency between ppc32 and ppc64:
idle functions return void; *_get_boot_time functions return
unsigned long (i.e. time_t) rather than filling in a struct rtc_time
(since that's useful to the callers and easier for pmac to
generate); *_get_rtc_time and *_set_rtc_time functions take
a struct rtc_time; irq_canonicalize is gone; nvram_sync returns
void.
Signed-off-by: Paul Mackerras <paulus@samba.org>
The only real user of this file outside platforms/iseries was
drivers/net/iseries_veth.c but all it wanted was ISERIES_HV_ADDR()
so we move that to abs_addr.h (and lowercase it).
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
On ARCH=ppc64 we were getting htab_hash_mask recalculated
to the correct value for our particular machine by accident.
In the merge tree, that code was commented out, so htab_hash_mask
was being corrupted.
We now set ppc64_pft_size instead which gets htab_has_mask
calculated correctly for us later. We should put an
ibm,pft-size property in the device tree at some point.
Also set -mno-minimal-toc in some makefiles.
Allow iSeries to configure PROC_DEVICETREE.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
This moves the Device_List member from struct device_node to
struct pci_dn, which cleans up the device_node and makes the code
a little simpler.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Since lparmap.s gets included in arch/powerpc/kernel/head_64.S,
this avoids depending on a file in another directory.
Signed-off-by: Paul Mackerras <paulus@samba.org>
