A Power6 can give up CPU cycles on a dedicated CPU (as opposed to a
shared CPU) to other shared processors if the administrator asks for it
(via the HMC).
This enables that to work properly on P6.
This just involves setting a bit in the CAS structure as well as the
VPA. To donate cycles, a CPU has to have all SMT threads idle and
have the donate bit set in the VPA. Then call H_CEDE.
The reason why shared processors just aren't used is because dedicated
CPUs are guaranteed an actual processor, yet the system is still able to
increase the capacity of the shared CPU pool.
Also rename the VPA's cpuctls_task_attrs field to a more accurate name.
Signed-off-by: Jake Moilanen <moilanen@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds a shadow buffer for the SLBs and regsiters it with PHYP.
Only the bolted SLB entries (top 3) are shadowed.
The SLB shadow buffer tells the hypervisor what the kernel needs to
have in the SLB for the kernel to be able to function. The hypervisor
can use this information to speed up partition context switches.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
sparse can't parse a struct definition in include/asm-powerpc/lppaca.h,
even though gcc can accept it. The form looks like this:
struct __attribute__((whatever)) foo { };
An equivalent that both gcc and sparse can handle is
struct foo { } __attribute__((whatever));
This is the only definition of this type in the tree, and fixing it is
easier than fixing sparse.
Signed-off-by: Bryan O'Sullivan <bos@serpentine.com>
[ Side note: fixing sparse wouldn't be hard, but the "attribute at the
end" version is the canonical one, and the one that makes sense. So
let's just fix the kernel instead. Luc Van Oostenryck already sent
out a sparse patch to the sparse mailing list in case anybody cares.
-- Linus ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
At present the lppaca - the structure shared with the iSeries
hypervisor and phyp - is contained within the PACA, our own low-level
per-cpu structure. This doesn't have to be so, the patch below
removes it, making a separate array of lppaca structures.
This saves approximately 500*NR_CPUS bytes of image size and kernel
memory, because we don't need aligning gap between the Linux and
hypervisor portions of every PACA. On the other hand it means an
extra level of dereference in many accesses to the lppaca.
The patch also gets rid of several places where we assign the paca
address to a local variable for no particular reason.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
include/asm-ppc/ had #ifdef __KERNEL__ in all header files that
are not meant for use by user space, include/asm-powerpc does
not have this yet.
This patch gets us a lot closer there. There are a few cases
where I was not sure, so I left them out. I have verified
that no CONFIG_* symbols are used outside of __KERNEL__
any more and that there are no obvious compile errors when
including any of the headers in user space libraries.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch moves a bunch of files from arch/ppc64 and
include/asm-ppc64 which have no equivalents in ppc32 code into
arch/powerpc and include/asm-powerpc. The file affected are:
abs_addr.h
compat.h
lppaca.h
paca.h
tce.h
cpu_setup_power4.S
ioctl32.c
firmware.c
pacaData.c
The only changes apart from the move and corresponding Makefile
changes are:
- #ifndef/#define in includes updated to _ASM_POWERPC_ form
- trailing whitespace removed
- comments giving full paths removed
- pacaData.c renamed paca.c to remove studlyCaps
- Misplaced { moved in lppaca.h
Built and booted on POWER5 LPAR (ARCH=powerpc and ARCH=ppc64), built
for 32-bit powermac (ARCH=powerpc).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Jake Moilanen