The pm_interval register in the Cell PMU is read/write, but was implemented in
the kernel as write-only. Previously, the written value was saved in a "shadow"
copy so calls to cbe_read_pm() could return the value.
Perfmon2 needs to be able to read the current values of pm_interval, so change
cbe_read_pm() to read the actual register instead of the "shadow" copy. There
is currently no code in the kernel that tries to read the pm_interval register
with cbe_read_pm() (expecting to receive the "shadow" value), so this should
not break any existing code.
Signed-off-by: Kevin Corry <kevcorry@us.ibm.com>
Signed-off-by: Carl Love <carll@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The new Cell EDAC driver needs that file, oprofile also does ugly
path tricks to get to it, it's time to move it to asm-powerpc. While
at it, rename it to be consistent with cell-pmu.h (and dashes look
nicer than underscores anyway).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This is a clean up patch that includes the following changes:
-Some comments were added to clarify the code based on feedback
from the community.
-The write_pm_cntrl() and set_count_mode() were passed a
structure element from a global variable. The argument was
removed so the functions now just operate on the global directly.
-The set_pm_event() function call in the cell_virtual_cntr()
routine was moved to a for-loop before the for_each_cpu loop
Signed-off-by: Carl Love <carll@us.ibm.com>
Signed-off-by: Maynard Johnson <mpjohn@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Make sure that the pmu is not initialised unless we are running on a cell.
Also make the init routine static.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add PPU event-based and cycle-based profiling support to Oprofile for Cell.
Oprofile is expected to collect data on all CPUs simultaneously.
However, there is one set of performance counters per node. There are
two hardware threads or virtual CPUs on each node. Hence, OProfile must
multiplex in time the performance counter collection on the two virtual
CPUs.
The multiplexing of the performance counters is done by a virtual
counter routine. Initially, the counters are configured to collect data
on the even CPUs in the system, one CPU per node. In order to capture
the PC for the virtual CPU when the performance counter interrupt occurs
(the specified number of events between samples has occurred), the even
processors are configured to handle the performance counter interrupts
for their node. The virtual counter routine is called via a kernel
timer after the virtual sample time. The routine stops the counters,
saves the current counts, loads the last counts for the other virtual
CPU on the node, sets interrupts to be handled by the other virtual CPU
and restarts the counters, the virtual timer routine is scheduled to run
again. The virtual sample time is kept relatively small to make sure
sampling occurs on both CPUs on the node with a relatively small
granularity. Whenever the counters overflow, the performance counter
interrupt is called to collect the PC for the CPU where data is being
collected.
The oprofile driver relies on a firmware RTAS call to setup the debug bus
to route the desired signals to the performance counter hardware to be
counted. The RTAS call must set the routing registers appropriately in
each of the islands to pass the signals down the debug bus as well as
routing the signals from a particular island onto the bus. There is a
second firmware RTAS call to reset the debug bus to the non pass thru
state when the counters are not in use.
Signed-off-by: Carl Love <carll@us.ibm.com>
Signed-off-by: Maynard Johnson <mpjohn@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The following routines are added to arch/powerpc/platforms/cell/pmu.c:
cbe_clear_pm_interrupts()
cbe_enable_pm_interrupts()
cbe_disable_pm_interrupts()
cbe_query_pm_interrupts()
cbe_pm_irq()
cbe_init_pm_irq()
This also adds a routine in arch/powerpc/platforms/cell/interrupt.c and
some macros in cbe_regs.h to manipulate the IIC_IR register:
iic_set_interrupt_routing()
Signed-off-by: Kevin Corry <kevcorry@us.ibm.com>
Signed-off-by: Carl Love <carll@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Move some PMU-related macros and function prototypes from cbe_regs.h
and pmu.h in arch/powerpc/platforms/cell/ to a new header at
include/asm-powerpc/cell-pmu.h
This is cleaner to use from the oprofile code, since that sits in
arch/powerpc/oprofile, not in the cell platform directory.
Signed-off-by: Kevin Corry <kevcorry@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add symbol-exports for the new routines in arch/powerpc/platforms/cell/pmu.c.
They are needed for Oprofile, which can be built as a module.
Signed-off-by: Kevin Corry <kevcorry@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add routines for accessing the registers and counters in the performance
monitoring unit.
Signed-off-by: Kevin Corry <kevcorry@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
