The powernv platform supports Power7 and later CPUs, all of which are
multithreaded and multicore.
As such we never build a SMP=n kernel for those machines, other than
possibly for debugging or running in a simulator.
In the debugging case we can get a similar effect by booting with
nr_cpus=1, or there's always the option of building a custom kernel with
SMP hacked out.
For running in simulators the code size reduction from building without
SMP is not particularly important, what matters is the number of
instructions executed. A quick test shows that a SMP=y kernel takes ~6%
more instructions to boot to a shell. Booting with nr_cpus=1 recovers
about half that deficit.
On the flip side, keeping the SMP=n kernel building can be a pain at
times. And although we've mostly kept it building in recent years, no
one is regularly testing that the SMP=n kernel actually boots and works
well on these machines.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This merges the arch part of the XIVE support, leaving the final commit
with the KVM specific pieces dangling on the branch for Paul to merge
via the kvm-ppc tree.
In the recent commit 1ab66d1fba ("powerpc/powernv: Introduce address
translation services for Nvlink2") the NPU code gained a dependency on MMU
notifiers.
All our defconfigs have KVM enabled, which selects MMU_NOTIFIER, but if KVM is
not enabled then the build breaks.
Fix it by always selecting MMU_NOTIFIER when we're building powernv.
Fixes: 1ab66d1fba ("powerpc/powernv: Introduce address translation services for Nvlink2")
Signed-off-by: Alistair Popple <alistair@popple.id.au>
[mpe: Reword change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The XIVE interrupt controller is the new interrupt controller
found in POWER9. It supports advanced virtualization capabilities
among other things.
Currently we use a set of firmware calls that simulate the old
"XICS" interrupt controller but this is fairly inefficient.
This adds the framework for using XIVE along with a native
backend which OPAL for configuration. Later, a backend allowing
the use in a KVM or PowerVM guest will also be provided.
This disables some fast path for interrupts in KVM when XIVE is
enabled as these rely on the firmware emulation code which is no
longer available when the XIVE is used natively by Linux.
A latter patch will make KVM also directly exploit the XIVE, thus
recovering the lost performance (and more).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Fixup pr_xxx("XIVE:"...), don't split pr_xxx() strings,
tweak Kconfig so XIVE_NATIVE selects XIVE and depends on POWERNV,
fix build errors when SMP=n, fold in fixes from Ben:
Don't call cpu_online() on an invalid CPU number
Fix irq target selection returning out of bounds cpu#
Extra sanity checks on cpu numbers
]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Bare metal systems without PCI don't exist, so there's no real point in
making PCI optional, it just breaks the build from time to time. In fact
the build is broken now if you turn off PCI_MSI but enable KVM.
Using select for PCI is OK because we (powerpc) define config PCI, and it
has no dependencies. Selecting PCI_MSI is slightly fishy, because it's
in drivers/pci and it is user-visible, but its only dependency is PCI,
so selecting it can't actually lead to breakage.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This change adds a char device to access the "PRD" (processor runtime
diagnostics) channel to OPAL firmware.
Includes contributions from Vaidyanathan Srinivasan, Neelesh Gupta &
Vishal Kulkarni.
Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The powernv code has some conditional support for running on bare metal
machines that have no OPAL firmware, but provide RTAS.
No released machines ever supported that, and even in the lab it was
just a transitional hack in the days when OPAL was still being
developed.
So remove the code.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
This patch enables POWER8 doorbell IPIs on powernv.
Since doorbells can only IPI within a core, we test to see when we can use
doorbells and if not we fall back to XICS. This also enables hypervisor
doorbells to wakeup us up from nap/sleep via the LPCR PECEDH bit.
Based on tests by Anton, the best case IPI latency between two threads dropped
from 894ns to 512ns.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Enable CPUFreq for PowerNV. Select "performance", "powersave",
"userspace" and "ondemand" governors. Choose "ondemand" to be the
default governor.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We currently have a user visible CONFIG_POWERNV_MSI option, but it
doesn't actually disable MSI for powernv. The MSI code is always built,
what it does disable is the inclusion of the MSI bitmap code, which
leads to a build error.
eg, with PPC_POWERNV=y and POWERNV_MSI=n we get:
arch/powerpc/platforms/built-in.o: In function `.pnv_teardown_msi_irqs':
pci.c:(.text+0x3558): undefined reference to `.msi_bitmap_free_hwirqs'
We don't really need a POWERNV_MSI symbol, just have the MSI bitmap code
depend directly on PPC_POWERNV.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Reviewed-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
OPAL v3 provides interfaces to access the chips XSCOM, expose
this via the existing scom infrastructure.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Add the plumbing to implement arch_get_random_long/int(). It didn't seem
worth adding an extra ppc_md hook for int, so we reuse the one for long.
Add an implementation for powernv based on the hwrng found in power7+
systems. We whiten the output of the hwrng, and the result passes all
the dieharder tests.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Legacy UARTs can exist on PowerNV, memory-mapped ones on PCI
or IO based ones on the LPC bus.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This uses the hooks provided by CONFIG_PPC_INDIRECT_PIO to
implement a set of hooks for IO port access to use the LPC
bus via OPAL calls for the first 64K of IO space
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The zImage.epapr wrapper allows to use zImages when booting via a flat
device-tree which can be used on powernv.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
As Michael Ellerman suggested, to add CONFIG_POWERNV_MSI for PowerNV
platform. That's similar to CONFIG_PSERIES_MSI for pSeries platform.
For now, we don't make it dependent on CONFIG_EEH since it's not ready
to enable that yet.
Apart from that, we also enable CONFIG_PPC_MSI_BITMAP on selecting
CONFIG_POWERNV_MSI.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Add definition of OPAL interfaces along with the wrappers to call
into OPAL runtime and the early device-tree parsing hook to locate
the OPAL runtime firmware.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This adds a skeletton for the new Power "Non Virtualized"
platform which will be used by machines supporting running
without an hypervisor, for example in order to run KVM.
These machines will be using a new firmware called OPAL
for which the support will be provided by later patches.
The PowerNV platform is intended to be also usable under
the BML environment used internally for early CPU bringup
which is why the code also supports using RTAS instead of
OPAL in various places.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
