On a real POWER8 system, the Pervasive Interconnect Bus (PIB) serves
as a backbone to connect different units of the system. The host
firmware connects to the PIB through a bridge unit, the
Alter-Display-Unit (ADU), which gives him access to all the chiplets
on the PCB network (Pervasive Connect Bus), the PIB acting as the root
of this network.
XSCOM (serial communication) is the interface to the sideband bus
provided by the POWER8 pervasive unit to read and write to chiplets
resources. This is needed by the host firmware, OPAL and to a lesser
extent, Linux. This is among others how the PCI Host bridges get
configured at boot or how the LPC bus is accessed.
To represent the ADU of a real system, we introduce a specific
AddressSpace to dispatch XSCOM accesses to the targeted chiplets. The
translation of an XSCOM address into a PCB register address is
slightly different between the P9 and the P8. This is handled before
the dispatch using a 8byte alignment for all.
To customize the device tree, a QOM InterfaceClass, PnvXScomInterface,
is provided with a populate() handler. The chip populates the device
tree by simply looping on its children. Therefore, each model needing
custom nodes should not forget to declare itself as a child at
instantiation time.
Based on previous work done by :
Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Added cpu parameter to xscom_complete()]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This is largy inspired by sPAPRCPUCore with some simplification, no
hotplug for instance. A set of PnvCore objects is added to the PnvChip
and the device tree is populated looping on these cores.
Real HW cpu ids are now generated depending on the chip cpu model, the
chip id and a core mask. The id is propagated to the CPU object, using
properties, to set the SPR_PIR (Processor Identification Register)
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The Processor Identification Register (PIR) is a register that holds a
processor identifier which is used for bus transactions (XSCOM) and
for processor differentiation in multiprocessor systems. It also used
in the interrupt vector entries (IVE) to identify the thread serving
the interrupts.
P9 and P8 have some differences in the CPU PIR encoding.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This will be used to build real HW ids for the cores and enforce some
limits on the available cores per chip.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This is is an abstraction of a POWER8 chip which is a set of cores
plus other 'units', like the pervasive unit, the interrupt controller,
the memory controller, the on-chip microcontroller, etc. The whole can
be seen as a socket. It depends on a cpu model and its characteristics:
max cores and specific inits are defined in a PnvChipClass.
We start with an near empty PnvChip with only a few cpu constants
which we will grow in the subsequent patches with the controllers
required to run the system.
The Chip CFAM (Common FRU Access Module) ID gives the model of the
chip and its version number. It is generally the first thing firmwares
fetch, available at XSCOM PCB address 0xf000f, to start initialization.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The goal is to emulate a PowerNV system at the level of the skiboot
firmware, which loads the OS and provides some runtime services. Power
Systems have a lower firmware (HostBoot) that does low level system
initialization, like DRAM training. This is beyond the scope of what
qemu will address in a PowerNV guest.
No devices yet, not even an interrupt controller. Just to get started,
some RAM to load the skiboot firmware, the kernel and initrd. The
device tree is fully created in the machine reset op.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[clg: - updated for qemu-2.7
- replaced fprintf by error_report
- used a common definition of _FDT macro
- removed VMStateDescription as migration is not yet supported
- added IBM Copyright statements
- reworked kernel_filename handling
- merged PnvSystem and sPowerNVMachineState
- removed PHANDLE_XICP
- added ppc_create_page_sizes_prop helper
- removed nmi support
- removed kvm support
- updated powernv machine to version 2.8
- removed chips and cpus, They will be provided in another patches
- added a machine reset routine to initialize the device tree (also)
- french has a squelette and english a skeleton.
- improved commit log.
- reworked prototypes parameters
- added a check on the ram size (thanks to Michael Ellerman)
- fixed chip-id cell
- changed MAX_CPUS to 2048
- simplified memory node creation to one node only
- removed machine version
- rewrote the device tree creation with the fdt "rw" routines
- s/sPowerNVMachineState/PnvMachineState/
- etc.]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
