To improve OPAL/skiboot support. We don't need to strictly model these
XSCOM accesses.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-14-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We now have enough support to let the XSCOM test run on POWER9.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-13-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The POWER9 processor does not support per-core frequency control. The
cores are arranged in groups of four, along with their respective L2
and L3 caches, into a structure known as a Quad. The frequency must be
managed at the Quad level.
Provide a basic Quad model to fake the settings done by the firmware
on the Non-Cacheable Unit (NCU). Each core pair (EX) needs a special
BAR setting for the TIMA area of XIVE because it resides on the same
address on all chips.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-12-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Provide a new class attribute to define XSCOM operations per CPU
family and add a couple of XSCOM addresses controlling the power
management states of the core on POWER9.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-11-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The OCC on POWER9 is very similar to the one found on POWER8. Provide
the same routines with P9 values for the registers and IRQ number.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-10-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
To ease the introduction of the OCC model for POWER9, provide a new
class attributes to define XSCOM operations per CPU family and a PSI
IRQ number.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190307223548.20516-9-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This is just a simple reminder that SerIRQ routing should be
addressed.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-8-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The LPC Controller on POWER9 is very similar to the one found on
POWER8 but accesses are now done via on MMIOs, without the XSCOM and
ECCB logic. The device tree is populated differently so we add a
specific POWER9 routine for the purpose.
SerIRQ routing is yet to be done.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-7-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The ISA bus has a different DT nodename on POWER9. Compute the name
when the PnvChip is realized, that is before it is used by the machine
to populate the device tree with the ISA devices.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-6-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
It will ease the introduction of the LPC Controller model for POWER9.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190307223548.20516-5-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The PowerNV LPC Controller exposes different sets of registers for
each of the functional units it encompasses, among which the OPB
(On-Chip Peripheral Bus) Master and Arbitrer and the LPC HOST
Controller.
The mapping addresses of each register range are correct but the sizes
are too large. Fix the sizes and define the OPB Arbitrer range to fill
the gap between the OPB Master registers and the LPC HOST Controller
registers.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The PSI bridge on POWER9 is very similar to POWER8. The BAR is still
set through XSCOM but the controls are now entirely done with MMIOs.
More interrupts are defined and the interrupt controller interface has
changed to XIVE. The POWER9 model is a first example of the usage of
the notify() handler of the XiveNotifier interface, linking the PSI
XiveSource to its owning device model.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
To ease the introduction of the PSI bridge model for POWER9, abstract
the POWER chip differences in a PnvPsi class model and introduce a
specific Pnv8Psi type for POWER8. POWER8 interface to the interrupt
controller is still XICS whereas POWER9 uses the new XIVE model.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190307223548.20516-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When using -drive to configure the hd drive for the New World machine, the node
name "disk" should be used instead of the "hd" alias.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20190307212058.4890-3-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When using -drive to configure the hd drive for the Old World machine, the node
name "disk" should be used instead of the "hd" alias.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20190307212058.4890-2-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Now that all VSX registers are stored in host endian order, there is no need
to go via different accessors depending upon the register number. Instead we
introduce vsr64_offset() and use it directly from within get_cpu_vsr{l,h}() and
set_cpu_vsr{l,h}().
This also allows us to rewrite avr64_offset() and fpr_offset() in terms of the
new vsr64_offset() function to more clearly express the relationship between the
VSX, FPR and VMX registers, and also remove vsrl_offset() which is no longer
required.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20190307180520.13868-8-mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When VSX support was initially added, the fpr registers were added at
offset 0 of the VSR register and the vsrl registers were added at offset
1. This is in contrast to the VMX registers (the last 32 VSX registers) which
are stored in host-endian order.
Switch the fpr/vsrl registers so that the lower 32 VSX registers are now also
stored in host endian order to match the VMX registers. This ensures that TCG
vector operations involving mixed VMX and VSX registers will function
correctly.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190307180520.13868-7-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
By using the VsrD macro in avr64_offset() the same offset calculation can be
used regardless of the host endian. This allows get_avr64() and set_avr64() to
be simplified accordingly.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20190307180520.13868-6-mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
All TCG vector operations require pointers to the base address of the vector
rather than separate access to the top and bottom 64-bits. Convert the VMX TCG
instructions to use a new avr_full_offset() function instead of avr64_offset()
which can then itself be written as a simple wrapper onto vsr_full_offset().
This same function can also reused in cpu_avr_ptr() to avoid having more than
one copy of the offset calculation logic.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20190307180520.13868-5-mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
It isn't possible to include internal.h from cpu.h so move the Vsr* macros
into cpu.h alongside the other VMX/VSX register access functions.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20190307180520.13868-4-mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Instead of having multiple copies of the offset calculation logic, move it to a
single vsrl_offset() function.
This commit also renames the existing get_vsr()/set_vsr() functions to
get_vsrl()/set_vsrl() which better describes their purpose.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190307180520.13868-3-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Instead of having multiple copies of the offset calculation logic, move it to a
single fpr_offset() function.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190307180520.13868-2-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
On sPAPR vfio_listener_region_add() is called in 2 situations:
1. a new listener is registered from vfio_connect_container();
2. a new IOMMU Memory Region is added from rtas_ibm_create_pe_dma_window().
In both cases vfio_listener_region_add() calls
memory_region_iommu_replay() to notify newly registered IOMMU notifiers
about existing mappings which is totally desirable for case 1.
However for case 2 it is nothing but noop as the window has just been
created and has no valid mappings so replaying those does not do anything.
It is barely noticeable with usual guests but if the window happens to be
really big, such no-op replay might take minutes and trigger RCU stall
warnings in the guest.
For example, a upcoming GPU RAM memory region mapped at 64TiB (right
after SPAPR_PCI_LIMIT) causes a 64bit DMA window to be at least 128TiB
which is (128<<40)/0x10000=2.147.483.648 TCEs to replay.
This mitigates the problem by adding an "skipping_replay" flag to
sPAPRTCETable and defining sPAPR own IOMMU MR replay() hook which does
exactly the same thing as the generic one except it returns early if
@skipping_replay==true.
Another way of fixing this would be delaying replay till the very first
H_PUT_TCE but this does not work if in-kernel H_PUT_TCE handler is
enabled (a likely case).
When "ibm,create-pe-dma-window" is complete, the guest will map only
required regions of the huge DMA window.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20190307050518.64968-2-aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reset all regs but keep the MMIO BAR enabled as it is at realize time.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-14-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This is a simple helper to translate XSCOM addresses to MMIO addresses
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-13-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The NSR register of the HV ring has a different, although similar, bit
layout. TM_QW3_NSR_HE_PHYS bit should now be raised when the
Hypervisor interrupt line is signaled. Other bits TM_QW3_NSR_HE_POOL
and TM_QW3_NSR_HE_LSI are not modeled. LSI are for special interrupts
reserved for HW bringup and the POOL bit is used when signaling a
group of VPs. This is not currently implemented in Linux but it is in
pHyp.
The most important special commands on the HV TIMA page are added to
let the core manage interrupts : acking and changing the CPU priority.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-10-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The POWER9 and POWER8 processors have different interrupt controllers,
and reporting their state requires calling different helper routines.
However, the interrupt presenters are still handled in the higher
level pic_print_info() routine because they are not related to the
chip.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-9-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The POWER9 and POWER8 processors have a different set of devices and a
different device tree layout.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-8-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This is a simple model of the POWER9 XIVE interrupt controller for the
PowerNV machine which only addresses the needs of the skiboot
firmware. The PowerNV model reuses the common XIVE framework developed
for sPAPR as the fundamentals aspects are quite the same. The
difference are outlined below.
The controller initial BAR configuration is performed using the XSCOM
bus from there, MMIO are used for further configuration.
The MMIO regions exposed are :
- Interrupt controller registers
- ESB pages for IPIs and ENDs
- Presenter MMIO (Not used)
- Thread Interrupt Management Area MMIO, direct and indirect
The virtualization controller MMIO region containing the IPI ESB pages
and END ESB pages is sub-divided into "sets" which map portions of the
VC region to the different ESB pages. These are modeled with custom
address spaces and the XiveSource and XiveENDSource objects are sized
to the maximum allowed by HW. The memory regions are resized at
run-time using the configuration of EDT set translation table provided
by the firmware.
The XIVE virtualization structure tables (EAT, ENDT, NVTT) are now in
the machine RAM and not in the hypervisor anymore. The firmware
(skiboot) configures these tables using Virtual Structure Descriptor
defining the characteristics of each table : SBE, EAS, END and
NVT. These are later used to access the virtual interrupt entries. The
internal cache of these tables in the interrupt controller is updated
and invalidated using a set of registers.
Still to address to complete the model but not fully required is the
support for block grouping. Escalation support will be necessary for
KVM guests.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-7-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The POWER9 PowerNV machine will use a XIVE interrupt presenter type.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-6-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The PowerNV machine with need to encode the block id in the source
interrupt number before forwarding the source event notification to
the Router.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-5-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The PowerNV machine can perform indirect loads and stores on the TIMA
on behalf of another CPU. Give the controller the possibility to call
the TIMA memory accessors with a XiveTCTX of its choice.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We will use it to get the CPU interrupt presenter in XIVE when the
TIMA is accessed from the indirect page.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
By default on P9, the HW CAM line (23bits) is hardwired to :
0x000||0b1||4Bit chip number||7Bit Thread number.
When the block group mode is enabled at the controller level (PowerNV),
the CAM line is changed for CAM compares to :
4Bit chip number||0x001||7Bit Thread number
This will require changes in xive_presenter_tctx_match() possibly.
This is a lowlevel functionality of the HW controller and it is not
strictly needed. Leave it for later.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Original commit message:
This patch adds an emulation model for i2c controller found on most of the FSL SoCs.
It also integrates the RTC (ds1338) that sits on the i2c Bus with e500 machine model.
Patch was originally written by Amit Singh Tomar <amit.tomar@freescale.com>
see http://patchwork.ozlabs.org/patch/431475/
I only fixed it enough for application on top of current qemu master
20b084c4b1, and hopefully fixed checkpatch errors
Tested by booting Linux kernel 4.20.12. Now e500 machine doesn't need
network time protocol daemon because it will have working RTC
(before all timestamps on files were from 2016)
Signed-off-by: Amit Singh Tomar <amit.tomar@freescale.com>
Signed-off-by: Andrew Randrianasulu <randrianasulu@gmail.com>
Message-Id: <20190306102812.28972-1-randrianasulu@gmail.com>
[dwg: Add Kconfig stanza to define the new symbol, update MAINTAINERS]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The H_CALL H_PAGE_INIT can be used to zero or copy a page of guest
memory. Enable the in-kernel H_PAGE_INIT handler.
The in-kernel handler takes half the time to complete compared to
handling the H_CALL in userspace.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190306060608.19935-1-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
SPAPR_MEMORY_BLOCK_SIZE is logically a difference in memory addresses, and
hence of type hwaddr which is 64-bit. Previously it wasn't marked as such
which means that it could be treated as 32-bit. That will work in some
circumstances but if multiplied by another 32-bit value it could lead to
a 32-bit overflow and an incorrect result.
One specific instance of this in spapr_lmb_dt_populate() was spotted by
Coverity (CID 1399145).
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
If we allocate a hash page table then we know that the guest won't be
using process tables, so set the partition table entry maintained for
the guest to zero. If this isn't done, then the guest radix bit will
remain set in the entry. This means that when the guest calls
H_REGISTER_PROCESS_TABLE there will be a mismatch between then flags
and the value in spapr->patb_entry, and the call will fail. The guest
will then panic:
Failed to register process table (rc=-4)
kernel BUG at arch/powerpc/platforms/pseries/lpar.c:959
The result being that it isn't possible to boot a hash guest on a P9
system.
Also fix a bug in the flags parsing in h_register_process_table() which
was introduced by the same patch, and simplify the handling to make it
less likely that errors will be introduced in the future. The effect
would have been setting the host radix bit LPCR_HR for a hash guest
using process tables, which currently isn't supported and so couldn't
have been triggered.
Fixes: 00fd075e18 "target/ppc/spapr: Set LPCR:HR when using Radix mode"
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190305022102.17610-1-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Quite a while has passed since we last updated U-Boot for e500. This patch
bumps it to the last released version 2019.01 to make sure users don't feel
like they're using out of date software.
Signed-off-by: Alexander Graf <agraf@csgraf.de>
Message-Id: <20190304103930.16319-1-agraf@csgraf.de>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
There are four scenarios being handled in this function:
- single stepping
- hardware breakpoints
- software breakpoints
- fallback (no debug supported)
A future patch will add code to handle specific single step and
software breakpoints cases so let's split each scenario into its own
function now to avoid hurting readability.
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20190228225759.21328-5-farosas@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This is in preparation for a refactoring of the kvm_handle_debug
function in the next patch.
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20190228225759.21328-4-farosas@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
There are currently 3 mitigations the availability of which is controlled
by the spapr-caps mechanism, cap-cfpc, cap-sbbc, and cap-ibs. Enable these
mitigations by default for the pseries-4.0 machine type.
By now machine firmware should have been upgraded to allow these
settings.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190301044609.9626-3-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The spapr_caps cap-cfpc, cap-sbbc and cap-ibs are used to control the
availability of certain mitigations to the guest. These haven't been
implemented under TCG, it is unlikely they ever will be, and it is unclear
as to whether they even need to be.
As such, make failure to apply these capabilities under TCG non-fatal.
Instead we print a warning message to the user but still allow the guest
to continue.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190301044609.9626-2-sjitindarsingh@gmail.com>
[dwg: Small style fix]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Introduce a new spapr_cap SPAPR_CAP_CCF_ASSIST to be used to indicate
the requirement for a hw-assisted version of the count cache flush
workaround.
The count cache flush workaround is a software workaround which can be
used to flush the count cache on context switch. Some revisions of
hardware may have a hardware accelerated flush, in which case the
software flush can be shortened. This cap is used to set the
availability of such hardware acceleration for the count cache flush
routine.
The availability of such hardware acceleration is indicated by the
H_CPU_CHAR_BCCTR_FLUSH_ASSIST flag being set in the characteristics
returned from the KVM_PPC_GET_CPU_CHAR ioctl.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190301031912.28809-2-sjitindarsingh@gmail.com>
[dwg: Small style fixes]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The spapr_cap SPAPR_CAP_IBS is used to indicate the level of capability
for mitigations for indirect branch speculation. Currently the available
values are broken (default), fixed-ibs (fixed by serialising indirect
branches) and fixed-ccd (fixed by diabling the count cache).
Introduce a new value for this capability denoted workaround, meaning that
software can work around the issue by flushing the count cache on
context switch. This option is available if the hypervisor sets the
H_CPU_BEHAV_FLUSH_COUNT_CACHE flag in the cpu behaviours returned from
the KVM_PPC_GET_CPU_CHAR ioctl.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190301031912.28809-1-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Enable the large decrementer by default for the pseries-4.0 machine type.
It is disabled again by default_caps_with_cpu() for pre-POWER9 cpus
since they don't support the large decrementer.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190301024317.22137-4-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Implement support to allow KVM guests to take advantage of the large
decrementer introduced on POWER9 cpus.
To determine if the host can support the requested large decrementer
size, we check it matches that specified in the ibm,dec-bits device-tree
property. We also need to enable it in KVM by setting the LPCR_LD bit in
the LPCR. Note that to do this we need to try and set the bit, then read
it back to check the host allowed us to set it, if so we can use it but
if we were unable to set it the host cannot support it and we must not
use the large decrementer.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190301024317.22137-3-sjitindarsingh@gmail.com>
[dwg: Small style fixes]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Prior to POWER9 the decrementer was a 32-bit register which decremented
with each tick of the timebase. From POWER9 onwards the decrementer can
be set to operate in a mode called large decrementer where it acts as a
n-bit decrementing register which is visible as a 64-bit register, that
is the value of the decrementer is sign extended to 64 bits (where n is
implementation dependant).
The mode in which the decrementer operates is controlled by the LPCR_LD
bit in the logical paritition control register (LPCR).
>From POWER9 onwards the HDEC (hypervisor decrementer) was enlarged to
h-bits, also sign extended to 64 bits (where h is implementation
dependant). Note this isn't configurable and is always enabled.
On POWER9 the large decrementer and hdec are both 56 bits, as
represented by the lrg_decr_bits cpu class property. Since they are the
same size we only add one property for now, which could be extended in
the case they ever differ in the future.
We also add the lrg_decr_bits property for POWER5+/7/8 since it is used
to determine the size of the hdec, which is only generated on the
POWER5+ processor and later. On these processors it is 32 bits.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190301024317.22137-2-sjitindarsingh@gmail.com>
[dwg: Small style fixes]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
