POWER9 processor comes with 3 PHB4 PEC (PCI Express Controller) and
each PEC can have several PHBs :
* PEC0 provides 1 PHB (PHB0)
* PEC1 provides 2 PHBs (PHB1 and PHB2)
* PEC2 provides 3 PHBs (PHB3, PHB4 and PHB5)
A num_pecs class attribute represents better the logic units of the
POWER9 chip. Use that instead of num_phbs which fits POWER8 chips.
This will ease adding support for user created devices.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211213132830.108372-8-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
When -nodefaults is supported for PHB3 devices, the phbs array under
the chip will be empty. This will break the XICSFabric handlers, and
all interrupt delivery, and the 'info pic' HMP command.
Do a QOM loop on the chip children and look for PHB3 devices instead.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211213132830.108372-7-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This change will help us providing support for user created PHB3
devices.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211213132830.108372-6-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
It is never used.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211213132830.108372-5-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The maximum number of PHB3 devices per chip can be different depending
on the POWER8 processor model.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211213132830.108372-4-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This change will help us move the mapping of XSCOM regions under the
PHB3 realize routine, which will be necessary for user created PHB3
devices.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211213132830.108372-3-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
An Event-Based Branch (EBB) allows applications to change the NIA when a
event-based exception occurs. Event-based exceptions are enabled by
setting the Branch Event Status and Control Register (BESCR). If the
event-based exception is enabled when the exception occurs, an EBB
happens.
The following operations happens during an EBB:
- Global Enable (GE) bit of BESCR is set to 0;
- bits 0-61 of the Event-Based Branch Return Register (EBBRR) are set
to the the effective address of the NIA that would have executed if the EBB
didn't happen;
- Instruction fetch and execution will continue in the effective address
contained in the Event-Based Branch Handler Register (EBBHR).
The EBB Handler will process the event and then execute the Return From
Event-Based Branch (rfebb) instruction. rfebb sets BESCR_GE and then
redirects execution to the address pointed in EBBRR. This process is
described in the PowerISA v3.1, Book II, Chapter 6 [1].
This patch implements the rfebb instruction. Descriptions of all
relevant BESCR bits are also added - this patch is only using BESCR_GE,
but the next patches will use the remaining bits.
[1] https://wiki.raptorcs.com/w/images/f/f5/PowerISA_public.v3.1.pdf
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211201151734.654994-9-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
PM_RUN_INST_CMPL, instructions completed with the run latch set, is
the architected PowerISA v3.1 event defined with PMC4SEL = 0xFA.
Implement it by checking for the CTRL RUN bit before incrementing the
counter. To make this work properly we also need to force a new
translation block each time SPR_CTRL is written. A small tweak in
pmu_increment_insns() is then needed to only increment this event
if the thread has the run latch.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211201151734.654994-8-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The PMU is already counting cycles by calculating time elapsed in
nanoseconds. Counting instructions is a different matter and requires
another approach.
This patch adds the capability of counting completed instructions (Perf
event PM_INST_CMPL) by counting the amount of instructions translated in
each translation block right before exiting it.
A new pmu_count_insns() helper in translation.c was added to do that.
After verifying that the PMU is counting instructions, call
helper_insns_inc(). This new helper from power8-pmu.c will add the
instructions to the relevant counters. It'll also be responsible for
triggering counter negative overflows as it is already being done with
cycles.
To verify whether the PMU is counting instructions or now, a new hflags
named 'HFLAGS_INSN_CNT' is introduced. This flag will match the internal
state of the PMU. We're be using this flag to avoid calling
helper_insn_inc() when we do not have a valid instruction event being
sampled.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211201151734.654994-7-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The PowerISA v3.1 defines that if the proper bits are set (MMCR0_PMC1CE
for PMC1 and MMCR0_PMCjCE for the remaining PMCs), counter negative
conditions are enabled. This means that if the counter value overflows
(i.e. exceeds 0x80000000) a performance monitor alert will occur. This alert
can trigger an event-based exception (to be implemented in the next patches)
if the MMCR0_EBE bit is set.
For now, overflowing the counter when the PMC is counting cycles will
just trigger a performance monitor alert. This is done by starting the
overflow timer to expire in the moment the overflow would be occuring. The
timer will call fire_PMC_interrupt() (via cpu_ppc_pmu_timer_cb) which will
trigger the PMU alert and, if the conditions are met, an EBB exception.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211201151734.654994-6-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
MMCR1 determines the events to be sampled by the PMU. Updating the
counters at every MMCR1 write ensures that we're not sampling more
or less events by looking only at MMCR0 and the PMCs.
It is worth noticing that both the Book3S PowerPC PMU, and this IBM
Power8+ PMU that we're modeling, also uses MMCRA, MMCR2 and MMCR3 to
control the PMU. These three registers aren't being handled in this
initial implementation, so for now we're controlling all the PMU
aspects using MMCR0, MMCR1 and the PMCs.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211201151734.654994-5-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Calling pmu_update_cycles() on every PMC read/write operation ensures
that the values being fetched are up to date with the current PMU state.
In theory we can get away by just trapping PMCs reads, but we're going
to trap PMC writes to deal with counter overflow logic later on. Let's
put the required wiring for that and make our lives a bit easier in the
next patches.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211201151734.654994-4-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This patch adds the barebones of the PMU logic by enabling cycle
counting. The overall logic goes as follows:
- MMCR0 reg initial value is set to 0x80000000 (MMCR0_FC set) to avoid
having to spin the PMU right at system init;
- to retrieve the events that are being profiled, pmc_get_event() will
check the current MMCR0 and MMCR1 value and return the appropriate
PMUEventType. For PMCs 1-4, event 0x2 is the implementation dependent
value of PMU_EVENT_INSTRUCTIONS and event 0x1E is the implementation
dependent value of PMU_EVENT_CYCLES. These events are supported by IBM
Power chips since Power8, at least, and the Linux Perf driver makes use
of these events until kernel v5.15. For PMC1, event 0xF0 is the
architected PowerISA event for cycles. Event 0xFE is the architected
PowerISA event for instructions;
- if the counter is frozen, either via the global MMCR0_FC bit or its
individual frozen counter bits, PMU_EVENT_INACTIVE is returned;
- pmu_update_cycles() will go through each counter and update the
values of all PMCs that are counting cycles. This function will be
called every time a MMCR0 update is done to keep counters values
up to date. Upcoming patches will use this function to allow the
counters to be properly updated during read/write of the PMCs
and MMCR1 writes.
Given that the base CPU frequency is fixed at 1Ghz for both powernv and
pseries clock, cycle calculation assumes that 1 nanosecond equals 1 CPU
cycle. Cycle value is then calculated by adding the elapsed time, in
nanoseconds, of the last cycle update done via pmu_update_cycles().
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211201151734.654994-3-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This patch starts an IBM Power8+ compatible PMU implementation by adding
the representation of PMU events that we are going to sample,
PMUEventType. This enum represents a Perf event that is being sampled by
a specific counter 'sprn'. Events that aren't available (i.e. no event
was set in MMCR1) will be of type 'PMU_EVENT_INVALID'. Events that are
inactive due to frozen counter bits state are of type
'PMU_EVENT_INACTIVE'. Other types added in this patch are
PMU_EVENT_CYCLES and PMU_EVENT_INSTRUCTIONS. More types will be added
later on.
Let's also add the required PMU cycle overflow timers. They will be used
to trigger cycle overflows when cycle events are being sampled. This
timer will call cpu_ppc_pmu_timer_cb(), which in turn calls
fire_PMC_interrupt(). Both functions are stubs that will be implemented
later on when EBB support is added.
Two new helper files are created to host this new logic.
cpu_ppc_pmu_init() will init all overflow timers during CPU init time.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211201151734.654994-2-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This reverts commit 336e91f853.
It breaks the --disable-tcg build:
../target/ppc/excp_helper.c:463:29: error: implicit declaration of
function ‘cpu_ldl_code’ [-Werror=implicit-function-declaration]
We should not have TCG code in powerpc_excp because some kvm-only
routines use it indirectly to dispatch interrupts. See
kvm_handle_debug, spapr_mce_req_event and
spapr_do_system_reset_on_cpu.
We can re-introduce the change once we have split the interrupt
injection code between KVM and TCG.
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20211209173323.2166642-1-farosas@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
When Altivec support was added to the e6500 kernel in 2012[1], the
QEMU code was not changed, so we don't register the VPU/VPUA
exceptions for the e6500:
qemu: fatal: Raised an exception without defined vector 73
Note that the error message says 73, instead of 32, which is the IVOR
for VPU. This is because QEMU knows only knows about the VPU interrupt
for the 7400s. In theory, we should not be raising _that_ VPU
interrupt, but instead another one specific for the e6500.
We unfortunately cannot register e6500-specific VPU/VPUA interrupts
because the SPEU/EFPDI interrupts also use IVOR32/33. These are
present only in the e500v1/2 versions. From the user manual:
e500v1, e500v2: only SPEU/EFPDI/EFPRI
e500mc, e5500: no SPEU/EFPDI/EFPRI/VPU/VPUA
e6500: only VPU/VPUA
So I'm leaving IVOR32/33 as SPEU/EFPDI, but altering the dispatch code
to convert the VPU #73 to a #32 when we're in the e6500. Since the
handling for SPEU and VPU is the same this is the only change that's
needed. The EFPDI is not implemented and will cause an abort. I don't
think it worth it changing the error message to take VPUA into
consideration, so I'm not changing anything there.
This bug was discussed in the thread:
https://lists.gnu.org/archive/html/qemu-ppc/2021-06/msg00222.html
1- https://git.kernel.org/torvalds/c/cd66cc2ee52
Reported-by: <mario@locati.it>
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211213133542.2608540-1-farosas@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This instruction has VRT and VRB fields instead of T/TX and B/BX.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20211213120958.24443-4-victor.colombo@eldorado.org.br>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Victor Colombo <victor.colombo@eldorado.org.br>
Message-Id: <20211213120958.24443-3-victor.colombo@eldorado.org.br>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
PPC instruction xsmaxcdp, xsmincdp, xsmaxjdp, and xsminjdp are using
vector registers when they should be using VSX ones. This happens
because the instructions are using GEN_VSX_HELPER_R3, which adds 32
to the register numbers, effectively making them vector registers.
This patch fixes it by changing these instructions to use
GEN_VSX_HELPER_X3.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Victor Colombo <victor.colombo@eldorado.org.br>
Message-Id: <20211213120958.24443-2-victor.colombo@eldorado.org.br>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Adapt the fields offset in the board information for Linux. Since
Linux relies on the CPU frequency value, I wonder how it ever worked.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-15-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The board information for the 405EP first appeared in commit 04f20795ac
("Move PowerPC 405 specific definitions into a separate file ...")
An Ethernet address is a 6 byte number. Fix that.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211206103712.1866296-14-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
These values are computed and updated by U-Boot at startup. Use them
as defaults to improve direct Linux boot.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-13-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The machine can already boot with kernel and initrd U-boot images if a
firmware is loaded first. Adapt and improve the load sequence to let
the machine boot directly from a Linux kernel ELF image and a usual
initrd image if a firmware image is not provided. For that, install a
custom CPU reset handler to setup the registers and to start the CPU
from the Linux kernel entry point.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-12-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This routine is a small helper to cleanup the code. The update of the
flash fields were removed because there are not of any use when booting
from a Linux kernel image. It should be functionally equivalent.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-11-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
QEMU installs a custom U-Boot in-memory descriptor to share board
information with Linux, which means that the QEMU machine was
initially designed to support booting Linux directly without using the
loaded FW. But, it's not that simple because the CPU still starts at
address 0xfffffffc where nothing is currently mapped. Support must
have been broken these last years.
Since we can not find a "ppc405_rom.bin" firmware file, request one to
be specified on the command line. A consequence of this change is that
the machine can be booted directly from Linux without any FW being
loaded. This is still broken and the CPU start address will be fixed
in the next changes.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-10-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
It is currently impossible to find a "ppc405_rom.bin" firmware file or
a full flash image for the PPC405EP evalution board. Even if it should
be technically possible to recreate such an image, it's unlikely that
anyone will do it since the board is obsolete and support in QEMU has
been broken for about 10 years.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-9-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
I will be useful to rework the boot from Linux.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-7-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
It was introduced in commit b8d3f5d126 ("Add flags to support
PowerPC 405 bootinfos variations.") but since its value has always
been set to '1'.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211206103712.1866296-6-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
and one error message to a LOG_GUEST_ERROR.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-5-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The PPC 405 CPU is a system-on-a-chip, so all 405 machines are very similar,
except for some external periphery. However, the periphery of the 'taihu'
machine is hardly emulated at all (e.g. neither the LCD nor the USB part had
been implemented), so there is not much value added by this board. The users
can use the 'ref405ep' machine to test their PPC405 code instead.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211203164904.290954-2-thuth@redhat.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-3-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The default addresses to load the kernel, fdt, initrd of AMCC boards
in U-Boot v2015.10 are :
"kernel_addr_r=1000000\0"
"fdt_addr_r=1800000\0"
"ramdisk_addr_r=1900000\0"
The taihu is one of these boards, the ref405ep is not but we don't
have much information on it and both boards have a very similar
address space layout.
Also, if loaded at address 0, U-Boot will partially overwrite the
uImage because of a bug in get_ram_size() (U-Boot v2015.10) not
restoring properly the probed RAM contents and because the exception
vectors are installed in the same range. Finally, a gzipped kernel
image will be uncompressed at 0x0. These are all good reasons for not
mappping a kernel image at this address.
Change the kernel load address to match U-Boot expectations and fix
loading.
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20211202191446.1292125-1-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-2-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
They have been there since 2007 without any board using them, most
were protected by a TODO define. Drop support.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211202191108.1291515-1-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The exception model id for 601v has been removed without mention
why. I assume it was inadvertent and restore it here.
Fixes: b632a148b6 ("target-ppc: Use QOM method dispatch for MMU fault handling")
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211208123029.2052625-4-farosas@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The 603e uses the same exception code as 603 so we don't need a
dedicated entry for it.
This is only a removal of redundant code, no functional change.
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211208123029.2052625-3-farosas@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The Floating-point Unavailable and Decrementer interrupts are being
registered at the same 0x900 address. The FPU should be at 0x800
instead.
Verified on MPC555, MPC860 and MPC885 user manuals.
Reported-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211208123029.2052625-2-farosas@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
(Applies to 7441, 7445, 7450, 7451, 7455, 7457, 7447, 7447a and 7448)
The QEMU-side software TLB implementation for the 7450 family of CPUs
is being removed due to lack of known users in the real world. The
last users in the code were removed by the two previous commits.
A brief history:
The feature was added in QEMU by commit 7dbe11acd8 ("Handle all MMU
models in switches...") with the mention that Linux was not able to
handle the TLB miss interrupts and the MMU model would be kept
disabled.
At some point later, commit 8ca3f6c382 ("Allow selection of all
defined PowerPC 74xx (aka G4) CPUs.") enabled the model for the 7450
family without further justification.
We have since the year 2011 [1] been unable to run OpenBIOS in the
7450s and have not heard of any other software that is used with those
CPUs in QEMU. Attempts were made to find a guest OS that implemented
the TLB miss handlers and none were found among Linux 5.15, FreeBSD 13,
MacOS9, MacOSX and MorphOS 3.15.
All CPUs that registered this feature were moved to an MMU model that
replaces the software TLB with a QEMU hardware TLB
implementation. They can now run the same software as the 7400 CPUs,
including the OSes mentioned above.
References:
- https://bugs.launchpad.net/qemu/+bug/812398https://gitlab.com/qemu-project/qemu/-/issues/86
- https://lists.nongnu.org/archive/html/qemu-ppc/2021-11/msg00289.html
message id: 20211119134431.406753-1-farosas@linux.ibm.com
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211130230123.781844-4-farosas@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The e600 CPU is a successor of the 7448 and like all the 7450s CPUs,
it has an optional software TLB feature.
We have determined that there is no OS software support for the 7450
software TLB available these days. See the previous commit for more
information.
This patch disables the SPRs and instructions related to software TLB
from the e600 CPU.
No functional change intended. These facilities should be used by the
OS in interrupt handlers for interrupts that QEMU never generates.
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211130230123.781844-3-farosas@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
(Applies to 7441, 7445, 7450, 7451, 7455, 7457, 7447 and 7447a)*
We have since 2011 [1] been unable to run OpenBIOS in the 7450s and
have not heard of any other software that is used with those CPUs in
QEMU. A current discussion [2] shows that the 7450 software TLB is
unsupported in Linux 5.15, FreeBSD 13, MacOS9, MacOSX and MorphOS
3.15. With no known support in firmware or OS, this means that no code
for any of the 7450 CPUs is ever ran in QEMU.
Since the implementation in QEMU of the 7400 MMU is the same as the
7450, except for the software TLB vs. hardware TLB search, this patch
changes all 7450 cpus to the 7400 MMU model. This has the practical
effect of disabling the software TLB feature while keeping other
aspects of address translation working as expected.
This allow us to run software on the 7450 family again.
*- note that the 7448 is currently aliased in QEMU for a 7400, so it
is unaffected by this change.
1- https://bugs.launchpad.net/qemu/+bug/812398https://gitlab.com/qemu-project/qemu/-/issues/86
2- https://lists.nongnu.org/archive/html/qemu-ppc/2021-11/msg00289.html
message id: 20211119134431.406753-1-farosas@linux.ibm.com
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211130230123.781844-2-farosas@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
When computing the predicate "is this value currently formatted
for single precision", we do not want to round the value according
to the current rounding mode, nor perform a floating-point equality.
We want to see if the N bits that make up single-precision are the
only ones set within the register, and then a bitwise equality.
Fixes a bug in which a single-precision NaN is considered !SP,
because float64_eq(nan, nan) is always false.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-35-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
There is no double-rounding bug here, because the result is
merely an estimate to within 1 part in 256, but perform the
operation with float64r32_div for consistency.
Use float_flag_invalid_snan instead of recomputing the
snan-ness of the operand.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-34-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
There is no double-rounding bug here, because the result is
merely an estimate to within 1 part in 32, but perform the
operation with float64r32_div for consistency.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-33-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Use float64r32_mul. Fixes a double-rounding issue with performing
the compuation in float64 and then rounding afterward.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-32-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Use float64r32_{add,sub,div}. Fixes a double-rounding issue with
performing the compuation in float64 and then rounding afterward.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-31-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Use float64r32_sqrt. Fixes a double-rounding issue with performing
the compuation in float64 and then rounding afterward.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-30-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Use float64r32_muladd. Fixes a double-rounding issue with performing
the compuation in float64 and then rounding afterward.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-29-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
These variants take a float64 as input, compute the result to
infinite precision (as we do with FloatParts), round the result
to the precision and dynamic range of float32, and then return
the result in the format of float64.
This is the operation PowerPC requires for its float32 operations.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-28-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Use float_flag_invalid_snan instead of recomputing
the snan-ness of the operand.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-27-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
