Hash virtual real mode addressing is defined by the architecture
to not perform virtual page class key protection checks.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Drop includes from header that is not needed by the header itself and
only include them from C files that really need it.
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
The ppc_hash64_hpt_base() and ppc_hash64_hpt_mask() functions are
mostly used by mmu-hash64.c only but there is one call to
ppc_hash64_hpt_mask() in hw/ppc/spapr_vhyp_mmu.c.in a helper function
that can be moved to mmu-hash64.c which allows these functions to be
removed from the header.
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Checking if a page protection bit is set for a given access type is a
common operation. Add a function to avoid repeating the same check at
multiple places. As this relies on access type and page protection bit
values having certain relation also add an assert to ensure that this
assumption holds.
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
PPC_VIRTUAL_HYPERVISOR_GET_CLASS is used in critical operations like
interrupts and TLB misses and is quite costly. Running the
kvm-unit-tests sieve program with radix MMU enabled thrashes the TCG
TLB and spends a lot of time in TLB and page table walking code. The
test takes 67 seconds to complete with a lot of time being spent in
code related to finding the vhyp class:
12.01% [.] g_str_hash
8.94% [.] g_hash_table_lookup
8.06% [.] object_class_dynamic_cast
6.21% [.] address_space_ldq
4.94% [.] __strcmp_avx2
4.28% [.] tlb_set_page_full
4.08% [.] address_space_translate_internal
3.17% [.] object_class_dynamic_cast_assert
2.84% [.] ppc_radix64_xlate
Keep a pointer to the class and avoid this lookup. This reduces the
execution time to 40 seconds.
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Per https://discourse.gnome.org/t/port-your-module-from-g-memdup-to-g-memdup2-now/5538
The old API took the size of the memory to duplicate as a guint,
whereas most memory functions take memory sizes as a gsize. This
made it easy to accidentally pass a gsize to g_memdup(). For large
values, that would lead to a silent truncation of the size from 64
to 32 bits, and result in a heap area being returned which is
significantly smaller than what the caller expects. This can likely
be exploited in various modules to cause a heap buffer overflow.
Replace g_memdup() by the safer g_memdup2() wrapper.
Trivially safe because the argument was directly from sizeof.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20210903174510.751630-27-philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Extract page-protection definitions from "exec/cpu-all.h"
to "exec/page-protection.h".
The list of files requiring the new header was generated
using:
$ git grep -wE \
'PAGE_(READ|WRITE|EXEC|RWX|VALID|ANON|RESERVED|TARGET_.|PASSTHROUGH)'
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240427155714.53669-3-philmd@linaro.org>
Until v2.07s, the VRMA page size (L||LP) was encoded in LPCR[VRMASD].
In v3.0 that moved to the partition table PS field.
The powernv machine can now run KVM HPT guests on POWER9/10 CPUs with
this fix and the patch to add ASDR.
Fixes: 3367c62f52 ("target/ppc: Support for POWER9 native hash")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-ID: <20230730111842.39292-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The ASDR register was introduced in ISA v3.0. It has not been
implemented for HPT. With HPT, ASDR is the format of the slbmte RS
operand (containing VSID), which matches the ppc_slb_t field.
Fixes: 3367c62f52 ("target/ppc: Support for POWER9 native hash")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-ID: <20230726182230.433945-2-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The 'hwaddr' type is defined in "exec/hwaddr.h" as:
hwaddr is the type of a physical address
(its size can be different from 'target_ulong').
All definitions use the 'HWADDR_' prefix, except TARGET_FMT_plx:
$ fgrep define include/exec/hwaddr.h
#define HWADDR_H
#define HWADDR_BITS 64
#define HWADDR_MAX UINT64_MAX
#define TARGET_FMT_plx "%016" PRIx64
^^^^^^
#define HWADDR_PRId PRId64
#define HWADDR_PRIi PRIi64
#define HWADDR_PRIo PRIo64
#define HWADDR_PRIu PRIu64
#define HWADDR_PRIx PRIx64
#define HWADDR_PRIX PRIX64
Since hwaddr's size can be *different* from target_ulong, it is
very confusing to read one of its format using the 'TARGET_FMT_'
prefix, normally used for the target_long / target_ulong types:
$ fgrep TARGET_FMT_ include/exec/cpu-defs.h
#define TARGET_FMT_lx "%08x"
#define TARGET_FMT_ld "%d"
#define TARGET_FMT_lu "%u"
#define TARGET_FMT_lx "%016" PRIx64
#define TARGET_FMT_ld "%" PRId64
#define TARGET_FMT_lu "%" PRIu64
Apparently this format was missed during commit a8170e5e97
("Rename target_phys_addr_t to hwaddr"), so complete it by
doing a bulk-rename with:
$ sed -i -e s/TARGET_FMT_plx/HWADDR_FMT_plx/g $(git grep -l TARGET_FMT_plx)
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230110212947.34557-1-philmd@linaro.org>
[thuth: Fix some warnings from checkpatch.pl along the way]
Signed-off-by: Thomas Huth <thuth@redhat.com>
When updating the R bit of a PTE, the Hash64 MMU was using a wrong byte
offset, causing the first byte of the adjacent PTE to be corrupted.
This caused a panic when booting FreeBSD, using the Hash MMU.
Fixes: a2dd4e83e7 ("ppc/hash64: Rework R and C bit updates")
Signed-off-by: Leandro Lupori <leandro.lupori@eldorado.org.br>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Changed hash64 address translation to use the supplied mmu_idx instead
of using the one stored in the msr, for parity purposes (other book3s
MMUs already use it).
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210628133610.1143-4-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Create one common dispatch for all of the ppc_*_xlate functions.
Use ppc64_v3_radix to directly dispatch between ppc_radix64_xlate
and ppc_hash64_xlate.
Remove the separate *_handle_mmu_fault and *_get_phys_page_debug
functions, using common code for ppc_cpu_tlb_fill and
ppc_cpu_get_phys_page_debug.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210621125115.67717-9-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Mirror the interface of ppc_radix64_xlate, putting all of
the logic for hash64 translation into a single function.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210621125115.67717-6-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
These changes were waiting until we didn't need to match
the function type of PowerPCCPUClass.handle_mmu_fault.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210621125115.67717-3-bruno.larsen@eldorado.org.br>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
excp_helper.c, mmu-hash64.c and mmu_helper.c have some function
declarations that are TCG-only, and couldn't be easily moved to a
TCG only file, so ifdefs were added around them.
We also needed ifdefs around some header files because helper-proto.h
includes trace/generated-helpers.h, which is never created when building
without TCG, and cpu_ldst.h includes tcg/tcg.h, whose containing folder
is not included as a -iquote. As future cleanup, we could change the
part of the configuration script to add those.
cpu_init.c also had a callback definition that is TCG only and could be
removed as part of a future cleanup (all the dump_statistics part is
almost never used and will become obsolete as we transition to using
decodetree).
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Message-Id: <20210525115355.8254-3-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We must leave the 'int rwx' parameter to ppc_hash64_handle_mmu_fault
for now, but will clean that up later.
Signed-off-by: Ricgard Henderson <richard.henderson@linaro.org>
Message-Id: <20210518201146.794854-4-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Use this in the three places we currently have a local array
indexed by rwx (which happens to have the same values).
The types will match up correctly with additional changes.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210518201146.794854-2-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Moved the function ppc_store from mmu-hash64.c to misc_helper.c and the
prototype from mmu-hash64.h to cpu.h as it is a more appropriate place,
but it will have to have its implementation moved to a new file as
misc_helper.c should not be compiled in a !TCG environment.
Signed-off-by: Lucas Mateus Castro (alqotel) <lucas.araujo@eldorado.org.br>
Message-Id: <20210506163941.106984-4-lucas.araujo@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The function ppc_hash64_filter_pagesizes has been moved from a function
with prototype in mmu-hash64.h and implemented in mmu-hash64.c to
a static function in hw/ppc/spapr_caps.c as it's only used in that file.
Signed-off-by: Lucas Mateus Castro (alqotel) <lucas.araujo@eldorado.org.br>
Message-Id: <20210506163941.106984-3-lucas.araujo@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Because this bit was not in hflags, the privilege check
for tlb instructions was essentially random.
Recompute hflags when storing to LPCR.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210323184340.619757-7-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Callers don't really need to know how 64-bit MMU model enums are
computed. Hide this in a helper.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201209173536.1437351-3-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.
Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Message-Id: <20201019061126.3102-1-chetan4windows@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
I found that there are many spelling errors in the comments of qemu/target/ppc.
I used spellcheck to check the spelling errors and found some errors in the folder.
Signed-off-by: zhaolichang <zhaolichang@huawei.com>
Reviewed-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <20201009064449.2336-3-zhaolichang@huawei.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tracked down with scripts/coccinelle/err-bad-newline.cocci.
Cc: Peter Xu <peterx@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200722084048.1726105-3-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Peter Xu <peterx@redhat.com>
The new ISA v3.0 slbia variants have not been implemented for TCG,
which can lead to crashing when a POWER9 machine boots Linux using
the hash MMU, for example ("disable_radix" kernel command line).
Add them.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200319064439.1020571-1-npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[dwg: Fixed compile error for USER_ONLY builds]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
slbia must invalidate TLBs even if it does not remove a valid SLB
entry, because slbmte can overwrite valid entries without removing
their TLBs.
As the architecture says, slbia invalidates all lookaside information,
not conditionally based on if it removed valid entries.
It does not seem possible for POWER8 or earlier Linux kernels to hit
this bug because it never changes its kernel SLB translations, and it
should always have valid entries if any accesses are made to userspace
regions. However other operating systems which may modify SLB entry 0
or do more fancy things with segments might be affected.
When POWER9 slbia support is added in the next patch, this becomes a
real problem because some new slbia variants don't invalidate all
non-zero entries.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200318044135.851716-1-npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently, we construct the SLBE used for VRMA translations when the LPCR
is written (which controls some bits in the SLBE), then use it later for
translations.
This is a bit complex and confusing - simplify it by simply constructing
the SLBE directly from the LPCR when we need it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
When the LPCR is written, we update the env->rmls field with the RMA limit
it implies. Simplify things by just calculating the value directly from
the LPCR value when we need it.
It's possible this is a little slower, but it's unlikely to be significant,
since this is only for real mode accesses in a translation configuration
that's not used very often, and the whole thing is behind the qemu TLB
anyway. Therefore, keeping the number of state variables down and not
having to worry about making sure it's always in sync seems the better
option.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
The table of RMA limits based on the LPCR[RMLS] field is slightly wrong.
We're missing the RMLS == 0 => 256 GiB RMA option, which is available on
POWER8, so add that.
The comment that goes with the table is much more wrong. We *don't* filter
invalid RMLS values when writing the LPCR, and there's not really a
sensible way to do so. Furthermore, while in theory the set of RMLS values
is implementation dependent, it seems in practice the same set has been
available since around POWER4+ up until POWER8, the last model which
supports RMLS at all. So, correct that as well.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Currently we use a big switch statement in ppc_hash64_update_rmls() to work
out what the right RMA limit is based on the LPCR[RMLS] field. There's no
formula for this - it's just an arbitrary mapping defined by the existing
CPU implementations - but we can make it a bit more readable by using a
lookup table rather than a switch. In addition we can use the MiB/GiB
symbols to make it a bit clearer.
While there we add a bit of clarity and rationale to the comment about
what happens if the LPCR[RMLS] doesn't contain a valid value.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
When we store the Logical Partitioning Control Register (LPCR) we have a
big switch statement to work out which are valid bits for the cpu model
we're emulating.
As well as being ugly, this isn't really conceptually correct, since it is
based on the mmu_model variable, whereas the LPCR isn't (only) about the
MMU, so mmu_model is basically just acting as a proxy for the cpu model.
Handle this in a simpler way, by adding a suitable lpcr_mask to the QOM
class.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
For the "pseries" machine, we use "virtual hypervisor" mode where we
only model the CPU in non-hypervisor privileged mode. This means that
we need guest physical addresses within the modelled cpu to be treated
as absolute physical addresses.
We used to do that by clearing LPCR[VPM0] and setting LPCR[RMLS] to a high
limit so that the old offset based translation for guest mode applied,
which does what we need. However, POWER9 has removed support for that
translation mode, which meant we had some ugly hacks to keep it working.
We now explicitly handle this sort of translation for virtual hypervisor
mode, so the hacks aren't necessary. We don't need to set VPM0 and RMLS
from the machine type code - they're now ignored in vhyp mode. On the cpu
side we don't need to allow LPCR[RMLS] to be set on POWER9 in vhyp mode -
that was only there to allow the hack on the machine side.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
When running guests under a hypervisor, the hypervisor obviously needs to
be protected from guest accesses even if those are in what the guest
considers real mode (translation off). The POWER hardware provides two
ways of doing that: The old way has guest real mode accesses simply offset
and bounds checked into host addresses. It works, but requires that a
significant chunk of the guest's memory - the RMA - be physically
contiguous in the host, which is pretty inconvenient. The new way, known
as VRMA, has guest real mode accesses translated in roughly the normal way
but with some special parameters.
In POWER7 and POWER8 the LPCR[VPM0] bit selected between the two modes, but
in POWER9 only VRMA mode is supported and LPCR[VPM0] no longer exists. We
handle that difference in behaviour in ppc_hash64_set_isi().. but not in
other places that we blindly check LPCR[VPM0].
Correct those instances with a new helper to tell if we should be in VRMA
mode.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
On ppc we have the concept of virtual hypervisor ("vhyp") mode, where we
only model the non-hypervisor-privileged parts of the cpu. Essentially we
model the hypervisor's behaviour from the point of view of a guest OS, but
we don't model the hypervisor's execution.
In particular, in this mode, qemu's notion of target physical address is
a guest physical address from the vcpu's point of view. So accesses in
guest real mode don't require translation. If we were modelling the
hypervisor mode, we'd need to translate the guest physical address into
a host physical address.
Currently, we handle this sloppily: we rely on setting up the virtual LPCR
and RMOR registers so that GPAs are simply HPAs plus an offset, which we
set to zero. This is already conceptually dubious, since the LPCR and RMOR
registers don't exist in the non-hypervisor portion of the CPU. It gets
worse with POWER9, where RMOR and LPCR[VPM0] no longer exist at all.
Clean this up by explicitly handling the vhyp case. While we're there,
remove some unnecessary nesting of if statements that made the logic to
select the correct real mode behaviour a bit less clear than it could be.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
The PowerPC 970 CPU was a cut-down POWER4, which had hypervisor capability.
However, it can be (and often was) strapped into "Apple mode", where the
hypervisor capabilities were disabled (essentially putting it always in
hypervisor mode).
That's actually the only mode of the 970 we support in qemu, and we're
unlikely to change that any time soon. However, we do have a partial
implementation of the 970's HID4 register which affects things only
relevant for hypervisor mode.
That stub is also really ugly, since it attempts to duplicate the effects
of HID4 by re-encoding it into the LPCR register used in newer CPUs, but
in a really confusing way.
Just get rid of it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Cleanup in the boilerplate that each target must define.
Replace ppc_env_get_cpu with env_archcpu. The combination
CPU(ppc_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
With MT-TCG, we are now running translation in a racy way, thus
we need to mimic hardware when it comes to updating the R and
C bits, by doing byte stores.
The current "store_hpte" abstraction is ill suited for this, we
replace it with two separate callbacks for setting R and C.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190411080004.8690-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The various dump_mmu() take an fprintf()-like callback and a FILE * to
pass to it, and so do their helper functions. Passing around callback
and argument is rather tiresome.
Most dump_mmu() are called only by the target's hmp_info_tlb(). These
all pass monitor_printf() cast to fprintf_function and the current
monitor cast to FILE *.
SPARC's dump_mmu() gets also called from target/sparc/ldst_helper.c a
few times #ifdef DEBUG_MMU. These calls pass fprintf() and stdout.
The type-punning is technically undefined behaviour, but works in
practice. Clean up: drop the callback, and call qemu_printf()
instead.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-11-armbru@redhat.com>
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>
(Might need more patch splitting)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190215170029.15641-12-clg@kaod.org>
[dwg: Hack to fix compile with some earlier include tweaks of mine]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
