Invalidate the last page of a demoted superpage mapping, instead of the
first page, as it results in slightly more promotions and fewer
failures. While here, replace 'boolean_t's with 'bool's in
mmu_radix_advise().
Simplify pmap_clear_modify() a bit, by assuming that since the superpage
demotion succeeded, all 4k mappings from it are valid. Deindent the
surrounding code, as there are no 'else' branches in the code anyway.
Summary:
Some methods are split between DMAP and non-DMAP, conditional on
hw_direct_map variable. Rather than checking this variable every time,
use it to install different functions via IFUNCs.
Reviewed By: luporl
Differential Revision: https://reviews.freebsd.org/D30071
Summary:
Since PCPU can live in a GPR for a while longer, let it, rather than
re-getting it in yet another register. MFSPR is an expensive operation,
12 clock latency on POWER9, so the fewer operations we need, the better.
Since the check is tightly coupled to the fetch, by reducing the number
of fetch+check, we reduce the stalls, and improve the performance
marginally. Buildworld was measured at a ~5-7% improvement on a single
run.
Reviewed By: nwhitehorn
Differential Revision: https://reviews.freebsd.org/D30003
Radix MMU code was missing TLB invalidations when some Level 3 PDEs were
modified. This caused TLB multi-hit machine check interrupts when
superpages were enabled.
Reviewed by: jhibbits
MFC after: 2 weeks
Sponsored by: Eldorado Research Institute (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D29511
This only works on single-CPU G4 systems, and more work is needed for
dual-CPU systems. That said, platform sleep does not work, and this is
currently only used for PMU-based CPU speed change.
The elimination of the platform_smp_timebase_sync() call is so that the
timebase sync rendezvous can be enhanced to perform better
synchronization, which requires a full rendezvous. This would be
impossible to do on this single-threaded run.
Rename cpu_sleep() to mpc745x_sleep() to denote what it's actually
intended for. This function is very G4-specific, and will not work on
any other CPU. This will afterward eliminate a
platform_smp_timebase_sync() call by directly updating the timebase
instead.
--Eliminate a big ifdef that encompassed all currently-supported
architectures except mips and powerpc32. This applied to the case
in which we've allocated a superpage but the pager-populated range
is insufficient for a superpage mapping. For platforms that don't
support superpages the check should be inexpensive as we shouldn't
get a superpage in the first place. Make the normal-page fallback
logic identical for all platforms and provide a simple implementation
of pmap_ps_enabled() for MIPS and Book-E/AIM32 powerpc.
--Apply the logic for handling pmap_enter() failure if a superpage
mapping can't be supported due to additional protection policy.
Use KERN_PROTECTION_FAILURE instead of KERN_FAILURE for this case,
and note Intel PKU on amd64 as the first example of such protection
policy.
Reviewed by: kib, markj, bdragon
Differential Revision: https://reviews.freebsd.org/D29439
Now that superpages for HPT MMU has landed, finish implementation of
pmap_mincore by adding support for superpages.
Submitted by: Fernando Eckhardt Valle <fernando.valle@eldorado.org.br>
Reviewed by: bdragon, luporl
MFC after: 1 week
Sponsored by: Eldorado Research Institute (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D29230
PowerISA 2.07B says that the low-order p-12 bits of the real page number
contained in ARPN and LP fields of a PTE must be 0s and are ignored
by the hardware (Book III-S, 5.7.7.1), where 2^p is the actual page size
in bytes, but we were clearing only the LP field.
This worked on bare metal and QEMU with KVM, that ignore these bits,
but caused a kernel panic on QEMU with TCG, that expects them to be
cleared.
This fixes running FreeBSD with HPT superpages enabled on QEMU
with TCG.
MFC after: 2 weeks
Sponsored by: Eldorado Research Institute (eldorado.org.br)
In r361544, the pmap drivers were converted to ifuncs. When doing so,
this changed the call type of pmap functions to be called via the
secure-plt stubs.
These stubs depend on the TOC base being loaded to r30 to run properly.
On SMP AIM (i.e. a dual processor G4 or running 32-bit on G5), since the
APs were being started up from the reset vector instead of going
through __start, they had never had r30 initialized properly, so when the
cpu_reset code in trap_subr32.S attempted to branch to
pmap_cpu_bootstrap(), it was loading the target from the wrong location.
Ensure r30 is set up directly in the cpu_reset trap code, so we can make
PLT calls as normal.
Fixes boot on my SMP G4.
Reviewed by: jhibbits
MFC after: 3 days
Sponsored by: Tag1 Consulting, Inc.
This macro returns true if a provided virtual address is contained
in the kernel's clean submap.
In CHERI kernels, the buffer cache and transient I/O map are allocated
as separate regions. Abstracting this check reduces the diff relative
to FreeBSD. It is perhaps slightly more readable as well.
Reviewed by: kib
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D28710
In 78599c32ef, CFI endproc decoration was
added to locore64.S. However, it missed the subtle detail that
__restartkernel_virtual() falls through to __restartkernel(). This was
causing boot failure on PowerMac G5, as it tried to execute the
epilogue as code.
Fix this by branching to __restartkernel() instead of intentionally
running off the end of the function.
While here, add some additional notes on how the virtual mode restart
works.
MFC after: 3 days
Follow-up to r353959 and r368070: do the same for other architectures.
arm32 already seems to use its own .fnstart/.fnend directives, which
appear to be ARM-specific variants of the same thing. Likewise, MIPS
uses .frame directives.
Reviewed by: arichardson
Differential Revision: https://reviews.freebsd.org/D27387
It can useful for code outside the VM system to look up the NUMA domain
of a page backing a virtual or physical address, specifically when
creating NUMA-aware data structures. We have _vm_phys_domain() for
this, but the leading underscore implies that it's an internal function,
and vm_phys.h has dependencies on a number of other headers.
Rename vm_phys_domain() to vm_page_domain(), and _vm_phys_domain() to
vm_phys_domain(). Make the latter an inline function.
Add _vm_phys.h and define struct vm_phys_seg there so that it's easier
to use in other headers. Include it from vm_page.h so that
vm_page_domain() can be defined there.
Include machine/vmparam.h from _vm_phys.h since it depends directly on
some constants defined there.
Reviewed by: alc
Reviewed by: dougm, kib (earlier versions)
Differential Revision: https://reviews.freebsd.org/D27207
After r367417, both mmu_oea64 and mmu_radix were defining the vm.pmap
sysctl node, resulting in the later definition hiding the properties of
the previous one. Avoid this issue by defining vm.pmap in a common
source file and declaring it where needed.
This change also standardizes the tunable name used to enable superpages
and change its default to disabled on radix MMU, because it still has some
issues with superpages.
Reviewed by: bdragon, jhibbits
Sponsored by: Eldorado Research Institute (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D27156
There were many, many endianness fixes needed for Radix MMU. The Radix
pagetable is stored in BE (as it is read and written to by the MMU hw),
so we need to convert back and forth every time we interact with it when
running in LE.
With these changes, I can successfully boot with radix enabled on POWER9 hw.
Reviewed by: luporl, jhibbits
Sponsored by: Tag1 Consulting, Inc.
Differential Revision: https://reviews.freebsd.org/D27181
The HPT is always stored in big-endian, as it is accessed directly by the
hardware as well as the kernel. As such, it is necessary to convert values
to and from native endian when running on LE.
Some unconverted accesses snuck in accidentally with r367417.
Apply the appropriate conversions to fix boot hanging on powerpc64le.
Sponsored by: Tag1 Consulting, Inc.
Fix build errors introduced by r367417 and r367390:
- Guard label reached only by powerpc64
- Guard vm_reserv_level_iffullpop call, that is not defined on powerpc
variants that don't support superpages
- Add missing hwpmc file, for when hwpmc is built into kernel
This change adds support for transparent superpages for PowerPC64
systems using Hashed Page Tables (HPT). All pmap operations are
supported.
The changes were inspired by RISC-V implementation of superpages,
by @markj (r344106), but heavily adapted to fit PPC64 HPT architecture
and existing MMU OEA64 code.
While these changes are not better tested, superpages support is disabled by
default. To enable it, use vm.pmap.superpages_enabled=1.
In this initial implementation, when superpages are disabled, system
performance stays at the same level as without these changes. When
superpages are enabled, buildworld time increases a bit (~2%). However,
for workloads that put a heavy pressure on the TLB the performance boost
is much bigger (see HPC Challenge and pgbench on D25237).
Reviewed by: jhibbits
Sponsored by: Eldorado Research Institute (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D25237
Move dump_avail[] extern declaration and inlines into a new header
vm/vm_dumpset.h. This fixes default gcc build for mips.
Reviewed by: alc, scottph
Tested by: kevans (previous version)
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D26741
OPAL unconditionally enters secondary CPUs with only HV and SF set.
I tried writing a secondary entry point instead, but OPAL rejected it
and I am unsure why, so I resorted to making the system reset interrupt
endian-flexible.
This means we take a slight performance hit on wakeup on LE, but it is
a good stopgap until we can figure out a reliable way to make OPAL enter
where we want it to.
It probably makes sense to have it around anyway, because I can imagine
scenarios where the cpu resets itself to BE and does a software reset.
Sponsored by: Tag1 Consulting, Inc.
It's much easier to implement this in an endian-independent way when we
don't also have to worry about masking half of the dword off.
Given that this code ran on a machine that ran a poudriere bulk with no
kernel oddities, I am relatively certain it is correctly implemented. ;)
This should be a minor performance boost on BE as well.
Sponsored by: Tag1 Consulting, Inc.
For a body of code that had its endian conversion bits written blind without
the ability to test, moea64 was VERY close to being correct.
There were only four instances where the existing code was getting it wrong.
Sponsored by: Tag1 Consulting, Inc.
Implement pmap_mincore() for moea64.
This will need some slight tweaks when large page support in HPT lands.
Submitted by: Fernando Eckhardt Valle <fernando.valle@eldorado.org.br>
Reviewed by: bdragon
Differential Revision: https://reviews.freebsd.org/D26314
When doing a build for a modern CPUTYPE, llvm will throw errors if obsolete
instructions are used, even if they will never run due to runtime checks.
Hiding the dssall instruction from the assembler fixes kernel build when
overriding CPUTYPE, without having any effect on the generated binary.
This has been in my local tree for over a year and is well tested across
a variety of machines.
Sponsored by: Tag1 Consulting, Inc.
Currently we use a single bit to indicate whether the virtual page is
part of a superpage. To support a forthcoming implementation of
non-transparent 1GB superpages, it is useful to provide more detailed
information about large page sizes.
The change converts MINCORE_SUPER into a mask for MINCORE_PSIND(psind)
values, indicating a mapping of size psind, where psind is an index into
the pagesizes array returned by getpagesizes(3), which in turn comes
from the hw.pagesizes sysctl. MINCORE_PSIND(1) is equal to the old
value of MINCORE_SUPER.
For now, two bits are used to record the page size, permitting values
of MAXPAGESIZES up to 4.
Reviewed by: alc, kib
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26238
After spending a lot of time trying to track down what was going on, I have
isolated the "black screen" failures when using boot1 to boot a G4 machine.
It turns out we were replacing the traps before installing the temporary
BAT entry for the bottom of physical memory. That meant that until the MMU
was bootstrapped, the cached translations were the only thing keeping us
from losing.
Throwing boot1 into the mix was affecting execution flow enough to cause us
to hit an uncached page and crash.
Fix this by properly setting up the initial BAT entry at the same time we
are replacing the OpenFirmware traps, so we can continue executing in
segment 0 until the rest of the DMAP has been set up.
A second thing discovered while researching this is that we were entering a
BAT region for segment 16. It turns out this range was a) considered part
of KVA, and b) has firmware mappings with varying attributes.
If we ever accessed an unmapped page in segment 16, it would cause a BAT
entry to be installed for the whole segment, which would bypass the
existing mappings until it was flushed out again.
Instead, translate the OFW memory attributes into VM memory attributes and
install the ranges into the kernel address space properly.
Reviewed by: adalava
MFC after: 3 weeks
Sponsored by: Tag1 Consulting, Inc.
Differential Revision: https://reviews.freebsd.org/D25547
Subsequent to r240317, kmem_free() was replaced with kva_free() (r254025).
kva_free() releases the KVA allocation for the mapped region, but no longer
clears the pmap (pagetable) entries.
An affected pmap_unmapdev operation would leave the still-pmap'd VA space
free for allocation by other KVA consumers. However, this bug easily
avoided notice for ~7 years because most devices (1) never call
pmap_unmapdev and (2) on amd64, mostly fit within the DMAP and do not need
KVA allocations. Other affected arch are less popular: i386, MIPS, and
PowerPC. Arm64, arm32, and riscv are not affected.
Reported by: Don Morris <dgmorris AT earthlink.net>
Submitted by: Don Morris (amd64 part)
Reviewed by: kib, markj, Don (!amd64 parts)
MFC after: I don't intend to, but you might want to
Sponsored by: Dell Isilon
Differential Revision: https://reviews.freebsd.org/D25689
Use PVO_PADDR macro to get the physical address from a PVO, instead of
explicitly ANDing pvo_pte.pa with LPTE_RPGN where it is needed. Besides
improving readability, this is needed to support superpages (D25237), where
the steps to get the PA from a PVO are different.
Reviewed by: markj
Sponsored by: Eldorado Research Institute (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D25654
Summary:
Radix on AIM, and all of Book-E (currently), can do direct addressing of
user space, instead of needing to map user addresses into kernel space.
Take advantage of this to optimize the copy(9) functions for this
behavior, and avoid effectively NOP translations.
Test Plan: Tested on powerpcspe, powerpc64/booke, powerpc64/AIM
Reviewed by: bdragon
Differential Revision: https://reviews.freebsd.org/D25129
Summary:
The point of this addition is to cache CPU behavior 'features', to avoid
having to recompute based on CPU, etc.
The first such use case is to avoid the unnecessary manipulation of the
SLBs (Segment Lookaside Buffers) when using the Radix pmap on POWER9.
Since we already get the PCPU pointer wherever we swap the SLB entries,
we can use a cached flag to check if it's necessary to perform the
operation anyway, and skip it when not.
Reviewed by: bdragon
Differential Revision: https://reviews.freebsd.org/D24908
Found by running libc tests with radix enabled.
Detect unsigned integer wrapping with a postcondition.
Note: Radix MMU is not enabled by default yet.
Sponsored by: Tag1 Consulting, Inc.
With IFUNC support in the kernel, we can finally get rid of our poor-man's
ifunc for pmap, utilizing kobj. Since moea64 uses a second tier kobj as
well, for its own private methods, this adds a second pmap install function
(pmap_mmu_init()) to perform pmap 'post-install pre-bootstrap'
initialization, before the IFUNCs get initialized.
Reviewed by: bdragon
