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Andrew Jones <ajones@ventanamicro.com> says:
Zawrs provides two instructions (wrs.nto and wrs.sto), where both are
meant to allow the hart to enter a low-power state while waiting on a
store to a memory location. The instructions also both wait an
implementation-defined "short" duration (unless the implementation
terminates the stall for another reason). The difference is that while
wrs.sto will terminate when the duration elapses, wrs.nto, depending on
configuration, will either just keep waiting or an ILL exception will be
raised. Linux will use wrs.nto, so if platforms have an implementation
which falls in the "just keep waiting" category (which is not expected),
then it should _not_ advertise Zawrs in the hardware description.
Like wfi (and with the same {m,h}status bits to configure it), when
wrs.nto is configured to raise exceptions it's expected that the higher
privilege level will see the instruction was a wait instruction, do
something, and then resume execution following the instruction. For
example, KVM does configure exceptions for wfi (hstatus.VTW=1) and
therefore also for wrs.nto. KVM does this for wfi since it's better to
allow other tasks to be scheduled while a VCPU waits for an interrupt.
For waits such as those where wrs.nto/sto would be used, which are
typically locks, it is also a good idea for KVM to be involved, as it
can attempt to schedule the lock holding VCPU.
This series starts with Christoph's addition of the riscv
smp_cond_load_relaxed function which applies wrs.sto when available.
That patch has been reworked to use wrs.nto and to use the same approach
as Arm for the wait loop, since we can't have arbitrary C code between
the load-reserved and the wrs. Then, hwprobe support is added (since the
instructions are also usable from usermode), and finally KVM is
taught about wrs.nto, allowing guests to see and use the Zawrs
extension.
We still don't have test results from hardware, and it's not possible to
prove that using Zawrs is a win when testing on QEMU, not even when
oversubscribing VCPUs to guests. However, it is possible to use KVM
selftests to force a scenario where we can prove Zawrs does its job and
does it well. [4] is a test which does this and, on my machine, without
Zawrs it takes 16 seconds to complete and with Zawrs it takes 0.25
seconds.
This series is also available here [1]. In order to use QEMU for testing
a build with [2] is needed. In order to enable guests to use Zawrs with
KVM using kvmtool, the branch at [3] may be used.
[1] https://github.com/jones-drew/linux/commits/riscv/zawrs-v3/
[2] https://lore.kernel.org/all/20240312152901.512001-2-ajones@ventanamicro.com/
[3] https://github.com/jones-drew/kvmtool/commits/riscv/zawrs/
[4] https://github.com/jones-drew/linux/commit/cb2beccebcece10881db842ed69bdd5715cfab5d
Link: https://lore.kernel.org/r/20240426100820.14762-8-ajones@ventanamicro.com
* b4-shazam-merge:
KVM: riscv: selftests: Add Zawrs extension to get-reg-list test
KVM: riscv: Support guest wrs.nto
riscv: hwprobe: export Zawrs ISA extension
riscv: Add Zawrs support for spinlocks
dt-bindings: riscv: Add Zawrs ISA extension description
riscv: Provide a definition for 'pause'
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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When a guest traps on wrs.nto, call kvm_vcpu_on_spin() to attempt
to yield to the lock holding VCPU. Also extend the KVM ISA extension
ONE_REG interface to allow KVM userspace to detect and enable the
Zawrs extension for the Guest/VM.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240426100820.14762-13-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Export Zawrs ISA extension through hwprobe.
[Palmer: there's a gap in the numbers here as there will be a merge
conflict when this is picked up. To avoid confusion I just set the
hwprobe ID to match what it would be post-merge.]
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Clément Léger <cleger@rivosinc.com>
Link: https://lore.kernel.org/r/20240426100820.14762-12-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD
LoongArch KVM changes for v6.11
1. Add ParaVirt steal time support.
2. Add some VM migration enhancement.
3. Add perf kvm-stat support for loongarch.
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KVM/riscv changes for 6.11
- Redirect AMO load/store access fault traps to guest
- Perf kvm stat support for RISC-V
- Use guest files for IMSIC virtualization, when available
ONE_REG support for the Zimop, Zcmop, Zca, Zcf, Zcd, Zcb and Zawrs ISA
extensions is coming through the RISC-V tree.
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RISC-V code uses the generic ticket lock implementation, which calls
the macros smp_cond_load_relaxed() and smp_cond_load_acquire().
Introduce a RISC-V specific implementation of smp_cond_load_relaxed()
which applies WRS.NTO of the Zawrs extension in order to reduce power
consumption while waiting and allows hypervisors to enable guests to
trap while waiting. smp_cond_load_acquire() doesn't need a RISC-V
specific implementation as the generic implementation is based on
smp_cond_load_relaxed() and smp_acquire__after_ctrl_dep() sufficiently
provides the acquire semantics.
This implementation is heavily based on Arm's approach which is the
approach Andrea Parri also suggested.
The Zawrs specification can be found here:
https://github.com/riscv/riscv-zawrs/blob/main/zawrs.adoc
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Co-developed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240426100820.14762-11-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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If we're going to provide the encoding for 'pause' in cpu_relax()
anyway, then we can drop the toolchain checks and just always use
it. The advantage of doing this is that other code that need
pause don't need to also define it (yes, another use is coming).
Add the definition to insn-def.h since it's an instruction
definition and also because insn-def.h doesn't include much, so
it's safe to include from asm/vdso/processor.h without concern for
circular dependencies.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240426100820.14762-9-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Cross-merge networking fixes after downstream PR.
Conflicts:
net/sched/act_ct.c
26488172b029 ("net/sched: Fix UAF when resolving a clash")
3abbd7ed8b76 ("act_ct: prepare for stolen verdict coming from conntrack and nat engine")
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Some userspace applications (OpenJDK for instance) uses the free MSBs
in pointers to insert additional information for their own logic and
need to get this information from somewhere. Currently they rely on
parsing /proc/cpuinfo "mmu=svxx" string to obtain the current value of
virtual address usable bits [1]. Since this reflect the raw supported
MMU mode, it might differ from the logical one used internally which is
why arch_get_mmap_end() is used. Exporting the highest mmapable address
through hwprobe will allow a more stable interface to be used. For that
purpose, add a new hwprobe key named
RISCV_HWPROBE_KEY_HIGHEST_VIRT_ADDRESS which will export the highest
userspace virtual address.
Link: https://github.com/openjdk/jdk/blob/master/src/hotspot/os_cpu/linux_riscv/vm_version_linux_riscv.cpp#L171 [1]
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240410144558.1104006-1-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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__builtin_clz() returns an int and casting the whole expression to int
is unnecessary. Remove it.
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
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The sbi_ecall() function arguments are not in the same order as the
ecall arguments, so we end up re-ordering the registers before the
ecall which is useless and costly.
So simply reorder the arguments in the same way as expected by ecall.
Instead of reordering directly the arguments of sbi_ecall(), use a proxy
macro since the current ordering is more natural.
Before:
Dump of assembler code for function sbi_ecall:
0xffffffff800085e0 <+0>: add sp,sp,-32
0xffffffff800085e2 <+2>: sd s0,24(sp)
0xffffffff800085e4 <+4>: mv t1,a0
0xffffffff800085e6 <+6>: add s0,sp,32
0xffffffff800085e8 <+8>: mv t3,a1
0xffffffff800085ea <+10>: mv a0,a2
0xffffffff800085ec <+12>: mv a1,a3
0xffffffff800085ee <+14>: mv a2,a4
0xffffffff800085f0 <+16>: mv a3,a5
0xffffffff800085f2 <+18>: mv a4,a6
0xffffffff800085f4 <+20>: mv a5,a7
0xffffffff800085f6 <+22>: mv a6,t3
0xffffffff800085f8 <+24>: mv a7,t1
0xffffffff800085fa <+26>: ecall
0xffffffff800085fe <+30>: ld s0,24(sp)
0xffffffff80008600 <+32>: add sp,sp,32
0xffffffff80008602 <+34>: ret
After:
Dump of assembler code for function __sbi_ecall:
0xffffffff8000b6b2 <+0>: add sp,sp,-32
0xffffffff8000b6b4 <+2>: sd s0,24(sp)
0xffffffff8000b6b6 <+4>: add s0,sp,32
0xffffffff8000b6b8 <+6>: ecall
0xffffffff8000b6bc <+10>: ld s0,24(sp)
0xffffffff8000b6be <+12>: add sp,sp,32
0xffffffff8000b6c0 <+14>: ret
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Yunhui Cui <cuiyunhui@bytedance.com>
Link: https://lore.kernel.org/r/20240322112629.68170-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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These are useful for measuring the latency of SBI calls. The SBI HSM
extension is excluded because those functions are called from contexts
such as cpuidle where instrumentation is not allowed.
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240321230131.1838105-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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As suggested by the B-ext spec, the Zbc (carry-less multiplication)
instructions can be used to accelerate CRC calculations. Currently, the
crc32 is the most widely used crc function inside kernel, so this patch
focuses on the optimization of just the crc32 APIs.
Compared with the current table-lookup based optimization, Zbc based
optimization can also achieve large stride during CRC calculation loop,
meantime, it avoids the memory access latency of the table-lookup based
implementation and it reduces memory footprint.
If Zbc feature is not supported in a runtime environment, then the
table-lookup based implementation would serve as fallback via alternative
mechanism.
By inspecting the vmlinux built by gcc v12.2.0 with default optimization
level (-O2), we can see below instruction count change for each 8-byte
stride in the CRC32 loop:
rv64: crc32_be (54->31), crc32_le (54->13), __crc32c_le (54->13)
rv32: crc32_be (50->32), crc32_le (50->16), __crc32c_le (50->16)
The compile target CPU is little endian, extra effort is needed for byte
swapping for the crc32_be API, thus, the instruction count change is not
as significant as that in the *_le cases.
This patch is tested on QEMU VM with the kernel CRC32 selftest for both
rv64 and rv32. Running the CRC32 selftest on a real hardware (SpacemiT K1)
with Zbc extension shows 65% and 125% performance improvement respectively
on crc32_test() and crc32c_test().
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240621054707.1847548-1-xiao.w.wang@intel.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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The uapi/asm/unistd_{32,64}.h and asm/syscall_table_{32,64}.h headers can
now be generated from scripts/syscall.tbl, which makes this consistent
with the other architectures that have their own syscall.tbl.
riscv has two extra system call that gets added to scripts/syscall.tbl.
The newstat and rlimit entries in the syscall_abis_64 line are for system
calls that were part of the generic ABI when riscv64 got added but are
no longer enabled by default for new architectures. Both riscv32 and
riscv64 also implement memfd_secret, which is optional for all
architectures.
Unlike all the other 32-bit architectures, the time32 and stat64
sets of syscalls are not enabled on riscv32.
Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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When clone3() was introduced, it was not obvious how each architecture
deals with setting up the stack and keeping the register contents in
a fork()-like system call, so this was left for the architecture
maintainers to implement, with __ARCH_WANT_SYS_CLONE3 defined by those
that already implement it.
Five years later, we still have a few architectures left that are missing
clone3(), and the macro keeps getting in the way as it's fundamentally
different from all the other __ARCH_WANT_SYS_* macros that are meant
to provide backwards-compatibility with applications using older
syscalls that are no longer provided by default.
Address this by reversing the polarity of the macro, adding an
__ARCH_BROKEN_SYS_CLONE3 macro to all architectures that don't
already provide the syscall, and remove __ARCH_WANT_SYS_CLONE3
from all the other ones.
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:
====================
pull-request: bpf-next 2024-07-08
The following pull-request contains BPF updates for your *net-next* tree.
We've added 102 non-merge commits during the last 28 day(s) which contain
a total of 127 files changed, 4606 insertions(+), 980 deletions(-).
The main changes are:
1) Support resilient split BTF which cuts down on duplication and makes BTF
as compact as possible wrt BTF from modules, from Alan Maguire & Eduard Zingerman.
2) Add support for dumping kfunc prototypes from BTF which enables both detecting
as well as dumping compilable prototypes for kfuncs, from Daniel Xu.
3) Batch of s390x BPF JIT improvements to add support for BPF arena and to implement
support for BPF exceptions, from Ilya Leoshkevich.
4) Batch of riscv64 BPF JIT improvements in particular to add 12-argument support
for BPF trampolines and to utilize bpf_prog_pack for the latter, from Pu Lehui.
5) Extend BPF test infrastructure to add a CHECKSUM_COMPLETE validation option
for skbs and add coverage along with it, from Vadim Fedorenko.
6) Inline bpf_get_current_task/_btf() helpers in the arm64 BPF JIT which gives
a small 1% performance improvement in micro-benchmarks, from Puranjay Mohan.
7) Extend the BPF verifier to track the delta between linked registers in order
to better deal with recent LLVM code optimizations, from Alexei Starovoitov.
8) Fix bpf_wq_set_callback_impl() kfunc signature where the third argument should
have been a pointer to the map value, from Benjamin Tissoires.
9) Extend BPF selftests to add regular expression support for test output matching
and adjust some of the selftest when compiled under gcc, from Cupertino Miranda.
10) Simplify task_file_seq_get_next() and remove an unnecessary loop which always
iterates exactly once anyway, from Dan Carpenter.
11) Add the capability to offload the netfilter flowtable in XDP layer through
kfuncs, from Florian Westphal & Lorenzo Bianconi.
12) Various cleanups in networking helpers in BPF selftests to shave off a few
lines of open-coded functions on client/server handling, from Geliang Tang.
13) Properly propagate prog->aux->tail_call_reachable out of BPF verifier, so
that x86 JIT does not need to implement detection, from Leon Hwang.
14) Fix BPF verifier to add a missing check_func_arg_reg_off() to prevent an
out-of-bounds memory access for dynpointers, from Matt Bobrowski.
15) Fix bpf_session_cookie() kfunc to return __u64 instead of long pointer as
it might lead to problems on 32-bit archs, from Jiri Olsa.
16) Enhance traffic validation and dynamic batch size support in xsk selftests,
from Tushar Vyavahare.
bpf-next-for-netdev
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (102 commits)
selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep
selftests/bpf: amend for wrong bpf_wq_set_callback_impl signature
bpf: helpers: fix bpf_wq_set_callback_impl signature
libbpf: Add NULL checks to bpf_object__{prev_map,next_map}
selftests/bpf: Remove exceptions tests from DENYLIST.s390x
s390/bpf: Implement exceptions
s390/bpf: Change seen_reg to a mask
bpf: Remove unnecessary loop in task_file_seq_get_next()
riscv, bpf: Optimize stack usage of trampoline
bpf, devmap: Add .map_alloc_check
selftests/bpf: Remove arena tests from DENYLIST.s390x
selftests/bpf: Add UAF tests for arena atomics
selftests/bpf: Introduce __arena_global
s390/bpf: Support arena atomics
s390/bpf: Enable arena
s390/bpf: Support address space cast instruction
s390/bpf: Support BPF_PROBE_MEM32
s390/bpf: Land on the next JITed instruction after exception
s390/bpf: Introduce pre- and post- probe functions
s390/bpf: Get rid of get_probe_mem_regno()
...
====================
Link: https://patch.msgid.link/20240708221438.10974-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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into soc/dt
RISC-V Devicetrees for v6.11
Sopgho:
Add clock support for SG2042.
Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
* tag 'riscv-sophgo-dt-for-v6.11' of https://github.com/sophgo/linux:
riscv: dts: add clock generator for Sophgo SG2042 SoC
Link: https://lore.kernel.org/r/PN1P287MB281861EA2B1706B430D2FA3EFEDB2@PN1P287MB2818.INDP287.PROD.OUTLOOK.COM
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Add clock generator node to device tree for SG2042, and enable clock for
uart.
Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
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https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux into soc/defconfig
RISC-V config update for v6.11
StarFive:
Enable most of the options needed for the jh7100 based boards to be
properly testable with defconfig.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
* tag 'riscv-config-for-v6.11' of https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux:
riscv: defconfig: Enable StarFive JH7110 drivers
Link: https://lore.kernel.org/r/20240707-unused-outflank-aa127ccb2cfe@spud
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux into soc/dt
RISC-V Devicetrees for v6.11
T-Head:
Last change from me before this starts going via Drew's tree is the
addition of the SBI PMU events node for the th1520.
StarFive:
A dts for the Pin64 Star64, another board with a jh7110 SoC. This board
is almost identical to the existing Milk-v Mars and VisionFive 2 boards
that are already support - just with a different PHY configuration and
only one of the two PCIe ports exposed. Additionally, the Mars and
VisionFive 2 get their PCie configuration added.
Microchip:
A dts for the BeagleV Fire. PCIe is disabled on it for now, as some
binding and driver changes are required.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
* tag 'riscv-dt-for-v6.11' of https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux:
riscv: dts: starfive: add PCIe dts configuration for JH7110
riscv: dts: microchip: add an initial devicetree for the BeagleV Fire
dt-bindings: riscv: microchip: document beaglev-fire
riscv: dts: starfive: Update flash partition layout
riscv: dts: thead: th1520: Add PMU event node
riscv: dts: starfive: add Star64 board devicetree
dt-bindings: riscv: starfive: add Star64 board compatible
dt-bindings: riscv: Add T-HEAD C908 compatible
Link: https://lore.kernel.org/r/20240707-nuttiness-lustfully-4aaf03c991b2@spud
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux into soc/dt
Allwinner SoC device tree changes for 6.11
This includes a commit shared with the clk tree. This commit adds clock
and reset indices to the device tree binding, and thus is needed for
both the device tree and driver changes.
ARM64 device tree and binding-only changes
- Add LRADC (low resolution ADC for resistor network based keys) for H616 SoC
- Add cache information for A64, H6, and H616 SoCs
- Correct model names and descriptions for Pine64 boards
- Add GPADC (general purpose ADC) for H616 SoC
- Add ADC joysticks based on GPADC for anbernic-rg35xx-h board
- Add additional CPU OPPs for the H700 on top of existing H616 ones
- Enable DVFS for rg35xx boards
- Add IOMMU for H616 SoC
RISC-V device tree changes
- Add system LDOs to D1s/T113 SoC
- Add ClockworkPi and DevTerm device trees
* tag 'sunxi-dt-for-6.11' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux:
riscv: dts: allwinner: Add ClockworkPi and DevTerm devicetrees
riscv: dts: allwinner: d1s-t113: Add system LDOs
arm64: dts: allwinner: h616: add IOMMU node
arm64: dts: allwinner: rg35xx: Enable DVFS CPU frequency scaling
arm64: dts: allwinner: h616: add additional CPU OPPs for the H700
arm64: dts: allwinner: anbernic-rg35xx-h: Add ADC joysticks
arm64: dts: allwinner: h616: Add GPADC device node
dt-bindings: clock: sun50i-h616-ccu: Add GPADC clocks
ARM: dts: sunxi: remove duplicated entries in makefile
arm64: dts: allwinner: Add cache information to the SoC dtsi for H616
arm64: dts: allwinner: Add cache information to the SoC dtsi for A64
arm64: dts: allwinner: Correct the model names for Pine64 boards
dt-bindings: arm: sunxi: Correct the descriptions for Pine64 boards
arm64: dts: allwinner: Add cache information to the SoC dtsi for H6
ARM: dts: sun50i: Add LRADC node
dt-bindings: input: sun4i-lradc-keys: Add H616 compatible
Link: https://lore.kernel.org/r/ZoQa8r1N8yi7FlPV@wens.tw
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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When BPF_TRAMP_F_CALL_ORIG is not set, stack space for passing arguments
on stack doesn't need to be reserved because the original function is
not called.
Only reserve space for stacked arguments when BPF_TRAMP_F_CALL_ORIG is
set.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Pu Lehui <pulehui@huawei.com>
Link: https://lore.kernel.org/bpf/20240708114758.64414-1-puranjay@kernel.org
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git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt:
- A fix for the CMODX example in the recently added icache flushing
prctl()
- A fix to the perf driver to avoid corrupting event data on counter
overflows when external overflow handlers are in use
- A fix to clear all hardware performance monitor events on boot, to
avoid dangling events firmware or previously booted kernels from
triggering spuriously
- A fix to the perf event probing logic to avoid erroneously reporting
the presence of unimplemented counters. This also prevents some
implemented counters from being reported
- A build fix for the vector sigreturn selftest on clang
- A fix to ftrace, which now requires the previously optional index
argument to ftrace_graph_ret_addr()
- A fix to avoid deadlocking if kexec crash handling triggers in an
interrupt context
* tag 'riscv-for-linus-6.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: kexec: Avoid deadlock in kexec crash path
riscv: stacktrace: fix usage of ftrace_graph_ret_addr()
riscv: selftests: Fix vsetivli args for clang
perf: RISC-V: Check standard event availability
drivers/perf: riscv: Reset the counter to hpmevent mapping while starting cpus
drivers/perf: riscv: Do not update the event data if uptodate
documentation: Fix riscv cmodx example
|
|
Cross-merge networking fixes after downstream PR.
Conflicts:
drivers/net/phy/aquantia/aquantia.h
219343755eae ("net: phy: aquantia: add missing include guards")
61578f679378 ("net: phy: aquantia: add support for PHY LEDs")
drivers/net/ethernet/wangxun/libwx/wx_hw.c
bd07a9817846 ("net: txgbe: remove separate irq request for MSI and INTx")
b501d261a5b3 ("net: txgbe: add FDIR ATR support")
https://lore.kernel.org/all/20240703112936.483c1975@canb.auug.org.au/
include/linux/mlx5/mlx5_ifc.h
048a403648fc ("net/mlx5: IFC updates for changing max EQs")
99be56171fa9 ("net/mlx5e: SHAMPO, Re-enable HW-GRO")
https://lore.kernel.org/all/20240701133951.6926b2e3@canb.auug.org.au/
Adjacent changes:
drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
4130c67cd123 ("wifi: iwlwifi: mvm: check vif for NULL/ERR_PTR before dereference")
3f3126515fbe ("wifi: iwlwifi: mvm: add mvm-specific guard")
include/net/mac80211.h
816c6bec09ed ("wifi: mac80211: fix BSS_CHANGED_UNSOL_BCAST_PROBE_RESP")
5a009b42e041 ("wifi: mac80211: track changes in AP's TPE")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Let's make update_mmu_tlb() simply a generic wrapper around
update_mmu_tlb_range(). Only the latter can now be overridden by the
architecture. We can now remove __HAVE_ARCH_UPDATE_MMU_TLB as well.
Link: https://lkml.kernel.org/r/20240522061204.117421-3-libang.li@antgroup.com
Signed-off-by: Bang Li <libang.li@antgroup.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "Add update_mmu_tlb_range() to simplify code", v4.
This series of commits mainly adds the update_mmu_tlb_range() to batch
update tlb in an address range and implement update_mmu_tlb() using
update_mmu_tlb_range().
After commit 19eaf44954df ("mm: thp: support allocation of anonymous
multi-size THP"), We may need to batch update tlb of a certain address
range by calling update_mmu_tlb() in a loop. Using the
update_mmu_tlb_range(), we can simplify the code and possibly reduce the
execution of some unnecessary code in some architectures.
This patch (of 3):
Add update_mmu_tlb_range(), we can batch update tlb of an address range.
Link: https://lkml.kernel.org/r/20240522061204.117421-1-libang.li@antgroup.com
Link: https://lkml.kernel.org/r/20240522061204.117421-2-libang.li@antgroup.com
Signed-off-by: Bang Li <libang.li@antgroup.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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If the kexec crash code is called in the interrupt context, the
machine_kexec_mask_interrupts() function will trigger a deadlock while
trying to acquire the irqdesc spinlock and then deactivate irqchip in
irq_set_irqchip_state() function.
Unlike arm64, riscv only requires irq_eoi handler to complete EOI and
keeping irq_set_irqchip_state() will only leave this possible deadlock
without any use. So we simply remove it.
Link: https://lore.kernel.org/linux-riscv/20231208111015.173237-1-songshuaishuai@tinylab.org/
Fixes: b17d19a5314a ("riscv: kexec: Fixup irq controller broken in kexec crash path")
Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
Reviewed-by: Ryo Takakura <takakura@valinux.co.jp>
Link: https://lore.kernel.org/r/20240626023316.539971-1-songshuaishuai@tinylab.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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ftrace_graph_ret_addr() takes an `idx` integer pointer that is used to
optimize the stack unwinding. Pass it a valid pointer to utilize the
optimizations that might be available in the future.
The commit is making riscv's usage of ftrace_graph_ret_addr() match
x86_64.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20240618145820.62112-1-puranjay@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
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Atish Patra <atishp@rivosinc.com> says:
This series contains 3 fixes out of which the first one is a new fix
for invalid event data reported in lkml[2]. The last two are v3 of Samuel's
patch[1]. I added the RB/TB/Fixes tag and moved 1 unrelated change
to its own patch. I also changed an error message in kvm vcpu_pmu from
pr_err to pr_debug to avoid redundant failure error messages generated
due to the boot time quering of events implemented in the patch[1]
Here is the original cover letter for the patch[1]
Before this patch:
$ perf list hw
List of pre-defined events (to be used in -e or -M):
branch-instructions OR branches [Hardware event]
branch-misses [Hardware event]
bus-cycles [Hardware event]
cache-misses [Hardware event]
cache-references [Hardware event]
cpu-cycles OR cycles [Hardware event]
instructions [Hardware event]
ref-cycles [Hardware event]
stalled-cycles-backend OR idle-cycles-backend [Hardware event]
stalled-cycles-frontend OR idle-cycles-frontend [Hardware event]
$ perf stat -ddd true
Performance counter stats for 'true':
4.36 msec task-clock # 0.744 CPUs utilized
1 context-switches # 229.325 /sec
0 cpu-migrations # 0.000 /sec
38 page-faults # 8.714 K/sec
4,375,694 cycles # 1.003 GHz (60.64%)
728,945 instructions # 0.17 insn per cycle
79,199 branches # 18.162 M/sec
17,709 branch-misses # 22.36% of all branches
181,734 L1-dcache-loads # 41.676 M/sec
5,547 L1-dcache-load-misses # 3.05% of all L1-dcache accesses
<not counted> LLC-loads (0.00%)
<not counted> LLC-load-misses (0.00%)
<not counted> L1-icache-loads (0.00%)
<not counted> L1-icache-load-misses (0.00%)
<not counted> dTLB-loads (0.00%)
<not counted> dTLB-load-misses (0.00%)
<not counted> iTLB-loads (0.00%)
<not counted> iTLB-load-misses (0.00%)
<not counted> L1-dcache-prefetches (0.00%)
<not counted> L1-dcache-prefetch-misses (0.00%)
0.005860375 seconds time elapsed
0.000000000 seconds user
0.010383000 seconds sys
After this patch:
$ perf list hw
List of pre-defined events (to be used in -e or -M):
branch-instructions OR branches [Hardware event]
branch-misses [Hardware event]
cache-misses [Hardware event]
cache-references [Hardware event]
cpu-cycles OR cycles [Hardware event]
instructions [Hardware event]
$ perf stat -ddd true
Performance counter stats for 'true':
5.16 msec task-clock # 0.848 CPUs utilized
1 context-switches # 193.817 /sec
0 cpu-migrations # 0.000 /sec
37 page-faults # 7.171 K/sec
5,183,625 cycles # 1.005 GHz
961,696 instructions # 0.19 insn per cycle
85,853 branches # 16.640 M/sec
20,462 branch-misses # 23.83% of all branches
243,545 L1-dcache-loads # 47.203 M/sec
5,974 L1-dcache-load-misses # 2.45% of all L1-dcache accesses
<not supported> LLC-loads
<not supported> LLC-load-misses
<not supported> L1-icache-loads
<not supported> L1-icache-load-misses
<not supported> dTLB-loads
19,619 dTLB-load-misses
<not supported> iTLB-loads
6,831 iTLB-load-misses
<not supported> L1-dcache-prefetches
<not supported> L1-dcache-prefetch-misses
0.006085625 seconds time elapsed
0.000000000 seconds user
0.013022000 seconds sys
[1] https://lore.kernel.org/linux-riscv/20240418014652.1143466-1-samuel.holland@sifive.com/
[2] https://lore.kernel.org/all/CC51D53B-846C-4D81-86FC-FBF969D0A0D6@pku.edu.cn/
* b4-shazam-merge:
perf: RISC-V: Check standard event availability
drivers/perf: riscv: Reset the counter to hpmevent mapping while starting cpus
drivers/perf: riscv: Do not update the event data if uptodate
Link: https://lore.kernel.org/r/20240628-misc_perf_fixes-v4-0-e01cfddcf035@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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The RISC-V SBI PMU specification defines several standard hardware and
cache events. Currently, all of these events are exposed to userspace,
even when not actually implemented. They appear in the `perf list`
output, and commands like `perf stat` try to use them.
This is more than just a cosmetic issue, because the PMU driver's .add
function fails for these events, which causes pmu_groups_sched_in() to
prematurely stop scheduling in other (possibly valid) hardware events.
Add logic to check which events are supported by the hardware (i.e. can
be mapped to some counter), so only usable events are reported to
userspace. Since the kernel does not know the mapping between events and
possible counters, this check must happen during boot, when no counters
are in use. Make the check asynchronous to minimize impact on boot time.
Fixes: e9991434596f ("RISC-V: Add perf platform driver based on SBI PMU extension")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20240628-misc_perf_fixes-v4-3-e01cfddcf035@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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This patch adds 12 function arguments support for riscv64 bpf trampoline.
The current bpf trampoline supports <= sizeof(u64) bytes scalar arguments [0]
and <= 16 bytes struct arguments [1]. Therefore, we focus on the situation
where scalars are at most XLEN bits and aggregates whose total size does not
exceed 2×XLEN bits in the riscv calling convention [2].
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://elixir.bootlin.com/linux/v6.8/source/kernel/bpf/btf.c#L6184 [0]
Link: https://elixir.bootlin.com/linux/v6.8/source/kernel/bpf/btf.c#L6769 [1]
Link: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/releases/download/draft-20230929-e5c800e661a53efe3c2678d71a306323b60eb13b/riscv-abi.pdf [2]
Link: https://lore.kernel.org/bpf/20240702121944.1091530-2-pulehui@huaweicloud.com
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git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull SoC fixes from Arnd Bergmann:
"A number of devicetree fixes came in for the rockchip platforms,
correcting some of the address information, and reverting a change to
the MMC controller configuration that caused regressions.
Four drivers have one code change each, addressing minor build issues
for the optee firmware driver, the litex SoC platform driver and two
reset drivers.
The riscv fixes as also simple, mainly turning off device nodes in the
canaan dts files unless they are actually usable on a particular
board.
Finally, Drew takes over maintaining the THEAD RISC-V SoC platform"
* tag 'arm-fixes-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
drivers/soc/litex: drop obsolete dependency on COMPILE_TEST
tee: optee: ffa: Fix missing-field-initializers warning
arm64: dts: rockchip: Add sound-dai-cells for RK3368
arm64: dts: rockchip: Fix the i2c address of es8316 on Cool Pi 4B
reset: hisilicon: hi6220: add missing MODULE_DESCRIPTION() macro
reset: gpio: Fix missing gpiolib dependency for GPIO reset controller
MAINTAINERS: thead: update Maintainer
arm64: dts: rockchip: fix PMIC interrupt pin on ROCK Pi E
riscv: dts: starfive: Set EMMC vqmmc maximum voltage to 3.3V on JH7110 boards
arm64: dts: rockchip: make poweroff(8) work on Radxa ROCK 5A
Revert "arm64: dts: rockchip: remove redundant cd-gpios from rk3588 sdmmc nodes"
ARM: dts: rockchip: rk3066a: add #sound-dai-cells to hdmi node
arm64: dts: rockchip: Fix the value of `dlg,jack-det-rate` mismatch on rk3399-gru
arm64: dts: rockchip: set correct pwm0 pinctrl on rk3588-tiger
riscv: dts: canaan: Disable I/O devices unless used
riscv: dts: canaan: Clean up serial aliases
arm64: dts: rockchip: Rename LED related pinctrl nodes on rk3308-rock-pi-s
arm64: dts: rockchip: Fix SD NAND and eMMC init on rk3308-rock-pi-s
arm64: dts: rockchip: Fix rk3308 codec@ff560000 reset-names
arm64: dts: rockchip: Fix the DCDC_REG2 minimum voltage on Quartz64 Model B
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We used bpf_prog_pack to aggregate bpf programs into huge page to
relieve the iTLB pressure on the system. We can apply it to bpf
trampoline, as Song had been implemented it in core and x86 [0]. This
patch is going to use bpf_prog_pack to RV64 bpf trampoline. Since Song
and Puranjay have done a lot of work for bpf_prog_pack on RV64,
implementing this function will be easy.
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Björn Töpel <bjorn@rivosinc.com> #riscv
Link: https://lore.kernel.org/all/20231206224054.492250-1-song@kernel.org [0]
Link: https://lore.kernel.org/bpf/20240622030437.3973492-4-pulehui@huaweicloud.com
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We get the size of the trampoline image during the dry run phase and
allocate memory based on that size. The allocated image will then be
populated with instructions during the real patch phase. But after
commit 26ef208c209a ("bpf: Use arch_bpf_trampoline_size"), the `im`
argument is inconsistent in the dry run and real patch phase. This may
cause emit_imm in RV64 to generate a different number of instructions
when generating the 'im' address, potentially causing out-of-bounds
issues. Let's emit the maximum number of instructions for the "im"
address during dry run to fix this problem.
Fixes: 26ef208c209a ("bpf: Use arch_bpf_trampoline_size")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240622030437.3973492-3-pulehui@huaweicloud.com
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|
Add PCIe dts configuraion for JH7110 SoC platform. The Star64 only has
one exposed PCIe port, so only the Mars and VisionFive 2 get two
enabled.
Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
Reviewed-by: Hal Feng <hal.feng@starfivetech.com>
[conor: squash in star64's single exposed port]
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
|
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This resolves the merge issues in the 8250 code due to some reverts in
6.10-rc6 in the console changes.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Clockwork Tech manufactures several SoMs for their RasPi CM3-compatible
"ClockworkPi" mainboard. Their R-01 SoM features the Allwinner D1 SoC.
The R-01 contains only the CPU, DRAM, and always-on voltage regulation;
it does not merit a separate devicetree.
The ClockworkPi mainboard features analog audio, a MIPI-DSI panel, USB
host and peripheral ports, an Ampak AP6256 WiFi/Bluetooth module, and an
X-Powers AXP228 PMIC for managing a Li-ion battery.
The DevTerm is a complete system which extends the ClockworkPi mainboard
with a MIPI-DSI panel and a pair of expansion boards. These expansion
boards provide a fan, a USB keyboard, speakers, and a thermal printer.
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20240622150731.1105901-4-wens@kernel.org
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
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Now that the bindings for the system LDOs have been merged, the nodes
for the system LDOs can be added. These are used on the ClockworkPi.
This was originally part of Samuel's D1 device tree series [1], but was
dropped in v5 as the regulator bindings weren't merged at the time.
[1] https://lore.kernel.org/linux-sunxi/20221231233851.24923-1-samuel@sholland.org/
Link: https://lore.kernel.org/r/20240622150731.1105901-3-wens@kernel.org
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt:
- A fix for vector load/store instruction decoding, which could result
in reserved vector element length encodings decoding as valid vector
instructions.
- Instruction patching now aggressively flushes the local instruction
cache, to avoid situations where patching functions on the flush path
results in torn instructions being fetched.
- A fix to prevent the stack walker from showing up as part of traces.
* tag 'riscv-for-linus-6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: stacktrace: convert arch_stack_walk() to noinstr
riscv: patch: Flush the icache right after patching to avoid illegal insns
RISC-V: fix vector insn load/store width mask
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Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
e3f02f32a050 ("ionic: fix kernel panic due to multi-buffer handling")
d9c04209990b ("ionic: Mark error paths in the data path as unlikely")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux into arm/fixes
RISC-V Devicetree fixes for v6.10-rc5+
T-Head:
Jisheng hasn't got enough time to look after the platform, so Drew
Fustini is going to take over.
StarFive:
A fix for a regulator voltage range that prevented using low performance
SD cards.
Canaan:
Cleanup for some "over eager" aliases for serial ports that did not
exist on some boards and I/O devices disabled on boards where they were
not actually in use.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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|
Björn Töpel <bjorn@kernel.org> says:
From: Björn Töpel <bjorn@rivosinc.com>
================================================================
Memory Hot(Un)Plug support (and ZONE_DEVICE) for the RISC-V port
================================================================
Introduction
============
To quote "Documentation/admin-guide/mm/memory-hotplug.rst": "Memory
hot(un)plug allows for increasing and decreasing the size of physical
memory available to a machine at runtime."
This series adds memory hot(un)plugging, and ZONE_DEVICE support for
the RISC-V Linux port.
MM configuration
================
RISC-V MM has the following configuration:
* Memory blocks are 128M, analogous to x86-64. It uses PMD
("hugepage") vmemmaps. From that follows that 2M (PMD) worth of
vmemmap spans 32768 pages á 4K which gets us 128M.
* The pageblock size is the minimum minimum virtio_mem size, and on
RISC-V it's 2M (2^9 * 4K).
Implementation
==============
The PGD table on RISC-V is shared/copied between for all processes. To
avoid doing page table synchronization, the first patch (patch 1)
pre-allocated the PGD entries for vmemmap/direct map. By doing that
the init_mm PGD will be fixed at kernel init, and synchronization can
be avoided all together.
The following two patches (patch 2-3) does some preparations, followed
by the actual MHP implementation (patch 4-5). Then, MHP and virtio-mem
are enabled (patch 6-7), and finally ZONE_DEVICE support is added
(patch 8).
MHP and locking
===============
TL;DR: The MHP does not step on any toes, except for ptdump.
Additional locking is required for ptdump.
Long version: For v2 I spent some time digging into init_mm
synchronization/update. Here are my findings, and I'd love them to be
corrected if incorrect.
It's been a gnarly path...
The `init_mm` structure is a special mm (perhaps not a "real" one).
It's a "lazy context" that tracks kernel page table resources, e.g.,
the kernel page table (swapper_pg_dir), a kernel page_table_lock (more
about the usage below), mmap_lock, and such.
`init_mm` does not track/contain any VMAs. Having the `init_mm` is
convenient, so that the regular kernel page table walk/modify
functions can be used.
Now, `init_mm` being special means that the locking for kernel page
tables are special as well.
On RISC-V the PGD (top-level page table structure), similar to x86, is
shared (copied) with user processes. If the kernel PGD is modified, it
has to be synched to user-mode processes PGDs. This is avoided by
pre-populating the PGD, so it'll be fixed from boot.
The in-kernel pgd regions are documented in
`Documentation/arch/riscv/vm-layout.rst`.
The distinct regions are:
* vmemmap
* vmalloc/ioremap space
* direct mapping of all physical memory
* kasan
* modules, BPF
* kernel
Memory hotplug is the process of adding/removing memory to/from the
kernel.
Adding is done in two phases:
1. Add the memory to the kernel
2. Online memory, making it available to the page allocator.
Step 1 is partially architecture dependent, and updates the init_mm
page table:
* Update the direct map page tables. The direct map is a linear map,
representing all physical memory: `virt = phys + PAGE_OFFSET`
* Add a `struct page` for each added page of memory. Update the
vmemmap (virtual mapping to the `struct page`, so we can easily
transform a kernel virtual address to a `struct page *` address.
From an MHP perspective, there are two regions of the PGD that are
updated:
* vmemmap
* direct mapping of all physical memory
The `struct mm_struct` has a couple of locks in play:
* `spinlock_t page_table_lock` protects the page table, and some
counters
* `struct rw_semaphore mmap_lock` protect an mm's VMAs
Note again that `init_mm` does not contain any VMAs, but still uses
the mmap_lock in some places.
The `page_table_lock` was originally used to to protect all pages
tables, but more recently a split page table lock has been introduced.
The split lock has a per-table lock for the PTE and PMD tables. If
split lock is disabled, all tables are guarded by
`mm->page_table_lock` (for user processes). Split page table locks are
not used for init_mm.
MHP operations is typically synchronized using
`DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock)`.
Actors
------
The following non-MHP actors in the kernel traverses (read), and/or
modifies the kernel PGD.
* `ptdump`
Walks the entire `init_mm`, via `ptdump_walk_pgd()` with the
`mmap_write_lock(init_mm)` taken.
Observation: ptdump can race with MHP, and needs additional locking
to avoid crashes/races.
* `set_direct_*` / `arch/riscv/mm/pageattr.c`
The `set_direct_*` functionality is used to "synchronize" the
direct map to other kernel mappings, e.g. modules/kernel text. The
direct map is using "as large huge table mappings as possible",
which means that the `set_direct_*` might need to split the direct
map.
The `set_direct_*` functions operates with the
`mmap_write_lock(init_mm)` taken.
Observation: `set_direct_*` uses the direct map, but will never
modify the same entry as MHP. If there is a mapping, that entry will
never race with MHP. Further, MHP acts when memory is offline.
* HVO / `mm/hugetlb_vmemmap`
HVO optimizes the backing `struct page` for hugetlb pages, which
means changing the "vmemmap" region. HVO can split (merge?) a
vmemmap pmd. However, it will never race with MHP, since HVO only
operates at online memory. HVO cannot touch memory being MHP added
or removed.
* `apply_to_page_range`
Walks a range, creates pages and applies a callback (setting
permissions) for the page.
When creating a table, it might use `int __pte_alloc_kernel(pmd_t
*pmd)` which takes the `init_mm.page_table_lock` to synchronize pmd
populate.
Used by: `mm/vmalloc.c` and `mm/kasan/shadow.c`. The KASAN callback
takes the `init_mm.page_table_lock` to synchronize pte creation.
Observations: `apply_to_page_range` applies to the "vmalloc/ioremap
space" region, and "kasan" region. *Not* affected by MHP.
* `apply_to_existing_page_range`
Walks a range, applies a callback (setting permissions) for the
page (no page creation).
Used by: `kernel/bpf/arena.c` and `mm/kasan/shadow.c`. The KASAN
callback takes the `init_mm.page_table_lock` to synchronize pte
creation. *Not* affected by MHP regions.
* `apply_to_existing_page_range` applies to the "vmalloc/ioremap
space" region, and "kasan" region. *Not* affected by MHP regions.
* `ioremap_page_range` and `vmap_page_range`
Uses the same internal function, and might create table entries at
the "vmalloc/ioremap space" region. Can call
`__pte_alloc_kernel()` which takes the `init_mm.page_table_lock`
synchronizing pmd populate in the region. *Not* affected by MHP
regions.
Summary:
* MHP add will never modify the same page table entries, as any of
the other actors.
* MHP remove is done when memory is offlined, and will not clash
with any of the actors.
* Functions that walk the entire kernel page table need
synchronization
* It's sufficient to add the MHP lock ptdump.
Testing
=======
This series adds basic DT supported hotplugging. There is a QEMU
series enabling MHP for the RISC-V "virt" machine here: [1]
ACPI/MSI support is still in the making for RISC-V, and prior proper
(ACPI) PCI MSI support lands [2] and NUMA SRAT support [3], it hard to
try it out.
I've prepared a QEMU branch with proper ACPI GED/PC-DIMM support [4],
and a this series with the required prerequisites [5] (AIA, ACPI AIA
MADT, ACPI NUMA SRAT).
To test with virtio-mem, e.g.:
| qemu-system-riscv64 \
| -machine virt,aia=aplic-imsic \
| -cpu rv64,v=true,vlen=256,elen=64,h=true,zbkb=on,zbkc=on,zbkx=on,zkr=on,zkt=on,svinval=on,svnapot=on,svpbmt=on \
| -nodefaults \
| -nographic -smp 8 -kernel rv64-u-boot.bin \
| -drive file=rootfs.img,format=raw,if=virtio \
| -device virtio-rng-pci \
| -m 16G,slots=3,maxmem=32G \
| -object memory-backend-ram,id=mem0,size=16G \
| -numa node,nodeid=0,memdev=mem0 \
| -serial chardev:char0 \
| -mon chardev=char0,mode=readline \
| -chardev stdio,mux=on,id=char0 \
| -device pci-serial,id=serial0,chardev=char0 \
| -object memory-backend-ram,id=vmem0,size=2G \
| -device virtio-mem-pci,id=vm0,memdev=vmem0,node=0
where "rv64-u-boot.bin" is U-boot with EFI/ACPI-support (use [6] if
you're lazy).
In the QEMU monitor:
| (qemu) info memory-devices
| (qemu) qom-set vm0 requested-size 1G
...to test DAX/KMEM, use the follow QEMU parameters:
| -object memory-backend-file,id=mem1,share=on,mem-path=virtio_pmem.img,size=4G \
| -device virtio-pmem-pci,memdev=mem1,id=nv1
and the regular ndctl/daxctl dance.
If you're brave to try the ACPI branch, add "acpi=on" to "-machine
virt", and test PC-DIMM MHP (in addition to virtio-{p},mem):
In the QEMU monitor:
| (qemu) object_add memory-backend-ram,id=mem1,size=1G
| (qemu) device_add pc-dimm,id=dimm1,memdev=mem1
You can also try hot-remove with some QEMU options, say:
| -object memory-backend-file,id=mem-1,size=256M,mem-path=/pagesize-2MB
| -device pc-dimm,id=mem1,memdev=mem-1
| -object memory-backend-file,id=mem-2,size=1G,mem-path=/pagesize-1GB
| -device pc-dimm,id=mem2,memdev=mem-2
| -object memory-backend-file,id=mem-3,size=256M,mem-path=/pagesize-2MB
| -device pc-dimm,id=mem3,memdev=mem-3
Remove "acpi=on" to run with DT.
Thanks to Alex, Andrew, David, and Oscar for all
comments/tests/fixups.
References
==========
[1] https://lore.kernel.org/qemu-devel/20240521105635.795211-1-bjorn@kernel.org/
[2] https://lore.kernel.org/linux-riscv/20240501121742.1215792-1-sunilvl@ventanamicro.com/
[3] https://lore.kernel.org/linux-riscv/cover.1713778236.git.haibo1.xu@intel.com/
[4] https://github.com/bjoto/qemu/commits/virtio-mem-pc-dimm-mhp-acpi-v2/
[5] https://github.com/bjoto/linux/commits/mhp-v4-acpi
[6] https://github.com/bjoto/riscv-rootfs-utils/tree/acpi
* b4-shazam-merge:
riscv: Enable DAX VMEMMAP optimization
riscv: mm: Add support for ZONE_DEVICE
virtio-mem: Enable virtio-mem for RISC-V
riscv: Enable memory hotplugging for RISC-V
riscv: mm: Take memory hotplug read-lock during kernel page table dump
riscv: mm: Add memory hotplugging support
riscv: mm: Add pfn_to_kaddr() implementation
riscv: mm: Refactor create_linear_mapping_range() for memory hot add
riscv: mm: Change attribute from __init to __meminit for page functions
riscv: mm: Pre-allocate vmemmap/direct map/kasan PGD entries
riscv: mm: Properly forward vmemmap_populate() altmap parameter
Link: https://lore.kernel.org/r/20240605114100.315918-1-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
|
Now that DAX is usable, enable the DAX VMEMMAP optimization as well.
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240605114100.315918-12-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
|
ZONE_DEVICE pages need DEVMAP PTEs support to function
(ARCH_HAS_PTE_DEVMAP). Claim another RSW (reserved for software) bit
in the PTE for DEVMAP mark, add the corresponding helpers, and enable
ARCH_HAS_PTE_DEVMAP for riscv64.
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20240605114100.315918-11-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
|
Enable ARCH_ENABLE_MEMORY_HOTPLUG and ARCH_ENABLE_MEMORY_HOTREMOVE for
RISC-V.
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20240605114100.315918-9-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
|
During memory hot remove, the ptdump functionality can end up touching
stale data. Avoid any potential crashes (or worse), by holding the
memory hotplug read-lock while traversing the page table.
This change is analogous to arm64's commit bf2b59f60ee1 ("arm64/mm:
Hold memory hotplug lock while walking for kernel page table dump").
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20240605114100.315918-8-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
|
For an architecture to support memory hotplugging, a couple of
callbacks needs to be implemented:
arch_add_memory()
This callback is responsible for adding the physical memory into the
direct map, and call into the memory hotplugging generic code via
__add_pages() that adds the corresponding struct page entries, and
updates the vmemmap mapping.
arch_remove_memory()
This is the inverse of the callback above.
vmemmap_free()
This function tears down the vmemmap mappings (if
CONFIG_SPARSEMEM_VMEMMAP is enabled), and also deallocates the
backing vmemmap pages. Note that for persistent memory, an
alternative allocator for the backing pages can be used; The
vmem_altmap. This means that when the backing pages are cleared,
extra care is needed so that the correct deallocation method is
used.
arch_get_mappable_range()
This functions returns the PA range that the direct map can map.
Used by the MHP internals for sanity checks.
The page table unmap/teardown functions are heavily based on code from
the x86 tree. The same remove_pgd_mapping() function is used in both
vmemmap_free() and arch_remove_memory(), but in the latter function
the backing pages are not removed.
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240605114100.315918-7-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
|
The pfn_to_kaddr() function is used by KASAN's memory hotplugging
path. Add the missing function to the RISC-V port, so that it can be
built with MHP and CONFIG_KASAN.
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240605114100.315918-6-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
|
Add a parameter to the direct map setup function, so it can be used in
arch_add_memory() later.
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20240605114100.315918-5-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
|
Prepare for memory hotplugging support by changing from __init to
__meminit for the page table functions that are used by the upcoming
architecture specific callbacks.
Changing the __init attribute to __meminit, avoids that the functions
are removed after init. The __meminit attribute makes sure the
functions are kept in the kernel text post init, but only if memory
hotplugging is enabled for the build.
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20240605114100.315918-4-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
