Alexandre Ghiti <alexghiti@rivosinc.com> says:

patch 1 removes a useless memory barrier and patch 2 actually fixes the
issue with IPI in the patching code.

* b4-shazam-merge:
  riscv: Fix text patching when IPI are used
  riscv: Remove superfluous smp_mb()

Link: https://lore.kernel.org/r/20240229121056.203419-1-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Export the Zihintpause ISA extension through hwprobe which allows using
"pause" instructions. Some userspace applications (OpenJDK for
instance) uses this to handle some locking back-off.
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20240221083108.1235311-1-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

While reworking code to fix sparse errors, it appears that the
RISCV_M_MODE specific could actually be removed and use the one for
normal mode. Even though RISCV_M_MODE can do direct user memory access,
using the user uaccess helpers is also going to work. Since there is no
need anymore for specific accessors (load_u8()/store_u8()), we can
directly use memcpy()/copy_{to/from}_user() and get rid of the copy
loop entirely. __read_insn() is also fixed to use an unsigned long
instead of a pointer which was cast in __user address space. The
insn_addr parameter is now cast from unsigned lnog to the correct
address space directly.
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240206154104.896809-1-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

While the processor is executing kernel code, the value of the scratch
CSR is always zero, so there is no need to save the value. Continue to
write the CSR during the resume flow, so we do not rely on firmware to
initialize it.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240312195641.1830521-1-samuel.holland@sifive.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Samuel Holland <samuel.holland@sifive.com> says:

This series aims to improve support for NOMMU, specifically by making it
easier to test NOMMU kernels in QEMU and on various widely-available
hardware (errata permitting). After all, everything supports Svbare...

After applying this series, a NOMMU kernel based on defconfig (changing
only the three options below*) boots to userspace on QEMU when passed as
-kernel.

  # CONFIG_RISCV_M_MODE is not set
  # CONFIG_MMU is not set
  CONFIG_NONPORTABLE=y

*if you are using LLD, you must also disable BPF_SYSCALL and KALLSYMS,
because LLD bails on out-of-range references to undefined weak symbols.

* b4-shazam-merge:
  riscv: Allow NOMMU kernels to run in S-mode
  riscv: Remove MMU dependency from Zbb and Zicboz
  riscv: Fix loading 64-bit NOMMU kernels past the start of RAM
  riscv: Fix TASK_SIZE on 64-bit NOMMU

Link: https://lore.kernel.org/r/20240227003630.3634533-1-samuel.holland@sifive.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

The rust modules work on 64-bit RISC-V, with no twiddling required.
Select HAVE_RUST and provide the required flags to kbuild so that the
modules can be used. The Makefile and Kconfig changes are lifted from
work done by Miguel in the Rust-for-Linux tree, hence his authorship.
Following the rabbit hole, the Makefile changes originated in a script,
created based on config files originally added by Gary, hence his
co-authorship.

32-bit is broken in core rust code, so support is limited to 64-bit:
ld.lld: error: undefined symbol: __udivdi3

As 64-bit RISC-V is now supported, add it to the arch support table.
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Co-developed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240409-silencer-book-ce1320f06aab@spudSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Leonardo Bras <leobras@redhat.com> says:

While studying riscv's cmpxchg.h file, I got really interested in
understanding how RISCV asm implemented the different versions of
{cmp,}xchg.

When I understood the pattern, it made sense for me to remove the
duplications and create macros to make it easier to understand what exactly
changes between the versions: Instruction sufixes & barriers.

Also, did the same kind of work on atomic.c.

After that, I noted both cmpxchg and xchg only accept variables of
size 4 and 8, compared to x86 and arm64 which do 1,2,4,8.

Now that deduplication is done, it is quite direct to implement them
for variable sizes 1 and 2, so I did it. Then Guo Ren already presented
me some possible users :)

I did compare the generated asm on a test.c that contained usage for every
changed function, and could not detect any change on patches 1 + 2 + 3
compared with upstream.

Pathes 4 & 5 were compiled-tested, merged with guoren/qspinlock_v11 and
booted just fine with qemu -machine virt -append "qspinlock".

(tree: https://gitlab.com/LeoBras/linux/-/commits/guo_qspinlock_v11)

Latest tests happened based on this tree:
https://github.com/guoren83/linux/tree/qspinlock_v12

* b4-shazam-lts:
  riscv/cmpxchg: Implement xchg for variables of size 1 and 2
  riscv/cmpxchg: Implement cmpxchg for variables of size 1 and 2
  riscv/atomic.h : Deduplicate arch_atomic.*
  riscv/cmpxchg: Deduplicate cmpxchg() asm and macros
  riscv/cmpxchg: Deduplicate xchg() asm functions

Link: https://lore.kernel.org/r/20240103163203.72768-2-leobras@redhat.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

For now, we use stop_machine() to patch the text and when we use IPIs for
remote icache flushes (which is emitted in patch_text_nosync()), the system
hangs.

So instead, make sure every CPU executes the stop_machine() patching
function and emit a local icache flush there.
Co-developed-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20240229121056.203419-3-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

This memory barrier is not needed and not documented so simply remove
it.
Suggested-by: Andrea Parri <andrea@rivosinc.com>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20240229121056.203419-2-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

For ease of testing, it is convenient to run NOMMU kernels in supervisor
mode. The only required change is to offset the kernel load address,
since the beginning of RAM is usually reserved for M-mode firmware.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240227003630.3634533-5-samuel.holland@sifive.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

The Zbb and Zicboz ISA extensions have no dependency on an MMU and are
equally useful on NOMMU kernels.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240227003630.3634533-4-samuel.holland@sifive.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

commit 3335068f ("riscv: Use PUD/P4D/PGD pages for the linear
mapping") added logic to allow using RAM below the kernel load address.
However, this does not work for NOMMU, where PAGE_OFFSET is fixed to the
kernel load address. Since that range of memory corresponds to PFNs
below ARCH_PFN_OFFSET, mm initialization runs off the beginning of
mem_map and corrupts adjacent kernel memory. Fix this by restoring the
previous behavior for NOMMU kernels.

Fixes: 3335068f ("riscv: Use PUD/P4D/PGD pages for the linear mapping")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240227003630.3634533-3-samuel.holland@sifive.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

On NOMMU, userspace memory can come from anywhere in physical RAM. The
current definition of TASK_SIZE is wrong if any RAM exists above 4G,
causing spurious failures in the userspace access routines.

Fixes: 6bd33e1e ("riscv: add nommu support")
Fixes: c3f896dc ("mm: switch the test_vmalloc module to use __vmalloc_node")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Bo Gan <ganboing@gmail.com>
Link: https://lore.kernel.org/r/20240227003630.3634533-2-samuel.holland@sifive.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

xchg for variables of size 1-byte and 2-bytes is not yet available for
riscv, even though its present in other architectures such as arm64 and
x86. This could lead to not being able to implement some locking mechanisms
or requiring some rework to make it work properly.

Implement 1-byte and 2-bytes xchg in order to achieve parity with other
architectures.
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Tested-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20240103163203.72768-7-leobras@redhat.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

cmpxchg for variables of size 1-byte and 2-bytes is not yet available for
riscv, even though its present in other architectures such as arm64 and
x86. This could lead to not being able to implement some locking mechanisms
or requiring some rework to make it work properly.

Implement 1-byte and 2-bytes cmpxchg in order to achieve parity with other
architectures.
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Tested-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20240103163203.72768-6-leobras@redhat.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Some functions use mostly the same asm for 32-bit and 64-bit versions.

Make a macro that is generic enough and avoid code duplication.

(This did not cause any change in generated asm)
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20240103163203.72768-5-leobras@redhat.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

In this header every cmpxchg define (_relaxed, _acquire, _release,
vanilla) contain it's own asm file, both for 4-byte variables an 8-byte
variables, on a total of 8 versions of mostly the same asm.

This is usually bad, as it means any change may be done in up to 8
different places.

Unify those versions by creating a new define with enough parameters to
generate any version of the previous 8.

Then unify the result under a more general define, and simplify
arch_cmpxchg* generation

(This did not cause any change in generated asm)
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20240103163203.72768-4-leobras@redhat.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

In this header every xchg define (_relaxed, _acquire, _release, vanilla)
contain it's own asm file, both for 4-byte variables an 8-byte variables,
on a total of 8 versions of mostly the same asm.

This is usually bad, as it means any change may be done in up to 8
different places.

Unify those versions by creating a new define with enough parameters to
generate any version of the previous 8.

Then unify the result under a more general define, and simplify
arch_xchg* generation.

(This did not cause any change in generated asm)
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20240103163203.72768-3-leobras@redhat.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

As I-Cache flush on current RISC-V needs to send IPIs to every CPU cores
in the system is very costly, limiting flush_icache_mm to be called only
when vma->vm_flags has VM_EXEC can help minimize the frequency of these
operations. It improves performance and reduces disturbances when
copy_from_user_page is needed such as profiling with perf.

For I-D coherence concerns, it will not fail if such a page adds VM_EXEC
flags in the future since we have checked it in the __set_pte_at function.
Signed-off-by: Yangyu Chen <cyy@cyyself.name>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/tencent_6D851035F6F2FD0B5A69FB391AE39AC6300A@qq.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/kernel/sys_riscv.c builds without using anything
from asm-generic/mman-common.h. There seems to be no reason
to include this file.
Signed-off-by: Tanzir Hasan <tanzirh@google.com>
Fixes: 9e2e6042 ("riscv: Allow PROT_WRITE-only mmap()")
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20231212-removeasmgeneric-v2-1-a0e6d7df34a7@google.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Commit 3a6dd5f6 ("riscv: remove unneeded #include
<asm-generic/export.h>") removed the last use of
include/asm-generic/export.h.

This deprecated header can go away.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240323090615.1244904-1-masahiroy@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

In arch/riscv/Makefile, KBUILD_IMAGE is assigned in two separate
if-blocks.

When CONFIG_XIP_KERNEL is disabled, the decision made by the first
if-block is overwritten by the second one, which is redundant and
unreadable.

Merge the two if-blocks.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240323113500.1249272-1-masahiroy@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

When riscv moved to common entry the definition and usage of
do_work_pending was removed.  This unused header file remains.

Remove the header file as it is not used.

I have tested compiling the kernel with this patch applied and saw no
issues.  Noticed when auditing how different ports handle signals
related to saving FPU state.

Fixes: f0bddf50 ("riscv: entry: Convert to generic entry")
Signed-off-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20240310112129.376134-1-shorne@gmail.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Pull EFI fixes from Ard Biesheuvel:

 - Fix logic that is supposed to prevent placement of the kernel image
   below LOAD_PHYSICAL_ADDR

 - Use the firmware stack in the EFI stub when running in mixed mode

 - Clear BSS only once when using mixed mode

 - Check efi.get_variable() function pointer for NULL before trying to
   call it

* tag 'efi-fixes-for-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: fix panic in kdump kernel
  x86/efistub: Don't clear BSS twice in mixed mode
  x86/efistub: Call mixed mode boot services on the firmware's stack
  efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or higher address

Pull x86 fixes from Thomas Gleixner:

 - Ensure that the encryption mask at boot is properly propagated on
   5-level page tables, otherwise the PGD entry is incorrectly set to
   non-encrypted, which causes system crashes during boot.

 - Undo the deferred 5-level page table setup as it cannot work with
   memory encryption enabled.

 - Prevent inconsistent XFD state on CPU hotplug, where the MSR is reset
   to the default value but the cached variable is not, so subsequent
   comparisons might yield the wrong result and as a consequence the
   result prevents updating the MSR.

 - Register the local APIC address only once in the MPPARSE enumeration
   to prevent triggering the related WARN_ONs() in the APIC and topology
   code.

 - Handle the case where no APIC is found gracefully by registering a
   fake APIC in the topology code. That makes all related topology
   functions work correctly and does not affect the actual APIC driver
   code at all.

 - Don't evaluate logical IDs during early boot as the local APIC IDs
   are not yet enumerated and the invoked function returns an error
   code. Nothing requires the logical IDs before the final CPUID
   enumeration takes place, which happens after the enumeration.

 - Cure the fallout of the per CPU rework on UP which misplaced the
   copying of boot_cpu_data to per CPU data so that the final update to
   boot_cpu_data got lost which caused inconsistent state and boot
   crashes.

 - Use copy_from_kernel_nofault() in the kprobes setup as there is no
   guarantee that the address can be safely accessed.

 - Reorder struct members in struct saved_context to work around another
   kmemleak false positive

 - Remove the buggy code which tries to update the E820 kexec table for
   setup_data as that is never passed to the kexec kernel.

 - Update the resource control documentation to use the proper units.

 - Fix a Kconfig warning observed with tinyconfig

* tag 'x86-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/64: Move 5-level paging global variable assignments back
  x86/boot/64: Apply encryption mask to 5-level pagetable update
  x86/cpu: Add model number for another Intel Arrow Lake mobile processor
  x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD
  Documentation/x86: Document that resctrl bandwidth control units are MiB
  x86/mpparse: Register APIC address only once
  x86/topology: Handle the !APIC case gracefully
  x86/topology: Don't evaluate logical IDs during early boot
  x86/cpu: Ensure that CPU info updates are propagated on UP
  kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address
  x86/pm: Work around false positive kmemleak report in msr_build_context()
  x86/kexec: Do not update E820 kexec table for setup_data
  x86/config: Fix warning for 'make ARCH=x86_64 tinyconfig'

Pull scheduler doc clarification from Thomas Gleixner:
 "A single update for the documentation of the base_slice_ns tunable to
  clarify that any value which is less than the tick slice has no effect
  because the scheduler tick is not guaranteed to happen within the set
  time slice"

* tag 'sched-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/doc: Update documentation for base_slice_ns and CONFIG_HZ relation

Pull dma-mapping fixes from Christoph Hellwig:
 "This has a set of swiotlb alignment fixes for sometimes very long
  standing bugs from Will. We've been discussion them for a while and
  they should be solid now"

* tag 'dma-mapping-6.9-2024-03-24' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZE
  iommu/dma: Force swiotlb_max_mapping_size on an untrusted device
  swiotlb: Fix alignment checks when both allocation and DMA masks are present
  swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc()
  swiotlb: Enforce page alignment in swiotlb_alloc()
  swiotlb: Fix double-allocation of slots due to broken alignment handling

Check if get_next_variable() is actually valid pointer before
calling it. In kdump kernel this method is set to NULL that causes
panic during the kexec-ed kernel boot.

Tested with QEMU and OVMF firmware.

Fixes: bad267f9 ("efi: verify that variable services are supported")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Clearing BSS should only be done once, at the very beginning.
efi_pe_entry() is the entrypoint from the firmware, which may not clear
BSS and so it is done explicitly. However, efi_pe_entry() is also used
as an entrypoint by the mixed mode startup code, in which case BSS will
already have been cleared, and doing it again at this point will corrupt
global variables holding the firmware's GDT/IDT and segment selectors.

So make the memset() conditional on whether the EFI stub is running in
native mode.

Fixes: b3810c5a ("x86/efistub: Clear decompressor BSS in native EFI entrypoint")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Normally, the EFI stub calls into the EFI boot services using the stack
that was live when the stub was entered. According to the UEFI spec,
this stack needs to be at least 128k in size - this might seem large but
all asynchronous processing and event handling in EFI runs from the same
stack and so quite a lot of space may be used in practice.

In mixed mode, the situation is a bit different: the bootloader calls
the 32-bit EFI stub entry point, which calls the decompressor's 32-bit
entry point, where the boot stack is set up, using a fixed allocation
of 16k. This stack is still in use when the EFI stub is started in
64-bit mode, and so all calls back into the EFI firmware will be using
the decompressor's limited boot stack.

Due to the placement of the boot stack right after the boot heap, any
stack overruns have gone unnoticed. However, commit

  5c4feadb0011983b ("x86/decompressor: Move global symbol references to C code")

moved the definition of the boot heap into C code, and now the boot
stack is placed right at the base of BSS, where any overruns will
corrupt the end of the .data section.

While it would be possible to work around this by increasing the size of
the boot stack, doing so would affect all x86 systems, and mixed mode
systems are a tiny (and shrinking) fraction of the x86 installed base.

So instead, record the firmware stack pointer value when entering from
the 32-bit firmware, and switch to this stack every time a EFI boot
service call is made.

Cc: <stable@kernel.org> # v6.1+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Commit 63bed966 ("x86/startup_64: Defer assignment of 5-level paging
global variables") moved assignment of 5-level global variables to later
in the boot in order to avoid having to use RIP relative addressing in
order to set them. However, when running with 5-level paging and SME
active (mem_encrypt=on), the variables are needed as part of the page
table setup needed to encrypt the kernel (using pgd_none(), p4d_offset(),
etc.). Since the variables haven't been set, the page table manipulation
is done as if 4-level paging is active, causing the system to crash on
boot.

While only a subset of the assignments that were moved need to be set
early, move all of the assignments back into check_la57_support() so that
these assignments aren't spread between two locations. Instead of just
reverting the fix, this uses the new RIP_REL_REF() macro when assigning
the variables.

Fixes: 63bed966 ("x86/startup_64: Defer assignment of 5-level paging global variables")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/2ca419f4d0de719926fd82353f6751f717590a86.1711122067.git.thomas.lendacky@amd.com

When running with 5-level page tables, the kernel mapping PGD entry is
updated to point to the P4D table. The assignment uses _PAGE_TABLE_NOENC,
which, when SME is active (mem_encrypt=on), results in a page table
entry without the encryption mask set, causing the system to crash on
boot.

Change the assignment to use _PAGE_TABLE instead of _PAGE_TABLE_NOENC so
that the encryption mask is set for the PGD entry.

Fixes: 533568e0 ("x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[]")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/8f20345cda7dbba2cf748b286e1bc00816fe649a.1711122067.git.thomas.lendacky@amd.com

This one is the regular laptop CPU.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240322161725.195614-1-tony.luck@intel.com

Commit 67236547 ("x86/fpu: Update XFD state where required") and
commit 8bf26758 ("x86/fpu: Add XFD state to fpstate") introduced a
per CPU variable xfd_state to keep the MSR_IA32_XFD value cached, in
order to avoid unnecessary writes to the MSR.

On CPU hotplug MSR_IA32_XFD is reset to the init_fpstate.xfd, which
wipes out any stale state. But the per CPU cached xfd value is not
reset, which brings them out of sync.

As a consequence a subsequent xfd_update_state() might fail to update
the MSR which in turn can result in XRSTOR raising a #NM in kernel
space, which crashes the kernel.

To fix this, introduce xfd_set_state() to write xfd_state together
with MSR_IA32_XFD, and use it in all places that set MSR_IA32_XFD.

Fixes: 67236547 ("x86/fpu: Update XFD state where required")
Signed-off-by: Adamos Ttofari <attofari@amazon.de>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240322230439.456571-1-chang.seok.bae@intel.com

Closes: https://lore.kernel.org/lkml/20230511152818.13839-1-attofari@amazon.de

The memory bandwidth software controller uses 2^20 units rather than
10^6. See mbm_bw_count() which computes bandwidth using the "SZ_1M"
Linux define for 0x00100000.

Update the documentation to use MiB when describing this feature.
It's too late to fix the mount option "mba_MBps" as that is now an
established user interface.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240322182016.196544-1-tony.luck@intel.com

Pull timer fixes from Thomas Gleixner:
 "Two regression fixes for the timer and timer migration code:

   - Prevent endless timer requeuing which is caused by two CPUs racing
     out of idle. This happens when the last CPU goes idle and therefore
     has to ensure to expire the pending global timers and some other
     CPU come out of idle at the same time and the other CPU wins the
     race and expires the global queue. This causes the last CPU to
     chase ghost timers forever and reprogramming it's clockevent device
     endlessly.

     Cure this by re-evaluating the wakeup time unconditionally.

   - The split into local (pinned) and global timers in the timer wheel
     caused a regression for NOHZ full as it broke the idle tracking of
     global timers. On NOHZ full this prevents an self IPI being sent
     which in turn causes the timer to be not programmed and not being
     expired on time.

     Restore the idle tracking for the global timer base so that the
     self IPI condition for NOHZ full is working correctly again"

* tag 'timers-urgent-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers: Fix removed self-IPI on global timer's enqueue in nohz_full
  timers/migration: Fix endless timer requeue after idle interrupts

Pull more clocksource updates from Thomas Gleixner:
 "A set of updates for clocksource and clockevent drivers:

   - A fix for the prescaler of the ARM global timer where the prescaler
     mask define only covered 4 bits while it is actully 8 bits wide.
     This obviously restricted the possible range of prescaler
     adjustments

   - A fix for the RISC-V timer which prevents a timer interrupt being
     raised while the timer is initialized

   - A set of device tree updates to support new system on chips in
     various drivers

   - Kernel-doc and other cleanups all over the place"

* tag 'timers-core-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/timer-riscv: Clear timer interrupt on timer initialization
  dt-bindings: timer: Add support for cadence TTC PWM
  clocksource/drivers/arm_global_timer: Simplify prescaler register access
  clocksource/drivers/arm_global_timer: Guard against division by zero
  clocksource/drivers/arm_global_timer: Make gt_target_rate unsigned long
  dt-bindings: timer: add Ralink SoCs system tick counter
  clocksource: arm_global_timer: fix non-kernel-doc comment
  clocksource/drivers/arm_global_timer: Remove stray tab
  clocksource/drivers/arm_global_timer: Fix maximum prescaler value
  clocksource/drivers/imx-sysctr: Add i.MX95 support
  clocksource/drivers/imx-sysctr: Drop use global variables
  dt-bindings: timer: nxp,sysctr-timer: support i.MX95
  dt-bindings: timer: renesas: ostm: Document RZ/Five SoC
  dt-bindings: timer: renesas,tmu: Document input capture interrupt
  clocksource/drivers/ti-32K: Fix misuse of "/**" comment
  clocksource/drivers/stm32: Fix all kernel-doc warnings
  dt-bindings: timer: exynos4210-mct: Add google,gs101-mct compatible
  clocksource/drivers/imx: Fix -Wunused-but-set-variable warning

Pull irq fixes from Thomas Gleixner:
 "A series of fixes for the Renesas RZG21 interrupt chip driver to
  prevent spurious and misrouted interrupts.

   - Ensure that posted writes are flushed in the eoi() callback

   - Ensure that interrupts are masked at the chip level when the
     trigger type is changed

   - Clear the interrupt status register when setting up edge type
     trigger modes

   - Ensure that the trigger type and routing information is set before
     the interrupt is enabled"

* tag 'irq-urgent-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/renesas-rzg2l: Do not set TIEN and TINT source at the same time
  irqchip/renesas-rzg2l: Prevent spurious interrupts when setting trigger type
  irqchip/renesas-rzg2l: Rename rzg2l_irq_eoi()
  irqchip/renesas-rzg2l: Rename rzg2l_tint_eoi()
  irqchip/renesas-rzg2l: Flush posted write in irq_eoi()

Pull core entry fix from Thomas Gleixner:
 "A single fix for the generic entry code:

  The trace_sys_enter() tracepoint can modify the syscall number via
  kprobes or BPF in pt_regs, but that requires that the syscall number
  is re-evaluted from pt_regs after the tracepoint.

  A seccomp fix in that area removed the re-evaluation so the change
  does not take effect as the code just uses the locally cached number.

  Restore the original behaviour by re-evaluating the syscall number
  after the tracepoint"

* tag 'core-entry-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Respect changes to system call number by trace_sys_enter()