* for-next/sve:
arm64/sve: Fix warnings when SVE is disabled
arm64/sve: Add stub for sve_max_virtualisable_vl()
arm64/sve: Track vector lengths for tasks in an array
arm64/sve: Explicitly load vector length when restoring SVE state
arm64/sve: Put system wide vector length information into structs
arm64/sve: Use accessor functions for vector lengths in thread_struct
arm64/sve: Rename find_supported_vector_length()
arm64/sve: Make access to FFR optional
arm64/sve: Make sve_state_size() static
arm64/sve: Remove sve_load_from_fpsimd_state()
arm64/fp: Reindent fpsimd_save()
* for-next/kselftest:
selftests: arm64: Factor out utility functions for assembly FP tests
selftests: arm64: Add coverage of ptrace flags for SVE VL inheritance
selftests: arm64: Verify that all possible vector lengths are handled
selftests: arm64: Fix and enable test for setting current VL in vec-syscfg
selftests: arm64: Remove bogus error check on writing to files
selftests: arm64: Fix printf() format mismatch in vec-syscfg
selftests: arm64: Move FPSIMD in SVE ptrace test into a function
selftests: arm64: More comprehensively test the SVE ptrace interface
selftests: arm64: Verify interoperation of SVE and FPSIMD register sets
selftests: arm64: Clarify output when verifying SVE register set
selftests: arm64: Document what the SVE ptrace test is doing
selftests: arm64: Remove extraneous register setting code
selftests: arm64: Don't log child creation as a test in SVE ptrace test
selftests: arm64: Use a define for the number of SVE ptrace tests to be run
* for-next/kexec:
arm64: trans_pgd: remove trans_pgd_map_page()
arm64: kexec: remove cpu-reset.h
arm64: kexec: remove the pre-kexec PoC maintenance
arm64: kexec: keep MMU enabled during kexec relocation
arm64: kexec: install a copy of the linear-map
arm64: kexec: use ld script for relocation function
arm64: kexec: relocate in EL1 mode
arm64: kexec: configure EL2 vectors for kexec
arm64: kexec: pass kimage as the only argument to relocation function
arm64: kexec: Use dcache ops macros instead of open-coding
arm64: kexec: skip relocation code for inplace kexec
arm64: kexec: flush image and lists during kexec load time
arm64: hibernate: abstract ttrb0 setup function
arm64: trans_pgd: hibernate: Add trans_pgd_copy_el2_vectors
arm64: kernel: add helper for booted at EL2 and not VHE
* for-next/8.6-timers:
arm64: Add HWCAP for self-synchronising virtual counter
arm64: Add handling of CNTVCTSS traps
arm64: Add CNT{P,V}CTSS_EL0 alternatives to cnt{p,v}ct_el0
arm64: Add a capability for FEAT_ECV
clocksource/drivers/arch_arm_timer: Move workaround synchronisation around
clocksource/drivers/arm_arch_timer: Fix masking for high freq counters
clocksource/drivers/arm_arch_timer: Drop unnecessary ISB on CVAL programming
clocksource/drivers/arm_arch_timer: Remove any trace of the TVAL programming interface
clocksource/drivers/arm_arch_timer: Work around broken CVAL implementations
clocksource/drivers/arm_arch_timer: Advertise 56bit timer to the core code
clocksource/drivers/arm_arch_timer: Move MMIO timer programming over to CVAL
clocksource/drivers/arm_arch_timer: Fix MMIO base address vs callback ordering issue
clocksource/drivers/arm_arch_timer: Move drop _tval from erratum function names
clocksource/drivers/arm_arch_timer: Move system register timer programming over to CVAL
clocksource/drivers/arm_arch_timer: Extend write side of timer register accessors to u64
clocksource/drivers/arm_arch_timer: Drop CNT*_TVAL read accessors
clocksource/arm_arch_timer: Add build-time guards for unhandled register accesses
The EAC1 release of the SME specification adds the FA64 feature which
requires enablement at higher ELs before lower ELs can use it. Document
what we require from higher ELs in our boot requirements.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211026111802.12853-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
In configurations where SVE is disabled we define but never reference the
functions for retrieving the default vector length, causing warnings. Fix
this by move the ifdef up, marking get_default_vl() inline since it is
referenced from code guarded by an IS_ENABLED() check, and do the same for
the other accessors for consistency.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211022141635.2360415-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Fixes build problems for configurations with KVM enabled but SVE disabled.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211022141635.2360415-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
The various floating point test programs written in assembly have a bunch
of helper functions and macros which are cut'n'pasted between them. Factor
them out into a separate source file which is linked into all of them.
We don't include memcmp() since it isn't as generic as it should be and
directly branches to report an error in the programs.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019181851.3341232-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
We no longer place anything into a `.fixup` section, so we no longer
need to place those sections into the `.text` section in the main kernel
Image.
Remove the use of `.fixup`.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-14-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
For inline assembly, we place exception fixups out-of-line in the
`.fixup` section such that these are out of the way of the fast path.
This has a few drawbacks:
* Since the fixup code is anonymous, backtraces will symbolize fixups as
offsets from the nearest prior symbol, currently
`__entry_tramp_text_end`. This is confusing, and painful to debug
without access to the relevant vmlinux.
* Since the exception handler adjusts the PC to execute the fixup, and
the fixup uses a direct branch back into the function it fixes,
backtraces of fixups miss the original function. This is confusing,
and violates requirements for RELIABLE_STACKTRACE (and therefore
LIVEPATCH).
* Inline assembly and associated fixups are generated from templates,
and we have many copies of logically identical fixups which only
differ in which specific registers are written to and which address is
branched to at the end of the fixup. This is potentially wasteful of
I-cache resources, and makes it hard to add additional logic to fixups
without significant bloat.
* In the case of load_unaligned_zeropad(), the logic in the fixup
requires a temporary register that we must allocate even in the
fast-path where it will not be used.
This patch address all four concerns for load_unaligned_zeropad() fixups
by adding a dedicated exception handler which performs the fixup logic
in exception context and subsequent returns back after the faulting
instruction. For the moment, the fixup logic is identical to the old
assembly fixup logic, but in future we could enhance this by taking the
ESR and FAR into account to constrain the faults we try to fix up, or to
specialize fixups for MTE tag check faults.
Other than backtracing, there should be no functional change as a result
of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-13-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
For inline assembly, we place exception fixups out-of-line in the
`.fixup` section such that these are out of the way of the fast path.
This has a few drawbacks:
* Since the fixup code is anonymous, backtraces will symbolize fixups as
offsets from the nearest prior symbol, currently
`__entry_tramp_text_end`. This is confusing, and painful to debug
without access to the relevant vmlinux.
* Since the exception handler adjusts the PC to execute the fixup, and
the fixup uses a direct branch back into the function it fixes,
backtraces of fixups miss the original function. This is confusing,
and violates requirements for RELIABLE_STACKTRACE (and therefore
LIVEPATCH).
* Inline assembly and associated fixups are generated from templates,
and we have many copies of logically identical fixups which only
differ in which specific registers are written to and which address is
branched to at the end of the fixup. This is potentially wasteful of
I-cache resources, and makes it hard to add additional logic to fixups
without significant bloat.
This patch address all three concerns for inline uaccess fixups by
adding a dedicated exception handler which updates registers in
exception context and subsequent returns back into the function which
faulted, removing the need for fixups specialized to each faulting
instruction.
Other than backtracing, there should be no functional change as a result
of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-12-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Subsequent patches will add specialized handlers for fixups, in addition
to the simple PC fixup and BPF handlers we have today. In preparation,
this patch adds a new `type` field to struct exception_table_entry, and
uses this to distinguish the fixup and BPF cases. A `data` field is also
added so that subsequent patches can associate data specific to each
exception site (e.g. register numbers).
Handlers are named ex_handler_*() for consistency, following the exmaple
of x86. At the same time, get_ex_fixup() is split out into a helper so
that it can be used by other ex_handler_*() functions ins subsequent
patches.
This patch will increase the size of the exception tables, which will be
remedied by subsequent patches removing redundant fixup code. There
should be no functional change as a result of this patch.
Since each entry is now 12 bytes in size, we must reduce the alignment
of each entry from `.align 3` (i.e. 8 bytes) to `.align 2` (i.e. 4
bytes), which is the natrual alignment of the `insn` and `fixup` fields.
The current 8-byte alignment is a holdover from when the `insn` and
`fixup` fields was 8 bytes, and while not harmful has not been necessary
since commit:
6c94f27ac8 ("arm64: switch to relative exception tables")
Similarly, RO_EXCEPTION_TABLE_ALIGN is dropped to 4 bytes.
Concurrently with this patch, x86's exception table entry format is
being updated (similarly to a 12-byte format, with 32-bytes of absolute
data). Once both have been merged it should be possible to unify the
sorttable logic for the two.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: James Morse <james.morse@arm.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-11-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Subsequent patches will extend `struct exception_table_entry` with more
fields, and the distinction between the entry and its `fixup` field will
become more important.
For clarity, let's consistently use `ex` to refer to refer to an entire
entry. In subsequent patches we'll use `fixup` to refer to the fixup
field specifically. This matches the naming convention used today in
arch/arm64/net/bpf_jit_comp.c.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-10-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
The return values of fixup_exception() and arm64_bpf_fixup_exception()
represent a boolean condition rather than an error code, so for clarity
it would be better to return `bool` rather than `int`.
This patch adjusts the code accordingly. While we're modifying the
prototype, we also remove the unnecessary `extern` keyword, so that this
won't look out of place when we make subsequent additions to the header.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: James Morse <james.morse@arm.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-9-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
In subsequent patches we'll alter the structure and usage of struct
exception_table_entry. For inline assembly, we create these using the
`_ASM_EXTABLE()` CPP macro defined in <asm/uaccess.h>, and for plain
assembly code we use the `_asm_extable()` GAS macro defined in
<asm/assembler.h>, which are largely identical save for different
escaping and stringification requirements.
This patch moves the common definitions to a new <asm/asm-extable.h>
header, so that it's easier to keep the two in-sync, and to remove the
implication that these are only used for uaccess helpers (as e.g.
load_unaligned_zeropad() is only used on kernel memory, and depends upon
`_ASM_EXTABLE()`.
At the same time, a few minor modifications are made for clarity and in
preparation for subsequent patches:
* The structure creation is factored out into an `__ASM_EXTABLE_RAW()`
macro. This will make it easier to support different fixup variants in
subsequent patches without needing to update all users of
`_ASM_EXTABLE()`, and makes it easier to see tha the CPP and GAS
variants of the macros are structurally identical.
For the CPP macro, the stringification of fields is left to the
wrapper macro, `_ASM_EXTABLE()`, as in subsequent patches it will be
necessary to stringify fields in wrapper macros to safely concatenate
strings which cannot be token-pasted together in CPP.
* The fields of the structure are created separately on their own lines.
This will make it easier to add/remove/modify individual fields
clearly.
* Additional parentheses are added around the use of macro arguments in
field definitions to avoid any potential problems with evaluation due
to operator precedence, and to make errors upon misuse clearer.
* USER() is moved into <asm/asm-uaccess.h>, as it is not required by all
assembly code, and is already refered to by comments in that file.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-8-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
In subsequent patches we'll want to map W registers to their register
numbers. Update gpr-num.h so that we can do this.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-7-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
In <asm/sysreg.h> we have macros to convert the names of general purpose
registers (GPRs) into integer constants, which we use to manually build
the encoding for `MRS` and `MSR` instructions where we can't rely on the
assembler to do so for us.
In subsequent patches we'll need to map the same GPR names to integer
constants so that we can use this to build metadata for exception
fixups.
So that the we can use the mappings elsewhere, factor out the
definitions into a new <asm/gpr-num.h> header, renaming the definitions
to align with this "GPR num" naming for clarity.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-6-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
In subsequent patches we'll alter `struct exception_table_entry`, adding
fields that are not needed for KVM exception fixups.
In preparation for this, migrate KVM to its own `struct
kvm_exception_table_entry`, which is identical to the current format of
`struct exception_table_entry`. Comments are updated accordingly.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-5-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Like other functions, __arch_copy_to_user() places its exception fixups
in the `.fixup` section without any clear association with
__arch_copy_to_user() itself. If we backtrace the fixup code, it will be
symbolized as an offset from the nearest prior symbol, which happens to
be `__entry_tramp_text_end`. Further, since the PC adjustment for the
fixup is akin to a direct branch rather than a function call,
__arch_copy_to_user() itself will be missing from the backtrace.
This is confusing and hinders debugging. In general this pattern will
also be problematic for CONFIG_LIVEPATCH, since fixups often return to
their associated function, but this isn't accurately captured in the
stacktrace.
To solve these issues for assembly functions, we must move fixups into
the body of the functions themselves, after the usual fast-path returns.
This patch does so for __arch_copy_to_user().
Inline assembly will be dealt with in subsequent patches.
Other than the improved backtracing, there should be no functional
change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-4-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Like other functions, __arch_copy_from_user() places its exception
fixups in the `.fixup` section without any clear association with
__arch_copy_from_user() itself. If we backtrace the fixup code, it will
be symbolized as an offset from the nearest prior symbol, which happens
to be `__entry_tramp_text_end`. Further, since the PC adjustment for the
fixup is akin to a direct branch rather than a function call,
__arch_copy_from_user() itself will be missing from the backtrace.
This is confusing and hinders debugging. In general this pattern will
also be problematic for CONFIG_LIVEPATCH, since fixups often return to
their associated function, but this isn't accurately captured in the
stacktrace.
To solve these issues for assembly functions, we must move fixups into
the body of the functions themselves, after the usual fast-path returns.
This patch does so for __arch_copy_from_user().
Inline assembly will be dealt with in subsequent patches.
Other than the improved backtracing, there should be no functional
change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Like other functions, __arch_clear_user() places its exception fixups in
the `.fixup` section without any clear association with
__arch_clear_user() itself. If we backtrace the fixup code, it will be
symbolized as an offset from the nearest prior symbol, which happens to
be `__entry_tramp_text_end`. Further, since the PC adjustment for the
fixup is akin to a direct branch rather than a function call,
__arch_clear_user() itself will be missing from the backtrace.
This is confusing and hinders debugging. In general this pattern will
also be problematic for CONFIG_LIVEPATCH, since fixups often return to
their associated function, but this isn't accurately captured in the
stacktrace.
To solve these issues for assembly functions, we must move fixups into
the body of the functions themselves, after the usual fast-path returns.
This patch does so for __arch_clear_user().
Inline assembly will be dealt with in subsequent patches.
Other than the improved backtracing, there should be no functional
change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
As for SVE we will track a per task SME vector length for tasks. Convert
the existing storage for the vector length into an array and update
fpsimd_flush_task() to initialise this in a function.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-10-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Currently when restoring the SVE state we supply the SVE vector length
as an argument to sve_load_state() and the underlying macros. This becomes
inconvenient with the addition of SME since we may need to restore any
combination of SVE and SME vector lengths, and we already separately
restore the vector length in the KVM code. We don't need to know the vector
length during the actual register load since the SME load instructions can
index into the data array for us.
Refactor the interface so we explicitly set the vector length separately
to restoring the SVE registers in preparation for adding SME support, no
functional change should be involved.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-9-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
With the introduction of SME we will have a second vector length in the
system, enumerated and configured in a very similar fashion to the
existing SVE vector length. While there are a few differences in how
things are handled this is a relatively small portion of the overall
code so in order to avoid code duplication we factor out
We create two structs, one vl_info for the static hardware properties
and one vl_config for the runtime configuration, with an array
instantiated for each and update all the users to reference these. Some
accessor functions are provided where helpful for readability, and the
write to set the vector length is put into a function since the system
register being updated needs to be chosen at compile time.
This is a mostly mechanical replacement, further work will be required
to actually make things generic, ensuring that we handle those places
where there are differences properly.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-8-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
In a system with SME there are parallel vector length controls for SVE and
SME vectors which function in much the same way so it is desirable to
share the code for handling them as much as possible. In order to prepare
for doing this add a layer of accessor functions for the various VL related
operations on tasks.
Since almost all current interactions are actually via task->thread rather
than directly with the thread_info the accessors use that. Accessors are
provided for both generic and SVE specific usage, the generic accessors
should be used for cases where register state is being manipulated since
the registers are shared between streaming and regular SVE so we know that
when SME support is implemented we will always have to be in the appropriate
mode already and hence can generalise now.
Since we are using task_struct and we don't want to cause widespread
inclusion of sched.h the acessors are all out of line, it is hoped that
none of the uses are in a sufficiently critical path for this to be an
issue. Those that are most likely to present an issue are in the same
translation unit so hopefully the compiler may be able to inline anyway.
This is purely adding the layer of abstraction, additional work will be
needed to support tasks using SME.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-7-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
The function has SVE specific checks in it and it will be more trouble
to add conditional code for SME than it is to simply rename it to be SVE
specific.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-6-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
SME introduces streaming SVE mode in which FFR is not present and the
instructions for accessing it UNDEF. In preparation for handling this
update the low level SVE state access functions to take a flag specifying
if FFR should be handled. When saving the register state we store a zero
for FFR to guard against uninitialized data being read. No behaviour change
should be introduced by this patch.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-5-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Following optimisations of the SVE register handling we no longer load the
SVE state from a saved copy of the FPSIMD registers, we convert directly
in registers or from one saved state to another. Remove the function so we
don't need to update it during further refactoring.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Currently all the active code in fpsimd_save() is inside a check for
TIF_FOREIGN_FPSTATE. Reduce the indentation level by changing to return
from the function if TIF_FOREIGN_FPSTATE is set.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Since userspace can make use of the CNTVSS_EL0 instruction, expose
it via a HWCAP.
Suggested-by: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-18-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Since CNTVCTSS obey the same control bits as CNTVCT, add the necessary
decoding to the hook table. Note that there is no known user of
this at the moment.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-17-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
CNTPCTSS_EL0 and CNTVCTSS_EL0 are alternatives to the usual
CNTPCT_EL0 and CNTVCT_EL0 that do not require a previous ISB
to be synchronised (SS stands for Self-Synchronising).
Use the ARM64_HAS_ECV capability to control alternative sequences
that switch to these low(er)-cost primitives. Note that the
counter access in the VDSO is for now left alone until we decide
whether we want to allow this.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-16-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Add a new capability to detect the Enhanced Counter Virtualization
feature (FEAT_ECV).
Reviewed-by: Oliver Upton <oupton@google.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-15-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Pull Arm architected timer driver rework from Marc (via Daniel) so that
we can add the Armv8.6 support on top.
Link: https://lore.kernel.org/r/d0c55386-2f7f-a940-45bb-d80ae5e0f378@linaro.org
* 'timers/drivers/armv8.6_arch_timer' of https://git.linaro.org/people/daniel.lezcano/linux:
clocksource/drivers/arch_arm_timer: Move workaround synchronisation around
clocksource/drivers/arm_arch_timer: Fix masking for high freq counters
clocksource/drivers/arm_arch_timer: Drop unnecessary ISB on CVAL programming
clocksource/drivers/arm_arch_timer: Remove any trace of the TVAL programming interface
clocksource/drivers/arm_arch_timer: Work around broken CVAL implementations
clocksource/drivers/arm_arch_timer: Advertise 56bit timer to the core code
clocksource/drivers/arm_arch_timer: Move MMIO timer programming over to CVAL
clocksource/drivers/arm_arch_timer: Fix MMIO base address vs callback ordering issue
clocksource/drivers/arm_arch_timer: Move drop _tval from erratum function names
clocksource/drivers/arm_arch_timer: Move system register timer programming over to CVAL
clocksource/drivers/arm_arch_timer: Extend write side of timer register accessors to u64
clocksource/drivers/arm_arch_timer: Drop CNT*_TVAL read accessors
clocksource/arm_arch_timer: Add build-time guards for unhandled register accesses
We currently handle synchronisation when workarounds are enabled
by having an ISB in the __arch_counter_get_cnt?ct_stable() helpers.
While this works, this prevents us from relaxing this synchronisation.
Instead, move it closer to the point where the synchronisation is
actually needed. Further patches will subsequently relax this.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-14-maz@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Unfortunately, the architecture provides no means to determine the bit
width of the system counter. However, we do know the following from the
specification:
- the system counter is at least 56 bits wide
- Roll-over time of not less than 40 years
To date, the arch timer driver has depended on the first property,
assuming any system counter to be 56 bits wide and masking off the rest.
However, combining a narrow clocksource mask with a high frequency
counter could result in prematurely wrapping the system counter by a
significant margin. For example, a 56 bit wide, 1GHz system counter
would wrap in a mere 2.28 years!
This is a problem for two reasons: v8.6+ implementations are required to
provide a 64 bit, 1GHz system counter. Furthermore, before v8.6,
implementers may select a counter frequency of their choosing.
Fix the issue by deriving a valid clock mask based on the second
property from above. Set the floor at 56 bits, since we know no system
counter is narrower than that.
[maz: fixed width computation not to lose the last bit, added
max delta generation for the timer]
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210807191428.3488948-1-oupton@google.com
Link: https://lore.kernel.org/r/20211017124225.3018098-13-maz@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Switching from TVAL to CVAL has a small drawback: we need an ISB
before reading the counter. We cannot get rid of it, but we can
instead remove the one that comes just after writing to CVAL.
This reduces the number of ISBs from 3 to 2 when programming
the timer.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-12-maz@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The Applied Micro XGene-1 SoC has a busted implementation of the
CVAL register: it looks like it is based on TVAL instead of the
other way around. The net effect of this implementation blunder
is that the maximum deadline you can program in the timer is
32bit wide.
Use a MIDR check to notice the broken CPU, and reduce the width
of the timer to 32bit.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-10-maz@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Similarily to the sysreg-based timer, move the MMIO over to using
the CVAL registers instead of TVAL. Note that there is no warranty
that the 64bit MMIO access will be atomic, but the timer is always
disabled at the point where we program CVAL.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-8-maz@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
