linux-stable/scripts/atomic/atomic-tbl.sh

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locking/atomics: Add common header generation files To minimize repetition, to allow for future rework, and to ensure regularity of the various atomic APIs, we'd like to automatically generate (the bulk of) a number of headers related to atomics. This patch adds the infrastructure to do so, leaving actual conversion of headers to subsequent patches. This infrastructure consists of: * atomics.tbl - a table describing the functions in the atomics API, with names, prototypes, and metadata describing the variants that exist (e.g fetch/return, acquire/release/relaxed). Note that the return type is dependent on the particular variant. * atomic-tbl.sh - a library of routines useful for dealing with atomics.tbl (e.g. querying which variants exist, or generating argument/parameter lists for a given function variant). * gen-atomic-fallback.sh - a script which generates a header of fallbacks, covering cases where architecture omit certain functions (e.g. omitting relaxed variants). * gen-atomic-long.sh - a script which generates wrappers providing the atomic_long API atomic of the relevant atomic or atomic64 API, ensuring the APIs are consistent. * gen-atomic-instrumented.sh - a script which generates atomic* wrappers atop of arch_atomic* functions, with automatically generated KASAN instrumentation. * fallbacks/* - a set of fallback implementations for atomics, which should be used when no implementation of a given atomic is provided. These are used by gen-atomic-fallback.sh to generate fallbacks, and these are also used by other scripts to determine the set of optional atomics (as required to generate preprocessor guards correctly). Fallbacks may use the following variables: ${atomic} atomic prefix: atomic/atomic64/atomic_long, which can be used to derive the atomic type, and to prefix functions ${int} integer type: int/s64/long ${pfx} variant prefix, e.g. fetch_ ${name} base function name, e.g. add ${sfx} variant suffix, e.g. _return ${order} order suffix, e.g. _relaxed ${atomicname} full name, e.g. atomic64_fetch_add_relaxed ${ret} return type of the function, e.g. void ${retstmt} a return statement (with a trailing space), unless the variant returns void ${params} parameter list for the function declaration, e.g. "int i, atomic_t *v" ${args} argument list for invoking the function, e.g. "i, v" ... for clarity, ${ret}, ${retstmt}, ${params}, and ${args} are open-coded for fallbacks where these do not vary, or are critical to understanding the logic of the fallback. The MAINTAINERS entry for the atomic infrastructure is updated to cover the new scripts. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com Cc: Will Deacon <will.deacon@arm.com> Cc: linuxdrivers@attotech.com Cc: dvyukov@google.com Cc: Boqun Feng <boqun.feng@gmail.com> Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: glider@google.com Link: http://lkml.kernel.org/r/20180904104830.2975-2-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-04 10:48:25 +00:00
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# helpers for dealing with atomics.tbl
#meta_in(meta, match)
meta_in()
{
case "$1" in
[$2]) return 0;;
esac
return 1
}
#meta_has_ret(meta)
meta_has_ret()
{
meta_in "$1" "bBiIfFlR"
}
#meta_has_acquire(meta)
meta_has_acquire()
{
meta_in "$1" "BFIlR"
}
#meta_has_release(meta)
meta_has_release()
{
meta_in "$1" "BFIRs"
}
#meta_has_relaxed(meta)
meta_has_relaxed()
{
meta_in "$1" "BFIR"
}
locking/atomic: scripts: generate kerneldoc comments Currently the atomics are documented in Documentation/atomic_t.txt, and have no kerneldoc comments. There are a sufficient number of gotchas (e.g. semantics, noinstr-safety) that it would be nice to have comments to call these out, and it would be nice to have kerneldoc comments such that these can be collated. While it's possible to derive the semantics from the code, this can be painful given the amount of indirection we currently have (e.g. fallback paths), and it's easy to be mislead by naming, e.g. * The unconditional void-returning ops *only* have relaxed variants without a _relaxed suffix, and can easily be mistaken for being fully ordered. It would be nice to give these a _relaxed() suffix, but this would result in significant churn throughout the kernel. * Our naming of conditional and unconditional+test ops is rather inconsistent, and it can be difficult to derive the name of an operation, or to identify where an op is conditional or unconditional+test. Some ops are clearly conditional: - dec_if_positive - add_unless - dec_unless_positive - inc_unless_negative Some ops are clearly unconditional+test: - sub_and_test - dec_and_test - inc_and_test However, what exactly those test is not obvious. A _test_zero suffix might be clearer. Others could be read ambiguously: - inc_not_zero // conditional - add_negative // unconditional+test It would probably be worth renaming these, e.g. to inc_unless_zero and add_test_negative. As a step towards making this more consistent and easier to understand, this patch adds kerneldoc comments for all generated *atomic*_*() functions. These are generated from templates, with some common text shared, making it easy to extend these in future if necessary. I've tried to make these as consistent and clear as possible, and I've deliberately ensured: * All ops have their ordering explicitly mentioned in the short and long description. * All test ops have "test" in their short description. * All ops are described as an expression using their usual C operator. For example: andnot: "Atomically updates @v to (@v & ~@i)" inc: "Atomically updates @v to (@v + 1)" Which may be clearer to non-naative English speakers, and allows all the operations to be described in the same style. * All conditional ops have their condition described as an expression using the usual C operators. For example: add_unless: "If (@v != @u), atomically updates @v to (@v + @i)" cmpxchg: "If (@v == @old), atomically updates @v to @new" Which may be clearer to non-naative English speakers, and allows all the operations to be described in the same style. * All bitwise ops (and,andnot,or,xor) explicitly mention that they are bitwise in their short description, so that they are not mistaken for performing their logical equivalents. * The noinstr safety of each op is explicitly described, with a description of whether or not to use the raw_ form of the op. There should be no functional change as a result of this patch. Reported-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230605070124.3741859-26-mark.rutland@arm.com
2023-06-05 07:01:22 +00:00
#meta_is_implicitly_relaxed(meta)
meta_is_implicitly_relaxed()
{
meta_in "$1" "vls"
}
#find_template(tmpltype, pfx, name, sfx, order)
find_template()
locking/atomics: Add common header generation files To minimize repetition, to allow for future rework, and to ensure regularity of the various atomic APIs, we'd like to automatically generate (the bulk of) a number of headers related to atomics. This patch adds the infrastructure to do so, leaving actual conversion of headers to subsequent patches. This infrastructure consists of: * atomics.tbl - a table describing the functions in the atomics API, with names, prototypes, and metadata describing the variants that exist (e.g fetch/return, acquire/release/relaxed). Note that the return type is dependent on the particular variant. * atomic-tbl.sh - a library of routines useful for dealing with atomics.tbl (e.g. querying which variants exist, or generating argument/parameter lists for a given function variant). * gen-atomic-fallback.sh - a script which generates a header of fallbacks, covering cases where architecture omit certain functions (e.g. omitting relaxed variants). * gen-atomic-long.sh - a script which generates wrappers providing the atomic_long API atomic of the relevant atomic or atomic64 API, ensuring the APIs are consistent. * gen-atomic-instrumented.sh - a script which generates atomic* wrappers atop of arch_atomic* functions, with automatically generated KASAN instrumentation. * fallbacks/* - a set of fallback implementations for atomics, which should be used when no implementation of a given atomic is provided. These are used by gen-atomic-fallback.sh to generate fallbacks, and these are also used by other scripts to determine the set of optional atomics (as required to generate preprocessor guards correctly). Fallbacks may use the following variables: ${atomic} atomic prefix: atomic/atomic64/atomic_long, which can be used to derive the atomic type, and to prefix functions ${int} integer type: int/s64/long ${pfx} variant prefix, e.g. fetch_ ${name} base function name, e.g. add ${sfx} variant suffix, e.g. _return ${order} order suffix, e.g. _relaxed ${atomicname} full name, e.g. atomic64_fetch_add_relaxed ${ret} return type of the function, e.g. void ${retstmt} a return statement (with a trailing space), unless the variant returns void ${params} parameter list for the function declaration, e.g. "int i, atomic_t *v" ${args} argument list for invoking the function, e.g. "i, v" ... for clarity, ${ret}, ${retstmt}, ${params}, and ${args} are open-coded for fallbacks where these do not vary, or are critical to understanding the logic of the fallback. The MAINTAINERS entry for the atomic infrastructure is updated to cover the new scripts. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com Cc: Will Deacon <will.deacon@arm.com> Cc: linuxdrivers@attotech.com Cc: dvyukov@google.com Cc: Boqun Feng <boqun.feng@gmail.com> Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: glider@google.com Link: http://lkml.kernel.org/r/20180904104830.2975-2-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-04 10:48:25 +00:00
{
locking/atomic: scripts: generate kerneldoc comments Currently the atomics are documented in Documentation/atomic_t.txt, and have no kerneldoc comments. There are a sufficient number of gotchas (e.g. semantics, noinstr-safety) that it would be nice to have comments to call these out, and it would be nice to have kerneldoc comments such that these can be collated. While it's possible to derive the semantics from the code, this can be painful given the amount of indirection we currently have (e.g. fallback paths), and it's easy to be mislead by naming, e.g. * The unconditional void-returning ops *only* have relaxed variants without a _relaxed suffix, and can easily be mistaken for being fully ordered. It would be nice to give these a _relaxed() suffix, but this would result in significant churn throughout the kernel. * Our naming of conditional and unconditional+test ops is rather inconsistent, and it can be difficult to derive the name of an operation, or to identify where an op is conditional or unconditional+test. Some ops are clearly conditional: - dec_if_positive - add_unless - dec_unless_positive - inc_unless_negative Some ops are clearly unconditional+test: - sub_and_test - dec_and_test - inc_and_test However, what exactly those test is not obvious. A _test_zero suffix might be clearer. Others could be read ambiguously: - inc_not_zero // conditional - add_negative // unconditional+test It would probably be worth renaming these, e.g. to inc_unless_zero and add_test_negative. As a step towards making this more consistent and easier to understand, this patch adds kerneldoc comments for all generated *atomic*_*() functions. These are generated from templates, with some common text shared, making it easy to extend these in future if necessary. I've tried to make these as consistent and clear as possible, and I've deliberately ensured: * All ops have their ordering explicitly mentioned in the short and long description. * All test ops have "test" in their short description. * All ops are described as an expression using their usual C operator. For example: andnot: "Atomically updates @v to (@v & ~@i)" inc: "Atomically updates @v to (@v + 1)" Which may be clearer to non-naative English speakers, and allows all the operations to be described in the same style. * All conditional ops have their condition described as an expression using the usual C operators. For example: add_unless: "If (@v != @u), atomically updates @v to (@v + @i)" cmpxchg: "If (@v == @old), atomically updates @v to @new" Which may be clearer to non-naative English speakers, and allows all the operations to be described in the same style. * All bitwise ops (and,andnot,or,xor) explicitly mention that they are bitwise in their short description, so that they are not mistaken for performing their logical equivalents. * The noinstr safety of each op is explicitly described, with a description of whether or not to use the raw_ form of the op. There should be no functional change as a result of this patch. Reported-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230605070124.3741859-26-mark.rutland@arm.com
2023-06-05 07:01:22 +00:00
local tmpltype="$1"; shift
locking/atomics: Add common header generation files To minimize repetition, to allow for future rework, and to ensure regularity of the various atomic APIs, we'd like to automatically generate (the bulk of) a number of headers related to atomics. This patch adds the infrastructure to do so, leaving actual conversion of headers to subsequent patches. This infrastructure consists of: * atomics.tbl - a table describing the functions in the atomics API, with names, prototypes, and metadata describing the variants that exist (e.g fetch/return, acquire/release/relaxed). Note that the return type is dependent on the particular variant. * atomic-tbl.sh - a library of routines useful for dealing with atomics.tbl (e.g. querying which variants exist, or generating argument/parameter lists for a given function variant). * gen-atomic-fallback.sh - a script which generates a header of fallbacks, covering cases where architecture omit certain functions (e.g. omitting relaxed variants). * gen-atomic-long.sh - a script which generates wrappers providing the atomic_long API atomic of the relevant atomic or atomic64 API, ensuring the APIs are consistent. * gen-atomic-instrumented.sh - a script which generates atomic* wrappers atop of arch_atomic* functions, with automatically generated KASAN instrumentation. * fallbacks/* - a set of fallback implementations for atomics, which should be used when no implementation of a given atomic is provided. These are used by gen-atomic-fallback.sh to generate fallbacks, and these are also used by other scripts to determine the set of optional atomics (as required to generate preprocessor guards correctly). Fallbacks may use the following variables: ${atomic} atomic prefix: atomic/atomic64/atomic_long, which can be used to derive the atomic type, and to prefix functions ${int} integer type: int/s64/long ${pfx} variant prefix, e.g. fetch_ ${name} base function name, e.g. add ${sfx} variant suffix, e.g. _return ${order} order suffix, e.g. _relaxed ${atomicname} full name, e.g. atomic64_fetch_add_relaxed ${ret} return type of the function, e.g. void ${retstmt} a return statement (with a trailing space), unless the variant returns void ${params} parameter list for the function declaration, e.g. "int i, atomic_t *v" ${args} argument list for invoking the function, e.g. "i, v" ... for clarity, ${ret}, ${retstmt}, ${params}, and ${args} are open-coded for fallbacks where these do not vary, or are critical to understanding the logic of the fallback. The MAINTAINERS entry for the atomic infrastructure is updated to cover the new scripts. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com Cc: Will Deacon <will.deacon@arm.com> Cc: linuxdrivers@attotech.com Cc: dvyukov@google.com Cc: Boqun Feng <boqun.feng@gmail.com> Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: glider@google.com Link: http://lkml.kernel.org/r/20180904104830.2975-2-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-04 10:48:25 +00:00
local pfx="$1"; shift
local name="$1"; shift
local sfx="$1"; shift
local order="$1"; shift
local base=""
local file=""
# We may have fallbacks for a specific case (e.g. read_acquire()), or
# an entire class, e.g. *inc*().
#
# Start at the most specific, and fall back to the most general. Once
# we find a specific fallback, don't bother looking for more.
locking/atomic: scripts: generate kerneldoc comments Currently the atomics are documented in Documentation/atomic_t.txt, and have no kerneldoc comments. There are a sufficient number of gotchas (e.g. semantics, noinstr-safety) that it would be nice to have comments to call these out, and it would be nice to have kerneldoc comments such that these can be collated. While it's possible to derive the semantics from the code, this can be painful given the amount of indirection we currently have (e.g. fallback paths), and it's easy to be mislead by naming, e.g. * The unconditional void-returning ops *only* have relaxed variants without a _relaxed suffix, and can easily be mistaken for being fully ordered. It would be nice to give these a _relaxed() suffix, but this would result in significant churn throughout the kernel. * Our naming of conditional and unconditional+test ops is rather inconsistent, and it can be difficult to derive the name of an operation, or to identify where an op is conditional or unconditional+test. Some ops are clearly conditional: - dec_if_positive - add_unless - dec_unless_positive - inc_unless_negative Some ops are clearly unconditional+test: - sub_and_test - dec_and_test - inc_and_test However, what exactly those test is not obvious. A _test_zero suffix might be clearer. Others could be read ambiguously: - inc_not_zero // conditional - add_negative // unconditional+test It would probably be worth renaming these, e.g. to inc_unless_zero and add_test_negative. As a step towards making this more consistent and easier to understand, this patch adds kerneldoc comments for all generated *atomic*_*() functions. These are generated from templates, with some common text shared, making it easy to extend these in future if necessary. I've tried to make these as consistent and clear as possible, and I've deliberately ensured: * All ops have their ordering explicitly mentioned in the short and long description. * All test ops have "test" in their short description. * All ops are described as an expression using their usual C operator. For example: andnot: "Atomically updates @v to (@v & ~@i)" inc: "Atomically updates @v to (@v + 1)" Which may be clearer to non-naative English speakers, and allows all the operations to be described in the same style. * All conditional ops have their condition described as an expression using the usual C operators. For example: add_unless: "If (@v != @u), atomically updates @v to (@v + @i)" cmpxchg: "If (@v == @old), atomically updates @v to @new" Which may be clearer to non-naative English speakers, and allows all the operations to be described in the same style. * All bitwise ops (and,andnot,or,xor) explicitly mention that they are bitwise in their short description, so that they are not mistaken for performing their logical equivalents. * The noinstr safety of each op is explicitly described, with a description of whether or not to use the raw_ form of the op. There should be no functional change as a result of this patch. Reported-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230605070124.3741859-26-mark.rutland@arm.com
2023-06-05 07:01:22 +00:00
for base in "${pfx}${name}${sfx}${order}" "${pfx}${name}${sfx}" "${name}"; do
file="${ATOMICDIR}/${tmpltype}/${base}"
locking/atomics: Add common header generation files To minimize repetition, to allow for future rework, and to ensure regularity of the various atomic APIs, we'd like to automatically generate (the bulk of) a number of headers related to atomics. This patch adds the infrastructure to do so, leaving actual conversion of headers to subsequent patches. This infrastructure consists of: * atomics.tbl - a table describing the functions in the atomics API, with names, prototypes, and metadata describing the variants that exist (e.g fetch/return, acquire/release/relaxed). Note that the return type is dependent on the particular variant. * atomic-tbl.sh - a library of routines useful for dealing with atomics.tbl (e.g. querying which variants exist, or generating argument/parameter lists for a given function variant). * gen-atomic-fallback.sh - a script which generates a header of fallbacks, covering cases where architecture omit certain functions (e.g. omitting relaxed variants). * gen-atomic-long.sh - a script which generates wrappers providing the atomic_long API atomic of the relevant atomic or atomic64 API, ensuring the APIs are consistent. * gen-atomic-instrumented.sh - a script which generates atomic* wrappers atop of arch_atomic* functions, with automatically generated KASAN instrumentation. * fallbacks/* - a set of fallback implementations for atomics, which should be used when no implementation of a given atomic is provided. These are used by gen-atomic-fallback.sh to generate fallbacks, and these are also used by other scripts to determine the set of optional atomics (as required to generate preprocessor guards correctly). Fallbacks may use the following variables: ${atomic} atomic prefix: atomic/atomic64/atomic_long, which can be used to derive the atomic type, and to prefix functions ${int} integer type: int/s64/long ${pfx} variant prefix, e.g. fetch_ ${name} base function name, e.g. add ${sfx} variant suffix, e.g. _return ${order} order suffix, e.g. _relaxed ${atomicname} full name, e.g. atomic64_fetch_add_relaxed ${ret} return type of the function, e.g. void ${retstmt} a return statement (with a trailing space), unless the variant returns void ${params} parameter list for the function declaration, e.g. "int i, atomic_t *v" ${args} argument list for invoking the function, e.g. "i, v" ... for clarity, ${ret}, ${retstmt}, ${params}, and ${args} are open-coded for fallbacks where these do not vary, or are critical to understanding the logic of the fallback. The MAINTAINERS entry for the atomic infrastructure is updated to cover the new scripts. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com Cc: Will Deacon <will.deacon@arm.com> Cc: linuxdrivers@attotech.com Cc: dvyukov@google.com Cc: Boqun Feng <boqun.feng@gmail.com> Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: glider@google.com Link: http://lkml.kernel.org/r/20180904104830.2975-2-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-04 10:48:25 +00:00
if [ -f "${file}" ]; then
printf "${file}"
break
fi
done
}
locking/atomic: scripts: generate kerneldoc comments Currently the atomics are documented in Documentation/atomic_t.txt, and have no kerneldoc comments. There are a sufficient number of gotchas (e.g. semantics, noinstr-safety) that it would be nice to have comments to call these out, and it would be nice to have kerneldoc comments such that these can be collated. While it's possible to derive the semantics from the code, this can be painful given the amount of indirection we currently have (e.g. fallback paths), and it's easy to be mislead by naming, e.g. * The unconditional void-returning ops *only* have relaxed variants without a _relaxed suffix, and can easily be mistaken for being fully ordered. It would be nice to give these a _relaxed() suffix, but this would result in significant churn throughout the kernel. * Our naming of conditional and unconditional+test ops is rather inconsistent, and it can be difficult to derive the name of an operation, or to identify where an op is conditional or unconditional+test. Some ops are clearly conditional: - dec_if_positive - add_unless - dec_unless_positive - inc_unless_negative Some ops are clearly unconditional+test: - sub_and_test - dec_and_test - inc_and_test However, what exactly those test is not obvious. A _test_zero suffix might be clearer. Others could be read ambiguously: - inc_not_zero // conditional - add_negative // unconditional+test It would probably be worth renaming these, e.g. to inc_unless_zero and add_test_negative. As a step towards making this more consistent and easier to understand, this patch adds kerneldoc comments for all generated *atomic*_*() functions. These are generated from templates, with some common text shared, making it easy to extend these in future if necessary. I've tried to make these as consistent and clear as possible, and I've deliberately ensured: * All ops have their ordering explicitly mentioned in the short and long description. * All test ops have "test" in their short description. * All ops are described as an expression using their usual C operator. For example: andnot: "Atomically updates @v to (@v & ~@i)" inc: "Atomically updates @v to (@v + 1)" Which may be clearer to non-naative English speakers, and allows all the operations to be described in the same style. * All conditional ops have their condition described as an expression using the usual C operators. For example: add_unless: "If (@v != @u), atomically updates @v to (@v + @i)" cmpxchg: "If (@v == @old), atomically updates @v to @new" Which may be clearer to non-naative English speakers, and allows all the operations to be described in the same style. * All bitwise ops (and,andnot,or,xor) explicitly mention that they are bitwise in their short description, so that they are not mistaken for performing their logical equivalents. * The noinstr safety of each op is explicitly described, with a description of whether or not to use the raw_ form of the op. There should be no functional change as a result of this patch. Reported-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230605070124.3741859-26-mark.rutland@arm.com
2023-06-05 07:01:22 +00:00
#find_fallback_template(pfx, name, sfx, order)
find_fallback_template()
{
find_template "fallbacks" "$@"
}
#find_kerneldoc_template(pfx, name, sfx, order)
find_kerneldoc_template()
{
find_template "kerneldoc" "$@"
}
locking/atomics: Add common header generation files To minimize repetition, to allow for future rework, and to ensure regularity of the various atomic APIs, we'd like to automatically generate (the bulk of) a number of headers related to atomics. This patch adds the infrastructure to do so, leaving actual conversion of headers to subsequent patches. This infrastructure consists of: * atomics.tbl - a table describing the functions in the atomics API, with names, prototypes, and metadata describing the variants that exist (e.g fetch/return, acquire/release/relaxed). Note that the return type is dependent on the particular variant. * atomic-tbl.sh - a library of routines useful for dealing with atomics.tbl (e.g. querying which variants exist, or generating argument/parameter lists for a given function variant). * gen-atomic-fallback.sh - a script which generates a header of fallbacks, covering cases where architecture omit certain functions (e.g. omitting relaxed variants). * gen-atomic-long.sh - a script which generates wrappers providing the atomic_long API atomic of the relevant atomic or atomic64 API, ensuring the APIs are consistent. * gen-atomic-instrumented.sh - a script which generates atomic* wrappers atop of arch_atomic* functions, with automatically generated KASAN instrumentation. * fallbacks/* - a set of fallback implementations for atomics, which should be used when no implementation of a given atomic is provided. These are used by gen-atomic-fallback.sh to generate fallbacks, and these are also used by other scripts to determine the set of optional atomics (as required to generate preprocessor guards correctly). Fallbacks may use the following variables: ${atomic} atomic prefix: atomic/atomic64/atomic_long, which can be used to derive the atomic type, and to prefix functions ${int} integer type: int/s64/long ${pfx} variant prefix, e.g. fetch_ ${name} base function name, e.g. add ${sfx} variant suffix, e.g. _return ${order} order suffix, e.g. _relaxed ${atomicname} full name, e.g. atomic64_fetch_add_relaxed ${ret} return type of the function, e.g. void ${retstmt} a return statement (with a trailing space), unless the variant returns void ${params} parameter list for the function declaration, e.g. "int i, atomic_t *v" ${args} argument list for invoking the function, e.g. "i, v" ... for clarity, ${ret}, ${retstmt}, ${params}, and ${args} are open-coded for fallbacks where these do not vary, or are critical to understanding the logic of the fallback. The MAINTAINERS entry for the atomic infrastructure is updated to cover the new scripts. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com Cc: Will Deacon <will.deacon@arm.com> Cc: linuxdrivers@attotech.com Cc: dvyukov@google.com Cc: Boqun Feng <boqun.feng@gmail.com> Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: glider@google.com Link: http://lkml.kernel.org/r/20180904104830.2975-2-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-04 10:48:25 +00:00
#gen_ret_type(meta, int)
gen_ret_type() {
local meta="$1"; shift
local int="$1"; shift
case "${meta}" in
[sv]) printf "void";;
[bB]) printf "bool";;
[aiIfFlR]) printf "${int}";;
esac
}
#gen_ret_stmt(meta)
gen_ret_stmt()
{
if meta_has_ret "${meta}"; then
printf "return ";
fi
}
# gen_param_name(arg)
gen_param_name()
{
# strip off the leading 'c' for 'cv'
local name="${1#c}"
printf "${name#*:}"
}
# gen_param_type(arg, int, atomic)
gen_param_type()
{
local type="${1%%:*}"; shift
local int="$1"; shift
local atomic="$1"; shift
case "${type}" in
i) type="${int} ";;
p) type="${int} *";;
v) type="${atomic}_t *";;
cv) type="const ${atomic}_t *";;
esac
printf "${type}"
}
#gen_param(arg, int, atomic)
gen_param()
{
local arg="$1"; shift
local int="$1"; shift
local atomic="$1"; shift
local name="$(gen_param_name "${arg}")"
local type="$(gen_param_type "${arg}" "${int}" "${atomic}")"
printf "${type}${name}"
}
#gen_params(int, atomic, arg...)
gen_params()
{
local int="$1"; shift
local atomic="$1"; shift
while [ "$#" -gt 0 ]; do
gen_param "$1" "${int}" "${atomic}"
[ "$#" -gt 1 ] && printf ", "
shift;
done
}
#gen_args(arg...)
gen_args()
{
while [ "$#" -gt 0 ]; do
printf "$(gen_param_name "$1")"
[ "$#" -gt 1 ] && printf ", "
shift;
done
}
locking/atomic: scripts: generate kerneldoc comments Currently the atomics are documented in Documentation/atomic_t.txt, and have no kerneldoc comments. There are a sufficient number of gotchas (e.g. semantics, noinstr-safety) that it would be nice to have comments to call these out, and it would be nice to have kerneldoc comments such that these can be collated. While it's possible to derive the semantics from the code, this can be painful given the amount of indirection we currently have (e.g. fallback paths), and it's easy to be mislead by naming, e.g. * The unconditional void-returning ops *only* have relaxed variants without a _relaxed suffix, and can easily be mistaken for being fully ordered. It would be nice to give these a _relaxed() suffix, but this would result in significant churn throughout the kernel. * Our naming of conditional and unconditional+test ops is rather inconsistent, and it can be difficult to derive the name of an operation, or to identify where an op is conditional or unconditional+test. Some ops are clearly conditional: - dec_if_positive - add_unless - dec_unless_positive - inc_unless_negative Some ops are clearly unconditional+test: - sub_and_test - dec_and_test - inc_and_test However, what exactly those test is not obvious. A _test_zero suffix might be clearer. Others could be read ambiguously: - inc_not_zero // conditional - add_negative // unconditional+test It would probably be worth renaming these, e.g. to inc_unless_zero and add_test_negative. As a step towards making this more consistent and easier to understand, this patch adds kerneldoc comments for all generated *atomic*_*() functions. These are generated from templates, with some common text shared, making it easy to extend these in future if necessary. I've tried to make these as consistent and clear as possible, and I've deliberately ensured: * All ops have their ordering explicitly mentioned in the short and long description. * All test ops have "test" in their short description. * All ops are described as an expression using their usual C operator. For example: andnot: "Atomically updates @v to (@v & ~@i)" inc: "Atomically updates @v to (@v + 1)" Which may be clearer to non-naative English speakers, and allows all the operations to be described in the same style. * All conditional ops have their condition described as an expression using the usual C operators. For example: add_unless: "If (@v != @u), atomically updates @v to (@v + @i)" cmpxchg: "If (@v == @old), atomically updates @v to @new" Which may be clearer to non-naative English speakers, and allows all the operations to be described in the same style. * All bitwise ops (and,andnot,or,xor) explicitly mention that they are bitwise in their short description, so that they are not mistaken for performing their logical equivalents. * The noinstr safety of each op is explicitly described, with a description of whether or not to use the raw_ form of the op. There should be no functional change as a result of this patch. Reported-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230605070124.3741859-26-mark.rutland@arm.com
2023-06-05 07:01:22 +00:00
#gen_desc_return(meta)
gen_desc_return()
{
local meta="$1"; shift
case "${meta}" in
[v])
printf "Return: Nothing."
;;
[Ff])
printf "Return: The original value of @v."
;;
[R])
printf "Return: The updated value of @v."
;;
[l])
printf "Return: The value of @v."
;;
esac
}
#gen_template_kerneldoc(template, class, meta, pfx, name, sfx, order, atomic, int, args...)
gen_template_kerneldoc()
{
local template="$1"; shift
local class="$1"; shift
local meta="$1"; shift
local pfx="$1"; shift
local name="$1"; shift
local sfx="$1"; shift
local order="$1"; shift
local atomic="$1"; shift
local int="$1"; shift
local atomicname="${atomic}_${pfx}${name}${sfx}${order}"
local ret="$(gen_ret_type "${meta}" "${int}")"
local retstmt="$(gen_ret_stmt "${meta}")"
local params="$(gen_params "${int}" "${atomic}" "$@")"
local args="$(gen_args "$@")"
local desc_order=""
local desc_instrumentation=""
local desc_return=""
if [ ! -z "${order}" ]; then
desc_order="${order##_}"
elif meta_is_implicitly_relaxed "${meta}"; then
desc_order="relaxed"
else
desc_order="full"
fi
if [ -z "${class}" ]; then
desc_noinstr="Unsafe to use in noinstr code; use raw_${atomicname}() there."
else
desc_noinstr="Safe to use in noinstr code; prefer ${atomicname}() elsewhere."
fi
desc_return="$(gen_desc_return "${meta}")"
. ${template}
}
#gen_kerneldoc(class, meta, pfx, name, sfx, order, atomic, int, args...)
gen_kerneldoc()
{
local class="$1"; shift
local meta="$1"; shift
local pfx="$1"; shift
local name="$1"; shift
local sfx="$1"; shift
local order="$1"; shift
local atomicname="${atomic}_${pfx}${name}${sfx}${order}"
local tmpl="$(find_kerneldoc_template "${pfx}" "${name}" "${sfx}" "${order}")"
if [ -z "${tmpl}" ]; then
printf "/*\n"
printf " * No kerneldoc available for ${class}${atomicname}\n"
printf " */\n"
else
gen_template_kerneldoc "${tmpl}" "${class}" "${meta}" "${pfx}" "${name}" "${sfx}" "${order}" "$@"
fi
}
locking/atomics: Add common header generation files To minimize repetition, to allow for future rework, and to ensure regularity of the various atomic APIs, we'd like to automatically generate (the bulk of) a number of headers related to atomics. This patch adds the infrastructure to do so, leaving actual conversion of headers to subsequent patches. This infrastructure consists of: * atomics.tbl - a table describing the functions in the atomics API, with names, prototypes, and metadata describing the variants that exist (e.g fetch/return, acquire/release/relaxed). Note that the return type is dependent on the particular variant. * atomic-tbl.sh - a library of routines useful for dealing with atomics.tbl (e.g. querying which variants exist, or generating argument/parameter lists for a given function variant). * gen-atomic-fallback.sh - a script which generates a header of fallbacks, covering cases where architecture omit certain functions (e.g. omitting relaxed variants). * gen-atomic-long.sh - a script which generates wrappers providing the atomic_long API atomic of the relevant atomic or atomic64 API, ensuring the APIs are consistent. * gen-atomic-instrumented.sh - a script which generates atomic* wrappers atop of arch_atomic* functions, with automatically generated KASAN instrumentation. * fallbacks/* - a set of fallback implementations for atomics, which should be used when no implementation of a given atomic is provided. These are used by gen-atomic-fallback.sh to generate fallbacks, and these are also used by other scripts to determine the set of optional atomics (as required to generate preprocessor guards correctly). Fallbacks may use the following variables: ${atomic} atomic prefix: atomic/atomic64/atomic_long, which can be used to derive the atomic type, and to prefix functions ${int} integer type: int/s64/long ${pfx} variant prefix, e.g. fetch_ ${name} base function name, e.g. add ${sfx} variant suffix, e.g. _return ${order} order suffix, e.g. _relaxed ${atomicname} full name, e.g. atomic64_fetch_add_relaxed ${ret} return type of the function, e.g. void ${retstmt} a return statement (with a trailing space), unless the variant returns void ${params} parameter list for the function declaration, e.g. "int i, atomic_t *v" ${args} argument list for invoking the function, e.g. "i, v" ... for clarity, ${ret}, ${retstmt}, ${params}, and ${args} are open-coded for fallbacks where these do not vary, or are critical to understanding the logic of the fallback. The MAINTAINERS entry for the atomic infrastructure is updated to cover the new scripts. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com Cc: Will Deacon <will.deacon@arm.com> Cc: linuxdrivers@attotech.com Cc: dvyukov@google.com Cc: Boqun Feng <boqun.feng@gmail.com> Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: glider@google.com Link: http://lkml.kernel.org/r/20180904104830.2975-2-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-04 10:48:25 +00:00
#gen_proto_order_variants(meta, pfx, name, sfx, ...)
gen_proto_order_variants()
{
local meta="$1"; shift
local pfx="$1"; shift
local name="$1"; shift
local sfx="$1"; shift
gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "" "$@"
if meta_has_acquire "${meta}"; then
gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_acquire" "$@"
fi
if meta_has_release "${meta}"; then
gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_release" "$@"
fi
if meta_has_relaxed "${meta}"; then
gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_relaxed" "$@"
fi
}
#gen_proto_variants(meta, name, ...)
gen_proto_variants()
{
local meta="$1"; shift
local name="$1"; shift
local pfx=""
local sfx=""
meta_in "${meta}" "fF" && pfx="fetch_"
meta_in "${meta}" "R" && sfx="_return"
gen_proto_order_variants "${meta}" "${pfx}" "${name}" "${sfx}" "$@"
}
#gen_proto(meta, ...)
gen_proto() {
local meta="$1"; shift
for m in $(echo "${meta}" | grep -o .); do
locking/atomics: Add common header generation files To minimize repetition, to allow for future rework, and to ensure regularity of the various atomic APIs, we'd like to automatically generate (the bulk of) a number of headers related to atomics. This patch adds the infrastructure to do so, leaving actual conversion of headers to subsequent patches. This infrastructure consists of: * atomics.tbl - a table describing the functions in the atomics API, with names, prototypes, and metadata describing the variants that exist (e.g fetch/return, acquire/release/relaxed). Note that the return type is dependent on the particular variant. * atomic-tbl.sh - a library of routines useful for dealing with atomics.tbl (e.g. querying which variants exist, or generating argument/parameter lists for a given function variant). * gen-atomic-fallback.sh - a script which generates a header of fallbacks, covering cases where architecture omit certain functions (e.g. omitting relaxed variants). * gen-atomic-long.sh - a script which generates wrappers providing the atomic_long API atomic of the relevant atomic or atomic64 API, ensuring the APIs are consistent. * gen-atomic-instrumented.sh - a script which generates atomic* wrappers atop of arch_atomic* functions, with automatically generated KASAN instrumentation. * fallbacks/* - a set of fallback implementations for atomics, which should be used when no implementation of a given atomic is provided. These are used by gen-atomic-fallback.sh to generate fallbacks, and these are also used by other scripts to determine the set of optional atomics (as required to generate preprocessor guards correctly). Fallbacks may use the following variables: ${atomic} atomic prefix: atomic/atomic64/atomic_long, which can be used to derive the atomic type, and to prefix functions ${int} integer type: int/s64/long ${pfx} variant prefix, e.g. fetch_ ${name} base function name, e.g. add ${sfx} variant suffix, e.g. _return ${order} order suffix, e.g. _relaxed ${atomicname} full name, e.g. atomic64_fetch_add_relaxed ${ret} return type of the function, e.g. void ${retstmt} a return statement (with a trailing space), unless the variant returns void ${params} parameter list for the function declaration, e.g. "int i, atomic_t *v" ${args} argument list for invoking the function, e.g. "i, v" ... for clarity, ${ret}, ${retstmt}, ${params}, and ${args} are open-coded for fallbacks where these do not vary, or are critical to understanding the logic of the fallback. The MAINTAINERS entry for the atomic infrastructure is updated to cover the new scripts. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com Cc: Will Deacon <will.deacon@arm.com> Cc: linuxdrivers@attotech.com Cc: dvyukov@google.com Cc: Boqun Feng <boqun.feng@gmail.com> Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: glider@google.com Link: http://lkml.kernel.org/r/20180904104830.2975-2-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-04 10:48:25 +00:00
gen_proto_variants "${m}" "$@"
done
}