Loading Documentation/ABI/testing/sysfs-class-power +2 −1 Original line number Diff line number Diff line Loading @@ -144,7 +144,8 @@ Description: Access: Read Valid values: "Unknown", "Good", "Overheat", "Dead", "Over voltage", "Unspecified failure", "Cold", "Watchdog timer expire", "Safety timer expire" "Watchdog timer expire", "Safety timer expire", "Over current", "Warm", "Cool", "Hot" What: /sys/class/power_supply/<supply_name>/precharge_current Date: June 2017 Loading Documentation/ABI/testing/sysfs-fs-f2fs +20 −0 Original line number Diff line number Diff line Loading @@ -318,3 +318,23 @@ Date: September 2019 Contact: "Hridya Valsaraju" <hridya@google.com> Description: Average number of valid blocks. Available when CONFIG_F2FS_STAT_FS=y. What: /sys/fs/f2fs/<disk>/mounted_time_sec Date: February 2020 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> Description: Show the mounted time in secs of this partition. What: /sys/fs/f2fs/<disk>/data_io_flag Date: April 2020 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> Description: Give a way to attach REQ_META|FUA to data writes given temperature-based bits. Now the bits indicate: * REQ_META | REQ_FUA | * 5 | 4 | 3 | 2 | 1 | 0 | * Cold | Warm | Hot | Cold | Warm | Hot | What: /sys/fs/f2fs/<disk>/iostat_period_ms Date: April 2020 Contact: "Daeho Jeong" <daehojeong@google.com> Description: Give a way to change iostat_period time. 3secs by default. The new iostat trace gives stats gap given the period. Documentation/arm64/index.rst 0 → 100644 +27 −0 Original line number Diff line number Diff line ================== ARM64 Architecture ================== .. toctree:: :maxdepth: 1 acpi_object_usage arm-acpi booting cpu-feature-registers elf_hwcaps hugetlbpage legacy_instructions memory pointer-authentication silicon-errata sve tagged-address-abi tagged-pointers .. only:: subproject and html Indices ======= * :ref:`genindex` Documentation/arm64/silicon-errata.txt +1 −0 Original line number Diff line number Diff line Loading @@ -60,6 +60,7 @@ stable kernels. | ARM | Cortex-A55 | #1024718 | ARM64_ERRATUM_1024718 | | ARM | Cortex-A76 | #1463225 | ARM64_ERRATUM_1463225 | | ARM | Cortex-A77 | #1542418 | ARM64_ERRATUM_1542418 | | ARM | Neoverse-N1 | #1542419 | ARM64_ERRATUM_1542419 | | ARM | MMU-500 | #841119,#826419 | N/A | | | | | | | Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 | Loading Documentation/arm64/tagged-pointers.rst 0 → 100644 +75 −0 Original line number Diff line number Diff line ========================================= Tagged virtual addresses in AArch64 Linux ========================================= Author: Will Deacon <will.deacon@arm.com> Date : 12 June 2013 This document briefly describes the provision of tagged virtual addresses in the AArch64 translation system and their potential uses in AArch64 Linux. The kernel configures the translation tables so that translations made via TTBR0 (i.e. userspace mappings) have the top byte (bits 63:56) of the virtual address ignored by the translation hardware. This frees up this byte for application use. Passing tagged addresses to the kernel -------------------------------------- All interpretation of userspace memory addresses by the kernel assumes an address tag of 0x00, unless the application enables the AArch64 Tagged Address ABI explicitly (Documentation/arm64/tagged-address-abi.rst). This includes, but is not limited to, addresses found in: - pointer arguments to system calls, including pointers in structures passed to system calls, - the stack pointer (sp), e.g. when interpreting it to deliver a signal, - the frame pointer (x29) and frame records, e.g. when interpreting them to generate a backtrace or call graph. Using non-zero address tags in any of these locations when the userspace application did not enable the AArch64 Tagged Address ABI may result in an error code being returned, a (fatal) signal being raised, or other modes of failure. For these reasons, when the AArch64 Tagged Address ABI is disabled, passing non-zero address tags to the kernel via system calls is forbidden, and using a non-zero address tag for sp is strongly discouraged. Programs maintaining a frame pointer and frame records that use non-zero address tags may suffer impaired or inaccurate debug and profiling visibility. Preserving tags --------------- Non-zero tags are not preserved when delivering signals. This means that signal handlers in applications making use of tags cannot rely on the tag information for user virtual addresses being maintained for fields inside siginfo_t. One exception to this rule is for signals raised in response to watchpoint debug exceptions, where the tag information will be preserved. The architecture prevents the use of a tagged PC, so the upper byte will be set to a sign-extension of bit 55 on exception return. This behaviour is maintained when the AArch64 Tagged Address ABI is enabled. Other considerations -------------------- Special care should be taken when using tagged pointers, since it is likely that C compilers will not hazard two virtual addresses differing only in the upper byte. Loading
Documentation/ABI/testing/sysfs-class-power +2 −1 Original line number Diff line number Diff line Loading @@ -144,7 +144,8 @@ Description: Access: Read Valid values: "Unknown", "Good", "Overheat", "Dead", "Over voltage", "Unspecified failure", "Cold", "Watchdog timer expire", "Safety timer expire" "Watchdog timer expire", "Safety timer expire", "Over current", "Warm", "Cool", "Hot" What: /sys/class/power_supply/<supply_name>/precharge_current Date: June 2017 Loading
Documentation/ABI/testing/sysfs-fs-f2fs +20 −0 Original line number Diff line number Diff line Loading @@ -318,3 +318,23 @@ Date: September 2019 Contact: "Hridya Valsaraju" <hridya@google.com> Description: Average number of valid blocks. Available when CONFIG_F2FS_STAT_FS=y. What: /sys/fs/f2fs/<disk>/mounted_time_sec Date: February 2020 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> Description: Show the mounted time in secs of this partition. What: /sys/fs/f2fs/<disk>/data_io_flag Date: April 2020 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> Description: Give a way to attach REQ_META|FUA to data writes given temperature-based bits. Now the bits indicate: * REQ_META | REQ_FUA | * 5 | 4 | 3 | 2 | 1 | 0 | * Cold | Warm | Hot | Cold | Warm | Hot | What: /sys/fs/f2fs/<disk>/iostat_period_ms Date: April 2020 Contact: "Daeho Jeong" <daehojeong@google.com> Description: Give a way to change iostat_period time. 3secs by default. The new iostat trace gives stats gap given the period.
Documentation/arm64/index.rst 0 → 100644 +27 −0 Original line number Diff line number Diff line ================== ARM64 Architecture ================== .. toctree:: :maxdepth: 1 acpi_object_usage arm-acpi booting cpu-feature-registers elf_hwcaps hugetlbpage legacy_instructions memory pointer-authentication silicon-errata sve tagged-address-abi tagged-pointers .. only:: subproject and html Indices ======= * :ref:`genindex`
Documentation/arm64/silicon-errata.txt +1 −0 Original line number Diff line number Diff line Loading @@ -60,6 +60,7 @@ stable kernels. | ARM | Cortex-A55 | #1024718 | ARM64_ERRATUM_1024718 | | ARM | Cortex-A76 | #1463225 | ARM64_ERRATUM_1463225 | | ARM | Cortex-A77 | #1542418 | ARM64_ERRATUM_1542418 | | ARM | Neoverse-N1 | #1542419 | ARM64_ERRATUM_1542419 | | ARM | MMU-500 | #841119,#826419 | N/A | | | | | | | Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 | Loading
Documentation/arm64/tagged-pointers.rst 0 → 100644 +75 −0 Original line number Diff line number Diff line ========================================= Tagged virtual addresses in AArch64 Linux ========================================= Author: Will Deacon <will.deacon@arm.com> Date : 12 June 2013 This document briefly describes the provision of tagged virtual addresses in the AArch64 translation system and their potential uses in AArch64 Linux. The kernel configures the translation tables so that translations made via TTBR0 (i.e. userspace mappings) have the top byte (bits 63:56) of the virtual address ignored by the translation hardware. This frees up this byte for application use. Passing tagged addresses to the kernel -------------------------------------- All interpretation of userspace memory addresses by the kernel assumes an address tag of 0x00, unless the application enables the AArch64 Tagged Address ABI explicitly (Documentation/arm64/tagged-address-abi.rst). This includes, but is not limited to, addresses found in: - pointer arguments to system calls, including pointers in structures passed to system calls, - the stack pointer (sp), e.g. when interpreting it to deliver a signal, - the frame pointer (x29) and frame records, e.g. when interpreting them to generate a backtrace or call graph. Using non-zero address tags in any of these locations when the userspace application did not enable the AArch64 Tagged Address ABI may result in an error code being returned, a (fatal) signal being raised, or other modes of failure. For these reasons, when the AArch64 Tagged Address ABI is disabled, passing non-zero address tags to the kernel via system calls is forbidden, and using a non-zero address tag for sp is strongly discouraged. Programs maintaining a frame pointer and frame records that use non-zero address tags may suffer impaired or inaccurate debug and profiling visibility. Preserving tags --------------- Non-zero tags are not preserved when delivering signals. This means that signal handlers in applications making use of tags cannot rely on the tag information for user virtual addresses being maintained for fields inside siginfo_t. One exception to this rule is for signals raised in response to watchpoint debug exceptions, where the tag information will be preserved. The architecture prevents the use of a tagged PC, so the upper byte will be set to a sign-extension of bit 55 on exception return. This behaviour is maintained when the AArch64 Tagged Address ABI is enabled. Other considerations -------------------- Special care should be taken when using tagged pointers, since it is likely that C compilers will not hazard two virtual addresses differing only in the upper byte.
