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* Merge tag 'riscv-for-linus-4.18-merge_window' of ↵Linus Torvalds2018-06-1615-14/+626
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux Pull RISC-V updates from Palmer Dabbelt: "This contains some small RISC-V updates I'd like to target for 4.18. They are all fairly small this time. Here's a short summary, there's more info in the commits/merges: - a fix to __clear_user to respect the passed arguments. - enough support for the perf subsystem to work with RISC-V's ISA defined performance counters. - support for sparse and cleanups suggested by it. - support for R_RISCV_32 (a relocation, not the 32-bit ISA). - some MAINTAINERS cleanups. - the addition of CONFIG_HVC_RISCV_SBI to our defconfig, as it's always present. I've given these a simple build+boot test" * tag 'riscv-for-linus-4.18-merge_window' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: RISC-V: Add CONFIG_HVC_RISCV_SBI=y to defconfig RISC-V: Handle R_RISCV_32 in modules riscv/ftrace: Export _mcount when DYNAMIC_FTRACE isn't set riscv: add riscv-specific predefines to CHECKFLAGS riscv: split the declaration of __copy_user riscv: no __user for probe_kernel_address() riscv: use NULL instead of a plain 0 perf: riscv: Add Document for Future Porting Guide perf: riscv: preliminary RISC-V support MAINTAINERS: Update Albert's email, he's back at Berkeley MAINTAINERS: Add myself as a maintainer for SiFive's drivers riscv: Fix the bug in memory access fixup code
| * RISC-V: Add CONFIG_HVC_RISCV_SBI=y to defconfigPalmer Dabbelt2018-06-111-0/+1
| | | | | | | | | | | | | | The SBI exists on all RISC-V systems, so there's no reason not to compile this driver in. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| * RISC-V: Make our port sparse-cleanPalmer Dabbelt2018-06-116-9/+14
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch set contains a handful of fixes that clean up the sparse results for the RISC-V port. These patches shouldn't have any functional difference. The patches: * Use NULL instead of 0. * Clean up __user annotations. * Split __copy_user into two functions, to make the __user annotations valid. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
| | * riscv: split the declaration of __copy_userLuc Van Oostenryck2018-06-093-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use a single __copy_user assembly function to copy memory both from and to userspace. While this works, it triggers sparse errors because we're implicitly casting between the kernel and user address spaces by calling __copy_user. This patch splits the C declaration into a pair of functions, __asm_copy_{to,from}_user, that have sane semantics WRT __user. This split make things fine from sparse's point of view. The assembly implementation keeps a single definition but add a double ENTRY() for it, one for __asm_copy_to_user and another one for __asm_copy_from_user. The result is a spare-safe implementation that pays no performance or code size penalty. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * riscv: no __user for probe_kernel_address()Luc Van Oostenryck2018-06-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In is_valid_bugaddr(), probe_kernel_address() is called with the PC casted to (bug_inst_t __user *) but this function only take a plain void* as argument, not a __user pointer. Fix this by removing the unnneded __user in the cast. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * riscv: use NULL instead of a plain 0Luc Van Oostenryck2018-06-072-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sbi_remote_sfence_vma() & sbi_remote_fence_i() takes a pointer as first argument but some macros call them with a plain 0 which, while legal C, is frowned upon in the kernel. Change this by replacing the 0 by NULL. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| * | RISC-V: Handle R_RISCV_32 in modulesAndreas Schwab2018-06-111-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | With CONFIG_MODVERSIONS=y the R_RISCV_32 relocation is used by the __kcrctab section. Signed-off-by: Andreas Schwab <schwab@suse.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| * | riscv/ftrace: Export _mcount when DYNAMIC_FTRACE isn't setAlan Kao2018-06-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The EXPORT_SYMBOL(_mcount) for RISC-V ended up inside a CONFIG_DYNAMIC_FTRACE ifdef. If you enable modules without enabling CONFIG_DYNAMIC_FTRACE then you'll get a build error without this patch because the modules won't be able to find _mcount. The new behavior is to export _mcount whenever CONFIG_FUNCTION_TRACER is defined. This matches what every other architecture is doing. Signed-off-by: Alan Kao <alankao@andestech.com> Cc: Greentime Hu <greentime@andestech.com> Cc: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| * | riscv: add riscv-specific predefines to CHECKFLAGSLuc Van Oostenryck2018-06-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RISC-V uses the macro __riscv_xlen, predefined by GCC, to make the distinction between 32 or 64 bit code. However, sparse doesn't know anything about this macro which lead to wrong warnings and failures. Fix this by adding a define of __riscv_xlen to CHECKFLAGS and add one for __riscv too. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| * | RISC-V: Preliminary Perf SupportPalmer Dabbelt2018-06-045-0/+586
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The RISC-V ISA defines a core set of performance counters that must exist on all processors along with a standard way to add more performance counters. This patch set adds preliminary perf support for RISC-V systems. Long term we'll move to model where all PMUs can be built into the kernel at the same time, detected at runtime (possibly via device tree), and provided to userspace. Since we currently only support the ISA-mandated performance counters there's no need to detect anything right now. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * | perf: riscv: preliminary RISC-V supportAlan Kao2018-06-045-0/+586
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch provide a basic PMU, riscv_base_pmu, which supports two general hardware event, instructions and cycles. Furthermore, this PMU serves as a reference implementation to ease the portings in the future. riscv_base_pmu should be able to run on any RISC-V machine that conforms to the Priv-Spec. Note that the latest qemu model hasn't fully support a proper behavior of Priv-Spec 1.10 yet, but work around should be easy with very small fixes. Please check https://github.com/riscv/riscv-qemu/pull/115 for future updates. Cc: Nick Hu <nickhu@andestech.com> Cc: Greentime Hu <greentime@andestech.com> Signed-off-by: Alan Kao <alankao@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| * | riscv: Fix the bug in memory access fixup codeAlan Kao2018-06-041-4/+9
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A piece of fixup code is currently shared by __copy_user and __clear_user. It first disables the access to user-space memory and then returns the "n" argument, which represents #(bytes not processed). However,__copy_user's "n" is in register a2, while __clear_user's in a1, and thus it causes errors for programs like setdomainname02 testcase in LTP. This patch fixes this issue by separating their fixup code and returning the right value for the kernel to handle a relative fault properly. Signed-off-by: Alan Kao <alankao@andestech.com> Cc: Greentime Hu <greentime@andestech.com> Cc: Zong Li <zong@andestech.com> Cc: Vincent Chen <vincentc@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
* | Merge tag 'mips_4.18' of ↵Linus Torvalds2018-06-121-3/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux Pull MIPS updates from James Hogan: "These are the main MIPS changes for 4.18. Rough overview: - MAINTAINERS: Add Paul Burton as MIPS co-maintainer - Misc: Generic compiler intrinsics, Y2038 improvements, Perf+MT fixes - Platform support: Netgear WNR1000 V3, Microsemi Ocelot integrated switch, Ingenic watchdog cleanups More detailed summary: Maintainers: - Add Paul Burton as MIPS co-maintainer, as I soon won't have access to much MIPS hardware, nor enough time to properly maintain MIPS on my own. Miscellaneous: - Use generic GCC library routines from lib/ - Add notrace to generic ucmpdi2 implementation - Rename compiler intrinsic selects to GENERIC_LIB_* - vmlinuz: Use generic ashldi3 - y2038: Convert update/read_persistent_clock() to *_clock64() - sni: Remove read_persistent_clock() - perf: Fix perf with MT counting other threads - Probe for per-TC perf counters in cpu-probe.c - Use correct VPE ID for VPE tracing Minor cleanups: - Avoid unneeded built-in.a in DTS dirs - sc-debugfs: Re-use kstrtobool_from_user - memset.S: Reinstate delay slot indentation - VPE: Fix spelling "uneeded" -> "Unneeded" Platform support: BCM47xx: - Add support for Netgear WNR1000 V3 - firmware: Support small NVRAM partitions - Use __initdata for LEDs platform data Ingenic: - Watchdog driver & platform code improvements: - Disable clock after stopping counter - Use devm_* functions - Drop module remove function - Move platform reset code to restart handler in driver - JZ4740: Convert watchdog instantiation to DT - JZ4780: Fix watchdog DT node - qi_lb60_defconfig: Enable watchdog driver Microsemi: - Ocelot: Add support for integrated switch - pcb123: Connect phys to ports" * tag 'mips_4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (30 commits) MAINTAINERS: Add Paul Burton as MIPS co-maintainer MIPS: ptrace: Make FPU context layout comments match reality MIPS: memset.S: Reinstate delay slot indentation MIPS: perf: Fix perf with MT counting other threads MIPS: perf: Use correct VPE ID when setting up VPE tracing MIPS: perf: More robustly probe for the presence of per-tc counters MIPS: Probe for MIPS MT perf counters per TC MIPS: mscc: Connect phys to ports on ocelot_pcb123 MIPS: mscc: Add switch to ocelot MIPS: JZ4740: Drop old platform reset code MIPS: qi_lb60: Enable the jz4740-wdt driver MIPS: JZ4780: dts: Fix watchdog node MIPS: JZ4740: dts: Add bindings for the jz4740-wdt driver watchdog: JZ4740: Drop module remove function watchdog: JZ4740: Register a restart handler watchdog: JZ4740: Use devm_* functions watchdog: JZ4740: Disable clock after stopping counter MIPS: VPE: Fix spelling mistake: "uneeded" -> "unneeded" MIPS: Re-use kstrtobool_from_user() MIPS: Convert update_persistent_clock() to update_persistent_clock64() ...
| * | lib: Rename compiler intrinsic selects to GENERIC_LIB_*Matt Redfearn2018-04-231-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When these are included into arch Kconfig files, maintaining alphabetical ordering of the selects means these get split up. To allow for keeping things tidier and alphabetical, rename the selects to GENERIC_LIB_* Signed-off-by: Matt Redfearn <matt.redfearn@mips.com> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Antony Pavlov <antonynpavlov@gmail.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-riscv@lists.infradead.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/19049/ Signed-off-by: James Hogan <jhogan@kernel.org>
* | | Merge tag 'arm64-upstream' of ↵Linus Torvalds2018-06-081-1/+0
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "Apart from the core arm64 and perf changes, the Spectre v4 mitigation touches the arm KVM code and the ACPI PPTT support touches drivers/ (acpi and cacheinfo). I should have the maintainers' acks in place. Summary: - Spectre v4 mitigation (Speculative Store Bypass Disable) support for arm64 using SMC firmware call to set a hardware chicken bit - ACPI PPTT (Processor Properties Topology Table) parsing support and enable the feature for arm64 - Report signal frame size to user via auxv (AT_MINSIGSTKSZ). The primary motivation is Scalable Vector Extensions which requires more space on the signal frame than the currently defined MINSIGSTKSZ - ARM perf patches: allow building arm-cci as module, demote dev_warn() to dev_dbg() in arm-ccn event_init(), miscellaneous cleanups - cmpwait() WFE optimisation to avoid some spurious wakeups - L1_CACHE_BYTES reverted back to 64 (for performance reasons that have to do with some network allocations) while keeping ARCH_DMA_MINALIGN to 128. cache_line_size() returns the actual hardware Cache Writeback Granule - Turn LSE atomics on by default in Kconfig - Kernel fault reporting tidying - Some #include and miscellaneous cleanups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (53 commits) arm64: Fix syscall restarting around signal suppressed by tracer arm64: topology: Avoid checking numa mask for scheduler MC selection ACPI / PPTT: fix build when CONFIG_ACPI_PPTT is not enabled arm64: cpu_errata: include required headers arm64: KVM: Move VCPU_WORKAROUND_2_FLAG macros to the top of the file arm64: signal: Report signal frame size to userspace via auxv arm64/sve: Thin out initialisation sanity-checks for sve_max_vl arm64: KVM: Add ARCH_WORKAROUND_2 discovery through ARCH_FEATURES_FUNC_ID arm64: KVM: Handle guest's ARCH_WORKAROUND_2 requests arm64: KVM: Add ARCH_WORKAROUND_2 support for guests arm64: KVM: Add HYP per-cpu accessors arm64: ssbd: Add prctl interface for per-thread mitigation arm64: ssbd: Introduce thread flag to control userspace mitigation arm64: ssbd: Restore mitigation status on CPU resume arm64: ssbd: Skip apply_ssbd if not using dynamic mitigation arm64: ssbd: Add global mitigation state accessor arm64: Add 'ssbd' command-line option arm64: Add ARCH_WORKAROUND_2 probing arm64: Add per-cpu infrastructure to call ARCH_WORKAROUND_2 arm64: Call ARCH_WORKAROUND_2 on transitions between EL0 and EL1 ...
| * | | drivers: base: cacheinfo: setup DT cache properties earlyJeremy Linton2018-05-171-1/+0
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original intent in cacheinfo was that an architecture specific populate_cache_leaves() would probe the hardware and then cache_shared_cpu_map_setup() and cache_override_properties() would provide firmware help to extend/expand upon what was probed. Arm64 was really the only architecture that was working this way, and with the removal of most of the hardware probing logic it became clear that it was possible to simplify the logic a bit. This patch combines the walk of the DT nodes with the code updating the cache size/line_size and nr_sets. cache_override_properties() (which was DT specific) is then removed. The result is that cacheinfo.of_node is no longer used as a temporary place to hold DT references for future calls that update cache properties. That change helps to clarify its one remaining use (matching cacheinfo nodes that represent shared caches) which will be used by the ACPI/PPTT code in the following patches. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Vijaya Kumar K <vkilari@codeaurora.org> Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* | | mm: introduce ARCH_HAS_PTE_SPECIALLaurent Dufour2018-06-072-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the PTE special supports is turned on in per architecture header files. Most of the time, it is defined in arch/*/include/asm/pgtable.h depending or not on some other per architecture static definition. This patch introduce a new configuration variable to manage this directly in the Kconfig files. It would later replace __HAVE_ARCH_PTE_SPECIAL. Here notes for some architecture where the definition of __HAVE_ARCH_PTE_SPECIAL is not obvious: arm __HAVE_ARCH_PTE_SPECIAL which is currently defined in arch/arm/include/asm/pgtable-3level.h which is included by arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set. So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE. powerpc __HAVE_ARCH_PTE_SPECIAL is defined in 2 files: - arch/powerpc/include/asm/book3s/64/pgtable.h - arch/powerpc/include/asm/pte-common.h The first one is included if (PPC_BOOK3S & PPC64) while the second is included in all the other cases. So select ARCH_HAS_PTE_SPECIAL all the time. sparc: __HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) && defined(__arch64__) which are defined through the compiler in sparc/Makefile if !SPARC32 which I assume to be if SPARC64. So select ARCH_HAS_PTE_SPECIAL if SPARC64 There is no functional change introduced by this patch. Link: http://lkml.kernel.org/r/1523433816-14460-2-git-send-email-ldufour@linux.vnet.ibm.com Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Suggested-by: Jerome Glisse <jglisse@redhat.com> Reviewed-by: Jerome Glisse <jglisse@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <albert@sifive.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Christophe LEROY <christophe.leroy@c-s.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'siginfo-linus' of ↵Linus Torvalds2018-06-041-14/+2
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull siginfo updates from Eric Biederman: "This set of changes close the known issues with setting si_code to an invalid value, and with not fully initializing struct siginfo. There remains work to do on nds32, arc, unicore32, powerpc, arm, arm64, ia64 and x86 to get the code that generates siginfo into a simpler and more maintainable state. Most of that work involves refactoring the signal handling code and thus careful code review. Also not included is the work to shrink the in kernel version of struct siginfo. That depends on getting the number of places that directly manipulate struct siginfo under control, as it requires the introduction of struct kernel_siginfo for the in kernel things. Overall this set of changes looks like it is making good progress, and with a little luck I will be wrapping up the siginfo work next development cycle" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits) signal/sh: Stop gcc warning about an impossible case in do_divide_error signal/mips: Report FPE_FLTUNK for undiagnosed floating point exceptions signal/um: More carefully relay signals in relay_signal. signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR} signal: Remove unncessary #ifdef SEGV_PKUERR in 32bit compat code signal/signalfd: Add support for SIGSYS signal/signalfd: Remove __put_user from signalfd_copyinfo signal/xtensa: Use force_sig_fault where appropriate signal/xtensa: Consistenly use SIGBUS in do_unaligned_user signal/um: Use force_sig_fault where appropriate signal/sparc: Use force_sig_fault where appropriate signal/sparc: Use send_sig_fault where appropriate signal/sh: Use force_sig_fault where appropriate signal/s390: Use force_sig_fault where appropriate signal/riscv: Replace do_trap_siginfo with force_sig_fault signal/riscv: Use force_sig_fault where appropriate signal/parisc: Use force_sig_fault where appropriate signal/parisc: Use force_sig_mceerr where appropriate signal/openrisc: Use force_sig_fault where appropriate signal/nios2: Use force_sig_fault where appropriate ...
| * | | signal/riscv: Replace do_trap_siginfo with force_sig_faultEric W. Biederman2018-04-251-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function force_sig_fault is just the generic version of do_trap_siginfo with a (void __user *) instead of an unsigned long parameter for the address. So just use force_sig_fault to simplify the code. Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <albert@sifive.com> Cc: linux-riscv@lists.infradead.org Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * | | signal/riscv: Use force_sig_fault where appropriateEric W. Biederman2018-04-251-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Filling in struct siginfo before calling force_sig_info a tedious and error prone process, where once in a great while the wrong fields are filled out, and siginfo has been inconsistently cleared. Simplify this process by using the helper force_sig_fault. Which takes as a parameters all of the information it needs, ensures all of the fiddly bits of filling in struct siginfo are done properly and then calls force_sig_info. In short about a 5 line reduction in code for every time force_sig_info is called, which makes the calling function clearer. Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <albert@sifive.com> Cc: linux-riscv@lists.infradead.org Acked-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * | | signal: Ensure every siginfo we send has all bits initializedEric W. Biederman2018-04-251-0/+1
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Call clear_siginfo to ensure every stack allocated siginfo is properly initialized before being passed to the signal sending functions. Note: It is not safe to depend on C initializers to initialize struct siginfo on the stack because C is allowed to skip holes when initializing a structure. The initialization of struct siginfo in tracehook_report_syscall_exit was moved from the helper user_single_step_siginfo into tracehook_report_syscall_exit itself, to make it clear that the local variable siginfo gets fully initialized. In a few cases the scope of struct siginfo has been reduced to make it clear that siginfo siginfo is not used on other paths in the function in which it is declared. Instances of using memset to initialize siginfo have been replaced with calls clear_siginfo for clarity. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | | riscv: add swiotlb supportChristoph Hellwig2018-05-193-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All RISC-V platforms today lack an IOMMU. However, legacy PCI devices sometimes require DMA-memory to be in the low 32 bits. To make this work, we enable the software-based bounce buffers from swiotlb. They only impose overhead when the device in question cannot address the full 64-bit address space, so a perfect fit. This patch assumes that DMA is coherent with the processor and the PCI bus. It also assumes that the processor and devices share a common address space. This is true for all RISC-V platforms so far. [changelog stolen from an earlier patch by Palmer Dabbelt that did the more complicated swiotlb wireup before the recent consolidation] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
* | | riscv: only enable ZONE_DMA32 for 64-bitChristoph Hellwig2018-05-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Until we actually support > 32bit physical addresses for 32-bit using highmem there is no point in enabling ZONE_DMA32. And even if such support is ever added it probably should be conditional to not burden low end embedded devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
* | | riscv: simplify Kconfig magic for 32-bit vs 64-bit kernelsChristoph Hellwig2018-05-191-25/+6
| | | | | | | | | | | | | | | | | | | | | We can deduct this directly using a select from ARCH_RV32I/ARCH_RV64I. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
* | | arch: define the ARCH_DMA_ADDR_T_64BIT config symbol in lib/KconfigChristoph Hellwig2018-05-091-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Define this symbol if the architecture either uses 64-bit pointers or the PHYS_ADDR_T_64BIT is set. This covers 95% of the old arch magic. We only need an additional select for Xen on ARM (why anyway?), and we now always set ARCH_DMA_ADDR_T_64BIT on mips boards with 64-bit physical addressing instead of only doing it when highmem is set. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: James Hogan <jhogan@kernel.org>
* | | arch: remove the ARCH_PHYS_ADDR_T_64BIT config symbolChristoph Hellwig2018-05-091-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | Instead select the PHYS_ADDR_T_64BIT for 32-bit architectures that need a 64-bit phys_addr_t type directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: James Hogan <jhogan@kernel.org>
* | | dma-debug: remove CONFIG_HAVE_DMA_API_DEBUGChristoph Hellwig2018-05-081-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | There is no arch specific code required for dma-debug, so there is no need to opt into the support either. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
* | | PCI: remove PCI_DMA_BUS_IS_PHYSChristoph Hellwig2018-05-071-3/+0
| |/ |/| | | | | | | | | | | | | | | | | | | This was used by the ide, scsi and networking code in the past to determine if they should bounce payloads. Now that the dma mapping always have to support dma to all physical memory (thanks to swiotlb for non-iommu systems) there is no need to this crude hack any more. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Palmer Dabbelt <palmer@sifive.com> (for riscv) Reviewed-by: Jens Axboe <axboe@kernel.dk>
* | RISC-V: build vdso-dummy.o with -no-pieAurelien Jarno2018-04-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Debian toolcahin defaults to PIE, and I guess that will also be the case of most distributions. This causes the following build failure: AS arch/riscv/kernel/vdso/getcpu.o AS arch/riscv/kernel/vdso/flush_icache.o VDSOLD arch/riscv/kernel/vdso/vdso.so.dbg OBJCOPY arch/riscv/kernel/vdso/vdso.so AS arch/riscv/kernel/vdso/vdso.o VDSOLD arch/riscv/kernel/vdso/vdso-dummy.o LD arch/riscv/kernel/vdso/vdso-syms.o riscv64-linux-gnu-ld: attempted static link of dynamic object `arch/riscv/kernel/vdso/vdso-dummy.o' make[2]: *** [arch/riscv/kernel/vdso/Makefile:43: arch/riscv/kernel/vdso/vdso-syms.o] Error 1 make[1]: *** [scripts/Makefile.build:575: arch/riscv/kernel/vdso] Error 2 make: *** [Makefile:1018: arch/riscv/kernel] Error 2 While the root Makefile correctly passes "-fno-PIE" to build individual object files, the RISC-V kernel also builds vdso-dummy.o as an executable, which is therefore linked as PIE. Fix that by updating this specific link rule to also include "-no-pie". Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
* | riscv: there is no <asm/handle_irq.h>Christoph Hellwig2018-04-241-1/+0
| | | | | | | | | | | | | | So don't list it as generic-y. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
* | riscv: select DMA_DIRECT_OPS instead of redefining itChristoph Hellwig2018-04-241-3/+1
|/ | | | | | | | DMA_DIRECT_OPS is defined in lib/Kconfig, so don't duplicate it in arch/riscv/Kconfig. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
* Merge tag 'riscv-for-linus-4.17-mw0' of ↵Linus Torvalds2018-04-0419-255/+1598
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux Pull RISC-V updates from Palmer Dabbelt: "This contains the new features we'd like to incorporate into the RISC-V port for 4.17. We might have a bit more stuff land later in the merge window, but I wanted to get this out earlier just so everyone can see where we currently stand. A short summary of the changes is: - We've added support for dynamic ftrace on RISC-V targets. - There have been a handful of cleanups to our atomic and locking routines. They now more closely match the released RISC-V memory model draft. - Our module loading support has been cleaned up and is now enabled by default, despite some limitations still existing. - A patch to define COMMANDLINE_FORCE instead of COMMANDLINE_OVERRIDE so the generic device tree code picks up handling all our command line stuff. There's more information in the merge commits for each patch set" * tag 'riscv-for-linus-4.17-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: (21 commits) RISC-V: Rename CONFIG_CMDLINE_OVERRIDE to CONFIG_CMDLINE_FORCE RISC-V: Add definition of relocation types RISC-V: Enable module support in defconfig RISC-V: Support SUB32 relocation type in kernel module RISC-V: Support ADD32 relocation type in kernel module RISC-V: Support ALIGN relocation type in kernel module RISC-V: Support RVC_BRANCH/JUMP relocation type in kernel modulewq RISC-V: Support HI20/LO12_I/LO12_S relocation type in kernel module RISC-V: Support CALL relocation type in kernel module RISC-V: Support GOT_HI20/CALL_PLT relocation type in kernel module RISC-V: Add section of GOT.PLT for kernel module RISC-V: Add sections of PLT and GOT for kernel module riscv/atomic: Strengthen implementations with fences riscv/spinlock: Strengthen implementations with fences riscv/barrier: Define __smp_{store_release,load_acquire} riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support riscv/ftrace: Add DYNAMIC_FTRACE_WITH_REGS support riscv/ftrace: Add ARCH_SUPPORTS_FTRACE_OPS support riscv/ftrace: Add dynamic function graph tracer support riscv/ftrace: Add dynamic function tracer support ...
| * RISC-V: Rename CONFIG_CMDLINE_OVERRIDE to CONFIG_CMDLINE_FORCEPalmer Dabbelt2018-04-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The device tree code looks for CONFIG_CMDLINE_FORCE, but we were using CONFIG_CMDLINE_OVERRIDE. It looks like this was just a hold over from before our device tree conversion -- in fact, we'd already removed the support for CONFIG_CMDLINE_OVERRIDE from our arch-specific code so it didn't even work any more. Thanks to Mortiz and Trung for finding the original bug, and for Michael for suggeting a better fix. CC: Trung Tran <trung.tran@ettus.com> CC: Michael J Clark <mjc@sifive.com> Reviewed-by: Moritz Fischer <mdf@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| * RISC-V: Fixes to module loadingPalmer Dabbelt2018-04-029-6/+470
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This cleans up the module support that was commited earlier to work with what's actually emitted from our GCC port as it lands upstream. Most of the work here is adding new relocations to the kernel. There's some limitations on module loading imposed by the kernel: * The kernel doesn't support linker relaxation, which is necessary to support R_RISCV_ALIGN. In order to get reliable module building you're going to need to a GCC that supports the new '-mno-relax', which IIRC isn't going to be out until 8.1.0. It's somewhat unlikely that R_RISCV_ALIGN will appear in a module even without '-mno-relax' support, so issues shouldn't be common. * There is no large code model for RISC-V, which means modules must be loaded within a 32-bit signed offset of the kernel. We don't currently have any mechanism for ensuring this memory remains free or moving pages around, so issues here might be common. I fixed a singcle merge conflict in arch/riscv/kernel/Makefile.
| | * RISC-V: Add definition of relocation typesZong Li2018-04-021-0/+7
| | | | | | | | | | | | | | | Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * RISC-V: Enable module support in defconfigZong Li2018-04-021-0/+2
| | | | | | | | | | | | | | | Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * RISC-V: Support SUB32 relocation type in kernel moduleZong Li2018-04-021-0/+8
| | | | | | | | | | | | | | | Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * RISC-V: Support ADD32 relocation type in kernel moduleZong Li2018-04-021-0/+8
| | | | | | | | | | | | | | | Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * RISC-V: Support ALIGN relocation type in kernel moduleZong Li2018-04-021-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just fail on align type. Kernel modules loader didn't do relax like linker, it is difficult to remove or migrate the code, but the remnant nop instructions harm the performaace of module. We expect the building module with the no-relax option. Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * RISC-V: Support RVC_BRANCH/JUMP relocation type in kernel modulewqZong Li2018-04-021-0/+35
| | | | | | | | | | | | | | | Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * RISC-V: Support HI20/LO12_I/LO12_S relocation type in kernel moduleZong Li2018-04-021-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | HI20 and LO12_I/LO12_S relocate the absolute address, the range of offset must in 32-bit. Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * RISC-V: Support CALL relocation type in kernel moduleZong Li2018-04-021-0/+22
| | | | | | | | | | | | | | | Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * RISC-V: Support GOT_HI20/CALL_PLT relocation type in kernel moduleZong Li2018-04-021-10/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For CALL_PLT, emit the plt entry only when offset is more than 32-bit. For PCREL_LO12, it uses the location of corresponding HI20 to get the address of external symbol. It should check the HI20 type is the PCREL_HI20 or GOT_HI20, because sometime the location will have two or more relocation types. For example: 0: 00000797 auipc a5,0x0 0: R_RISCV_ALIGN *ABS* 0: R_RISCV_GOT_HI20 SYMBOL 4: 0007b783 ld a5,0(a5) # 0 <SYMBOL> 4: R_RISCV_PCREL_LO12_I .L0 4: R_RISCV_RELAX *ABS* Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * RISC-V: Add section of GOT.PLT for kernel moduleZong Li2018-04-023-17/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Separate the function symbol address from .plt to .got.plt section. The original plt entry has trampoline code with symbol address, there is a 32-bit padding bwtween jar instruction and symbol address. Extract the symbol address to .got.plt to reduce the module size. Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * RISC-V: Add sections of PLT and GOT for kernel moduleZong Li2018-04-026-0/+260
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The address of external symbols will locate more than 32-bit offset in 64-bit kernel with sv39 or sv48 virtual addressing. Module loader emits the GOT and PLT entries for data symbols and function symbols respectively. The PLT entry is a trampoline code for jumping to the 64-bit real address. The GOT entry is just the data symbol address. Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| * | RISC-V: Assorted memory model fixesPalmer Dabbelt2018-04-025-234/+630
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These fixes fall into three categories * The definiton of __smp_{store_release,load_acquire}, which allow us to emit a full fence when unnecessary. * Fixes to avoid relying on the behavior of "*.aqrl" atomics, as those are specified in the currently released RISC-V memory model draft in a way that makes them useless for Linux. This might change in the future, but now the code matches the memory model spec as it's written so at least we're getting closer to something sane. The actual fix is to delete the RISC-V specific atomics and drop back to generic versions that use the new fences from above. * Cleanups to our atomic macros, which are mostly non-functional changes. Unfortunately I haven't given these as thorough of a testing as I probably should have, but I've poked through the code and they seem generally OK.
| | * | riscv/atomic: Strengthen implementations with fencesAndrea Parri2018-04-022-220/+588
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Atomics present the same issue with locking: release and acquire variants need to be strengthened to meet the constraints defined by the Linux-kernel memory consistency model [1]. Atomics present a further issue: implementations of atomics such as atomic_cmpxchg() and atomic_add_unless() rely on LR/SC pairs, which do not give full-ordering with .aqrl; for example, current implementations allow the "lr-sc-aqrl-pair-vs-full-barrier" test below to end up with the state indicated in the "exists" clause. In order to "synchronize" LKMM and RISC-V's implementation, this commit strengthens the implementations of the atomics operations by replacing .rl and .aq with the use of ("lightweigth") fences, and by replacing .aqrl LR/SC pairs in sequences such as: 0: lr.w.aqrl %0, %addr bne %0, %old, 1f ... sc.w.aqrl %1, %new, %addr bnez %1, 0b 1: with sequences of the form: 0: lr.w %0, %addr bne %0, %old, 1f ... sc.w.rl %1, %new, %addr /* SC-release */ bnez %1, 0b fence rw, rw /* "full" fence */ 1: following Daniel's suggestion. These modifications were validated with simulation of the RISC-V memory consistency model. C lr-sc-aqrl-pair-vs-full-barrier {} P0(int *x, int *y, atomic_t *u) { int r0; int r1; WRITE_ONCE(*x, 1); r0 = atomic_cmpxchg(u, 0, 1); r1 = READ_ONCE(*y); } P1(int *x, int *y, atomic_t *v) { int r0; int r1; WRITE_ONCE(*y, 1); r0 = atomic_cmpxchg(v, 0, 1); r1 = READ_ONCE(*x); } exists (u=1 /\ v=1 /\ 0:r1=0 /\ 1:r1=0) [1] https://marc.info/?l=linux-kernel&m=151930201102853&w=2 https://groups.google.com/a/groups.riscv.org/forum/#!topic/isa-dev/hKywNHBkAXM https://marc.info/?l=linux-kernel&m=151633436614259&w=2 Suggested-by: Daniel Lustig <dlustig@nvidia.com> Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <albert@sifive.com> Cc: Daniel Lustig <dlustig@nvidia.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Will Deacon <will.deacon@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Jade Alglave <j.alglave@ucl.ac.uk> Cc: Luc Maranget <luc.maranget@inria.fr> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Akira Yokosawa <akiyks@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-riscv@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * | riscv/spinlock: Strengthen implementations with fencesAndrea Parri2018-04-022-14/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current implementations map locking operations using .rl and .aq annotations. However, this mapping is unsound w.r.t. the kernel memory consistency model (LKMM) [1]: Referring to the "unlock-lock-read-ordering" test reported below, Daniel wrote: "I think an RCpc interpretation of .aq and .rl would in fact allow the two normal loads in P1 to be reordered [...] The intuition would be that the amoswap.w.aq can forward from the amoswap.w.rl while that's still in the store buffer, and then the lw x3,0(x4) can also perform while the amoswap.w.rl is still in the store buffer, all before the l1 x1,0(x2) executes. That's not forbidden unless the amoswaps are RCsc, unless I'm missing something. Likewise even if the unlock()/lock() is between two stores. A control dependency might originate from the load part of the amoswap.w.aq, but there still would have to be something to ensure that this load part in fact performs after the store part of the amoswap.w.rl performs globally, and that's not automatic under RCpc." Simulation of the RISC-V memory consistency model confirmed this expectation. In order to "synchronize" LKMM and RISC-V's implementation, this commit strengthens the implementations of the locking operations by replacing .rl and .aq with the use of ("lightweigth") fences, resp., "fence rw, w" and "fence r , rw". C unlock-lock-read-ordering {} /* s initially owned by P1 */ P0(int *x, int *y) { WRITE_ONCE(*x, 1); smp_wmb(); WRITE_ONCE(*y, 1); } P1(int *x, int *y, spinlock_t *s) { int r0; int r1; r0 = READ_ONCE(*y); spin_unlock(s); spin_lock(s); r1 = READ_ONCE(*x); } exists (1:r0=1 /\ 1:r1=0) [1] https://marc.info/?l=linux-kernel&m=151930201102853&w=2 https://groups.google.com/a/groups.riscv.org/forum/#!topic/isa-dev/hKywNHBkAXM https://marc.info/?l=linux-kernel&m=151633436614259&w=2 Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <albert@sifive.com> Cc: Daniel Lustig <dlustig@nvidia.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Will Deacon <will.deacon@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Jade Alglave <j.alglave@ucl.ac.uk> Cc: Luc Maranget <luc.maranget@inria.fr> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Akira Yokosawa <akiyks@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-riscv@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| | * | riscv/barrier: Define __smp_{store_release,load_acquire}Andrea Parri2018-04-021-0/+15
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | Introduce __smp_{store_release,load_acquire}, and rely on the generic definitions for smp_{store_release,load_acquire}. This avoids the use of full ("rw,rw") fences on SMP. Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| * | riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR supportAlan Kao2018-04-022-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In walk_stackframe, the pc now receives the address from calling ftrace_graph_ret_addr instead of manual calculation. Note that the original calculation, pc = frame->ra - 4 is buggy when the instruction at the return address happened to be a compressed inst. But since it is not a critical part of ftrace, it is ignored for now to ease the review process. Cc: Greentime Hu <greentime@andestech.com> Signed-off-by: Alan Kao <alankao@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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