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2018-06-05Merge branch 'siginfo-linus' of ↵Linus Torvalds1-14/+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 ...
2018-05-19riscv: add swiotlb supportChristoph Hellwig3-0/+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>
2018-05-19riscv: only enable ZONE_DMA32 for 64-bitChristoph Hellwig1-1/+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>
2018-05-19riscv: simplify Kconfig magic for 32-bit vs 64-bit kernelsChristoph Hellwig1-25/+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>
2018-05-09arch: define the ARCH_DMA_ADDR_T_64BIT config symbol in lib/KconfigChristoph Hellwig1-3/+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>
2018-05-09arch: remove the ARCH_PHYS_ADDR_T_64BIT config symbolChristoph Hellwig1-4/+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>
2018-05-08dma-debug: remove CONFIG_HAVE_DMA_API_DEBUGChristoph Hellwig1-1/+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>
2018-05-07PCI: remove PCI_DMA_BUS_IS_PHYSChristoph Hellwig1-3/+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>
2018-04-25signal/riscv: Replace do_trap_siginfo with force_sig_faultEric W. Biederman1-8/+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>
2018-04-25signal/riscv: Use force_sig_fault where appropriateEric W. Biederman1-8/+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>
2018-04-25signal: Ensure every siginfo we send has all bits initializedEric W. Biederman1-0/+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>
2018-04-24RISC-V: build vdso-dummy.o with -no-pieAurelien Jarno1-1/+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>
2018-04-24riscv: there is no <asm/handle_irq.h>Christoph Hellwig1-1/+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>
2018-04-24riscv: select DMA_DIRECT_OPS instead of redefining itChristoph Hellwig1-3/+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>
2018-04-05Merge tag 'riscv-for-linus-4.17-mw0' of ↵Linus Torvalds19-255/+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 ...
2018-04-05Merge branch 'irq-core-for-linus' of ↵Linus Torvalds4-17/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "The usual pile of boring changes: - Consolidate tasklet functions to share code instead of duplicating it - The first step for making the low level entry handler management on multi-platform kernels generic - A new sysfs file which allows to retrieve the wakeup state of interrupts. - Ensure that the interrupt thread follows the effective affinity and not the programmed affinity to avoid cross core wakeups. - Two new interrupt controller drivers (Microsemi Ocelot and Qualcomm PDC) - Fix the wakeup path clock handling for Reneasas interrupt chips. - Rework the boot time register reset for ARM GIC-V2/3 - Better suspend/resume support for ARM GIV-V3/ITS - Add missing locking to the ARM GIC set_type() callback - Small fixes for the irq simulator code - SPDX identifiers for the irq core code and removal of boiler plate - Small cleanups all over the place" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) openrisc: Set CONFIG_MULTI_IRQ_HANDLER arm64: Set CONFIG_MULTI_IRQ_HANDLER genirq: Make GENERIC_IRQ_MULTI_HANDLER depend on !MULTI_IRQ_HANDLER irqchip/gic: Take lock when updating irq type irqchip/gic: Update supports_deactivate static key to modern api irqchip/gic-v3: Ensure GICR_CTLR.EnableLPI=0 is observed before enabling irqchip: Add a driver for the Microsemi Ocelot controller dt-bindings: interrupt-controller: Add binding for the Microsemi Ocelot interrupt controller irqchip/gic-v3: Probe for SCR_EL3 being clear before resetting AP0Rn irqchip/gic-v3: Don't try to reset AP0Rn irqchip/gic-v3: Do not check trigger configuration of partitionned LPIs genirq: Remove license boilerplate/references genirq: Add missing SPDX identifiers genirq/matrix: Cleanup SPDX identifier genirq: Cleanup top of file comments genirq: Pass desc to __irq_free instead of irq number irqchip/gic-v3: Loudly complain about the use of IRQ_TYPE_NONE irqchip/gic: Loudly complain about the use of IRQ_TYPE_NONE RISC-V: Move to the new GENERIC_IRQ_MULTI_HANDLER handler genirq: Add CONFIG_GENERIC_IRQ_MULTI_HANDLER ...
2018-04-03RISC-V: Rename CONFIG_CMDLINE_OVERRIDE to CONFIG_CMDLINE_FORCEPalmer Dabbelt1-2/+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>
2018-04-03RISC-V: Fixes to module loadingPalmer Dabbelt9-6/+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.
2018-04-03RISC-V: Assorted memory model fixesPalmer Dabbelt5-234/+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.
2018-04-03RISC-V: Add definition of relocation typesZong Li1-0/+7
Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-03RISC-V: Enable module support in defconfigZong Li1-0/+2
Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-03RISC-V: Support SUB32 relocation type in kernel moduleZong Li1-0/+8
Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-03RISC-V: Support ADD32 relocation type in kernel moduleZong Li1-0/+8
Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-03RISC-V: Support ALIGN relocation type in kernel moduleZong Li1-0/+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>
2018-04-03RISC-V: Support RVC_BRANCH/JUMP relocation type in kernel modulewqZong Li1-0/+35
Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-03RISC-V: Support HI20/LO12_I/LO12_S relocation type in kernel moduleZong Li1-0/+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>
2018-04-03RISC-V: Support CALL relocation type in kernel moduleZong Li1-0/+22
Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-03RISC-V: Support GOT_HI20/CALL_PLT relocation type in kernel moduleZong Li1-10/+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>
2018-04-03RISC-V: Add section of GOT.PLT for kernel moduleZong Li3-17/+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>
2018-04-03RISC-V: Add sections of PLT and GOT for kernel moduleZong Li6-0/+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>
2018-04-03riscv/atomic: Strengthen implementations with fencesAndrea Parri2-220/+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>
2018-04-03riscv/spinlock: Strengthen implementations with fencesAndrea Parri2-14/+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>
2018-04-03riscv/barrier: Define __smp_{store_release,load_acquire}Andrea Parri1-0/+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>
2018-04-03riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR supportAlan Kao2-1/+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>
2018-04-03riscv/ftrace: Add DYNAMIC_FTRACE_WITH_REGS supportAlan Kao4-0/+141
Cc: Greentime Hu <greentime@andestech.com> Signed-off-by: Alan Kao <alankao@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-03riscv/ftrace: Add ARCH_SUPPORTS_FTRACE_OPS supportAlan Kao2-0/+4
Cc: Greentime Hu <greentime@andestech.com> Signed-off-by: Alan Kao <alankao@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-03riscv/ftrace: Add dynamic function graph tracer supportAlan Kao2-1/+118
Once the function_graph tracer is enabled, a filtered function has the following call sequence: * ftracer_caller ==> on/off by ftrace_make_call/ftrace_make_nop * ftrace_graph_caller * ftrace_graph_call ==> on/off by ftrace_en/disable_ftrace_graph_caller * prepare_ftrace_return Considering the following DYNAMIC_FTRACE_WITH_REGS feature, it would be more extendable to have a ftrace_graph_caller function, instead of calling prepare_ftrace_return directly in ftrace_caller. Cc: Greentime Hu <greentime@andestech.com> Signed-off-by: Alan Kao <alankao@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-03riscv/ftrace: Add dynamic function tracer supportAlan Kao6-12/+223
We now have dynamic ftrace with the following added items: * ftrace_make_call, ftrace_make_nop (in kernel/ftrace.c) The two functions turn each recorded call site of filtered functions into a call to ftrace_caller or nops * ftracce_update_ftrace_func (in kernel/ftrace.c) turns the nops at ftrace_call into a call to a generic entry for function tracers. * ftrace_caller (in kernel/mcount-dyn.S) The entry where each _mcount call sites calls to once they are filtered to be traced. Also, this patch fixes the semantic problems in mcount.S, which will be treated as only a reference implementation once we have the dynamic ftrace. Cc: Greentime Hu <greentime@andestech.com> Signed-off-by: Alan Kao <alankao@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-03riscv/ftrace: Add RECORD_MCOUNT supportAlan Kao2-0/+4
Now recordmcount.pl recognizes RISC-V object files. For the mechanism to work, we have to disable the linker relaxation. Cc: Greentime Hu <greentime@andestech.com> Signed-off-by: Alan Kao <alankao@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff()Dominik Brodowski1-2/+2
Using this helper allows us to avoid the in-kernel calls to the sys_mmap_pgoff() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_mmap_pgoff(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-03-14RISC-V: Move to the new GENERIC_IRQ_MULTI_HANDLER handlerPalmer Dabbelt4-17/+5
The existing mechanism for handling IRQs on RISC-V is pretty ugly: the irq entry code selects the handler via Kconfig dependencies. Use the new generic IRQ handling infastructure, which allows boot time registration of the low level entry handler. This does add an additional load to the interrupt latency, but there's a lot of tuning left to be done there on RISC-V so it's OK for now. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Stafford Horne <shorne@gmail.com> Cc: jonas@southpole.se Cc: catalin.marinas@arm.com Cc: Will Deacon <will.deacon@arm.com> Cc: linux@armlinux.org.uk Cc: stefan.kristiansson@saunalahti.fi Cc: openrisc@lists.librecores.org Cc: linux-riscv@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lkml.kernel.org/r/20180307235731.22627-3-palmer@sifive.com
2018-02-26riscv/barrier: Define __smp_{mb,rmb,wmb}Andrea Parri1-3/+3
Introduce __smp_{mb,rmb,wmb}, and rely on the generic definitions for smp_{mb,rmb,wmb}. A first consequence is that smp_{mb,rmb,wmb} map to a compiler barrier on !SMP (while their definition remains unchanged on SMP). As a further consequence, smp_load_acquire and smp_store_release have "fence rw,rw" instead of "fence iorw,iorw". Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-02-20Rename sbi_save to parse_dtb to improve code readabilityMichael Clark2-2/+2
The sbi_ prefix would seem to indicate an SBI interface, and save is not very specific. After applying this patch, reading head.S makes more sense. Signed-off-by: Michael Clark <michaeljclark@mac.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-02-20RISC-V: Enable IRQ during exception handlingzongbox@gmail.com1-2/+3
Interrupt is allowed during exception handling. There are warning messages if the kernel enables the configuration 'CONFIG_DEBUG_ATOMIC_SLEEP=y'. BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:23 in_atomic(): 0, irqs_disabled(): 1, pid: 43, name: ash CPU: 0 PID: 43 Comm: ash Tainted: G W 4.15.0-rc8-00089-g89ffdae-dirty #17 Call Trace: [<000000009abb1587>] walk_stackframe+0x0/0x7a [<00000000d4f3d088>] ___might_sleep+0x102/0x11a [<00000000b1fd792a>] down_read+0x18/0x28 [<000000000289ec01>] do_page_fault+0x86/0x2f6 [<00000000012441f6>] _do_fork+0x1b4/0x1e0 [<00000000f46c3e3b>] ret_from_syscall+0xa/0xe Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Zong Li <zong@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-02-20riscv: Remove ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE selectUlf Magnusson1-1/+0
The ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE symbol was removed in commit 51a021244b9d ("atomic64: no need for CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE"). Remove the ARCH_HAS_ATOMIC64_DEC_IS_POSITIVE select from RISCV. Discovered with the https://github.com/ulfalizer/Kconfiglib/blob/master/examples/list_undefined.py script. Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com> Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-02-20riscv: kconfig: Remove RISCV_IRQ_INTC selectUlf Magnusson1-1/+0
The RISCV_IRQ_INTC configuration symbol is undefined, but RISCV selects it. Quoting Palmer Dabbelt: It looks like this slipped through, the symbol has been renamed RISCV_INTC. No RISCV_INTC configuration symbol has been merged either. Just remove the RISCV_IRQ_INTC select for now. Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-02-20riscv: Remove ARCH_WANT_OPTIONAL_GPIOLIB selectUlf Magnusson1-1/+0
The ARCH_WANT_OPTIONAL_GPIOLIB symbol was removed in commit 65053e1a7743 ("gpio: delete ARCH_[WANTS_OPTIONAL|REQUIRE]_GPIOLIB"). GPIOLIB should just be selected explicitly if needed. Remove the ARCH_WANT_OPTIONAL_GPIOLIB select from RISCV. See commit 0145071b3314 ("x86: Do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB") and commit da9a1c6767 ("arm64: do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB") as well. Discovered with the https://github.com/ulfalizer/Kconfiglib/blob/master/examples/list_undefined.py script. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2018-02-07Merge tag 'riscv-for-linus-4.16-merge_window' of ↵Linus Torvalds16-76/+248
git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux Pull RISC-V updates from Palmer Dabbelt: "This contains the fixes we'd like to target for the 4.16 merge window. It's not as much as I was originally hoping to do but between glibc, the chip, and FOSDEM there just wasn't enough time to get everything put together. As such, this merge window is essentially just going to be small changes. This includes mostly cleanups: - A build fix failure to the audit test cases. RISC-V doesn't have renameat because the generic syscall ABI moved to renameat2 by the time of our port. The syscall audit test cases don't understand this, so I added a trivial fix. This went through mailing list review during the 4.15 merge window, but nobody has picked it up so I think it's best to just do this here. - The removal of our command-line argument processing code. The "mem_end" stuff was broken and the rest duplicated generic device tree code. The generic code was already being called. - Some unused/redundant code has been removed, including __ARCH_HAVE_MMU, current_pgdir, and the initialization of init_mm.pgd. - SUM is disabled upon taking a trap, which means that user memory is protected during traps taking inside copy_{to,from}_user(). - The sptbr CSR has been renamed to satp in C code. We haven't changed the assembly code in order to maintain compatibility with binutils 2.29, which doesn't understand the new name. Additionally, we're adding some new features: - Basic ftrace support, thanks to Alan Kao! - Support for ZONE_DMA32. This is necessary for all the normal reasons, but also to deal with a deficiency in the Xilinx PCIe controller we're using on our FPGA-based systems. While the ZONE_DMA32 addition should be sufficient for most uses, it doesn't complete the fix for the Xilinx controller. - TLB shootdowns now only target the harts where they're necessary, instead of applying to all harts in the system. These patches have all been sitting on our linux-next branch for a while now. Due to time constraints this is all I feel comfortable submitting during the 4.16 merge window, hopefully we'll do better next time!" [ Note to self: "harts" is RISC-V speak for "hardware threads". I had to look that up. - Linus ] * tag 'riscv-for-linus-4.16-merge_window' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: riscv: inline set_pgdir into its only caller riscv: rename sptbr to satp riscv: don't read back satp in paging_init riscv: remove the unused current_pgdir function riscv: add ZONE_DMA32 RISC-V: Limit the scope of TLB shootdowns riscv: disable SUM in the exception handler riscv: remove redundant unlikely() riscv: remove unused __ARCH_HAVE_MMU define riscv/ftrace: Add basic support RISC-V: Remove mem_end command line processing RISC-V: Remove duplicate command-line parsing logic audit: Avoid build failures on systems without renameat
2018-02-02Merge tag 'clk-for-linus' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux Pull clk updates from Stephen Boyd: "The core framework has a handful of patches this time around, mostly due to the clk rate protection support added by Jerome Brunet. This feature will allow consumers to lock in a certain rate on the output of a clk so that things like audio playback don't hear pops when the clk frequency changes due to shared parent clks changing rates. Currently the clk API doesn't guarantee the rate of a clk stays at the rate you request after clk_set_rate() is called, so this new API will allow drivers to express that requirement. Beyond this, the core got some debugfs pretty printing patches and a couple minor non-critical fixes. Looking outside of the core framework diff we have some new driver additions and the removal of a legacy TI clk driver. Both of these hit high in the dirstat. Also, the removal of the asm-generic/clkdev.h file causes small one-liners in all the architecture Kbuild files. Overall, the driver diff seems to be the normal stuff that comes all the time to fix little problems here and there and to support new hardware. Summary: Core: - Clk rate protection - Symbolic clk flags in debugfs output - Clk registration enabled clks while doing bookkeeping updates New Drivers: - Spreadtrum SC9860 - HiSilicon hi3660 stub - Qualcomm A53 PLL, SPMI clkdiv, and MSM8916 APCS - Amlogic Meson-AXG - ASPEED BMC Removed Drivers: - TI OMAP 3xxx legacy clk (non-DT) support - asm*/clkdev.h got removed (not really a driver) Updates: - Renesas FDP1-0 module clock on R-Car M3-W - Renesas LVDS module clock on R-Car V3M - Misc fixes to pr_err() prints - Qualcomm MSM8916 audio fixes - Qualcomm IPQ8074 rounded out support for more peripherals - Qualcomm Alpha PLL variants - Divider code was using container_of() on bad pointers - Allwinner DE2 clks on H3 - Amlogic minor data fixes and dropping of CLK_IGNORE_UNUSED - Mediatek clk driver compile test support - AT91 PMC clk suspend/resume restoration support - PLL issues fixed on si5351 - Broadcom IProc PLL calculation updates - DVFS support for Armada mvebu CPU clks - Allwinner fixed post-divider support - TI clkctrl fixes and support for newer SoCs" * tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (125 commits) clk: aspeed: Handle inverse polarity of USB port 1 clock gate clk: aspeed: Fix return value check in aspeed_cc_init() clk: aspeed: Add reset controller clk: aspeed: Register gated clocks clk: aspeed: Add platform driver and register PLLs clk: aspeed: Register core clocks clk: Add clock driver for ASPEED BMC SoCs clk: mediatek: adjust dependency of reset.c to avoid unexpectedly being built clk: fix reentrancy of clk_enable() on UP systems clk: meson-axg: fix potential NULL dereference in axg_clkc_probe() clk: Simplify debugfs registration clk: Fix debugfs_create_*() usage clk: Show symbolic clock flags in debugfs clk: renesas: r8a7796: Add FDP clock clk: Move __clk_{get,put}() into private clk.h API clk: sunxi: Use CLK_IS_CRITICAL flag for critical clks clk: Improve flags doc for of_clk_detect_critical() arch: Remove clkdev.h asm-generic from Kbuild clk: sunxi-ng: a83t: Add M divider to TCON1 clock clk: Prepare to remove asm-generic/clkdev.h ...
2018-02-01Merge branch 'work.whack-a-mole' of ↵Linus Torvalds2-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull asm/uaccess.h whack-a-mole from Al Viro: "It's linux/uaccess.h, damnit... Oh, well - eventually they'll stop cropping up..." * 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: asm-prototypes.h: use linux/uaccess.h, not asm/uaccess.h riscv: use linux/uaccess.h, not asm/uaccess.h... ppc: for put_user() pull linux/uaccess.h, not asm/uaccess.h