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2017-12-11RISC-V: Remove unused CONFIG_HVC_RISCV_SBI codePalmer Dabbelt1-11/+0
This is code that probably should never have made it into the kernel in the first place: it depends on a driver that hadn't been reviewed yet. During the HVC_SBI_RISCV review process a better way of doing this was suggested, but that means this code is defunct. It's compile-time disabled in 4.15 because the driver isn't in, so I think it's safe to just remove this for now. CC: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-12-11RISC-V: Resurrect smp_mb__after_spinlock()Palmer Dabbelt1-0/+19
I removed this last week because of an incorrect comment: smp_mb__after_spinlock() is actually still used, and is necessary on RISC-V. It's been resurrected, with a comment that describes what it actually does this time. Thanks to Andrea for finding the bug! Fixes: 3343eb6806f3 ("RISC-V: Remove smb_mb__{before,after}_spinlock()") CC: Andrea Parri <parri.andrea@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-12-11RISC-V: Logical vs Bitwise typoDan Carpenter1-1/+1
In the current code, there is a ! logical NOT where a bitwise ~ NOT was intended. It means that we never return -EINVAL. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-12-05bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program typeHendrik Brueckner1-0/+1
Commit 0515e5999a466dfe ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type") introduced the bpf_perf_event_data structure which exports the pt_regs structure. This is OK for multiple architectures but fail for s390 and arm64 which do not export pt_regs. Programs using them, for example, the bpf selftest fail to compile on these architectures. For s390, exporting the pt_regs is not an option because s390 wants to allow changes to it. For arm64, there is a user_pt_regs structure that covers parts of the pt_regs structure for use by user space. To solve the broken uapi for s390 and arm64, introduce an abstract type for pt_regs and add an asm/bpf_perf_event.h file that concretes the type. An asm-generic header file covers the architectures that export pt_regs today. The arch-specific enablement for s390 and arm64 follows in separate commits. Reported-by: Thomas Richter <tmricht@linux.vnet.ibm.com> Fixes: 0515e5999a466dfe ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type") Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-01RISC-V: Fixes for clean allmodconfig buildPalmer Dabbelt12-21/+39
Olaf said: Here's a short series of patches that produces a working allmodconfig. Would be nice to see them go in so we can add build coverage. I've dropped patches 8 and 10 from the original set: * [PATCH 08/10] (RISC-V: Set __ARCH_WANT_RENAMEAT to pick up generic version) has a better fix that I've sent out for review, we don't want renameat. * [PATCH 10/10] (input: joystick: riscv has get_cycles) has already been taken into Dmitry Torokhov's tree.
2017-12-01RISC-V: __io_writes should respect the length argumentPalmer Dabbelt1-1/+1
2017-12-01RISC-V: User-Visible ChangesPalmer Dabbelt19-34/+392
This merge contains the user-visible, ABI-breaking changes that we want to make sure we have in Linux before our first release. Highlights include: * VDSO entries for clock_get/gettimeofday/getcpu have been added. These are simple syscalls now, but we want to let glibc use them from the start so we can make them faster later. * A VDSO entry for instruction cache flushing has been added so userspace can flush the instruction cache. * The VDSO symbol versions for __vdso_cmpxchg{32,64} have been removed, as those VDSO entries don't actually exist. Conflicts: arch/riscv/include/asm/tlbflush.h
2017-12-01RISC-V: __io_writes should respect the length argumentPalmer Dabbelt1-1/+1
Whoops -- I must have just been being an idiot again. Thanks to Segher for finding the bug :). CC: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: Clean up an unused includePalmer Dabbelt1-1/+0
We used to have some cmpxchg syscalls. They're no longer there, so we no longer need the include. CC: Christoph Hellwig <hch@infradead.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: Allow userspace to flush the instruction cacheAndrew Waterman8-0/+105
Despite RISC-V having a direct 'fence.i' instruction available to userspace (which we can't trap!), that's not actually viable when running on Linux because the kernel might schedule a process on another hart. There is no way for userspace to handle this without invoking the kernel (as it doesn't know the thread->hart mappings), so we've defined a RISC-V specific system call to flush the instruction cache. This patch adds both a system call and a VDSO entry. If possible, we'd like to avoid having the system call be considered part of the user-facing ABI and instead restrict that to the VDSO entry -- both just in general to avoid having additional user-visible ABI to maintain, and because we'd prefer that users just call the VDSO entry because there might be a better way to do this in the future (ie, one that doesn't require entering the kernel). Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: Flush I$ when making a dirty page executableAndrew Waterman8-30/+174
The RISC-V ISA allows for instruction caches that are not coherent WRT stores, even on a single hart. As a result, we need to explicitly flush the instruction cache whenever marking a dirty page as executable in order to preserve the correct system behavior. Local instruction caches aren't that scary (our implementations actually flush the cache, but RISC-V is defined to allow higher-performance implementations to exist), but RISC-V defines no way to perform an instruction cache shootdown. When explicitly asked to do so we can shoot down remote instruction caches via an IPI, but this is a bit on the slow side. Instead of requiring an IPI to all harts whenever marking a page as executable, we simply flush the currently running harts. In order to maintain correct behavior, we additionally mark every other hart as needing a deferred instruction cache which will be taken before anything runs on it. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: Add missing includeOlof Johansson1-0/+1
Fixes: include/asm-generic/mm_hooks.h:20:11: warning: 'struct vm_area_struct' declared inside parameter list will not be visible outside of this definition or declaration include/asm-generic/mm_hooks.h:19:38: warning: 'struct mm_struct' declared inside parameter list will not be visible outside of this definition or declaration Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: Use define for get_cycles like other architecturesOlof Johansson1-1/+2
Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: Provide stub of setup_profiling_timer()Olof Johansson1-0/+7
Fixes the following on allmodconfig build: profile.c:(.text+0x3e4): undefined reference to `setup_profiling_timer' Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: Export some expected symbols for modulesOlof Johansson3-0/+6
These are the ones needed by current allmodconfig, so add them instead of everything other architectures are exporting -- the rest can be added on demand later if needed. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: move empty_zero_page definition to C and export itOlof Johansson2-3/+3
Needed by some modules (exported by other architectures). Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: io.h: type fixes for warningsOlof Johansson2-8/+10
include <linux/types.h> for __iomem definition. Also, add volatile to iounmap() like other architectures have it to avoid "discarding volatile" warnings from some drivers. Finally, explicitly promote the base address for INB/OUTB functions to avoid some old legacy drivers complaining about int-to-ptr promotions. The drivers are unlikely to work but they're included in allmodconfig so the warnings are noisy. Fixes, among other warnings, these with allmodconfig: ../arch/riscv/include/asm/io.h:24:21: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token extern void __iomem *ioremap(phys_addr_t offset, unsigned long size); sound/pci/echoaudio/echoaudio.c: In function 'snd_echo_free': sound/pci/echoaudio/echoaudio.c:1879:10: warning: passing argument 1 of 'iounmap' discards 'volatile' qualifier from pointer target type [-Wdiscarded-qualifiers] Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: use RISCV_{INT,SHORT} instead of {INT,SHORT} for asm macrosOlof Johansson2-9/+9
INT and SHORT are used by some drivers that pull in the include files, so prefixing helps avoid namespace conflicts. Other constructs in the same file already uses this. Fixes, among others, these warnings with allmodconfig: ../sound/core/pcm_misc.c:43:0: warning: "INT" redefined #define INT __force int Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30RISC-V: use generic serial.hOlof Johansson1-0/+1
Fixes this from allmodconfig: drivers/tty/serial/earlycon.c:27:10: fatal error: asm/serial.h: No such file or directory Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28RISC-V: remove spin_unlock_wait()Palmer Dabbelt1-9/+0
This was removed from the other architectures in commit 952111d7db02 ("arch: Remove spin_unlock_wait() arch-specific definitions"). That landed between when we got upstream and when our patches were reviewed, so this is a followup patch. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28RISC-V: `sfence.vma` orderes the instruction cachePalmer Dabbelt1-1/+4
This is just a comment change, but it's one that bit me on the mailing list. It turns out that issuing a `sfence.vma` enforces instruction cache ordering in addition to TLB ordering. This isn't explicitly called out in the ISA manual, but Andrew will be making that more clear in a future revision. CC: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28RISC-V: Add READ_ONCE in arch_spin_is_locked()Palmer Dabbelt1-1/+1
This was just incorrect in the original version. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28RISC-V: __test_and_op_bit_ord should be strongly orderedPalmer Dabbelt1-1/+1
I mis-read the documentation. After looking at it again the documentation is actually as clear as it can be, it's just that I didn't actually read it in order and therefor did the wrong thing. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28RISC-V: Remove smb_mb__{before,after}_spinlock()Palmer Dabbelt1-8/+0
These are obselete. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28RISC-V: Remove __smp_bp__{before,after}_atomicPalmer Dabbelt1-15/+0
These duplicate the asm-generic definitions are therefor aren't useful. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28RISC-V: Comment on why {,cmp}xchg is ordered how it isPalmer Dabbelt1-2/+7
This is another memory model FIXME. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28RISC-V: Remove unused arguments from ATOMIC_OPPalmer Dabbelt1-47/+47
Our atomics are generated from a complicated series of preprocessor macros, each of which is slightly different from the last. When writing the macros I'd accidentally left some unused arguments floating around. This patch removes the unused macro arguments. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-11-27RISC-V: Add VDSO entries for clock_get/gettimeofday/getcpuAndrew Waterman6-1/+113
For now these are just placeholders that execute the syscall. We will later optimize them to avoid kernel crossings, but we'd like to have the VDSO entries from the first released kernel version to make the ABI simpler. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-27RISC-V: Remove __vdso_cmpxchg{32,64} symbol versionsPalmer Dabbelt1-2/+0
These were left over from an earlier version of the port. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-15Merge tag 'riscv-for-linus-4.15-arch-v9-premerge' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linuxLinus Torvalds102-0/+9776
Pull RISC-V architecture support from Palmer Dabbelt: "This contains the core RISC-V Linux port, which has been through nine rounds of review on various mailing lists. The port is not complete: there's some cleanup patches moving through the review process, a whole bunch of drivers that need some work, and a lot of feature additions that will be needed. The patches contained in this tag have been through nine rounds of review on the various mailing lists. I have some outstanding cleanup patches, but since there's been so much review on these patches I thought it would be best to submit them as-is and then submit explicit cleanup patches so everyone can review them. This first patch set is big enough that it's a bit of a pain to constantly rewrite, and it's caused a few headaches with various contributors. The port is definately a work in progress. While what's there builds and boots with 4.14, it's a bit hard to actually see anything happen because there are no device drivers yet. I maintain a staging branch that contains all the device drivers and cleanup that actually works, but those patches won't all be ready for a while. I'd like to get what we currently have into your tree so everyone can start working from a single base -- of particular importance is allowing the glibc upstreaming process to proceed so we can sort out any possibly lingering user-visible ABI problems we might have. Copied below is the ChangeLog that contains the history of this patch set: (v9) As per suggestions on our v8 patch set, I've split the core architecture code out from our drivers and would like to submit this patch set to be included into linux-next, with the goal being to be merged in during the next merge window. This patch set is based on 4.14-rc2, but if it's better to have it based on something else then I can change it around. This patch set contains just the core arch code for RISC-V, so while it builds an nominally boots, you can't print or take an interrupt so it's not that useful. If you're looking to actually boot a system it would probably be better to use the full patch set listed below. We've collected a handful of tags from reviewers, and the remainder of the patch set only got minimal feedback last time. Here's what changed: - We now use the device tree to initialize the timer driver so it's less tighly coupled with the arch port. - I cleaned up the defconfigs -- there's actually now just one, and it's empty. For now I think we're OK with what the kernel sets as defaults, but I anticipate we'll begin to expand this as people start to use the port more. - The VDSO symbols version is sane. - We WFI while spinning in the boot loop. - A handful of comments have been added. While there are still a handful of FIXMEs in this patch set, we've started to get enough interest from various users and contributors that maintaining an out of tree patch set is starting to become a big burden. Hopefully the patches are good enough to merge now, which will at least get everyone working in a more reasonable manner as we clean up the remaining issues. (v8) I know it may not be the ideal time to submit a patch set right now, as it's the middle of the merge window, but things have calmed down quite a bit in the last month so I thought it would be good to get everyone on the same page. There's been a handful of changes since the last patch set, but most of them are fairly minor: - We changed PAGE_OFFSET to allowing mapping more physical memory on 64-bit systems. This is user configurable, as it triggers a different code model that generates slightly less efficient code. - The device tree binding documentation is back, I'd managed to lose it at some point. - We now pass the atomic64 test suite - The SBI timer driver has been refactored. (v7) It's been a while since my last patch set, but the changes han been fairly minimal: - The PCI cleanup patches have been dropped, we'll do them as a separate patch set later. - We've the Kconfig entries from CONFIG_ISA_* to CONFIG_RISCV_ISA_*, to make grep easier. - There have been a handful of memory model related tweaks in I/O land, particularly relating the PCI and the upcoming platform specification. There are significant comments in the relevant files. This is still a WIP, but I think we're close to getting as good as we're going to get until we end up with some more specifications. (v6) As it's been only a day since the v5 patch set, the changes are pretty minimal: - The patch set is now based on linux-next/master, which I believe is a better base now that we're getting closer to upstream. - EARLY_PRINTK is no longer an option. Since the SBI console is reasonable, there's no penalty to enabling it (and thus no benefit to disabling it). - The mmap syscalls were refactored a bit. (v5) Things have really started to calm down, so this is fairly similar to the v4 patch set. The most interesting changes include: - We've moved back to a single patch set. - SMP support has been fixed, I was accidentally running on a non-SMP configuration. There were various mistakes all over the tree as a result of this. - The cmpxchg syscalls have been removed, as they were deemed a bad idea. As a result, RISC-V Linux systems mandate the A extension. The corresponding Kconfig entry to enable builds on non-A systems has been removed. - A few more atomic fixes: mostly fence changes, but those resulted in a handful of additional macros that were no longer necessary. - riscv_early_sie has been removed. (v4) There have only been a few changes since the v3 patch set: - The cmpxchg64 syscall is no longer enabled on 32-bit systems. It's not possible to provide this on SMP systems, and it's not necessary as glibc knows not to call it. - We provide a ELF_HWCAP so users can determine the ISA of the machine the kernel is running on. - The multi-line comments are in a better form. - There were a handful of headers that could be replaced with the asm-generic versions, and a few unnecessary definitions. - We no longer use printk, but instead use pr_*. - A few Kconfig and defconfig entries have been cleaned up. (v3) A highlight of the changes since the v2 patch set includes: - We've split out all our drivers into separate patch sets, which I've already sent out to the relevant maintainers. I haven't included those patches in this patch set, but some of them are necessary to build our port. - The patch set is now split up differently: rather than being split per directory it is split per topic. Hopefully this will make it easier to review the port on the mailing list. The split is a bit rough, so you probably still want to look at the patch set as a whole. - atomic.h has been completely rewritten and is hopefully now correct. I've attempted to sanitize the various other memory model related code as well, and I think it should all be sane now aside from a handful of FIXMEs commented in the code. - We've changed the cmpexchg syscall to always exist and to not be multiplexed. There is also a VDSO entry for compare and exchange, which allows kernels with the A extension to execute user code without the A extension reasonably fast. - Our user-visible register state now contains enough space for the Q extension for 128-bit floating point, as well as a few words to allow extensibility to future ISA extensions like the eventual V extension for vectors. - A handful of driver cleanups, but these have been split into separate patch sets now so I won't duplicate them here. (v2) A highlight of the changes since the v1 patch set includes: - We've split out our drivers into the right places, which means now there's a lot more patches. I'll be submitting these patches to various subsystem maintainers and including them in any future RISC-V patch sets until they've been merged. - The SBI console driver has been completely rewritten to use the HVC helpers and is now significantly smaller. - We've begun to use weaker barriers as opposed to just the big "fence". There's still some work to do here, specifically: - We need fences in the relaxed MMIO functions. - The non-relaxed MMIO functions are missing R/W bits on their fences. - Many AMOs need the aq and rl bits set. - We now have thread_info in task_struct. As a result, sscratch now contains TP instead of SP. This was necessary because thread_info is no longer on the stack. - A few shared routines have been added that we use instead of creating another arch copy" Reviewed-by: Arnd Bergmann <arnd@arndb.de> * tag 'riscv-for-linus-4.15-arch-v9-premerge' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux: RISC-V: Build Infrastructure RISC-V: User-facing API RISC-V: Paging and MMU RISC-V: Device, timer, IRQs, and the SBI RISC-V: Task implementation RISC-V: ELF and module implementation RISC-V: Generic library routines and assembly RISC-V: Atomic and Locking Code RISC-V: Init and Halt Code dt-bindings: RISC-V CPU Bindings lib: Add shared copies of some GCC library routines MAINTAINERS: Add RISC-V
2017-09-26RISC-V: Build InfrastructurePalmer Dabbelt9-0/+579
This patch contains all the build infrastructure that actually enables the RISC-V port. This includes Makefiles, linker scripts, and Kconfig files. It also contains the only top-level change, which adds RISC-V to the list of architectures that need a sed run to produce the ARCH variable when building locally. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26RISC-V: User-facing APIPalmer Dabbelt27-0/+1687
This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26RISC-V: Paging and MMUPalmer Dabbelt8-0/+1192
This patch contains code to manage the RISC-V MMU, including definitions of the page tables and the page walking code. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26RISC-V: Device, timer, IRQs, and the SBIPalmer Dabbelt9-0/+566
This patch contains code that interfaces with devices that are mandated by the RISC-V supervisor specification and that don't have explicit drivers anywhere else in the tree. This includes the staticly defined interrupts, the CSR-mapped timer, and virtualized SBI devices. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26RISC-V: Task implementationPalmer Dabbelt9-0/+1243
This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26RISC-V: ELF and module implementationPalmer Dabbelt4-0/+187
This patch contains the code that interfaces with ELF objects on RISC-V systems, the vast majority of which is present to load kernel modules. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26RISC-V: Generic library routines and assemblyPalmer Dabbelt11-0/+1389
This patch contains code that is more specific to the RISC-V ISA than it is to Linux. It contains string and math operations, C wrappers for various assembly instructions, stack walking code, and uaccess. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26RISC-V: Atomic and Locking CodePalmer Dabbelt10-0/+1423
This contains all the code that directly interfaces with the RISC-V memory model. While this code corforms to the current RISC-V ISA specifications (user 2.2 and priv 1.10), the memory model is somewhat underspecified in those documents. There is a working group that hopes to produce a formal memory model by the end of the year, but my understanding is that the basic definitions we're relying on here won't change significantly. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26RISC-V: Init and Halt CodePalmer Dabbelt15-0/+1524
This contains the various __init C functions, the initial assembly kernel entry point, and the code to reset the system. When a file was init-related this patch contains the entire file. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>