summaryrefslogtreecommitdiff
path: root/arch/riscv/kernel
AgeCommit message (Collapse)Author
2018-02-07Merge tag 'riscv-for-linus-4.16-merge_window' of ↵Linus Torvalds
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
2018-01-31Merge branch 'work.whack-a-mole' of ↵Linus Torvalds
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
2018-01-30riscv: rename sptbr to satpChristoph Hellwig
satp is the name used by the current privileged spec 1.10, use it instead of the old name. The most recent release binutils release (2.29) doesn't know about the satp name yet, so stick to the name from the previous privileged ISA release and comment on the fact. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30riscv: add ZONE_DMA32Christoph Hellwig
This patch allows devices that require memory that can be addressed using 32-bit addresses to work easily on RISC-V systems. The newly improved dma-direct ops will tap into this pool automatically for 32-bit addressing. Based on an earlier patch from Wesley W. Terpstra. CC: Wesley W. Terpstra <terpstra@sifive.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30riscv: disable SUM in the exception handlerChristoph Hellwig
The SUM bit is enabled at the beginning of the copy_{to,from}_user and {get,put}_user routines, and cleared before they return. But these user copy helper can be interrupted by exceptions, in which case the SUM bit will remain set, which leads to elevated privileges for the code running in exception context, as that can now access userspace address space unconditionally. This frequently happens when the user copy routines access freshly allocated user memory that hasn't been faulted in, and a pagefault needs to be taken before the user copy routines can continue. Fix this by unconditionally clearing SUM when the exception handler is called - the restore code will automatically restore it based on the saved value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30riscv: remove redundant unlikely()Tobias Klauser
IS_ERR_VALUE() already implies unlikely(), so it can be omitted. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30riscv/ftrace: Add basic supportAlan Kao
This patch contains basic ftrace support for RV64I platform. Specifically, function tracer (HAVE_FUNCTION_TRACER), function graph tracer (HAVE_FUNCTION_GRAPH_TRACER), and a frame pointer test (HAVE_FUNCTION_GRAPH_FP_TEST) are implemented following the instructions in Documentation/trace/ftrace-design.txt. Note that the functions in both ftrace.c and setup.c should not be hooked with the compiler's -pg option: to prevent infinite self- referencing for the former, and to ignore early setup stuff for the latter. Signed-off-by: Alan Kao <alankao@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30RISC-V: Remove mem_end command line processingPalmer Dabbelt
This is just some cruft left over from before the port converted to device tree. The right way to handle memory regions is to specify them in the device tree, which BBL (our simplest bootloader) is already capable of doing. This patch simply removes the cruft. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30RISC-V: Remove duplicate command-line parsing logicMichael Clark
builtin_cmdline handling is present in drivers/of/fdt.c so the duplicate logic in arch/riscv/setup.c results in duplication of the builtin command line. e.g. CONFIG_CMDLINE="root=/dev/vda ro" gets appended twice and gives "root=/dev/vda ro root=/dev/vda ro" Before this patch: [ 0.000000] Kernel command line: root=/dev/vda ro root=/dev/vda ro After this patch: [ 0.000000] Kernel command line: root=/dev/vda ro Signed-off-by: Michael Clark <mjc@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-07riscv: rename SR_* constants to match the specChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-07RISC-V: Make __NR_riscv_flush_icache visible to userspacePalmer Dabbelt
We were hoping to avoid making this visible to userspace, but it looks like we're going to have to because QEMU's user-mode emulation doesn't want to emulate a vDSO. Having vDSO-only system calls was a bit unothodox anyway, so I think in this case it's OK to just make the actual system call number public. This patch simply moves the definition of __NR_riscv_flush_icache availiable to userspace, which results in the deletion of the now empty vdso-syscalls.h. Changes since v1: * I've moved the definition into uapi/asm/syscalls.h rathen than uapi/asm/unistd.h. This allows me to keep asm/unistd.h, so we can keep the syscall table macros sane. * As a side effect of the above, this no longer disables all system calls on RISC-V. Whoops! Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-12-11RISC-V: Remove unused CONFIG_HVC_RISCV_SBI codePalmer Dabbelt
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: Logical vs Bitwise typoDan Carpenter
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>
2017-12-04riscv: use linux/uaccess.h, not asm/uaccess.h...Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-12-01RISC-V: Fixes for clean allmodconfig buildPalmer Dabbelt
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.
2017-11-30RISC-V: Clean up an unused includePalmer Dabbelt
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 Waterman
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 Waterman
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: Provide stub of setup_profiling_timer()Olof Johansson
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 Johansson
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 Johansson
Needed by some modules (exported by other architectures). Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-27RISC-V: Add VDSO entries for clock_get/gettimeofday/getcpuAndrew Waterman
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 Dabbelt
These were left over from an earlier version of the port. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-09-26RISC-V: Build InfrastructurePalmer Dabbelt
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 Dabbelt
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: Task implementationPalmer Dabbelt
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: Generic library routines and assemblyPalmer Dabbelt
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: Init and Halt CodePalmer Dabbelt
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>