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path: root/arch/riscv/kernel/smp.c
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2019-03-04RISC-V: Fixmap support and MM cleanupsPalmer Dabbelt
This patchset does: 1. Moves MM related code from kernel/setup.c to mm/init.c 2. Implements compile-time fixed mappings Using fixed mappings, we get earlyprints even without SBI calls. For example, we can now use kernel parameter "earlycon=uart8250,mmio,0x10000000" to get early prints on QEMU virt machine without using SBI calls. The patchset is tested on QEMU virt machine. Palmer: It looks like some of the code movement here conflicted with the patches to move hartid handling around. As far as I can tell the only changed code was in smp_setup_processor_id(), and I've kept the one in smp.c.
2019-03-04RISC-V: Allow hartid-to-cpuid function to fail.Atish Patra
It is perfectly okay to call riscv_hartid_to_cpuid for a hartid that is not mapped with an CPU id. It can happen if the calling functions retrieves the hartid from DT. However, that hartid was never brought online by the firmware or kernel for any reasons. No need to BUG() in the above case. A negative error return is sufficient and the calling function should check for the return value always. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-03-04RISC-V: Move cpuid to hartid mapping to SMP.Atish Patra
Currently, logical CPU id to physical hartid mapping is defined for both smp and non-smp configurations. This is not required as we need this only for smp configuration. The mapping function can define directly boot_cpu_hartid for non-smp use case. The reverse mapping function i.e. hartid to cpuid can be called for any valid but not booted harts. So it should return default cpu 0 only if it is a boot hartid. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-07riscv: don't stop itself in smp_send_stopAndreas Schwab
Add IPI_CPU_STOP message and use it in smp_send_stop to stop other cpus, but not itself. Mark cpu offline on reception of IPI_CPU_STOP. Signed-off-by: Andreas Schwab <schwab@suse.de> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22RISC-V: Show IPI statsAnup Patel
This patch provides arch_show_interrupts() implementation to show IPI stats via /proc/interrupts. Now the contents of /proc/interrupts" will look like below: CPU0 CPU1 CPU2 CPU3 8: 17 7 6 14 SiFive PLIC 8 virtio0 10: 10 10 9 11 SiFive PLIC 10 ttyS0 IPI0: 170 673 251 79 Rescheduling interrupts IPI1: 1 12 27 1 Function call interrupts Signed-off-by: Anup Patel <anup@brainfault.org> [Atish - Fixed checkpatch errors] Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Changes since v2: - Remove use of IPI_CALL_WAKEUP because it's being removed Changes since v1: - Add stub inline show_ipi_stats() function for !CONFIG_SMP - Make ipi_names[] dynamically sized at compile time - Minor beautification of ipi_names[] using tabs Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22RISC-V: Use Linux logical CPU number instead of hartidAtish Patra
Setup the cpu_logical_map during boot. Moreover, every SBI call and PLIC context are based on the physical hartid. Use the logical CPU to hartid mapping to pass correct hartid to respective functions. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22RISC-V: Add logical CPU indexing for RISC-VAtish Patra
Currently, both Linux CPU id and hart id are same. This is not recommended as it will lead to discontinuous CPU indexing in Linux. Moreover, kdump kernel will run from CPU0 which would be absent if we follow existing scheme. Implement a logical mapping between Linux CPU id and hart id to decouple these two. Always mark the boot processor as CPU0 and all other CPUs get the logical CPU id based on their booting order. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13RISC-V: simplify software interrupt / IPI codeChristoph Hellwig
Rename handle_ipi to riscv_software_interrupt, drop the unused return value and move the prototype to irq.h together with riscv_timer_interupt. This allows simplifying the upcoming interrupt handling support. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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: 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>
2017-09-26RISC-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>