#
dded618c |
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30-Oct-2023 |
Yang Li <yang.lee@linux.alibaba.com> |
RISC-V: Remove duplicated include in smpboot.c ./arch/riscv/kernel/smpboot.c: asm/cpufeature.h is included more than once. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=7086 Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Link: https://lore.kernel.org/r/20231031004018.45074-1-yang.lee@linux.alibaba.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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71261072 |
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04-Mar-2024 |
Thomas Gleixner <tglx@linutronix.de> |
smp: Consolidate smp_prepare_boot_cpu() There is no point in having seven architectures implementing the same empty stub. Provide a weak function in the init code and remove the stubs. This also allows to utilize the function on UP which is required to sanitize the per CPU handling on X86 UP. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240304005104.567671691@linutronix.de
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#
62ff2622 |
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21-Nov-2023 |
Samuel Holland <samuel.holland@sifive.com> |
riscv: Use the same CPU operations for all CPUs RISC-V provides no binding (ACPI or DT) to describe per-cpu start/stop operations, so cpu_set_ops() will always detect the same operations for every CPU. Replace the cpu_ops array with a single pointer to save space and reduce boot time. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20231121234736.3489608-4-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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79093f3e |
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21-Nov-2023 |
Samuel Holland <samuel.holland@sifive.com> |
riscv: Remove unused members from struct cpu_operations name is not used anywhere at all. cpu_prepare and cpu_disable do nothing and always return 0 if implemented. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20231121234736.3489608-3-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
a4166aec |
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21-Nov-2023 |
Samuel Holland <samuel.holland@sifive.com> |
riscv: Deduplicate code in setup_smp() Both the ACPI and DT implementations contain some of the same code. Move it to the calling function so it is not duplicated. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20231121234736.3489608-2-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
55e0bf49 |
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06-Nov-2023 |
Evan Green <evan@rivosinc.com> |
RISC-V: Probe misaligned access speed in parallel Probing for misaligned access speed takes about 0.06 seconds. On a system with 64 cores, doing this in smp_callin() means it's done serially, extending boot time by 3.8 seconds. That's a lot of boot time. Instead of measuring each CPU serially, let's do the measurements on all CPUs in parallel. If we disable preemption on all CPUs, the jiffies stop ticking, so we can do this in stages of 1) everybody except core 0, then 2) core 0. The allocations are all done outside of on_each_cpu() to avoid calling alloc_pages() with interrupts disabled. For hotplugged CPUs that come in after the boot time measurement, register CPU hotplug callbacks, and do the measurement there. Interrupts are enabled in those callbacks, so they're fine to do alloc_pages() in. Reported-by: Jisheng Zhang <jszhang@kernel.org> Closes: https://lore.kernel.org/all/mhng-9359993d-6872-4134-83ce-c97debe1cf9a@palmer-ri-x1c9/T/#mae9b8f40016f9df428829d33360144dc5026bcbf Fixes: 584ea6564bca ("RISC-V: Probe for unaligned access speed") Signed-off-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20231106225855.3121724-1-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
71c54b3d |
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04-Oct-2023 |
Clément Léger <cleger@rivosinc.com> |
riscv: report misaligned accesses emulation to hwprobe hwprobe provides a way to report if misaligned access are emulated. In order to correctly populate that feature, we can check if it actually traps when doing a misaligned access. This can be checked using an exception table entry which will actually be used when a misaligned access is done from kernel mode. Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-8-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
43c16d51 |
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18-Sep-2023 |
Andrew Jones <ajones@ventanamicro.com> |
RISC-V: Enable cbo.zero in usermode When Zicboz is present, enable its instruction (cbo.zero) in usermode by setting its respective senvcfg bit. We don't bother trying to set this bit per-task, which would also require an interface for tasks to request enabling and/or disabling. Instead, permanently set the bit for each hart which has the extension when bringing it online. This patch also introduces riscv_cpu_has_extension_[un]likely() functions to check a specific hart's ISA bitmap for extensions. Prior to checking the specific hart's bitmap in these functions we try the bitmap which represents the LCD of extensions, but only when we know it will use its optimized, alternatives path by gating its call on CONFIG_RISCV_ALTERNATIVE. When alternatives are used, the compiler ensures that the invocation of the LCD search becomes a constant true or false. When it's true, even the new functions will completely vanish from their callsites. OTOH, when the LCD check is false, we need to do a search of the hart's ISA bitmap. Had we also checked the LCD bitmap without the use of alternatives, then we would have ended up with two bitmap searches instead of one. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230918131518.56803-10-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
f2d14bc4 |
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18-Aug-2023 |
Evan Green <evan@rivosinc.com> |
RISC-V: alternative: Remove feature_probe_func Now that we're testing unaligned memory copy and making that determination generically, there are no more users of the vendor feature_probe_func(). While I think it's probably going to need to come back, there are no users right now, so let's remove it until it's needed. Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230818194136.4084400-3-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
584ea656 |
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18-Aug-2023 |
Evan Green <evan@rivosinc.com> |
RISC-V: Probe for unaligned access speed Rather than deferring unaligned access speed determinations to a vendor function, let's probe them and find out how fast they are. If we determine that an unaligned word access is faster than N byte accesses, mark the hardware's unaligned access as "fast". Otherwise, we mark accesses as slow. The algorithm itself runs for a fixed amount of jiffies. Within each iteration it attempts to time a single loop, and then keeps only the best (fastest) loop it saw. This algorithm was found to have lower variance from run to run than my first attempt, which counted the total number of iterations that could be done in that fixed amount of jiffies. By taking only the best iteration in the loop, assuming at least one loop wasn't perturbed by an interrupt, we eliminate the effects of interrupts and other "warm up" factors like branch prediction. The only downside is it depends on having an rdtime granular and accurate enough to measure a single copy. If we ever manage to complete a loop in 0 rdtime ticks, we leave the unaligned setting at UNKNOWN. There is a slight change in user-visible behavior here. Previously, all boards except the THead C906 reported misaligned access speed of UNKNOWN. C906 reported FAST. With this change, since we're now measuring misaligned access speed on each hart, all RISC-V systems will have this key set as either FAST or SLOW. Currently, we don't have a way to confidently measure the difference between SLOW and EMULATED, so we label anything not fast as SLOW. This will mislabel some systems that are actually EMULATED as SLOW. When we get support for delegating misaligned access traps to the kernel (as opposed to the firmware quietly handling it), we can explicitly test in Linux to see if unaligned accesses trap. Those systems will start to report EMULATED, though older (today's) systems without that new SBI mechanism will continue to report SLOW. I've updated the documentation for those hwprobe values to reflect this, specifically: SLOW may or may not be emulated by software, and FAST represents means being faster than equivalent byte accesses. The change in documentation is accurate with respect to both the former and current behavior. Signed-off-by: Evan Green <evan@rivosinc.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230818194136.4084400-2-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
6259f344 |
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03-Jul-2023 |
Marc Zyngier <maz@kernel.org> |
risc-v: Fix order of IPI enablement vs RCU startup Conor reports that risc-v tries to enable IPIs before telling the core code to enable RCU. With the introduction of the mapple tree as a backing store for the irq descriptors, this results in a very shouty boot sequence, as RCU is legitimately upset. Restore some sanity by moving the risc_ipi_enable() call after notify_cpu_starting(), which explicitly enables RCU on the calling CPU. Fixes: 832f15f42646 ("RISC-V: Treat IPIs as normal Linux IRQs") Reported-by: Conor Dooley <conor@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230703-dupe-frying-79ae2ccf94eb@spud Cc: Anup Patel <apatel@ventanamicro.com> Cc: Palmer Dabbelt <palmer@rivosinc.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230703183126.1567625-1-maz@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
2ac87434 |
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07-Jun-2023 |
Conor Dooley <conor.dooley@microchip.com> |
RISC-V: split early & late of_node to hartid mapping Some back and forth with Drew [1] about riscv_fill_hwcap() resulted in the realisation that it is not very useful to parse the DT & perform validation of riscv,isa every time we would like to get the id for a hart. Although it is no longer called in riscv_fill_hwcap(), riscv_of_processor_hartid() is called in several other places. Notably in setup_smp() it forms part of the logic for filling the mask of possible CPUs. Since a possible CPU must have passed this basic validation of riscv,isa, a repeat validation is not required. Rename riscv_of_processor_id() to riscv_early_of_processor_id(), which will be called from setup_smp() & introduce a new riscv_of_processor_id() which makes use of the pre-populated mask of possible cpus. Link: https://lore.kernel.org/linux-riscv/xvdswl3iyikwvamny7ikrxo2ncuixshtg3f6uucjahpe3xpc5c@ud4cz4fkg5dj/ [1] Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Sunil V L <sunilvl@ventanamicro.com> Link: https://lore.kernel.org/r/20230607-glade-pastel-d8cbd9d9f3c6@spud Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
7017858e |
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05-Jun-2023 |
Greentime Hu <greentime.hu@sifive.com> |
riscv: Introduce riscv_v_vsize to record size of Vector context This patch is used to detect the size of CPU vector registers and use riscv_v_vsize to save the size of all the vector registers. It assumes all harts has the same capabilities in a SMP system. If a core detects VLENB that is different from the boot core, then it warns and turns off V support for user space. Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-9-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
ce92546c |
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14-May-2023 |
Sunil V L <sunilvl@ventanamicro.com> |
RISC-V: smpboot: Add ACPI support in setup_smp() Enable SMP boot on ACPI based platforms by using the RINTC structures in the MADT table. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20230515054928.2079268-13-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
61946127 |
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14-May-2023 |
Sunil V L <sunilvl@ventanamicro.com> |
RISC-V: smpboot: Create wrapper setup_smp() setup_smp() currently assumes DT-based platforms. To enable ACPI, first make this a wrapper function and move existing code to a separate DT-specific function. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230515054928.2079268-12-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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62a31d6e |
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07-Apr-2023 |
Evan Green <evan@rivosinc.com> |
RISC-V: hwprobe: Support probing of misaligned access performance This allows userspace to select various routines to use based on the performance of misaligned access on the target hardware. Rather than adding DT bindings, this change taps into the alternatives mechanism used to probe CPU errata. Add a new function pointer alongside the vendor-specific errata_patch_func() that probes for desirable errata (otherwise known as "features"). Unlike the errata_patch_func(), this function is called on each CPU as it comes up, so it can save feature information per-CPU. The T-head C906 has fast unaligned access, both as defined by GCC [1], and in performing a basic benchmark, which determined that byte copies are >50% slower than a misaligned word copy of the same data size (source for this test at [2]): bytecopy size f000 count 50000 offset 0 took 31664899 us wordcopy size f000 count 50000 offset 0 took 5180919 us wordcopy size f000 count 50000 offset 1 took 13416949 us [1] https://github.com/gcc-mirror/gcc/blob/master/gcc/config/riscv/riscv.cc#L353 [2] https://pastebin.com/EPXvDHSW Co-developed-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com> Link: https://lore.kernel.org/r/20230407231103.2622178-5-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
832f15f4 |
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27-Mar-2023 |
Anup Patel <apatel@ventanamicro.com> |
RISC-V: Treat IPIs as normal Linux IRQs Currently, the RISC-V kernel provides arch specific hooks (i.e. struct riscv_ipi_ops) to register IPI handling methods. The stats gathering of IPIs is also arch specific in the RISC-V kernel. Other architectures (such as ARM, ARM64, and MIPS) have moved away from custom arch specific IPI handling methods. Currently, these architectures have Linux irqchip drivers providing a range of Linux IRQ numbers to be used as IPIs and IPI triggering is done using generic IPI APIs. This approach allows architectures to treat IPIs as normal Linux IRQs and IPI stats gathering is done by the generic Linux IRQ subsystem. We extend the RISC-V IPI handling as-per above approach so that arch specific IPI handling methods (struct riscv_ipi_ops) can be removed and the IPI handling is done through the Linux IRQ subsystem. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230328035223.1480939-4-apatel@ventanamicro.com
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#
c1d61058 |
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04-Jan-2023 |
Ley Foon Tan <leyfoon.tan@starfivetech.com> |
riscv: Move call to init_cpu_topology() to later initialization stage If "capacity-dmips-mhz" is present in a CPU DT node, topology_parse_cpu_capacity() will fail to allocate memory. arm64, with which this code path is shared, does not call topology_parse_cpu_capacity() until later in boot where memory allocation is available. While "capacity-dmips-mhz" is not yet a valid property on RISC-V, invalid properties should be ignored rather than cause issues. Move init_cpu_topology(), which calls topology_parse_cpu_capacity(), to a later initialization stage, to match arm64. As a side effect of this change, RISC-V is "protected" from changes to core topology code that would work on arm64 where memory allocation is safe but on RISC-V isn't. Fixes: 03f11f03dbfe ("RISC-V: Parse cpu topology during boot.") Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Ley Foon Tan <leyfoon.tan@starfivetech.com> Link: https://lore.kernel.org/r/20230105033705.3946130-1-leyfoon.tan@starfivetech.com [Palmer: use Conor's commit text] Link: https://lore.kernel.org/linux-riscv/20230104183033.755668-1-pierre.gondois@arm.com/T/#me592d4c8b9508642954839f0077288a353b0b9b2 Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
fbd92809 |
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15-Jul-2022 |
Conor Dooley <conor.dooley@microchip.com> |
riscv: topology: fix default topology reporting RISC-V has no sane defaults to fall back on where there is no cpu-map in the devicetree. Without sane defaults, the package, core and thread IDs are all set to -1. This causes user-visible inaccuracies for tools like hwloc/lstopo which rely on the sysfs cpu topology files to detect a system's topology. On a PolarFire SoC, which should have 4 harts with a thread each, lstopo currently reports: Machine (793MB total) Package L#0 NUMANode L#0 (P#0 793MB) Core L#0 L1d L#0 (32KB) + L1i L#0 (32KB) + PU L#0 (P#0) L1d L#1 (32KB) + L1i L#1 (32KB) + PU L#1 (P#1) L1d L#2 (32KB) + L1i L#2 (32KB) + PU L#2 (P#2) L1d L#3 (32KB) + L1i L#3 (32KB) + PU L#3 (P#3) Adding calls to store_cpu_topology() in {boot,smp} hart bringup code results in the correct topolgy being reported: Machine (793MB total) Package L#0 NUMANode L#0 (P#0 793MB) L1d L#0 (32KB) + L1i L#0 (32KB) + Core L#0 + PU L#0 (P#0) L1d L#1 (32KB) + L1i L#1 (32KB) + Core L#1 + PU L#1 (P#1) L1d L#2 (32KB) + L1i L#2 (32KB) + Core L#2 + PU L#2 (P#2) L1d L#3 (32KB) + L1i L#3 (32KB) + Core L#3 + PU L#3 (P#3) CC: stable@vger.kernel.org # 456797da792f: arm64: topology: move store_cpu_topology() to shared code Fixes: 03f11f03dbfe ("RISC-V: Parse cpu topology during boot.") Reported-by: Brice Goglin <Brice.Goglin@inria.fr> Link: https://github.com/open-mpi/hwloc/issues/536 Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
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ad635e72 |
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26-May-2022 |
Sunil V L <sunilvl@ventanamicro.com> |
riscv: cpu: Add 64bit hartid support on RV64 The hartid can be a 64bit value on RV64 platforms. Add support for 64bit hartid in riscv_of_processor_hartid() and update its callers. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20220527051743.2829940-5-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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ffb0b0af |
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11-May-2022 |
Heiko Stuebner <heiko@sntech.de> |
riscv: move boot alternatives to after fill_hwcap Move the application of boot alternatives to after the hw-capabilities are populated. This allows to check for available extensions when determining which alternatives to apply and also makes it actually work if CONFIG_SMP is disabled for whatever reason. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220511192921.2223629-8-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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e64f737a |
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11-May-2022 |
Heiko Stuebner <heiko@sntech.de> |
riscv: integrate alternatives better into the main architecture Right now the alternatives need to be explicitly enabled and erratas are limited to SiFive ones. We want to use alternatives not only for patching soc erratas, but in the future also for handling different behaviour depending on the existence of future extensions. So move the core alternatives over to the kernel subdirectory and move the CONFIG_RISCV_ALTERNATIVE to be a hidden symbol which we expect relevant erratas and extensions to just select if needed. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu> Link: https://lore.kernel.org/r/20220511192921.2223629-2-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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26fb751c |
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20-Jan-2022 |
Atish Patra <atishp@rivosinc.com> |
RISC-V: Do not use cpumask data structure for hartid bitmap Currently, SBI APIs accept a hartmask that is generated from struct cpumask. Cpumask data structure can hold upto NR_CPUs value. Thus, it is not the correct data structure for hartids as it can be higher than NR_CPUs for platforms with sparse or discontguous hartids. Remove all association between hartid mask and struct cpumask. Reviewed-by: Anup Patel <anup@brainfault.org> (For Linux RISC-V changes) Acked-by: Anup Patel <anup@brainfault.org> (For KVM RISC-V changes) Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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#
f1a0a376 |
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12-May-2021 |
Valentin Schneider <valentin.schneider@arm.com> |
sched/core: Initialize the idle task with preemption disabled As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
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#
6f4eea90 |
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22-Mar-2021 |
Vincent Chen <vincent.chen@sifive.com> |
riscv: Introduce alternative mechanism to apply errata solution Introduce the "alternative" mechanism from ARM64 and x86 to apply the CPU vendors' errata solution at runtime. The main purpose of this patch is to provide a framework. Therefore, the implementation is quite basic for now so that some scenarios could not use this schemei, such as patching code to a module, relocating the patching code and heterogeneous CPU topology. Users could use the macro ALTERNATIVE to apply an errata to the existing code flow. In the macro ALTERNATIVE, users need to specify the manufacturer information(vendorid, archid, and impid) for this errata. Therefore, kernel will know this errata is suitable for which CPU core. During the booting procedure, kernel will select the errata required by the CPU core and then patch it. It means that the kernel only applies the errata to the specified CPU core. In this case, the vendor's errata does not affect each other at runtime. The above patching procedure only occurs during the booting phase, so we only take the overhead of the "alternative" mechanism once. This "alternative" mechanism is enabled by default to ensure that all required errata will be applied. However, users can disable this feature by the Kconfig "CONFIG_RISCV_ERRATA_ALTERNATIVE". Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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4f0e8eef |
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18-Nov-2020 |
Atish Patra <atish.patra@wdc.com> |
riscv: Add numa support for riscv64 platform Use the generic numa implementation to add NUMA support for RISC-V. This is based on Greentime's patch[1] but modified to use generic NUMA implementation and few more fixes. [1] https://lkml.org/lkml/2020/1/10/233 Co-developed-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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2bc3fc87 |
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17-Aug-2020 |
Anup Patel <anup.patel@wdc.com> |
RISC-V: Remove CLINT related code from timer and arch Right now the RISC-V timer driver is convoluted to support: 1. Linux RISC-V S-mode (with MMU) where it will use TIME CSR for clocksource and SBI timer calls for clockevent device. 2. Linux RISC-V M-mode (without MMU) where it will use CLINT MMIO counter register for clocksource and CLINT MMIO compare register for clockevent device. We now have a separate CLINT timer driver which also provide CLINT based IPI operations so let's remove CLINT MMIO related code from arch/riscv directory and RISC-V timer driver. Signed-off-by: Anup Patel <anup.patel@wdc.com> Tested-by: Emil Renner Berhing <kernel@esmil.dk> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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cc7f3f72 |
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17-Aug-2020 |
Anup Patel <anup.patel@wdc.com> |
RISC-V: Add mechanism to provide custom IPI operations We add mechanism to set custom IPI operations so that CLINT driver from drivers directory can provide custom IPI operations. Signed-off-by: Anup Patel <anup.patel@wdc.com> Tested-by: Emil Renner Berhing <kernel@esmil.dk> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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635093e3 |
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29-Jul-2020 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Fix build warning for smpboot.c The following warnings are reported by kbuild with W=1. >> arch/riscv/kernel/smpboot.c:109:5: warning: no previous prototype for 'start_secondary_cpu' [-Wmissing-prototypes] 109 | int start_secondary_cpu(int cpu, struct task_struct *tidle) | ^~~~~~~~~~~~~~~~~~~ arch/riscv/kernel/smpboot.c:146:34: warning: no previous prototype for 'smp_callin' [-Wmissing-prototypes] 146 | asmlinkage __visible void __init smp_callin(void) | ^~~~~~~~~~ Fix the warnings by marking the local functions static and adding the prototype for the global function. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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79b1feba |
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15-Jul-2020 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Setup exception vector early The trap vector is set only in trap_init which may be too late in some cases. Early ioremap/efi spits many warning messages which may be useful. Setup the trap vector early so that any warning/bug can be handled before generic code invokes trap_init. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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c1595992 |
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27-Jun-2020 |
Zong Li <zong.li@sifive.com> |
riscv: Fixup lockdep_assert_held with wrong param cpu_running The cpu_running is not a lock-class, it lacks the dep_map member in completion. It causes the error as follow: arch/riscv/kernel/smpboot.c: In function '__cpu_up': ./include/linux/lockdep.h:364:52: error: 'struct completion' has no member named 'dep_map' 364 | #define lockdep_is_held(lock) lock_is_held(&(lock)->dep_map) | ^~ ./include/asm-generic/bug.h:113:25: note: in definition of macro 'WARN_ON' 113 | int __ret_warn_on = !!(condition); \ | ^~~~~~~~~ ./include/linux/lockdep.h:390:27: note: in expansion of macro 'lockdep_is_held' 390 | WARN_ON(debug_locks && !lockdep_is_held(l)); \ | ^~~~~~~~~~~~~~~ arch/riscv/kernel/smpboot.c:118:2: note: in expansion of macro 'lockdep_assert_held' 118 | lockdep_assert_held(&cpu_running); There are a lot of archs which use cpu_running in smpboot.c (arm, arm64, openrisc, xtensa, s390, x86, mips), but none of them try lockdep_assert_held(&cpu_running.wait.lock). So Just remove it. Signed-off-by: Zong Li <zong.li@sifive.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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a2693fe2 |
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22-Jun-2020 |
Greentime Hu <greentime.hu@sifive.com> |
RISC-V: Use a local variable instead of smp_processor_id() Store the smp_processor_id() in a local variable to save some pointer chasing. Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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cfafe260 |
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17-Mar-2020 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Add supported for ordered booting method using HSM Currently, all harts have to jump Linux in RISC-V. This complicates the multi-stage boot process as every transient stage also has to ensure all harts enter to that stage and jump to Linux afterwards. It also obstructs a clean Kexec implementation. SBI HSM extension provides alternate solutions where only a single hart need to boot and enter Linux. The booting hart can bring up secondary harts one by one afterwards. Add SBI HSM based cpu_ops that implements an ordered booting method in RISC-V. This change is also backward compatible with older firmware not implementing HSM extension. If a latest kernel is used with older firmware, it will continue to use the default spinning booting method. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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2875fe05 |
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17-Mar-2020 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Add cpu_ops and modify default booting method Currently, all non-booting harts start booting after the booting hart updates the per-hart stack pointer. This is done in a way that, it's difficult to implement any other booting method without breaking the backward compatibility. Define a cpu_ops method that allows to introduce other booting methods in future. Modify the current booting method to be compatible with cpu_ops. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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fcdc6537 |
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28-Oct-2019 |
Christoph Hellwig <hch@lst.de> |
riscv: provide native clint access for M-mode RISC-V has the concept of a cpu level interrupt controller. The interface for it is split between a standardized part that is exposed as bits in the mstatus/sstatus register and the mie/mip/sie/sip CRS. But the bit to actually trigger IPIs is not standardized and just mentioned as implementable using MMIO. Add support for IPIs using MMIO using the SiFive clint layout (which is also shared by Ariane, Kendryte and the Qemu virt platform). Additionally the MMIO block also supports the time value and timer compare registers, so they are also set up using the same OF node. Support for other layouts should also be relatively easy to add in the future. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> [paul.walmsley@sifive.com: update include guard format; fix checkpatch issues; minor commit message cleanup] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
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f3073079 |
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17-Oct-2019 |
Paul Walmsley <paul.walmsley@sifive.com> |
riscv: for C functions called only from assembly, mark with __visible Rather than adding prototypes for C functions called only by assembly code, mark them as __visible. This avoids adding prototypes that will never be used by the callers. Resolves the following sparse warnings: arch/riscv/kernel/irq.c:27:29: warning: symbol 'do_IRQ' was not declared. Should it be static? arch/riscv/kernel/ptrace.c:151:6: warning: symbol 'do_syscall_trace_enter' was not declared. Should it be static? arch/riscv/kernel/ptrace.c:165:6: warning: symbol 'do_syscall_trace_exit' was not declared. Should it be static? arch/riscv/kernel/signal.c:295:17: warning: symbol 'do_notify_resume' was not declared. Should it be static? arch/riscv/kernel/traps.c:92:1: warning: symbol 'do_trap_unknown' was not declared. Should it be static? arch/riscv/kernel/traps.c:94:1: warning: symbol 'do_trap_insn_misaligned' was not declared. Should it be static? arch/riscv/kernel/traps.c:96:1: warning: symbol 'do_trap_insn_fault' was not declared. Should it be static? arch/riscv/kernel/traps.c:98:1: warning: symbol 'do_trap_insn_illegal' was not declared. Should it be static? arch/riscv/kernel/traps.c:100:1: warning: symbol 'do_trap_load_misaligned' was not declared. Should it be static? arch/riscv/kernel/traps.c:102:1: warning: symbol 'do_trap_load_fault' was not declared. Should it be static? arch/riscv/kernel/traps.c:104:1: warning: symbol 'do_trap_store_misaligned' was not declared. Should it be static? arch/riscv/kernel/traps.c:106:1: warning: symbol 'do_trap_store_fault' was not declared. Should it be static? arch/riscv/kernel/traps.c:108:1: warning: symbol 'do_trap_ecall_u' was not declared. Should it be static? arch/riscv/kernel/traps.c:110:1: warning: symbol 'do_trap_ecall_s' was not declared. Should it be static? arch/riscv/kernel/traps.c:112:1: warning: symbol 'do_trap_ecall_m' was not declared. Should it be static? arch/riscv/kernel/traps.c:124:17: warning: symbol 'do_trap_break' was not declared. Should it be static? arch/riscv/kernel/smpboot.c:136:24: warning: symbol 'smp_callin' was not declared. Should it be static? Based on a suggestion from Luc Van Oostenryck. This version includes changes based on feedback from Christoph Hellwig <hch@lst.de>. Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> # for do_syscall_trace_*
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5ed881bc |
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17-Oct-2019 |
Paul Walmsley <paul.walmsley@sifive.com> |
riscv: add missing header file includes sparse identifies several missing prototypes caused by missing preprocessor include directives: arch/riscv/kernel/cpufeature.c:16:6: warning: symbol 'has_fpu' was not declared. Should it be static? arch/riscv/kernel/process.c:26:6: warning: symbol 'arch_cpu_idle' was not declared. Should it be static? arch/riscv/kernel/reset.c:15:6: warning: symbol 'pm_power_off' was not declared. Should it be static? arch/riscv/kernel/syscall_table.c:15:6: warning: symbol 'sys_call_table' was not declared. Should it be static? arch/riscv/kernel/traps.c:149:13: warning: symbol 'trap_init' was not declared. Should it be static? arch/riscv/kernel/vdso.c:54:5: warning: symbol 'arch_setup_additional_pages' was not declared. Should it be static? arch/riscv/kernel/smp.c:64:6: warning: symbol 'arch_match_cpu_phys_id' was not declared. Should it be static? arch/riscv/kernel/module-sections.c:89:5: warning: symbol 'module_frob_arch_sections' was not declared. Should it be static? arch/riscv/mm/context.c:42:6: warning: symbol 'switch_mm' was not declared. Should it be static? Fix by including the appropriate header files in the appropriate source files. This patch should have no functional impact. Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
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ffaee272 |
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17-Oct-2019 |
Paul Walmsley <paul.walmsley@sifive.com> |
riscv: add prototypes for assembly language functions from head.S Add prototypes for assembly language functions defined in head.S, and include these prototypes into C source files that call those functions. This patch resolves the following warnings from sparse: arch/riscv/kernel/setup.c:39:10: warning: symbol 'hart_lottery' was not declared. Should it be static? arch/riscv/kernel/setup.c:42:13: warning: symbol 'parse_dtb' was not declared. Should it be static? arch/riscv/kernel/smpboot.c:33:6: warning: symbol '__cpu_up_stack_pointer' was not declared. Should it be static? arch/riscv/kernel/smpboot.c:34:6: warning: symbol '__cpu_up_task_pointer' was not declared. Should it be static? arch/riscv/mm/fault.c:25:17: warning: symbol 'do_page_fault' was not declared. Should it be static? This change should have no functional impact. Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
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03f11f03 |
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27-Jun-2019 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Parse cpu topology during boot. Currently, there are no topology defined for RISC-V. Parse the cpu-map node from device tree and setup the cpu topology. CPU topology after applying the patch. $cat /sys/devices/system/cpu/cpu2/topology/core_siblings_list 0-3 $cat /sys/devices/system/cpu/cpu3/topology/core_siblings_list 0-3 $cat /sys/devices/system/cpu/cpu3/topology/physical_package_id 0 $cat /sys/devices/system/cpu/cpu3/topology/core_id 3 Signed-off-by: Atish Patra <atish.patra@wdc.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
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1802d0be |
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27-May-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 655 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8b4302a4 |
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24-Apr-2019 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Support nr_cpus command line option. If nr_cpus command line option is set, maximum possible cpu should be set to that value. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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ab3d2650 |
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24-Apr-2019 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Implement nosmp commandline option. nosmp command line option sets max_cpus to zero. No secondary harts will boot if this is enabled. But present cpu mask will still point to all possible masks. Fix present cpu mask for nosmp usecase. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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291debb3 |
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22-Feb-2019 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Compare cpuid with NR_CPUS before mapping. We should never have a cpuid greater that NR_CPUS. Compare with NR_CPUS before creating the mapping between logical and physical CPU ids. This is also mandatory as NR_CPUS check is removed from riscv_of_processor_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>
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e15c6e37 |
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22-Feb-2019 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Do not wait indefinitely in __cpu_up In SMP path, __cpu_up waits for other CPU to come online indefinitely. This is wrong as other CPU might be disabled in machine mode and possible CPU is set to the cpus present in DT. Introduce a completion variable and waits only for a second. 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>
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dd81c8ab |
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18-Jan-2019 |
Johan Hovold <johan@kernel.org> |
riscv: use for_each_of_cpu_node iterator Use the new for_each_of_cpu_node() helper to iterate over cpu nodes instead of open coding. Note that this will allow matching also on the node name instead of the (for FDT) deprecated device_type property. Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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2bb10639 |
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07-Jan-2019 |
Andreas Schwab <schwab@suse.de> |
RISC-V: fix bad use of of_node_put of_find_node_by_type already calls of_node_put, don't call it again. Fixes: 94f9bf118f ("RISC-V: Fix of_node_* refcount") Signed-off-by: Andreas Schwab <schwab@suse.de> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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94f9bf11 |
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20-Nov-2018 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Fix of_node_* refcount Fix of_node* refcount at various places by using of_node_put. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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f99fb607 |
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02-Oct-2018 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Use Linux logical CPU number instead of hartid 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>
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a37d56fc |
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02-Oct-2018 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Use WRITE_ONCE instead of direct access The secondary harts spin on couple of per cpu variables until both of these are non-zero so it's not necessary to have any ordering here. However, WRITE_ONCE should be used to avoid tearing. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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46373cb4 |
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02-Oct-2018 |
Palmer Dabbelt <palmer@sifive.com> |
RISC-V: Use mmgrab() commit f1f1007644ff ("mm: add new mmgrab() helper") added a helper that we missed out on. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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177fae45 |
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02-Oct-2018 |
Palmer Dabbelt <palmer@sifive.com> |
RISC-V: Rename im_okay_therefore_i_am to found_boot_cpu The old name was a bit odd. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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b2f8cfa7 |
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02-Oct-2018 |
Palmer Dabbelt <palmer@sifive.com> |
RISC-V: Rename riscv_of_processor_hart to riscv_of_processor_hartid It's a bit confusing exactly what this function does: it actually returns the hartid of an OF processor node, failing with -1 on invalid nodes. I've changed the name to _hartid() in order to make that a bit more clear, as well as adding a comment. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> [Atish: code comment formatting update] Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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6db170ff |
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02-Oct-2018 |
Atish Patra <atish.patra@wdc.com> |
RISC-V: Disable preemption before enabling interrupts Currently, irq is enabled before preemption disabling happens. If the scheduler fired right here and cpu is scheduled then it may blow up. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> [Atish: Commit text and code comment formatting update] Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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b18d6f05 |
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02-Oct-2018 |
Palmer Dabbelt <palmer@sifive.com> |
RISC-V: Comment on the TLB flush in smp_callin() This isn't readily apparent from reading the code. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> [Atish: code comment formatting update] Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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62b01943 |
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04-Aug-2018 |
Palmer Dabbelt <palmer@dabbelt.com> |
clocksource: new RISC-V SBI timer driver The RISC-V ISA defines a per-hart real-time clock and timer, which is present on all systems. The clock is accessed via the 'rdtime' pseudo-instruction (which reads a CSR), and the timer is set via an SBI call. Contains various improvements from Atish Patra <atish.patra@wdc.com>. Signed-off-by: Dmitriy Cherkasov <dmitriy@oss-tech.org> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com> [hch: remove dead code, add SPDX tags, used riscv_of_processor_hart(), minor cleanups, merged hotplug cpu support and other improvements from Atish] Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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76d2a049 |
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10-Jul-2017 |
Palmer Dabbelt <palmer@dabbelt.com> |
RISC-V: Init and Halt Code 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>
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