kernel.git/arch/riscv/kernel/smpboot.c, branch linux-5.9.y

RISC-V: Remove CLINT related code from timer and arch

2020-08-20T17:58:13Z

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 Tested-by: Emil Renner Berhing Acked-by: Daniel Lezcano Reviewed-by: Atish Patra Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt

RISC-V: Add mechanism to provide custom IPI operations

2020-08-20T17:55:40Z

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 Tested-by: Emil Renner Berhing Reviewed-by: Atish Patra Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt

RISC-V: Fix build warning for smpboot.c

2020-08-04T22:02:42Z

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 Signed-off-by: Palmer Dabbelt

RISC-V: Setup exception vector early

2020-07-30T18:37:48Z

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 Signed-off-by: Palmer Dabbelt

riscv: Fixup lockdep_assert_held with wrong param cpu_running

2020-07-30T18:37:31Z

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 Signed-off-by: Guo Ren Signed-off-by: Palmer Dabbelt

RISC-V: Use a local variable instead of smp_processor_id()

2020-06-29T22:23:28Z

Store the smp_processor_id() in a local variable to save some pointer chasing. Signed-off-by: Greentime Hu Signed-off-by: Atish Patra Signed-off-by: Palmer Dabbelt

RISC-V: Add supported for ordered booting method using HSM

2020-03-31T18:27:50Z

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 Reviewed-by: Anup Patel Signed-off-by: Palmer Dabbelt

RISC-V: Add cpu_ops and modify default booting method

2020-03-31T18:25:56Z

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 Reviewed-by: Anup Patel Signed-off-by: Palmer Dabbelt

riscv: provide native clint access for M-mode

2019-11-17T23:17:39Z

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 Reviewed-by: Anup Patel [paul.walmsley@sifive.com: update include guard format; fix checkpatch issues; minor commit message cleanup] Signed-off-by: Paul Walmsley

riscv: for C functions called only from assembly, mark with __visible

2019-10-28T07:46:02Z

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 . Signed-off-by: Paul Walmsley Cc: Luc Van Oostenryck Reviewed-by: Christoph Hellwig # for do_syscall_trace_*