From a4c3733d32a72f11dee86d0731d7565aa6ebe22d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 28 Oct 2019 13:10:32 +0100 Subject: riscv: abstract out CSR names for supervisor vs machine mode Many of the privileged CSRs exist in a supervisor and machine version that are used very similarly. Provide versions of the CSR names and fields that map to either the S-mode or M-mode variant depending on a new CONFIG_RISCV_M_MODE kconfig symbol. Contains contributions from Damien Le Moal and Paul Walmsley . Signed-off-by: Christoph Hellwig Acked-by: Thomas Gleixner # for drivers/clocksource, drivers/irqchip [paul.walmsley@sifive.com: updated to apply] Signed-off-by: Paul Walmsley --- arch/riscv/kernel/asm-offsets.c | 8 ++--- arch/riscv/kernel/entry.S | 74 ++++++++++++++++++++++---------------- arch/riscv/kernel/fpu.S | 8 ++--- arch/riscv/kernel/head.S | 12 +++---- arch/riscv/kernel/irq.c | 17 +++------ arch/riscv/kernel/perf_callchain.c | 2 +- arch/riscv/kernel/process.c | 17 ++++----- arch/riscv/kernel/signal.c | 21 ++++++----- arch/riscv/kernel/smp.c | 2 +- arch/riscv/kernel/traps.c | 16 ++++----- 10 files changed, 91 insertions(+), 86 deletions(-) (limited to 'arch/riscv/kernel') diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c index 9f5628c38ac9..07cb9c10de4e 100644 --- a/arch/riscv/kernel/asm-offsets.c +++ b/arch/riscv/kernel/asm-offsets.c @@ -71,7 +71,7 @@ void asm_offsets(void) OFFSET(TASK_THREAD_FCSR, task_struct, thread.fstate.fcsr); DEFINE(PT_SIZE, sizeof(struct pt_regs)); - OFFSET(PT_SEPC, pt_regs, sepc); + OFFSET(PT_EPC, pt_regs, epc); OFFSET(PT_RA, pt_regs, ra); OFFSET(PT_FP, pt_regs, s0); OFFSET(PT_S0, pt_regs, s0); @@ -105,9 +105,9 @@ void asm_offsets(void) OFFSET(PT_T6, pt_regs, t6); OFFSET(PT_GP, pt_regs, gp); OFFSET(PT_ORIG_A0, pt_regs, orig_a0); - OFFSET(PT_SSTATUS, pt_regs, sstatus); - OFFSET(PT_SBADADDR, pt_regs, sbadaddr); - OFFSET(PT_SCAUSE, pt_regs, scause); + OFFSET(PT_STATUS, pt_regs, status); + OFFSET(PT_BADADDR, pt_regs, badaddr); + OFFSET(PT_CAUSE, pt_regs, cause); /* * THREAD_{F,X}* might be larger than a S-type offset can handle, but diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 8ca479831142..b84f8d7f4911 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -26,14 +26,14 @@ /* * If coming from userspace, preserve the user thread pointer and load - * the kernel thread pointer. If we came from the kernel, sscratch - * will contain 0, and we should continue on the current TP. + * the kernel thread pointer. If we came from the kernel, the scratch + * register will contain 0, and we should continue on the current TP. */ - csrrw tp, CSR_SSCRATCH, tp + csrrw tp, CSR_SCRATCH, tp bnez tp, _save_context _restore_kernel_tpsp: - csrr tp, CSR_SSCRATCH + csrr tp, CSR_SCRATCH REG_S sp, TASK_TI_KERNEL_SP(tp) _save_context: REG_S sp, TASK_TI_USER_SP(tp) @@ -79,16 +79,16 @@ _save_context: li t0, SR_SUM | SR_FS REG_L s0, TASK_TI_USER_SP(tp) - csrrc s1, CSR_SSTATUS, t0 - csrr s2, CSR_SEPC - csrr s3, CSR_STVAL - csrr s4, CSR_SCAUSE - csrr s5, CSR_SSCRATCH + csrrc s1, CSR_STATUS, t0 + csrr s2, CSR_EPC + csrr s3, CSR_TVAL + csrr s4, CSR_CAUSE + csrr s5, CSR_SCRATCH REG_S s0, PT_SP(sp) - REG_S s1, PT_SSTATUS(sp) - REG_S s2, PT_SEPC(sp) - REG_S s3, PT_SBADADDR(sp) - REG_S s4, PT_SCAUSE(sp) + REG_S s1, PT_STATUS(sp) + REG_S s2, PT_EPC(sp) + REG_S s3, PT_BADADDR(sp) + REG_S s4, PT_CAUSE(sp) REG_S s5, PT_TP(sp) .endm @@ -97,7 +97,7 @@ _save_context: * registers from the stack. */ .macro RESTORE_ALL - REG_L a0, PT_SSTATUS(sp) + REG_L a0, PT_STATUS(sp) /* * The current load reservation is effectively part of the processor's * state, in the sense that load reservations cannot be shared between @@ -115,11 +115,11 @@ _save_context: * completes, implementations are allowed to expand reservations to be * arbitrarily large. */ - REG_L a2, PT_SEPC(sp) - REG_SC x0, a2, PT_SEPC(sp) + REG_L a2, PT_EPC(sp) + REG_SC x0, a2, PT_EPC(sp) - csrw CSR_SSTATUS, a0 - csrw CSR_SEPC, a2 + csrw CSR_STATUS, a0 + csrw CSR_EPC, a2 REG_L x1, PT_RA(sp) REG_L x3, PT_GP(sp) @@ -163,10 +163,10 @@ ENTRY(handle_exception) SAVE_ALL /* - * Set sscratch register to 0, so that if a recursive exception + * Set the scratch register to 0, so that if a recursive exception * occurs, the exception vector knows it came from the kernel */ - csrw CSR_SSCRATCH, x0 + csrw CSR_SCRATCH, x0 /* Load the global pointer */ .option push @@ -185,11 +185,13 @@ ENTRY(handle_exception) move a0, sp /* pt_regs */ tail do_IRQ 1: - /* Exceptions run with interrupts enabled or disabled - depending on the state of sstatus.SR_SPIE */ - andi t0, s1, SR_SPIE + /* + * Exceptions run with interrupts enabled or disabled depending on the + * state of SR_PIE in m/sstatus. + */ + andi t0, s1, SR_PIE beqz t0, 1f - csrs CSR_SSTATUS, SR_SIE + csrs CSR_STATUS, SR_IE 1: /* Handle syscalls */ @@ -217,7 +219,7 @@ handle_syscall: * scall instruction on sret */ addi s2, s2, 0x4 - REG_S s2, PT_SEPC(sp) + REG_S s2, PT_EPC(sp) /* Trace syscalls, but only if requested by the user. */ REG_L t0, TASK_TI_FLAGS(tp) andi t0, t0, _TIF_SYSCALL_WORK @@ -244,9 +246,15 @@ ret_from_syscall: bnez t0, handle_syscall_trace_exit ret_from_exception: - REG_L s0, PT_SSTATUS(sp) - csrc CSR_SSTATUS, SR_SIE + REG_L s0, PT_STATUS(sp) + csrc CSR_STATUS, SR_IE +#ifdef CONFIG_RISCV_M_MODE + /* the MPP value is too large to be used as an immediate arg for addi */ + li t0, SR_MPP + and s0, s0, t0 +#else andi s0, s0, SR_SPP +#endif bnez s0, resume_kernel resume_userspace: @@ -260,14 +268,18 @@ resume_userspace: REG_S s0, TASK_TI_KERNEL_SP(tp) /* - * Save TP into sscratch, so we can find the kernel data structures - * again. + * Save TP into the scratch register , so we can find the kernel data + * structures again. */ - csrw CSR_SSCRATCH, tp + csrw CSR_SCRATCH, tp restore_all: RESTORE_ALL +#ifdef CONFIG_RISCV_M_MODE + mret +#else sret +#endif #if IS_ENABLED(CONFIG_PREEMPT) resume_kernel: @@ -287,7 +299,7 @@ work_pending: bnez s1, work_resched work_notifysig: /* Handle pending signals and notify-resume requests */ - csrs CSR_SSTATUS, SR_SIE /* Enable interrupts for do_notify_resume() */ + csrs CSR_STATUS, SR_IE /* Enable interrupts for do_notify_resume() */ move a0, sp /* pt_regs */ move a1, s0 /* current_thread_info->flags */ tail do_notify_resume diff --git a/arch/riscv/kernel/fpu.S b/arch/riscv/kernel/fpu.S index 631d31540660..dd2205473de7 100644 --- a/arch/riscv/kernel/fpu.S +++ b/arch/riscv/kernel/fpu.S @@ -23,7 +23,7 @@ ENTRY(__fstate_save) li a2, TASK_THREAD_F0 add a0, a0, a2 li t1, SR_FS - csrs CSR_SSTATUS, t1 + csrs CSR_STATUS, t1 frcsr t0 fsd f0, TASK_THREAD_F0_F0(a0) fsd f1, TASK_THREAD_F1_F0(a0) @@ -58,7 +58,7 @@ ENTRY(__fstate_save) fsd f30, TASK_THREAD_F30_F0(a0) fsd f31, TASK_THREAD_F31_F0(a0) sw t0, TASK_THREAD_FCSR_F0(a0) - csrc CSR_SSTATUS, t1 + csrc CSR_STATUS, t1 ret ENDPROC(__fstate_save) @@ -67,7 +67,7 @@ ENTRY(__fstate_restore) add a0, a0, a2 li t1, SR_FS lw t0, TASK_THREAD_FCSR_F0(a0) - csrs CSR_SSTATUS, t1 + csrs CSR_STATUS, t1 fld f0, TASK_THREAD_F0_F0(a0) fld f1, TASK_THREAD_F1_F0(a0) fld f2, TASK_THREAD_F2_F0(a0) @@ -101,6 +101,6 @@ ENTRY(__fstate_restore) fld f30, TASK_THREAD_F30_F0(a0) fld f31, TASK_THREAD_F31_F0(a0) fscsr t0 - csrc CSR_SSTATUS, t1 + csrc CSR_STATUS, t1 ret ENDPROC(__fstate_restore) diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 72f89b7590dd..5cfd2c582945 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -47,8 +47,8 @@ ENTRY(_start) .global _start_kernel _start_kernel: /* Mask all interrupts */ - csrw CSR_SIE, zero - csrw CSR_SIP, zero + csrw CSR_IE, zero + csrw CSR_IP, zero /* Load the global pointer */ .option push @@ -61,7 +61,7 @@ _start_kernel: * floating point in kernel space */ li t0, SR_FS - csrc CSR_SSTATUS, t0 + csrc CSR_STATUS, t0 #ifdef CONFIG_SMP li t0, CONFIG_NR_CPUS @@ -116,7 +116,7 @@ relocate: /* Point stvec to virtual address of intruction after satp write */ la a2, 1f add a2, a2, a1 - csrw CSR_STVEC, a2 + csrw CSR_TVEC, a2 /* Compute satp for kernel page tables, but don't load it yet */ srl a2, a0, PAGE_SHIFT @@ -138,7 +138,7 @@ relocate: 1: /* Set trap vector to spin forever to help debug */ la a0, .Lsecondary_park - csrw CSR_STVEC, a0 + csrw CSR_TVEC, a0 /* Reload the global pointer */ .option push @@ -161,7 +161,7 @@ relocate: #ifdef CONFIG_SMP /* Set trap vector to spin forever to help debug */ la a3, .Lsecondary_park - csrw CSR_STVEC, a3 + csrw CSR_TVEC, a3 slli a3, a0, LGREG la a1, __cpu_up_stack_pointer diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c index fffac6ddb0e0..3f07a91d5afb 100644 --- a/arch/riscv/kernel/irq.c +++ b/arch/riscv/kernel/irq.c @@ -11,13 +11,6 @@ #include #include -/* - * Possible interrupt causes: - */ -#define INTERRUPT_CAUSE_SOFTWARE IRQ_S_SOFT -#define INTERRUPT_CAUSE_TIMER IRQ_S_TIMER -#define INTERRUPT_CAUSE_EXTERNAL IRQ_S_EXT - int arch_show_interrupts(struct seq_file *p, int prec) { show_ipi_stats(p, prec); @@ -29,12 +22,12 @@ asmlinkage __visible void __irq_entry do_IRQ(struct pt_regs *regs) struct pt_regs *old_regs = set_irq_regs(regs); irq_enter(); - switch (regs->scause & ~SCAUSE_IRQ_FLAG) { - case INTERRUPT_CAUSE_TIMER: + switch (regs->cause & ~CAUSE_IRQ_FLAG) { + case IRQ_TIMER: riscv_timer_interrupt(); break; #ifdef CONFIG_SMP - case INTERRUPT_CAUSE_SOFTWARE: + case IRQ_SOFT: /* * We only use software interrupts to pass IPIs, so if a non-SMP * system gets one, then we don't know what to do. @@ -42,11 +35,11 @@ asmlinkage __visible void __irq_entry do_IRQ(struct pt_regs *regs) riscv_software_interrupt(); break; #endif - case INTERRUPT_CAUSE_EXTERNAL: + case IRQ_EXT: handle_arch_irq(regs); break; default: - pr_alert("unexpected interrupt cause 0x%lx", regs->scause); + pr_alert("unexpected interrupt cause 0x%lx", regs->cause); BUG(); } irq_exit(); diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c index 8d2804f05cf9..cf190197a22f 100644 --- a/arch/riscv/kernel/perf_callchain.c +++ b/arch/riscv/kernel/perf_callchain.c @@ -67,7 +67,7 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry, return; fp = regs->s0; - perf_callchain_store(entry, regs->sepc); + perf_callchain_store(entry, regs->epc); fp = user_backtrace(entry, fp, regs->ra); while (fp && !(fp & 0x3) && entry->nr < entry->max_stack) diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 85e3c39bb60b..95a3031e5c7c 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -35,8 +35,8 @@ void show_regs(struct pt_regs *regs) { show_regs_print_info(KERN_DEFAULT); - pr_cont("sepc: " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n", - regs->sepc, regs->ra, regs->sp); + pr_cont("epc: " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n", + regs->epc, regs->ra, regs->sp); pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n", regs->gp, regs->tp, regs->t0); pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n", @@ -58,23 +58,23 @@ void show_regs(struct pt_regs *regs) pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n", regs->t5, regs->t6); - pr_cont("sstatus: " REG_FMT " sbadaddr: " REG_FMT " scause: " REG_FMT "\n", - regs->sstatus, regs->sbadaddr, regs->scause); + pr_cont("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n", + regs->status, regs->badaddr, regs->cause); } void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) { - regs->sstatus = SR_SPIE; + regs->status = SR_PIE; if (has_fpu) { - regs->sstatus |= SR_FS_INITIAL; + regs->status |= SR_FS_INITIAL; /* * Restore the initial value to the FP register * before starting the user program. */ fstate_restore(current, regs); } - regs->sepc = pc; + regs->epc = pc; regs->sp = sp; set_fs(USER_DS); } @@ -110,7 +110,8 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, const register unsigned long gp __asm__ ("gp"); memset(childregs, 0, sizeof(struct pt_regs)); childregs->gp = gp; - childregs->sstatus = SR_SPP | SR_SPIE; /* Supervisor, irqs on */ + /* Supervisor/Machine, irqs on: */ + childregs->status = SR_PP | SR_PIE; p->thread.ra = (unsigned long)ret_from_kernel_thread; p->thread.s[0] = usp; /* fn */ diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c index d0f6f212f5df..b7f9a5565c4b 100644 --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -124,7 +124,7 @@ badframe: pr_info_ratelimited( "%s[%d]: bad frame in %s: frame=%p pc=%p sp=%p\n", task->comm, task_pid_nr(task), __func__, - frame, (void *)regs->sepc, (void *)regs->sp); + frame, (void *)regs->epc, (void *)regs->sp); } force_sig(SIGSEGV); return 0; @@ -199,7 +199,7 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, * We always pass siginfo and mcontext, regardless of SA_SIGINFO, * since some things rely on this (e.g. glibc's debug/segfault.c). */ - regs->sepc = (unsigned long)ksig->ka.sa.sa_handler; + regs->epc = (unsigned long)ksig->ka.sa.sa_handler; regs->sp = (unsigned long)frame; regs->a0 = ksig->sig; /* a0: signal number */ regs->a1 = (unsigned long)(&frame->info); /* a1: siginfo pointer */ @@ -208,7 +208,7 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, #if DEBUG_SIG pr_info("SIG deliver (%s:%d): sig=%d pc=%p ra=%p sp=%p\n", current->comm, task_pid_nr(current), ksig->sig, - (void *)regs->sepc, (void *)regs->ra, frame); + (void *)regs->epc, (void *)regs->ra, frame); #endif return 0; @@ -220,10 +220,9 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) int ret; /* Are we from a system call? */ - if (regs->scause == EXC_SYSCALL) { + if (regs->cause == EXC_SYSCALL) { /* Avoid additional syscall restarting via ret_from_exception */ - regs->scause = -1UL; - + regs->cause = -1UL; /* If so, check system call restarting.. */ switch (regs->a0) { case -ERESTART_RESTARTBLOCK: @@ -239,7 +238,7 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) /* fallthrough */ case -ERESTARTNOINTR: regs->a0 = regs->orig_a0; - regs->sepc -= 0x4; + regs->epc -= 0x4; break; } } @@ -261,9 +260,9 @@ static void do_signal(struct pt_regs *regs) } /* Did we come from a system call? */ - if (regs->scause == EXC_SYSCALL) { + if (regs->cause == EXC_SYSCALL) { /* Avoid additional syscall restarting via ret_from_exception */ - regs->scause = -1UL; + regs->cause = -1UL; /* Restart the system call - no handlers present */ switch (regs->a0) { @@ -271,12 +270,12 @@ static void do_signal(struct pt_regs *regs) case -ERESTARTSYS: case -ERESTARTNOINTR: regs->a0 = regs->orig_a0; - regs->sepc -= 0x4; + regs->epc -= 0x4; break; case -ERESTART_RESTARTBLOCK: regs->a0 = regs->orig_a0; regs->a7 = __NR_restart_syscall; - regs->sepc -= 0x4; + regs->epc -= 0x4; break; } } diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c index 5c9ec78422c2..c0fbc04e6810 100644 --- a/arch/riscv/kernel/smp.c +++ b/arch/riscv/kernel/smp.c @@ -108,7 +108,7 @@ static void send_ipi_single(int cpu, enum ipi_message_type op) static inline void clear_ipi(void) { - csr_clear(CSR_SIP, SIE_SSIE); + csr_clear(CSR_IP, IE_SIE); } void riscv_software_interrupt(void) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 473de3ae8bb7..f4cad5163bf2 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -41,7 +41,7 @@ void die(struct pt_regs *regs, const char *str) print_modules(); show_regs(regs); - ret = notify_die(DIE_OOPS, str, regs, 0, regs->scause, SIGSEGV); + ret = notify_die(DIE_OOPS, str, regs, 0, regs->cause, SIGSEGV); bust_spinlocks(0); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); @@ -86,7 +86,7 @@ static void do_trap_error(struct pt_regs *regs, int signo, int code, #define DO_ERROR_INFO(name, signo, code, str) \ asmlinkage __visible void name(struct pt_regs *regs) \ { \ - do_trap_error(regs, signo, code, regs->sepc, "Oops - " str); \ + do_trap_error(regs, signo, code, regs->epc, "Oops - " str); \ } DO_ERROR_INFO(do_trap_unknown, @@ -124,9 +124,9 @@ static inline unsigned long get_break_insn_length(unsigned long pc) asmlinkage __visible void do_trap_break(struct pt_regs *regs) { if (user_mode(regs)) - force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->sepc); - else if (report_bug(regs->sepc, regs) == BUG_TRAP_TYPE_WARN) - regs->sepc += get_break_insn_length(regs->sepc); + force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->epc); + else if (report_bug(regs->epc, regs) == BUG_TRAP_TYPE_WARN) + regs->epc += get_break_insn_length(regs->epc); else die(regs, "Kernel BUG"); } @@ -153,9 +153,9 @@ void __init trap_init(void) * Set sup0 scratch register to 0, indicating to exception vector * that we are presently executing in the kernel */ - csr_write(CSR_SSCRATCH, 0); + csr_write(CSR_SCRATCH, 0); /* Set the exception vector address */ - csr_write(CSR_STVEC, &handle_exception); + csr_write(CSR_TVEC, &handle_exception); /* Enable all interrupts */ - csr_write(CSR_SIE, -1); + csr_write(CSR_IE, -1); } -- cgit v1.2.3