18 files changed, 89 insertions, 40 deletions

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index b1ade9a49347..a5ad00043104 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -10,6 +10,7 @@
 #include <asm/processor.h>
 #include <asm/hwcap.h>
 #include <asm/smp.h>
+#include <asm/switch_to.h>
 
 unsigned long elf_hwcap __read_mostly;
 #ifdef CONFIG_FPU
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 74ccfd464071..8ca479831142 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -98,7 +98,26 @@ _save_context:
  */
 	.macro RESTORE_ALL
 	REG_L a0, PT_SSTATUS(sp)
-	REG_L a2, PT_SEPC(sp)
+	/*
+	 * The current load reservation is effectively part of the processor's
+	 * state, in the sense that load reservations cannot be shared between
+	 * different hart contexts.  We can't actually save and restore a load
+	 * reservation, so instead here we clear any existing reservation --
+	 * it's always legal for implementations to clear load reservations at
+	 * any point (as long as the forward progress guarantee is kept, but
+	 * we'll ignore that here).
+	 *
+	 * Dangling load reservations can be the result of taking a trap in the
+	 * middle of an LR/SC sequence, but can also be the result of a taken
+	 * forward branch around an SC -- which is how we implement CAS.  As a
+	 * result we need to clear reservations between the last CAS and the
+	 * jump back to the new context.  While it is unlikely the store
+	 * completes, implementations are allowed to expand reservations to be
+	 * arbitrarily large.
+	 */
+	REG_L  a2, PT_SEPC(sp)
+	REG_SC x0, a2, PT_SEPC(sp)
+
 	csrw CSR_SSTATUS, a0
 	csrw CSR_SEPC, a2
 
@@ -166,9 +185,13 @@ ENTRY(handle_exception)
 	move a0, sp /* pt_regs */
 	tail do_IRQ
 1:
-	/* Exceptions run with interrupts enabled */
+	/* Exceptions run with interrupts enabled or disabled
+	   depending on the state of sstatus.SR_SPIE */
+	andi t0, s1, SR_SPIE
+	beqz t0, 1f
 	csrs CSR_SSTATUS, SR_SIE
 
+1:
 	/* Handle syscalls */
 	li t0, EXC_SYSCALL
 	beq s4, t0, handle_syscall
@@ -250,12 +273,11 @@ restore_all:
 resume_kernel:
 	REG_L s0, TASK_TI_PREEMPT_COUNT(tp)
 	bnez s0, restore_all
-need_resched:
 	REG_L s0, TASK_TI_FLAGS(tp)
 	andi s0, s0, _TIF_NEED_RESCHED
 	beqz s0, restore_all
 	call preempt_schedule_irq
-	j need_resched
+	j restore_all
 #endif
 
 work_pending:
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 15a9189f91ad..72f89b7590dd 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -63,6 +63,11 @@ _start_kernel:
 	li t0, SR_FS
 	csrc CSR_SSTATUS, t0
 
+#ifdef CONFIG_SMP
+	li t0, CONFIG_NR_CPUS
+	bgeu a0, t0, .Lsecondary_park
+#endif
+
 	/* Pick one hart to run the main boot sequence */
 	la a3, hart_lottery
 	li a2, 1
@@ -154,9 +159,6 @@ relocate:
 
 .Lsecondary_start:
 #ifdef CONFIG_SMP
-	li a1, CONFIG_NR_CPUS
-	bgeu a0, a1, .Lsecondary_park
-
 	/* Set trap vector to spin forever to help debug */
 	la a3, .Lsecondary_park
 	csrw CSR_STVEC, a3
diff --git a/arch/riscv/kernel/head.h b/arch/riscv/kernel/head.h
new file mode 100644
index 000000000000..105fb0496b24
--- /dev/null
+++ b/arch/riscv/kernel/head.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 SiFive, Inc.
+ */
+#ifndef __ASM_HEAD_H
+#define __ASM_HEAD_H
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+extern atomic_t hart_lottery;
+
+asmlinkage void do_page_fault(struct pt_regs *regs);
+asmlinkage void __init setup_vm(uintptr_t dtb_pa);
+
+extern void *__cpu_up_stack_pointer[];
+extern void *__cpu_up_task_pointer[];
+
+void __init parse_dtb(void);
+
+#endif /* __ASM_HEAD_H */
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index 6d8659388c49..fffac6ddb0e0 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -24,7 +24,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 	return 0;
 }
 
-asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs)
+asmlinkage __visible void __irq_entry do_IRQ(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
diff --git a/arch/riscv/kernel/module-sections.c b/arch/riscv/kernel/module-sections.c
index c9ae48333114..e264e59e596e 100644
--- a/arch/riscv/kernel/module-sections.c
+++ b/arch/riscv/kernel/module-sections.c
@@ -8,6 +8,7 @@
 #include <linux/elf.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/moduleloader.h>
 
 unsigned long module_emit_got_entry(struct module *mod, unsigned long val)
 {
diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index 70bb94ae61c5..b7401858d872 100644
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -315,8 +315,8 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
 			/* Ignore unresolved weak symbol */
 			if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
 				continue;
-			pr_warning("%s: Unknown symbol %s\n",
-				   me->name, strtab + sym->st_name);
+			pr_warn("%s: Unknown symbol %s\n",
+				me->name, strtab + sym->st_name);
 			return -ENOENT;
 		}
 
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index fb3a082362eb..85e3c39bb60b 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -7,6 +7,7 @@
  * Copyright (C) 2017 SiFive
  */
 
+#include <linux/cpu.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
@@ -19,6 +20,7 @@
 #include <asm/csr.h>
 #include <asm/string.h>
 #include <asm/switch_to.h>
+#include <asm/thread_info.h>
 
 extern asmlinkage void ret_from_fork(void);
 extern asmlinkage void ret_from_kernel_thread(void);
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index 368751438366..1252113ef8b2 100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -148,7 +148,7 @@ long arch_ptrace(struct task_struct *child, long request,
  * Allows PTRACE_SYSCALL to work.  These are called from entry.S in
  * {handle,ret_from}_syscall.
  */
-void do_syscall_trace_enter(struct pt_regs *regs)
+__visible void do_syscall_trace_enter(struct pt_regs *regs)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		if (tracehook_report_syscall_entry(regs))
@@ -162,7 +162,7 @@ void do_syscall_trace_enter(struct pt_regs *regs)
 	audit_syscall_entry(regs->a7, regs->a0, regs->a1, regs->a2, regs->a3);
 }
 
-void do_syscall_trace_exit(struct pt_regs *regs)
+__visible void do_syscall_trace_exit(struct pt_regs *regs)
 {
 	audit_syscall_exit(regs);
 
diff --git a/arch/riscv/kernel/reset.c b/arch/riscv/kernel/reset.c
index d0fe623bfb8f..aa56bb135ec4 100644
--- a/arch/riscv/kernel/reset.c
+++ b/arch/riscv/kernel/reset.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/reboot.h>
+#include <linux/pm.h>
 #include <asm/sbi.h>
 
 static void default_power_off(void)
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index a990a6cb184f..845ae0e12115 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -24,6 +24,8 @@
 #include <asm/tlbflush.h>
 #include <asm/thread_info.h>
 
+#include "head.h"
+
 #ifdef CONFIG_DUMMY_CONSOLE
 struct screen_info screen_info = {
 	.orig_video_lines	= 30,
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index b14d7647d800..d0f6f212f5df 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -26,7 +26,7 @@ struct rt_sigframe {
 
 #ifdef CONFIG_FPU
 static long restore_fp_state(struct pt_regs *regs,
-			     union __riscv_fp_state *sc_fpregs)
+			     union __riscv_fp_state __user *sc_fpregs)
 {
 	long err;
 	struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
@@ -53,7 +53,7 @@ static long restore_fp_state(struct pt_regs *regs,
 }
 
 static long save_fp_state(struct pt_regs *regs,
-			  union __riscv_fp_state *sc_fpregs)
+			  union __riscv_fp_state __user *sc_fpregs)
 {
 	long err;
 	struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
@@ -292,8 +292,8 @@ static void do_signal(struct pt_regs *regs)
  * notification of userspace execution resumption
  * - triggered by the _TIF_WORK_MASK flags
  */
-asmlinkage void do_notify_resume(struct pt_regs *regs,
-	unsigned long thread_info_flags)
+asmlinkage __visible void do_notify_resume(struct pt_regs *regs,
+					   unsigned long thread_info_flags)
 {
 	/* Handle pending signal delivery */
 	if (thread_info_flags & _TIF_SIGPENDING)
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 3836760d7aaf..5c9ec78422c2 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -8,7 +8,9 @@
  * Copyright (C) 2017 SiFive
  */
 
+#include <linux/cpu.h>
 #include <linux/interrupt.h>
+#include <linux/profile.h>
 #include <linux/smp.h>
 #include <linux/sched.h>
 #include <linux/seq_file.h>
@@ -206,3 +208,4 @@ void smp_send_reschedule(int cpu)
 {
 	send_ipi_single(cpu, IPI_RESCHEDULE);
 }
+EXPORT_SYMBOL_GPL(smp_send_reschedule);
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 18ae6da5115e..261f4087cc39 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -29,6 +29,9 @@
 #include <asm/tlbflush.h>
 #include <asm/sections.h>
 #include <asm/sbi.h>
+#include <asm/smp.h>
+
+#include "head.h"
 
 void *__cpu_up_stack_pointer[NR_CPUS];
 void *__cpu_up_task_pointer[NR_CPUS];
@@ -130,7 +133,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
 /*
  * C entry point for a secondary processor.
  */
-asmlinkage void __init smp_callin(void)
+asmlinkage __visible void __init smp_callin(void)
 {
 	struct mm_struct *mm = &init_mm;
 
diff --git a/arch/riscv/kernel/syscall_table.c b/arch/riscv/kernel/syscall_table.c
index e5dd52d8f633..f1ead9df96ca 100644
--- a/arch/riscv/kernel/syscall_table.c
+++ b/arch/riscv/kernel/syscall_table.c
@@ -8,6 +8,7 @@
 #include <linux/syscalls.h>
 #include <asm-generic/syscalls.h>
 #include <asm/vdso.h>
+#include <asm/syscall.h>
 
 #undef __SYSCALL
 #define __SYSCALL(nr, call)	[nr] = (call),
diff --git a/arch/riscv/kernel/time.c b/arch/riscv/kernel/time.c
index 541a2b885814..6a53c02e9c73 100644
--- a/arch/riscv/kernel/time.c
+++ b/arch/riscv/kernel/time.c
@@ -7,8 +7,10 @@
 #include <linux/clocksource.h>
 #include <linux/delay.h>
 #include <asm/sbi.h>
+#include <asm/processor.h>
 
 unsigned long riscv_timebase;
+EXPORT_SYMBOL_GPL(riscv_timebase);
 
 void __init time_init(void)
 {
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 424eb72d56b1..473de3ae8bb7 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -3,6 +3,7 @@
  * Copyright (C) 2012 Regents of the University of California
  */
 
+#include <linux/cpu.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/sched.h>
@@ -83,7 +84,7 @@ static void do_trap_error(struct pt_regs *regs, int signo, int code,
 }
 
 #define DO_ERROR_INFO(name, signo, code, str)				\
-asmlinkage void name(struct pt_regs *regs)				\
+asmlinkage __visible void name(struct pt_regs *regs)			\
 {									\
 	do_trap_error(regs, signo, code, regs->sepc, "Oops - " str);	\
 }
@@ -111,7 +112,6 @@ DO_ERROR_INFO(do_trap_ecall_s,
 DO_ERROR_INFO(do_trap_ecall_m,
 	SIGILL, ILL_ILLTRP, "environment call from M-mode");
 
-#ifdef CONFIG_GENERIC_BUG
 static inline unsigned long get_break_insn_length(unsigned long pc)
 {
 	bug_insn_t insn;
@@ -120,28 +120,15 @@ static inline unsigned long get_break_insn_length(unsigned long pc)
 		return 0;
 	return (((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) ? 4UL : 2UL);
 }
-#endif /* CONFIG_GENERIC_BUG */
 
-asmlinkage void do_trap_break(struct pt_regs *regs)
+asmlinkage __visible void do_trap_break(struct pt_regs *regs)
 {
-#ifdef CONFIG_GENERIC_BUG
-	if (!user_mode(regs)) {
-		enum bug_trap_type type;
-
-		type = report_bug(regs->sepc, regs);
-		switch (type) {
-		case BUG_TRAP_TYPE_NONE:
-			break;
-		case BUG_TRAP_TYPE_WARN:
-			regs->sepc += get_break_insn_length(regs->sepc);
-			break;
-		case BUG_TRAP_TYPE_BUG:
-			die(regs, "Kernel BUG");
-		}
-	}
-#endif /* CONFIG_GENERIC_BUG */
-
-	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc));
+	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);
+	else
+		die(regs, "Kernel BUG");
 }
 
 #ifdef CONFIG_GENERIC_BUG
diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
index c9c21e0d5641..484d95a70907 100644
--- a/arch/riscv/kernel/vdso.c
+++ b/arch/riscv/kernel/vdso.c
@@ -6,6 +6,7 @@
  * Copyright (C) 2015 Regents of the University of California
  */
 
+#include <linux/elf.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/binfmts.h>
@@ -25,7 +26,7 @@ static union {
 	struct vdso_data	data;
 	u8			page[PAGE_SIZE];
 } vdso_data_store __page_aligned_data;
-struct vdso_data *vdso_data = &vdso_data_store.data;
+static struct vdso_data *vdso_data = &vdso_data_store.data;
 
 static int __init vdso_init(void)
 {