14 files changed, 115 insertions, 127 deletions

diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c
index dac98348c6a3..578bb5efc085 100644
--- a/arch/riscv/kernel/asm-offsets.c
+++ b/arch/riscv/kernel/asm-offsets.c
@@ -312,9 +312,6 @@ void asm_offsets(void)
 		- offsetof(struct task_struct, thread.fstate.f[0])
 	);
 
-	/* The assembler needs access to THREAD_SIZE as well. */
-	DEFINE(ASM_THREAD_SIZE, THREAD_SIZE);
-
 	/*
 	 * We allocate a pt_regs on the stack when entering the kernel.  This
 	 * ensures the alignment is sane.
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index cf2fca12414a..c8d2a3223099 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -136,8 +136,7 @@ static void c_stop(struct seq_file *m, void *v)
 static int c_show(struct seq_file *m, void *v)
 {
 	unsigned long cpu_id = (unsigned long)v - 1;
-	struct device_node *node = of_get_cpu_node(cpuid_to_hartid_map(cpu_id),
-						   NULL);
+	struct device_node *node = of_get_cpu_node(cpu_id, NULL);
 	const char *compat, *isa, *mmu;
 
 	seq_printf(m, "processor\t: %lu\n", cpu_id);
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index fd9b57c8b4ce..1c1ecc238cfa 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -37,11 +37,11 @@
 	 * the kernel thread pointer.  If we came from the kernel, sscratch
 	 * will contain 0, and we should continue on the current TP.
 	 */
-	csrrw tp, sscratch, tp
+	csrrw tp, CSR_SSCRATCH, tp
 	bnez tp, _save_context
 
 _restore_kernel_tpsp:
-	csrr tp, sscratch
+	csrr tp, CSR_SSCRATCH
 	REG_S sp, TASK_TI_KERNEL_SP(tp)
 _save_context:
 	REG_S sp, TASK_TI_USER_SP(tp)
@@ -87,11 +87,11 @@ _save_context:
 	li t0, SR_SUM | SR_FS
 
 	REG_L s0, TASK_TI_USER_SP(tp)
-	csrrc s1, sstatus, t0
-	csrr s2, sepc
-	csrr s3, sbadaddr
-	csrr s4, scause
-	csrr s5, sscratch
+	csrrc s1, CSR_SSTATUS, t0
+	csrr s2, CSR_SEPC
+	csrr s3, CSR_STVAL
+	csrr s4, CSR_SCAUSE
+	csrr s5, CSR_SSCRATCH
 	REG_S s0, PT_SP(sp)
 	REG_S s1, PT_SSTATUS(sp)
 	REG_S s2, PT_SEPC(sp)
@@ -107,8 +107,8 @@ _save_context:
 	.macro RESTORE_ALL
 	REG_L a0, PT_SSTATUS(sp)
 	REG_L a2, PT_SEPC(sp)
-	csrw sstatus, a0
-	csrw sepc, a2
+	csrw CSR_SSTATUS, a0
+	csrw CSR_SEPC, a2
 
 	REG_L x1,  PT_RA(sp)
 	REG_L x3,  PT_GP(sp)
@@ -155,7 +155,7 @@ ENTRY(handle_exception)
 	 * Set sscratch register to 0, so that if a recursive exception
 	 * occurs, the exception vector knows it came from the kernel
 	 */
-	csrw sscratch, x0
+	csrw CSR_SSCRATCH, x0
 
 	/* Load the global pointer */
 .option push
@@ -248,7 +248,7 @@ resume_userspace:
 	 * Save TP into sscratch, so we can find the kernel data structures
 	 * again.
 	 */
-	csrw sscratch, tp
+	csrw CSR_SSCRATCH, tp
 
 restore_all:
 	RESTORE_ALL
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index fe884cd69abd..370c66ce187a 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -23,7 +23,8 @@
 __INIT
 ENTRY(_start)
 	/* Mask all interrupts */
-	csrw sie, zero
+	csrw CSR_SIE, zero
+	csrw CSR_SIP, zero
 
 	/* Load the global pointer */
 .option push
@@ -68,14 +69,10 @@ clear_bss_done:
 	/* Restore C environment */
 	la tp, init_task
 	sw zero, TASK_TI_CPU(tp)
-
-	la sp, init_thread_union
-	li a0, ASM_THREAD_SIZE
-	add sp, sp, a0
+	la sp, init_thread_union + THREAD_SIZE
 
 	/* Start the kernel */
-	mv a0, s0
-	mv a1, s1
+	mv a0, s1
 	call parse_dtb
 	tail start_kernel
 
@@ -89,7 +86,7 @@ relocate:
 	/* Point stvec to virtual address of intruction after satp write */
 	la a0, 1f
 	add a0, a0, a1
-	csrw stvec, a0
+	csrw CSR_STVEC, a0
 
 	/* Compute satp for kernel page tables, but don't load it yet */
 	la a2, swapper_pg_dir
@@ -99,18 +96,20 @@ relocate:
 
 	/*
 	 * Load trampoline page directory, which will cause us to trap to
-	 * stvec if VA != PA, or simply fall through if VA == PA
+	 * stvec if VA != PA, or simply fall through if VA == PA.  We need a
+	 * full fence here because setup_vm() just wrote these PTEs and we need
+	 * to ensure the new translations are in use.
 	 */
 	la a0, trampoline_pg_dir
 	srl a0, a0, PAGE_SHIFT
 	or a0, a0, a1
 	sfence.vma
-	csrw sptbr, a0
+	csrw CSR_SATP, a0
 .align 2
 1:
 	/* Set trap vector to spin forever to help debug */
 	la a0, .Lsecondary_park
-	csrw stvec, a0
+	csrw CSR_STVEC, a0
 
 	/* Reload the global pointer */
 .option push
@@ -118,8 +117,14 @@ relocate:
 	la gp, __global_pointer$
 .option pop
 
-	/* Switch to kernel page tables */
-	csrw sptbr, a2
+	/*
+	 * Switch to kernel page tables.  A full fence is necessary in order to
+	 * avoid using the trampoline translations, which are only correct for
+	 * the first superpage.  Fetching the fence is guarnteed to work
+	 * because that first superpage is translated the same way.
+	 */
+	csrw CSR_SATP, a2
+	sfence.vma
 
 	ret
 
@@ -130,7 +135,7 @@ relocate:
 
 	/* Set trap vector to spin forever to help debug */
 	la a3, .Lsecondary_park
-	csrw stvec, a3
+	csrw CSR_STVEC, 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 48e6b7db83a1..6d8659388c49 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -14,17 +14,9 @@
 /*
  * Possible interrupt causes:
  */
-#define INTERRUPT_CAUSE_SOFTWARE    1
-#define INTERRUPT_CAUSE_TIMER       5
-#define INTERRUPT_CAUSE_EXTERNAL    9
-
-/*
- * The high order bit of the trap cause register is always set for
- * interrupts, which allows us to differentiate them from exceptions
- * quickly.  The INTERRUPT_CAUSE_* macros don't contain that bit, so we
- * need to mask it off.
- */
-#define INTERRUPT_CAUSE_FLAG	(1UL << (__riscv_xlen - 1))
+#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)
 {
@@ -37,7 +29,7 @@ asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs)
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
 	irq_enter();
-	switch (regs->scause & ~INTERRUPT_CAUSE_FLAG) {
+	switch (regs->scause & ~SCAUSE_IRQ_FLAG) {
 	case INTERRUPT_CAUSE_TIMER:
 		riscv_timer_interrupt();
 		break;
@@ -54,7 +46,8 @@ asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs)
 		handle_arch_irq(regs);
 		break;
 	default:
-		panic("unexpected interrupt cause");
+		pr_alert("unexpected interrupt cause 0x%lx", regs->scause);
+		BUG();
 	}
 	irq_exit();
 
diff --git a/arch/riscv/kernel/perf_event.c b/arch/riscv/kernel/perf_event.c
index 667ee70defea..91626d9ae5f2 100644
--- a/arch/riscv/kernel/perf_event.c
+++ b/arch/riscv/kernel/perf_event.c
@@ -185,10 +185,10 @@ static inline u64 read_counter(int idx)
 
 	switch (idx) {
 	case RISCV_PMU_CYCLE:
-		val = csr_read(cycle);
+		val = csr_read(CSR_CYCLE);
 		break;
 	case RISCV_PMU_INSTRET:
-		val = csr_read(instret);
+		val = csr_read(CSR_INSTRET);
 		break;
 	default:
 		WARN_ON_ONCE(idx < 0 ||	idx > RISCV_MAX_COUNTERS);
diff --git a/arch/riscv/kernel/reset.c b/arch/riscv/kernel/reset.c
index 2a53d26ffdd6..ed637aee514b 100644
--- a/arch/riscv/kernel/reset.c
+++ b/arch/riscv/kernel/reset.c
@@ -12,11 +12,15 @@
  */
 
 #include <linux/reboot.h>
-#include <linux/export.h>
 #include <asm/sbi.h>
 
-void (*pm_power_off)(void) = machine_power_off;
-EXPORT_SYMBOL(pm_power_off);
+static void default_power_off(void)
+{
+	sbi_shutdown();
+	while (1);
+}
+
+void (*pm_power_off)(void) = default_power_off;
 
 void machine_restart(char *cmd)
 {
@@ -26,11 +30,10 @@ void machine_restart(char *cmd)
 
 void machine_halt(void)
 {
-	machine_power_off();
+	pm_power_off();
 }
 
 void machine_power_off(void)
 {
-	sbi_shutdown();
-	while (1);
+	pm_power_off();
 }
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 540a331d1376..d93bcce004e3 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -52,9 +52,11 @@ struct screen_info screen_info = {
 atomic_t hart_lottery;
 unsigned long boot_cpu_hartid;
 
-void __init parse_dtb(unsigned int hartid, void *dtb)
+void __init parse_dtb(phys_addr_t dtb_phys)
 {
-	if (early_init_dt_scan(__va(dtb)))
+	void *dtb = __va(dtb_phys);
+
+	if (early_init_dt_scan(dtb))
 		return;
 
 	pr_err("No DTB passed to the kernel\n");
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index 837e1646091a..804d6ee4f3c5 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -234,6 +234,9 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 
 	/* Are we from a system call? */
 	if (regs->scause == EXC_SYSCALL) {
+		/* Avoid additional syscall restarting via ret_from_exception */
+		regs->scause = -1UL;
+
 		/* If so, check system call restarting.. */
 		switch (regs->a0) {
 		case -ERESTART_RESTARTBLOCK:
@@ -272,6 +275,9 @@ static void do_signal(struct pt_regs *regs)
 
 	/* Did we come from a system call? */
 	if (regs->scause == EXC_SYSCALL) {
+		/* Avoid additional syscall restarting via ret_from_exception */
+		regs->scause = -1UL;
+
 		/* Restart the system call - no handlers present */
 		switch (regs->a0) {
 		case -ERESTARTNOHAND:
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 0c41d07ec281..b2537ffa855c 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -42,7 +42,7 @@ unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
 
 void __init smp_setup_processor_id(void)
 {
-       cpuid_to_hartid_map(0) = boot_cpu_hartid;
+	cpuid_to_hartid_map(0) = boot_cpu_hartid;
 }
 
 /* A collection of single bit ipi messages.  */
@@ -53,7 +53,7 @@ static struct {
 
 int riscv_hartid_to_cpuid(int hartid)
 {
-	int i = -1;
+	int i;
 
 	for (i = 0; i < NR_CPUS; i++)
 		if (cpuid_to_hartid_map(i) == hartid)
@@ -70,6 +70,12 @@ void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out)
 	for_each_cpu(cpu, in)
 		cpumask_set_cpu(cpuid_to_hartid_map(cpu), out);
 }
+
+bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return phys_id == cpuid_to_hartid_map(cpu);
+}
+
 /* Unsupported */
 int setup_profiling_timer(unsigned int multiplier)
 {
@@ -89,7 +95,7 @@ void riscv_software_interrupt(void)
 	unsigned long *stats = ipi_data[smp_processor_id()].stats;
 
 	/* Clear pending IPI */
-	csr_clear(sip, SIE_SSIE);
+	csr_clear(CSR_SIP, SIE_SSIE);
 
 	while (true) {
 		unsigned long ops;
@@ -199,52 +205,3 @@ void smp_send_reschedule(int cpu)
 	send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
 }
 
-/*
- * Performs an icache flush for the given MM context.  RISC-V has no direct
- * mechanism for instruction cache shoot downs, so instead we send an IPI that
- * informs the remote harts they need to flush their local instruction caches.
- * To avoid pathologically slow behavior in a common case (a bunch of
- * single-hart processes on a many-hart machine, ie 'make -j') we avoid the
- * IPIs for harts that are not currently executing a MM context and instead
- * schedule a deferred local instruction cache flush to be performed before
- * execution resumes on each hart.
- */
-void flush_icache_mm(struct mm_struct *mm, bool local)
-{
-	unsigned int cpu;
-	cpumask_t others, hmask, *mask;
-
-	preempt_disable();
-
-	/* Mark every hart's icache as needing a flush for this MM. */
-	mask = &mm->context.icache_stale_mask;
-	cpumask_setall(mask);
-	/* Flush this hart's I$ now, and mark it as flushed. */
-	cpu = smp_processor_id();
-	cpumask_clear_cpu(cpu, mask);
-	local_flush_icache_all();
-
-	/*
-	 * Flush the I$ of other harts concurrently executing, and mark them as
-	 * flushed.
-	 */
-	cpumask_andnot(&others, mm_cpumask(mm), cpumask_of(cpu));
-	local |= cpumask_empty(&others);
-	if (mm != current->active_mm || !local) {
-		cpumask_clear(&hmask);
-		riscv_cpuid_to_hartid_mask(&others, &hmask);
-		sbi_remote_fence_i(hmask.bits);
-	} else {
-		/*
-		 * It's assumed that at least one strongly ordered operation is
-		 * performed on this hart between setting a hart's cpumask bit
-		 * and scheduling this MM context on that hart.  Sending an SBI
-		 * remote message will do this, but in the case where no
-		 * messages are sent we still need to order this hart's writes
-		 * with flush_icache_deferred().
-		 */
-		smp_mb();
-	}
-
-	preempt_enable();
-}
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index eb533b5c2c8c..7a0b62252524 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -47,6 +47,17 @@ void __init smp_prepare_boot_cpu(void)
 
 void __init smp_prepare_cpus(unsigned int max_cpus)
 {
+	int cpuid;
+
+	/* This covers non-smp usecase mandated by "nosmp" option */
+	if (max_cpus == 0)
+		return;
+
+	for_each_possible_cpu(cpuid) {
+		if (cpuid == smp_processor_id())
+			continue;
+		set_cpu_present(cpuid, true);
+	}
 }
 
 void __init setup_smp(void)
@@ -73,12 +84,19 @@ void __init setup_smp(void)
 		}
 
 		cpuid_to_hartid_map(cpuid) = hart;
-		set_cpu_possible(cpuid, true);
-		set_cpu_present(cpuid, true);
 		cpuid++;
 	}
 
 	BUG_ON(!found_boot_cpu);
+
+	if (cpuid > nr_cpu_ids)
+		pr_warn("Total number of cpus [%d] is greater than nr_cpus option value [%d]\n",
+			cpuid, nr_cpu_ids);
+
+	for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) {
+		if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID)
+			set_cpu_possible(cpuid, true);
+	}
 }
 
 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index a4b1d94371a0..e80a5e8da119 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -33,9 +33,9 @@ static void notrace walk_stackframe(struct task_struct *task,
 	unsigned long fp, sp, pc;
 
 	if (regs) {
-		fp = GET_FP(regs);
-		sp = GET_USP(regs);
-		pc = GET_IP(regs);
+		fp = frame_pointer(regs);
+		sp = user_stack_pointer(regs);
+		pc = instruction_pointer(regs);
 	} else if (task == NULL || task == current) {
 		const register unsigned long current_sp __asm__ ("sp");
 		fp = (unsigned long)__builtin_frame_address(0);
@@ -64,12 +64,8 @@ static void notrace walk_stackframe(struct task_struct *task,
 		frame = (struct stackframe *)fp - 1;
 		sp = fp;
 		fp = frame->fp;
-#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
 		pc = ftrace_graph_ret_addr(current, NULL, frame->ra,
 					   (unsigned long *)(fp - 8));
-#else
-		pc = frame->ra - 0x4;
-#endif
 	}
 }
 
@@ -82,8 +78,8 @@ static void notrace walk_stackframe(struct task_struct *task,
 	unsigned long *ksp;
 
 	if (regs) {
-		sp = GET_USP(regs);
-		pc = GET_IP(regs);
+		sp = user_stack_pointer(regs);
+		pc = instruction_pointer(regs);
 	} else if (task == NULL || task == current) {
 		const register unsigned long current_sp __asm__ ("sp");
 		sp = current_sp;
@@ -169,8 +165,6 @@ static bool save_trace(unsigned long pc, void *arg)
 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 {
 	walk_stackframe(tsk, NULL, save_trace, trace);
-	if (trace->nr_entries < trace->max_entries)
-		trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
 
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 24a9333dda2c..3d1a651dc54c 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -70,7 +70,7 @@ void do_trap(struct pt_regs *regs, int signo, int code,
 	    && printk_ratelimit()) {
 		pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT,
 			tsk->comm, task_pid_nr(tsk), signo, code, addr);
-		print_vma_addr(KERN_CONT " in ", GET_IP(regs));
+		print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
 		pr_cont("\n");
 		show_regs(regs);
 	}
@@ -118,6 +118,17 @@ 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;
+
+	if (probe_kernel_address((bug_insn_t *)pc, insn))
+		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)
 {
 #ifdef CONFIG_GENERIC_BUG
@@ -129,8 +140,8 @@ asmlinkage void do_trap_break(struct pt_regs *regs)
 		case BUG_TRAP_TYPE_NONE:
 			break;
 		case BUG_TRAP_TYPE_WARN:
-			regs->sepc += sizeof(bug_insn_t);
-			return;
+			regs->sepc += get_break_insn_length(regs->sepc);
+			break;
 		case BUG_TRAP_TYPE_BUG:
 			die(regs, "Kernel BUG");
 		}
@@ -145,11 +156,14 @@ int is_valid_bugaddr(unsigned long pc)
 {
 	bug_insn_t insn;
 
-	if (pc < PAGE_OFFSET)
+	if (pc < VMALLOC_START)
 		return 0;
 	if (probe_kernel_address((bug_insn_t *)pc, insn))
 		return 0;
-	return (insn == __BUG_INSN);
+	if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
+		return (insn == __BUG_INSN_32);
+	else
+		return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16);
 }
 #endif /* CONFIG_GENERIC_BUG */
 
@@ -159,9 +173,9 @@ 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(sscratch, 0);
+	csr_write(CSR_SSCRATCH, 0);
 	/* Set the exception vector address */
-	csr_write(stvec, &handle_exception);
+	csr_write(CSR_STVEC, &handle_exception);
 	/* Enable all interrupts */
-	csr_write(sie, -1);
+	csr_write(CSR_SIE, -1);
 }
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index fec62b24df89..b07b765f312a 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -36,7 +36,7 @@ $(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
 # these symbols in the kernel code rather than hand-coded addresses.
 
 SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
-                            $(call cc-ldoption, -Wl$(comma)--hash-style=both)
+	-Wl,--hash-style=both
 $(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
 	$(call if_changed,vdsold)