RISC-V: Use common riscv_cpuid_to_hartid_mask() for both SMP=y and SMP=n

Use what is currently the SMP=y version of riscv_cpuid_to_hartid_mask()
for both SMP=y and SMP=n to fix a build failure with KVM=m and SMP=n due
to boot_cpu_hartid not being exported.  This also fixes a second bug
where the SMP=n version assumes the sole CPU in the system is in the
incoming mask, which may not hold true in kvm_riscv_vcpu_sbi_ecall() if
the KVM guest VM has multiple vCPUs (on a SMP=n system).

Fixes: 1ef46c2 ("RISC-V: Implement new SBI v0.2 extensions")
Reported-by: Adam Borowski <kilobyte@angband.pl>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Author: sean-jc

arch/riscv/include/asm/smp.h

@@ -43,7 +43,6 @@ void arch_send_call_function_ipi_mask(struct cpumask *mask);
 void arch_send_call_function_single_ipi(int cpu);
 
 int riscv_hartid_to_cpuid(int hartid);
-void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out);
 
 /* Set custom IPI operations */
 void riscv_set_ipi_ops(const struct riscv_ipi_ops *ops);
@@ -83,13 +82,6 @@ static inline unsigned long cpuid_to_hartid_map(int cpu)
 	return boot_cpu_hartid;
 }
 
-static inline void riscv_cpuid_to_hartid_mask(const struct cpumask *in,
-					      struct cpumask *out)
-{
-	cpumask_clear(out);
-	cpumask_set_cpu(boot_cpu_hartid, out);
-}
-
 static inline void riscv_set_ipi_ops(const struct riscv_ipi_ops *ops)
 {
 }
@@ -100,6 +92,8 @@ static inline void riscv_clear_ipi(void)
 
 #endif /* CONFIG_SMP */
 
+void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out);
+
 #if defined(CONFIG_HOTPLUG_CPU) && (CONFIG_SMP)
 bool cpu_has_hotplug(unsigned int cpu);
 #else

arch/riscv/kernel/setup.c

@@ -59,6 +59,16 @@ atomic_t hart_lottery __section(".sdata")
 unsigned long boot_cpu_hartid;
 static DEFINE_PER_CPU(struct cpu, cpu_devices);
 
+void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out)
+{
+	int cpu;
+
+	cpumask_clear(out);
+	for_each_cpu(cpu, in)
+		cpumask_set_cpu(cpuid_to_hartid_map(cpu), out);
+}
+EXPORT_SYMBOL_GPL(riscv_cpuid_to_hartid_mask);
+
 /*
  * Place kernel memory regions on the resource tree so that
  * kexec-tools can retrieve them from /proc/iomem. While there

arch/riscv/kernel/smp.c

@@ -59,16 +59,6 @@ int riscv_hartid_to_cpuid(int hartid)
 	return -ENOENT;
 }
 
-void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out)
-{
-	int cpu;
-
-	cpumask_clear(out);
-	for_each_cpu(cpu, in)
-		cpumask_set_cpu(cpuid_to_hartid_map(cpu), out);
-}
-EXPORT_SYMBOL_GPL(riscv_cpuid_to_hartid_mask);
-
 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
 {
 	return phys_id == cpuid_to_hartid_map(cpu);