[PATCH v2 2/8] RISC-V: Move cpuid to hartid mapping to SMP.

Atish Patra
2019-01-08T09:39:13Z

Currently, logical CPU id to physical hartid mapping is
defined for both smp and non-smp configurations. This
is not required as we need this only for smp configuration.
The mapping function can define directly boot_cpu_hartid
for non-smp use case.

The reverse mapping function i.e. hartid to cpuid can be called
for any valid but not booted harts. So it should return default
cpu 0 only if it is a boot hartid.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
---
arch/riscv/include/asm/smp.h | 15 ++++++++++++---
arch/riscv/kernel/setup.c | 9 ---------
arch/riscv/kernel/smp.c | 9 +++++++++
3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/arch/riscv/include/asm/smp.h b/arch/riscv/include/asm/smp.h
index 41aa73b4..8f30300f 100644
--- a/arch/riscv/include/asm/smp.h
+++ b/arch/riscv/include/asm/smp.h
@@ -22,12 +22,13 @@
/*
* Mapping between linux logical cpu index and hartid.
*/
-extern unsigned long __cpuid_to_hartid_map[NR_CPUS];
-#define cpuid_to_hartid_map(cpu) __cpuid_to_hartid_map[cpu]

+extern unsigned long boot_cpu_hartid;
struct seq_file;

#ifdef CONFIG_SMP
+extern unsigned long __cpuid_to_hartid_map[NR_CPUS];
+#define cpuid_to_hartid_map(cpu) __cpuid_to_hartid_map[cpu]

/* print IPI stats */
void show_ipi_stats(struct seq_file *p, int prec);
@@ -58,7 +59,15 @@ static inline void show_ipi_stats(struct seq_file *p, int prec)

static inline int riscv_hartid_to_cpuid(int hartid)
{
- return 0;
+ if (hartid == boot_cpu_hartid)
+ return 0;
+ else
+ return -1;
+}
+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,
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index fc8006a0..f377add4 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -61,15 +61,6 @@ EXPORT_SYMBOL(empty_zero_page);
atomic_t hart_lottery;
unsigned long boot_cpu_hartid;

-unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
- [0 ... NR_CPUS-1] = INVALID_HARTID
-};
-
-void __init smp_setup_processor_id(void)
-{
- cpuid_to_hartid_map(0) = boot_cpu_hartid;
-}
-
#ifdef CONFIG_BLK_DEV_INITRD
static void __init setup_initrd(void)
{
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 57b1383e..e407bd4f 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -34,6 +34,15 @@ enum ipi_message_type {
IPI_MAX
};

+unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
+ [0 ... NR_CPUS-1] = INVALID_HARTID
+};
+
+void __init smp_setup_processor_id(void)
+{
+ cpuid_to_hartid_map(0) = boot_cpu_hartid;
+}
+
/* A collection of single bit ipi messages. */
static struct {
unsigned long stats[IPI_MAX] ____cacheline_aligned;
--
2.7.4