@@ -89,6 +89,8 @@ static void mcip_ipi_clear(int irq)
static void mcip_probe_n_setup(void)
{
struct mcip_bcr mp;
+ u32 mcip_mask = 0;
+ int i;
READ_BCR(ARC_REG_MCIP_BCR, mp);
@@ -102,9 +104,13 @@ static void mcip_probe_n_setup(void)
cpuinfo_arc700[0].extn.gfrc = mp.gfrc;
+ for (i = 0; i < NR_CPUS; i++)
+ if (cpu_possible(i))
+ mcip_mask |= BIT(i);
+
if (mp.dbg) {
- __mcip_cmd_data(CMD_DEBUG_SET_SELECT, 0, 0xf);
- __mcip_cmd_data(CMD_DEBUG_SET_MASK, 0xf, 0xf);
+ __mcip_cmd_data(CMD_DEBUG_SET_SELECT, 0, mcip_mask);
+ __mcip_cmd_data(CMD_DEBUG_SET_MASK, 0xf, mcip_mask);
}
}
@@ -24,6 +24,8 @@
#include <linux/reboot.h>
#include <linux/irqdomain.h>
#include <linux/export.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
#include <asm/processor.h>
#include <asm/setup.h>
@@ -47,6 +49,29 @@ void __init smp_prepare_boot_cpu(void)
{
}
+/* Mark cpu as possible if cpu status is "okay" or status absents */
+void __init smp_init_cpumask(void)
+{
+ const struct fdt_property *prop;
+ char fdt_cpu_path[25];
+ unsigned int i, oft;
+
+ for (i = 0; i < NR_CPUS; i++) {
+ sprintf(fdt_cpu_path, "/cpus/cpu@%u", i);
+ oft = fdt_path_offset(initial_boot_params, fdt_cpu_path);
+ prop = fdt_get_property(initial_boot_params, oft, "status", NULL);
+
+ /* No status property == status OK */
+ if (!prop) {
+ set_cpu_possible(i, true);
+ continue;
+ }
+
+ if (!strcmp("okay", prop->data))
+ set_cpu_possible(i, true);
+ }
+}
+
/*
* Called from setup_arch() before calling setup_processor()
*
@@ -58,10 +83,7 @@ void __init smp_prepare_boot_cpu(void)
*/
void __init smp_init_cpus(void)
{
- unsigned int i;
-
- for (i = 0; i < NR_CPUS; i++)
- set_cpu_possible(i, true);
+ smp_init_cpumask();
if (plat_smp_ops.init_early_smp)
plat_smp_ops.init_early_smp();
As we have option in u-boot to set CPU mask for running linux, we want to pass information to kernel about CPU cores should be brought up. So we patch kernel dtb in u-boot to set CPUs status. On linux boot we setup cpu possible mask according to status field in each cpu node. It is generic method according to ePAPR: status - a standard property describing the state of a CPU. This property shall be present for nodes representing CPUs in a symmetric multiprocessing (SMP) configuration. For a CPU node the meaning of the "okay" and "disabled" values are as follows: "okay" - The CPU is running; "disabled" - The CPU is in a quiescent state." Also we setup MCIP debug mask according cpu possible mask. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> --- arch/arc/kernel/mcip.c | 10 ++++++++-- arch/arc/kernel/smp.c | 30 ++++++++++++++++++++++++++---- 2 files changed, 34 insertions(+), 6 deletions(-)