Hi Catalin,
On 2014年01月24日 01:50, Catalin Marinas wrote:
On Fri, Jan 17, 2014 at 12:25:05PM +0000, Hanjun Guo wrote:
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -48,6 +48,7 @@
#include <asm/sections.h>
#include <asm/tlbflush.h>
#include <asm/ptrace.h>
+#include <asm/acpi.h>
/*
* as from 2.5, kernels no longer have an init_tasks structure
@@ -280,7 +281,7 @@ static void (*smp_cross_call)(const struct cpumask *, unsigned int);
* cpu logical map array containing MPIDR values related to logical
* cpus. Assumes that cpu_logical_map(0) has already been initialized.
*/
-void __init smp_init_cpus(void)
+static int __init of_smp_init_cpus(void)
{
struct device_node *dn = NULL;
unsigned int i, cpu = 1;
@@ -364,6 +365,10 @@ next:
cpu++;
}
+ /* No device tree or no CPU node in DT */
+ if (cpu == 1 && !bootcpu_valid)
+ return -ENODEV;
+
/* sanity check */
if (cpu > NR_CPUS)
pr_warning("no. of cores (%d) greater than configured maximum of %d - clipping\n",
@@ -371,7 +376,7 @@ next:
if (!bootcpu_valid) {
pr_err("DT missing boot CPU MPIDR, not enabling secondaries\n");
- return;
+ return -EINVAL;
}
/*
@@ -381,6 +386,39 @@ next:
for (i = 0; i < NR_CPUS; i++)
if (cpu_logical_map(i) != INVALID_HWID)
set_cpu_possible(i, true);
+
+ return 0;
+}
+
+/*
+ * In ACPI mode, the cpu possible map was enumerated before SMP
+ * initialization when MADT table was parsed, so we can get the
+ * possible map here to initialize CPUs.
+ */
+static void __init acpi_smp_init_cpus(void)
+{
+ int cpu;
+ const char *enable_method;
+
+ for_each_possible_cpu(cpu) {
+ enable_method = acpi_get_enable_method(cpu);
+ if (!enable_method)
+ continue;
+
+ cpu_ops[cpu] = cpu_get_ops(enable_method);
+ if (!cpu_ops[cpu])
+ continue;
+
+ cpu_ops[cpu]->cpu_init(NULL, cpu);
+ }
+}
+
+void __init smp_init_cpus(void)
+{
+ if (!of_smp_init_cpus())
+ return;
+
+ acpi_smp_init_cpus();
}
With DT we initialise the cpu_ops[0] via cpu_read_bootcpu_ops() called
from setup_arch(). This is needed because with PSCI we use cpu_ops for
power management even if it's a UP system. Do you get a some kernel
warning about device node for the boot cpu not found?
Thanks for pointing this out, actually we didn't find a dts file with
spin-table method for SMP initialization, and this patch is not fully
tested (only spin-table method is supported in ACPI now), we are
working on that and get this patch fully tested.
I will review the code carefully in your comments, and update
the code accordingly.
--- a/drivers/acpi/plat/arm-core.c
+++ b/drivers/acpi/plat/arm-core.c
@@ -367,6 +367,32 @@ static void __init acpi_process_madt(void)
}
/*
+ * To see PCSI is enabled or not.
+ *
+ * PSCI is not available for ACPI 5.0, return FALSE for now.
+ *
+ * FIXME: should we introduce early_param("psci", func) for test purpose?
+ */
+static bool acpi_psci_smp_available(int cpu)
+{
+ return FALSE;
+}
+
+static const char *enable_method[] = {
+ "psci",
+ "spin-table",
+ NULL
+};
+
+const char *acpi_get_enable_method(int cpu)
+{
+ if (acpi_psci_smp_available(cpu))
+ return enable_method[0];
+ else
+ return enable_method[1];
+}
You could just use literal strings here, actually even ignoring PSCI
until available.
Ok.
Thanks
Hanjun
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