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Diffstat (limited to 'arch/arm64/kernel/smp_spin_table.c')
-rw-r--r--arch/arm64/kernel/smp_spin_table.c97
1 files changed, 91 insertions, 6 deletions
diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c
index 7c35fa682f76..44c22805d2e2 100644
--- a/arch/arm64/kernel/smp_spin_table.c
+++ b/arch/arm64/kernel/smp_spin_table.c
@@ -16,15 +16,39 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/delay.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/smp.h>
#include <asm/cacheflush.h>
+#include <asm/cpu_ops.h>
+#include <asm/cputype.h>
+#include <asm/smp_plat.h>
+
+extern void secondary_holding_pen(void);
+volatile unsigned long secondary_holding_pen_release = INVALID_HWID;
static phys_addr_t cpu_release_addr[NR_CPUS];
+static DEFINE_RAW_SPINLOCK(boot_lock);
+
+/*
+ * Write secondary_holding_pen_release in a way that is guaranteed to be
+ * visible to all observers, irrespective of whether they're taking part
+ * in coherency or not. This is necessary for the hotplug code to work
+ * reliably.
+ */
+static void write_pen_release(u64 val)
+{
+ void *start = (void *)&secondary_holding_pen_release;
+ unsigned long size = sizeof(secondary_holding_pen_release);
-static int __init smp_spin_table_init_cpu(struct device_node *dn, int cpu)
+ secondary_holding_pen_release = val;
+ __flush_dcache_area(start, size);
+}
+
+
+static int smp_spin_table_cpu_init(struct device_node *dn, unsigned int cpu)
{
/*
* Determine the address from which the CPU is polling.
@@ -40,7 +64,7 @@ static int __init smp_spin_table_init_cpu(struct device_node *dn, int cpu)
return 0;
}
-static int __init smp_spin_table_prepare_cpu(int cpu)
+static int smp_spin_table_cpu_prepare(unsigned int cpu)
{
void **release_addr;
@@ -48,7 +72,16 @@ static int __init smp_spin_table_prepare_cpu(int cpu)
return -ENODEV;
release_addr = __va(cpu_release_addr[cpu]);
- release_addr[0] = (void *)__pa(secondary_holding_pen);
+
+ /*
+ * We write the release address as LE regardless of the native
+ * endianess of the kernel. Therefore, any boot-loaders that
+ * read this address need to convert this address to the
+ * boot-loader's endianess before jumping. This is mandated by
+ * the boot protocol.
+ */
+ release_addr[0] = (void *) cpu_to_le64(__pa(secondary_holding_pen));
+
__flush_dcache_area(release_addr, sizeof(release_addr[0]));
/*
@@ -59,8 +92,60 @@ static int __init smp_spin_table_prepare_cpu(int cpu)
return 0;
}
-const struct smp_enable_ops smp_spin_table_ops __initconst = {
+static int smp_spin_table_cpu_boot(unsigned int cpu)
+{
+ unsigned long timeout;
+
+ /*
+ * Set synchronisation state between this boot processor
+ * and the secondary one
+ */
+ raw_spin_lock(&boot_lock);
+
+ /*
+ * Update the pen release flag.
+ */
+ write_pen_release(cpu_logical_map(cpu));
+
+ /*
+ * Send an event, causing the secondaries to read pen_release.
+ */
+ sev();
+
+ timeout = jiffies + (1 * HZ);
+ while (time_before(jiffies, timeout)) {
+ if (secondary_holding_pen_release == INVALID_HWID)
+ break;
+ udelay(10);
+ }
+
+ /*
+ * Now the secondary core is starting up let it run its
+ * calibrations, then wait for it to finish
+ */
+ raw_spin_unlock(&boot_lock);
+
+ return secondary_holding_pen_release != INVALID_HWID ? -ENOSYS : 0;
+}
+
+void smp_spin_table_cpu_postboot(void)
+{
+ /*
+ * Let the primary processor know we're out of the pen.
+ */
+ write_pen_release(INVALID_HWID);
+
+ /*
+ * Synchronise with the boot thread.
+ */
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
+}
+
+const struct cpu_operations smp_spin_table_ops = {
.name = "spin-table",
- .init_cpu = smp_spin_table_init_cpu,
- .prepare_cpu = smp_spin_table_prepare_cpu,
+ .cpu_init = smp_spin_table_cpu_init,
+ .cpu_prepare = smp_spin_table_cpu_prepare,
+ .cpu_boot = smp_spin_table_cpu_boot,
+ .cpu_postboot = smp_spin_table_cpu_postboot,
};