powerpc: Properly handshake CPUs going out of boot spin loop

We need to wait a bit for them to have done their CPU setup
or we might end up with translation and EE on with different
LPCR values between threads

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 10 insertions, 17 deletions

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index e74fa12afc8..c391dc4c8ba 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -268,13 +268,12 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
                                           const char *uname, int depth,
                                           void *data)
 {
-        static int logical_cpuid = 0;
         char *type = of_get_flat_dt_prop(node, "device_type", NULL);
         const u32 *prop;
         const u32 *intserv;
         int i, nthreads;
         unsigned long len;
-        int found = 0;
+        int found = -1;
 
         /* We are scanning "cpu" nodes only */
         if (type == NULL || strcmp(type, "cpu") != 0)
@@ -299,11 +298,8 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
                  * booted proc.
                  */
                 if (initial_boot_params && initial_boot_params->version >= 2) {
-                        if (intserv[i] ==
-                                        initial_boot_params->boot_cpuid_phys) {
-                                found = 1;
-                                break;
-                        }
+                        if (intserv[i] == initial_boot_params->boot_cpuid_phys)
+                                found = boot_cpu_count;
                 } else {
                         /*
                          * Check if it's the boot-cpu, set it's hw index now,
@@ -311,23 +307,20 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
                          * off secondary threads.
                          */
                         if (of_get_flat_dt_prop(node,
-                                        "linux,boot-cpu", NULL) != NULL) {
-                                found = 1;
-                                break;
-                        }
+                                        "linux,boot-cpu", NULL) != NULL)
+                                found = boot_cpu_count;
                 }
-
 #ifdef CONFIG_SMP
                 /* logical cpu id is always 0 on UP kernels */
-                logical_cpuid++;
+                boot_cpu_count++;
 #endif
         }
 
-        if (found) {
-                DBG("boot cpu: logical %d physical %d\n", logical_cpuid,
+        if (found >= 0) {
+                DBG("boot cpu: logical %d physical %d\n", found,
                         intserv[i]);
-                boot_cpuid = logical_cpuid;
-                set_hard_smp_processor_id(boot_cpuid, intserv[i]);
+                boot_cpuid = found;
+                set_hard_smp_processor_id(found, intserv[i]);
 
                 /*
                  * PAPR defines "logical" PVR values for cpus that