[Skiboot] [PATCH 5/9] cpu: Keep track of the "ec_primary" in big core more

[Benjamin Herrenschmidt]

The "EC" primary is the primary thread of an EC, ie, the corresponding
small core "half" of the big core where the thread resides.

It will be necessary for the direct controls to target the right
half when doing special wakeups among others.

Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
 core/cpu.c    | 20 ++++++++++++++------
 include/cpu.h |  1 +
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/core/cpu.c b/core/cpu.c
index 4b7bd059..0a0c5d7e 100644
--- a/core/cpu.c
+++ b/core/cpu.c
@@ -803,9 +803,11 @@ struct cpu_thread *first_ungarded_cpu(void)
 
 struct cpu_thread *next_ungarded_primary(struct cpu_thread *cpu)
 {
+	bool is_primary;
 	do {
 		cpu = next_cpu(cpu);
-	} while(cpu && (cpu->state == cpu_state_unavailable || cpu->primary != cpu));
+		is_primary = cpu == cpu->primary || cpu == cpu->ec_primary;
+	} while(cpu && (cpu->state == cpu_state_unavailable || !is_primary));
 
 	return cpu;
 }
@@ -1148,7 +1150,7 @@ void init_all_cpus(void)
 		unsigned int pir, server_no, chip_id, threads;
 		enum cpu_thread_state state;
 		const struct dt_property *p;
-		struct cpu_thread *t, *pt;
+		struct cpu_thread *t, *pt0, *pt1;
 
 		/* Skip cache nodes */
 		if (strcmp(dt_prop_get(cpu, "device_type"), "cpu"))
@@ -1183,14 +1185,18 @@ void init_all_cpus(void)
 
 		/* Setup thread 0 */
 		assert(pir <= cpu_max_pir);
-		t = pt = &cpu_stacks[pir].cpu;
+		t = pt0 = &cpu_stacks[pir].cpu;
 		if (t != boot_cpu) {
 			init_cpu_thread(t, state, pir);
 			/* Each cpu gets its own later in init_trace_buffers */
 			t->trace = boot_cpu->trace;
 		}
+		if (t->is_fused_core)
+			pt1 = &cpu_stacks[pir + 1].cpu;
+		else
+			pt1 = pt0;
 		t->server_no = server_no;
-		t->primary = t;
+		t->primary = t->ec_primary = t;
 		t->node = cpu;
 		t->chip_id = chip_id;
 		t->icp_regs = NULL; /* Will be set later */
@@ -1228,10 +1234,12 @@ void init_all_cpus(void)
 			t->trace = boot_cpu->trace;
 			t->server_no = ((const u32 *)p->prop)[thread];
 			t->is_secondary = true;
-			t->primary = pt;
+			t->is_fused_core = pt0->is_fused_core;
+			t->primary = pt0;
+			t->ec_primary = (thread & 1) ? pt1 : pt0;
 			t->node = cpu;
 			t->chip_id = chip_id;
-			t->core_hmi_state_ptr = &pt->core_hmi_state;
+			t->core_hmi_state_ptr = &pt0->core_hmi_state;
 		}
 		prlog(PR_INFO, "CPU:  %d secondary threads\n", thread);
 	}
diff --git a/include/cpu.h b/include/cpu.h
index 2fb5edd2..a8ac5678 100644
--- a/include/cpu.h
+++ b/include/cpu.h
@@ -56,6 +56,7 @@ struct cpu_thread {
 	bool				is_secondary;
 	bool				is_fused_core;
 	struct cpu_thread		*primary;
+	struct cpu_thread		*ec_primary;
 	enum cpu_thread_state		state;
 	struct dt_node			*node;
 	struct trace_info		*trace;
-- 
2.17.1