powerpc/85xx: Move ePAPR paravirt initialization earlier

At console init, when the kernel tries to flush the log buffer
the ePAPR byte-channel based console write fails silently,
losing the buffered messages.
This happens because The ePAPR para-virtualization init isn't
done early enough so that the hcall instruction to be set,
causing the byte-channel write hcall to be a nop.
To fix, change the ePAPR para-virt init to use early device
tree functions and move it in early init.

Signed-off-by: Laurentiu Tudor <Laurentiu.Tudor@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

1 files changed, 16 insertions, 12 deletions

diff --git a/arch/powerpc/kernel/epapr_paravirt.c b/arch/powerpc/kernel/epapr_paravirt.c
index d44a571e45a7..6300c13bbde4 100644
--- a/arch/powerpc/kernel/epapr_paravirt.c
+++ b/arch/powerpc/kernel/epapr_paravirt.c
@@ -30,22 +30,20 @@ extern u32 epapr_ev_idle_start[];
 
 bool epapr_paravirt_enabled;
 
-static int __init epapr_paravirt_init(void)
+static int __init early_init_dt_scan_epapr(unsigned long node,
+					   const char *uname,
+					   int depth, void *data)
 {
-	struct device_node *hyper_node;
 	const u32 *insts;
-	int len, i;
+	unsigned long len;
+	int i;
 
-	hyper_node = of_find_node_by_path("/hypervisor");
-	if (!hyper_node)
-		return -ENODEV;
-
-	insts = of_get_property(hyper_node, "hcall-instructions", &len);
+	insts = of_get_flat_dt_prop(node, "hcall-instructions", &len);
 	if (!insts)
-		return -ENODEV;
+		return 0;
 
 	if (len % 4 || len > (4 * 4))
-		return -ENODEV;
+		return -1;
 
 	for (i = 0; i < (len / 4); i++) {
 		patch_instruction(epapr_hypercall_start + i, insts[i]);
@@ -55,13 +53,19 @@ static int __init epapr_paravirt_init(void)
 	}
 
 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
-	if (of_get_property(hyper_node, "has-idle", NULL))
+	if (of_get_flat_dt_prop(node, "has-idle", NULL))
 		ppc_md.power_save = epapr_ev_idle;
 #endif
 
 	epapr_paravirt_enabled = true;
 
+	return 1;
+}
+
+int __init epapr_paravirt_early_init(void)
+{
+	of_scan_flat_dt(early_init_dt_scan_epapr, NULL);
+
 	return 0;
 }
 
-early_initcall(epapr_paravirt_init);