drm/amd/display: refactor gpio to allocate hw_container in constructor

[why]
if dynamic allocation fails during gpio_open, it will cause crash due to
page fault.

[how]
handle allocation when gpio object gets created and prevent from calling
gpio_open if allocation failed

Signed-off-by: Su Sung Chung <Su.Chung@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 18 insertions, 14 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/gpio/hw_generic.c b/drivers/gpu/drm/amd/display/dc/gpio/hw_generic.c
index 8b7a8ffe3cd7..69b899741f6d 100644
--- a/drivers/gpu/drm/amd/display/dc/gpio/hw_generic.c
+++ b/drivers/gpu/drm/amd/display/dc/gpio/hw_generic.c
@@ -27,6 +27,7 @@
 
 #include "dm_services.h"
 
+#include "include/gpio_interface.h"
 #include "include/gpio_types.h"
 #include "hw_gpio.h"
 #include "hw_generic.h"
@@ -43,6 +44,8 @@
 #define REG(reg)\
 	(generic->regs->reg)
 
+struct gpio;
+
 static void dal_hw_generic_construct(
 	struct hw_generic *pin,
 	enum gpio_id id,
@@ -106,29 +109,30 @@ static void construct(
 	generic->base.base.funcs = &funcs;
 }
 
-struct hw_gpio_pin *dal_hw_generic_create(
+void dal_hw_generic_init(
+	struct hw_generic **hw_generic,
 	struct dc_context *ctx,
 	enum gpio_id id,
 	uint32_t en)
 {
-	struct hw_generic *generic;
-
-	if (id != GPIO_ID_GENERIC) {
+	if ((en < GPIO_DDC_LINE_MIN) || (en > GPIO_DDC_LINE_MAX)) {
 		ASSERT_CRITICAL(false);
-		return NULL;
+		*hw_generic = NULL;
 	}
 
-	if ((en < GPIO_GENERIC_MIN) || (en > GPIO_GENERIC_MAX)) {
+	*hw_generic = kzalloc(sizeof(struct hw_generic), GFP_KERNEL);
+	if (!*hw_generic) {
 		ASSERT_CRITICAL(false);
-		return NULL;
+		return;
 	}
 
-	generic = kzalloc(sizeof(struct hw_generic), GFP_KERNEL);
-	if (!generic) {
-		ASSERT_CRITICAL(false);
-		return NULL;
-	}
+	construct(*hw_generic, id, en, ctx);
+}
+
+
+struct hw_gpio_pin *dal_hw_generic_get_pin(struct gpio *gpio)
+{
+	struct hw_generic *hw_generic = dal_gpio_get_generic(gpio);
 
-	construct(generic, id, en, ctx);
-	return &generic->base.base;
+	return &hw_generic->base.base;
 }