drm/i915/bios: store child devices in a list

Using the array is getting clumsy. Make things a bit more dynamic.

Remove early returns on not having child devices when the end result
after "iterating" the empty list would be the same.

v3:
- use list_add_tail to not reverse the child device list (Ville)

v2:
- stick to previous naming of child devices (Ville)
- use kzalloc, handle failure
- initialize list head earlier to keep intel_bios_driver_remove() safe

Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/3e72da0b412354ed8be6719df55b0e0cc4caa61a.1573227240.git.jani.nikula@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index c19b234bebe650b7c7aa66814136f7ac32e3c27e..7c0ca733bef8f1d9ff0f089dfe141c9ffa834e93 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -58,6 +58,12 @@
  * that.
  */
 
+/* Wrapper for VBT child device config */
+struct display_device_data {
+       struct child_device_config child;
+       struct list_head node;
+};
+
 #define        SLAVE_ADDR1     0x70
 #define        SLAVE_ADDR2     0x72
 
@@ -449,8 +455,9 @@ static void
 parse_sdvo_device_mapping(struct drm_i915_private *dev_priv, u8 bdb_version)
 {
        struct sdvo_device_mapping *mapping;
+       const struct display_device_data *devdata;
        const struct child_device_config *child;
-       int i, count = 0;
+       int count = 0;
 
        /*
         * Only parse SDVO mappings on gens that could have SDVO. This isn't
@@ -461,8 +468,8 @@ parse_sdvo_device_mapping(struct drm_i915_private *dev_priv, u8 bdb_version)
                return;
        }
 
-       for (i = 0, count = 0; i < dev_priv->vbt.child_dev_num; i++) {
-               child = dev_priv->vbt.child_dev + i;
+       list_for_each_entry(devdata, &dev_priv->vbt.display_devices, node) {
+               child = &devdata->child;
 
                if (child->slave_addr != SLAVE_ADDR1 &&
                    child->slave_addr != SLAVE_ADDR2) {
@@ -1572,8 +1579,7 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv,
 
 static void parse_ddi_ports(struct drm_i915_private *dev_priv, u8 bdb_version)
 {
-       const struct child_device_config *child;
-       int i;
+       const struct display_device_data *devdata;
 
        if (!HAS_DDI(dev_priv) && !IS_CHERRYVIEW(dev_priv))
                return;
@@ -1581,11 +1587,8 @@ static void parse_ddi_ports(struct drm_i915_private *dev_priv, u8 bdb_version)
        if (bdb_version < 155)
                return;
 
-       for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
-               child = dev_priv->vbt.child_dev + i;
-
-               parse_ddi_port(dev_priv, child, bdb_version);
-       }
+       list_for_each_entry(devdata, &dev_priv->vbt.display_devices, node)
+               parse_ddi_port(dev_priv, &devdata->child, bdb_version);
 }
 
 static void
@@ -1593,8 +1596,9 @@ parse_general_definitions(struct drm_i915_private *dev_priv,
                          const struct bdb_header *bdb)
 {
        const struct bdb_general_definitions *defs;
+       struct display_device_data *devdata;
        const struct child_device_config *child;
-       int i, child_device_num, count;
+       int i, child_device_num;
        u8 expected_size;
        u16 block_size;
        int bus_pin;
@@ -1650,26 +1654,7 @@ parse_general_definitions(struct drm_i915_private *dev_priv,
 
        /* get the number of child device */
        child_device_num = (block_size - sizeof(*defs)) / defs->child_dev_size;
-       count = 0;
-       /* get the number of child device that is present */
-       for (i = 0; i < child_device_num; i++) {
-               child = child_device_ptr(defs, i);
-               if (!child->device_type)
-                       continue;
-               count++;
-       }
-       if (!count) {
-               DRM_DEBUG_KMS("no child dev is parsed from VBT\n");
-               return;
-       }
-       dev_priv->vbt.child_dev = kcalloc(count, sizeof(*child), GFP_KERNEL);
-       if (!dev_priv->vbt.child_dev) {
-               DRM_DEBUG_KMS("No memory space for child device\n");
-               return;
-       }
 
-       dev_priv->vbt.child_dev_num = count;
-       count = 0;
        for (i = 0; i < child_device_num; i++) {
                child = child_device_ptr(defs, i);
                if (!child->device_type)
@@ -1678,15 +1663,23 @@ parse_general_definitions(struct drm_i915_private *dev_priv,
                DRM_DEBUG_KMS("Found VBT child device with type 0x%x\n",
                              child->device_type);
 
+               devdata = kzalloc(sizeof(*devdata), GFP_KERNEL);
+               if (!devdata)
+                       break;
+
                /*
                 * Copy as much as we know (sizeof) and is available
-                * (child_dev_size) of the child device. Accessing the data must
-                * depend on VBT version.
+                * (child_dev_size) of the child device config. Accessing the
+                * data must depend on VBT version.
                 */
-               memcpy(dev_priv->vbt.child_dev + count, child,
+               memcpy(&devdata->child, child,
                       min_t(size_t, defs->child_dev_size, sizeof(*child)));
-               count++;
+
+               list_add_tail(&devdata->node, &dev_priv->vbt.display_devices);
        }
+
+       if (list_empty(&dev_priv->vbt.display_devices))
+               DRM_DEBUG_KMS("no child dev is parsed from VBT\n");
 }
 
 /* Common defaults which may be overridden by VBT. */
@@ -1836,6 +1829,8 @@ void intel_bios_init(struct drm_i915_private *dev_priv)
        const struct bdb_header *bdb;
        u8 __iomem *bios = NULL;
 
+       INIT_LIST_HEAD(&dev_priv->vbt.display_devices);
+
        if (!HAS_DISPLAY(dev_priv) || !INTEL_DISPLAY_ENABLED(dev_priv)) {
                DRM_DEBUG_KMS("Skipping VBT init due to disabled display.\n");
                return;
@@ -1895,9 +1890,13 @@ out:
  */
 void intel_bios_driver_remove(struct drm_i915_private *dev_priv)
 {
-       kfree(dev_priv->vbt.child_dev);
-       dev_priv->vbt.child_dev = NULL;
-       dev_priv->vbt.child_dev_num = 0;
+       struct display_device_data *devdata, *n;
+
+       list_for_each_entry_safe(devdata, n, &dev_priv->vbt.display_devices, node) {
+               list_del(&devdata->node);
+               kfree(devdata);
+       }
+
        kfree(dev_priv->vbt.sdvo_lvds_vbt_mode);
        dev_priv->vbt.sdvo_lvds_vbt_mode = NULL;
        kfree(dev_priv->vbt.lfp_lvds_vbt_mode);
@@ -1921,17 +1920,18 @@ void intel_bios_driver_remove(struct drm_i915_private *dev_priv)
  */
 bool intel_bios_is_tv_present(struct drm_i915_private *dev_priv)
 {
+       const struct display_device_data *devdata;
        const struct child_device_config *child;
-       int i;
 
        if (!dev_priv->vbt.int_tv_support)
                return false;
 
-       if (!dev_priv->vbt.child_dev_num)
+       if (list_empty(&dev_priv->vbt.display_devices))
                return true;
 
-       for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
-               child = dev_priv->vbt.child_dev + i;
+       list_for_each_entry(devdata, &dev_priv->vbt.display_devices, node) {
+               child = &devdata->child;
+
                /*
                 * If the device type is not TV, continue.
                 */
@@ -1963,14 +1963,14 @@ bool intel_bios_is_tv_present(struct drm_i915_private *dev_priv)
  */
 bool intel_bios_is_lvds_present(struct drm_i915_private *dev_priv, u8 *i2c_pin)
 {
+       const struct display_device_data *devdata;
        const struct child_device_config *child;
-       int i;
 
-       if (!dev_priv->vbt.child_dev_num)
+       if (list_empty(&dev_priv->vbt.display_devices))
                return true;
 
-       for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
-               child = dev_priv->vbt.child_dev + i;
+       list_for_each_entry(devdata, &dev_priv->vbt.display_devices, node) {
+               child = &devdata->child;
 
                /* If the device type is not LFP, continue.
                 * We have to check both the new identifiers as well as the
@@ -2012,6 +2012,7 @@ bool intel_bios_is_lvds_present(struct drm_i915_private *dev_priv, u8 *i2c_pin)
  */
 bool intel_bios_is_port_present(struct drm_i915_private *dev_priv, enum port port)
 {
+       const struct display_device_data *devdata;
        const struct child_device_config *child;
        static const struct {
                u16 dp, hdmi;
@@ -2022,7 +2023,6 @@ bool intel_bios_is_port_present(struct drm_i915_private *dev_priv, enum port por
                [PORT_E] = { DVO_PORT_DPE, DVO_PORT_HDMIE, },
                [PORT_F] = { DVO_PORT_DPF, DVO_PORT_HDMIF, },
        };
-       int i;
 
        if (HAS_DDI(dev_priv)) {
                const struct ddi_vbt_port_info *port_info =
@@ -2037,11 +2037,8 @@ bool intel_bios_is_port_present(struct drm_i915_private *dev_priv, enum port por
        if (WARN_ON(port == PORT_A) || port >= ARRAY_SIZE(port_mapping))
                return false;
 
-       if (!dev_priv->vbt.child_dev_num)
-               return false;
-
-       for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
-               child = dev_priv->vbt.child_dev + i;
+       list_for_each_entry(devdata, &dev_priv->vbt.display_devices, node) {
+               child = &devdata->child;
 
                if ((child->dvo_port == port_mapping[port].dp ||
                     child->dvo_port == port_mapping[port].hdmi) &&
@@ -2062,6 +2059,7 @@ bool intel_bios_is_port_present(struct drm_i915_private *dev_priv, enum port por
  */
 bool intel_bios_is_port_edp(struct drm_i915_private *dev_priv, enum port port)
 {
+       const struct display_device_data *devdata;
        const struct child_device_config *child;
        static const short port_mapping[] = {
                [PORT_B] = DVO_PORT_DPB,
@@ -2070,16 +2068,12 @@ bool intel_bios_is_port_edp(struct drm_i915_private *dev_priv, enum port port)
                [PORT_E] = DVO_PORT_DPE,
                [PORT_F] = DVO_PORT_DPF,
        };
-       int i;
 
        if (HAS_DDI(dev_priv))
                return dev_priv->vbt.ddi_port_info[port].supports_edp;
 
-       if (!dev_priv->vbt.child_dev_num)
-               return false;
-
-       for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
-               child = dev_priv->vbt.child_dev + i;
+       list_for_each_entry(devdata, &dev_priv->vbt.display_devices, node) {
+               child = &devdata->child;
 
                if (child->dvo_port == port_mapping[port] &&
                    (child->device_type & DEVICE_TYPE_eDP_BITS) ==
@@ -2128,13 +2122,10 @@ static bool child_dev_is_dp_dual_mode(const struct child_device_config *child,
 bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv,
                                     enum port port)
 {
-       const struct child_device_config *child;
-       int i;
+       const struct display_device_data *devdata;
 
-       for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
-               child = dev_priv->vbt.child_dev + i;
-
-               if (child_dev_is_dp_dual_mode(child, port))
+       list_for_each_entry(devdata, &dev_priv->vbt.display_devices, node) {
+               if (child_dev_is_dp_dual_mode(&devdata->child, port))
                        return true;
        }
 
@@ -2151,12 +2142,12 @@ bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv,
 bool intel_bios_is_dsi_present(struct drm_i915_private *dev_priv,
                               enum port *port)
 {
+       const struct display_device_data *devdata;
        const struct child_device_config *child;
        u8 dvo_port;
-       int i;
 
-       for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
-               child = dev_priv->vbt.child_dev + i;
+       list_for_each_entry(devdata, &dev_priv->vbt.display_devices, node) {
+               child = &devdata->child;
 
                if (!(child->device_type & DEVICE_TYPE_MIPI_OUTPUT))
                        continue;

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 9d95125f17980b4a498e5ba7be8729f90a606a2c..50809ffdc6b2af97d00a14efc2e7d4d3d02d37e5 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -720,8 +720,7 @@ struct intel_vbt_data {
 
        int crt_ddc_pin;
 
-       int child_dev_num;
-       struct child_device_config *child_dev;
+       struct list_head display_devices;
 
        struct ddi_vbt_port_info ddi_port_info[I915_MAX_PORTS];
        struct sdvo_device_mapping sdvo_mappings[2];