[3/8] usb: gadget: uvc: configfs: Allocate groups dynamically
From: Kieran Bingham <kieran.bingham@ideasonboard.com>
Date: 2018-08-01 09:58:40
Hi Laurent, Thank you for the patch, On 01/08/18 01:29, Laurent Pinchart wrote:
The UVC configfs implementation creates all groups as global static variables. This prevents creationg of multiple UVC function instances,
/creationg/creation/
as they would all require their own configfs group instances. Fix this by allocating all groups dynamically. To avoid duplicating code around, extend the config_item_type structure with group name and children, and implement helper functions to create children automatically for most groups. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
I'm struggling to see what paths free all of the dynamically created children in this patch. Is this already supported by the config_group framework? I see a reference to config_group_put(&opts->func_inst.group); in one error path - but that's about it. Am I missing something nice and obvious? (or is it already handled by framework code not in this patch) In fact, I can't see how it could be handled by core - as the children are added to a new structure you have created. I'll let you look into this :)
quoted hunk
--- drivers/usb/gadget/function/f_uvc.c | 8 +- drivers/usb/gadget/function/uvc_configfs.c | 480 +++++++++++++++++------------ 2 files changed, 282 insertions(+), 206 deletions(-)diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c index d8ce7868fe22..95cb1b5f5ffe 100644 --- a/drivers/usb/gadget/function/f_uvc.c +++ b/drivers/usb/gadget/function/f_uvc.c@@ -792,6 +792,7 @@ static struct usb_function_instance *uvc_alloc_inst(void) struct uvc_output_terminal_descriptor *od; struct uvc_color_matching_descriptor *md; struct uvc_descriptor_header **ctl_cls; + int ret; opts = kzalloc(sizeof(*opts), GFP_KERNEL); if (!opts)@@ -868,7 +869,12 @@ static struct usb_function_instance *uvc_alloc_inst(void) opts->streaming_interval = 1; opts->streaming_maxpacket = 1024; - uvcg_attach_configfs(opts); + ret = uvcg_attach_configfs(opts); + if (ret < 0) { + kfree(opts); + return ERR_PTR(ret); + } + return &opts->func_inst; }diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c index dbc95c9558de..e019ea317c7a 100644 --- a/drivers/usb/gadget/function/uvc_configfs.c +++ b/drivers/usb/gadget/function/uvc_configfs.c@@ -41,6 +41,49 @@ static inline struct f_uvc_opts *to_f_uvc_opts(struct config_item *item) func_inst.group); } +struct uvcg_config_group_type { + struct config_item_type type; + const char *name; + const struct uvcg_config_group_type **children; + int (*create_children)(struct config_group *group); +}; + +static int uvcg_config_create_group(struct config_group *parent, + const struct uvcg_config_group_type *type); + +static int uvcg_config_create_children(struct config_group *group, + const struct uvcg_config_group_type *type) +{ + const struct uvcg_config_group_type **child; + int ret; + + if (type->create_children) + return type->create_children(group); + + for (child = type->children; child && *child; ++child) { + ret = uvcg_config_create_group(group, *child); + if (ret < 0) + return ret; + } + + return 0; +} + +static int uvcg_config_create_group(struct config_group *parent, + const struct uvcg_config_group_type *type) +{ + struct config_group *group; + + group = kzalloc(sizeof(*group), GFP_KERNEL); + if (!group) + return -ENOMEM; + + config_group_init_type_name(group, type->name, &type->type); + configfs_add_default_group(group, parent); + + return uvcg_config_create_children(group, type); +} + /* ----------------------------------------------------------------------------- * control/header/<NAME> * control/header@@ -169,24 +212,23 @@ static void uvcg_control_header_drop(struct config_group *group, kfree(h); } -static struct config_group uvcg_control_header_grp; - static struct configfs_group_operations uvcg_control_header_grp_ops = { .make_item = uvcg_control_header_make, .drop_item = uvcg_control_header_drop, }; -static const struct config_item_type uvcg_control_header_grp_type = { - .ct_group_ops = &uvcg_control_header_grp_ops, - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_control_header_grp_type = { + .type = { + .ct_group_ops = &uvcg_control_header_grp_ops, + .ct_owner = THIS_MODULE, + }, + .name = "header", }; /* ----------------------------------------------------------------------------- * control/processing/default */ -static struct config_group uvcg_default_processing_grp; - #define UVCG_DEFAULT_PROCESSING_ATTR(cname, aname, conv) \ static ssize_t uvcg_default_processing_##cname##_show( \ struct config_item *item, char *page) \@@ -265,27 +307,33 @@ static struct configfs_attribute *uvcg_default_processing_attrs[] = { NULL, }; -static const struct config_item_type uvcg_default_processing_type = { - .ct_attrs = uvcg_default_processing_attrs, - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_default_processing_type = { + .type = { + .ct_attrs = uvcg_default_processing_attrs, + .ct_owner = THIS_MODULE, + }, + .name = "default", }; /* ----------------------------------------------------------------------------- * control/processing */ -static struct config_group uvcg_processing_grp; - -static const struct config_item_type uvcg_processing_grp_type = { - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_processing_grp_type = { + .type = { + .ct_owner = THIS_MODULE, + }, + .name = "processing", + .children = (const struct uvcg_config_group_type*[]) { + &uvcg_default_processing_type, + NULL, + }, }; /* ----------------------------------------------------------------------------- * control/terminal/camera/default */ -static struct config_group uvcg_default_camera_grp; - #define UVCG_DEFAULT_CAMERA_ATTR(cname, aname, conv) \ static ssize_t uvcg_default_camera_##cname##_show( \ struct config_item *item, char *page) \@@ -375,27 +423,33 @@ static struct configfs_attribute *uvcg_default_camera_attrs[] = { NULL, }; -static const struct config_item_type uvcg_default_camera_type = { - .ct_attrs = uvcg_default_camera_attrs, - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_default_camera_type = { + .type = { + .ct_attrs = uvcg_default_camera_attrs, + .ct_owner = THIS_MODULE, + }, + .name = "default", }; /* ----------------------------------------------------------------------------- * control/terminal/camera */ -static struct config_group uvcg_camera_grp; - -static const struct config_item_type uvcg_camera_grp_type = { - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_camera_grp_type = { + .type = { + .ct_owner = THIS_MODULE, + }, + .name = "camera", + .children = (const struct uvcg_config_group_type*[]) { + &uvcg_default_camera_type, + NULL, + }, }; /* ----------------------------------------------------------------------------- * control/terminal/output/default */ -static struct config_group uvcg_default_output_grp; - #define UVCG_DEFAULT_OUTPUT_ATTR(cname, aname, conv) \ static ssize_t uvcg_default_output_##cname##_show( \ struct config_item *item, char *page) \@@ -446,47 +500,65 @@ static struct configfs_attribute *uvcg_default_output_attrs[] = { NULL, }; -static const struct config_item_type uvcg_default_output_type = { - .ct_attrs = uvcg_default_output_attrs, - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_default_output_type = { + .type = { + .ct_attrs = uvcg_default_output_attrs, + .ct_owner = THIS_MODULE, + }, + .name = "default", }; /* ----------------------------------------------------------------------------- * control/terminal/output */ -static struct config_group uvcg_output_grp; - -static const struct config_item_type uvcg_output_grp_type = { - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_output_grp_type = { + .type = { + .ct_owner = THIS_MODULE, + }, + .name = "output", + .children = (const struct uvcg_config_group_type*[]) { + &uvcg_default_output_type, + NULL, + }, }; /* ----------------------------------------------------------------------------- * control/terminal */ -static struct config_group uvcg_terminal_grp; - -static const struct config_item_type uvcg_terminal_grp_type = { - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_terminal_grp_type = { + .type = { + .ct_owner = THIS_MODULE, + }, + .name = "terminal", + .children = (const struct uvcg_config_group_type*[]) {
Is this cast really needed? Or is it just to constify the array ?
quoted hunk
+ &uvcg_camera_grp_type, + &uvcg_output_grp_type, + NULL, + }, }; /* ----------------------------------------------------------------------------- * control/class/{fs|ss} */ -static struct config_group uvcg_control_class_fs_grp; -static struct config_group uvcg_control_class_ss_grp; +struct uvcg_control_class_group { + struct config_group group; + const char *name; +}; static inline struct uvc_descriptor_header **uvcg_get_ctl_class_arr(struct config_item *i, struct f_uvc_opts *o) { - struct config_group *group = to_config_group(i); + struct uvcg_control_class_group *group = + container_of(i, struct uvcg_control_class_group, + group.cg_item); - if (group == &uvcg_control_class_fs_grp) + if (!strcmp(group->name, "fs")) return o->uvc_fs_control_cls; - if (group == &uvcg_control_class_ss_grp) + if (!strcmp(group->name, "ss")) return o->uvc_ss_control_cls; return NULL;@@ -581,20 +653,52 @@ static const struct config_item_type uvcg_control_class_type = { * control/class */ -static struct config_group uvcg_control_class_grp; +static int uvcg_control_class_create_children(struct config_group *parent) +{ + static const char * const names[] = { "fs", "ss" }; + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(names); ++i) { + struct uvcg_control_class_group *group; + + group = kzalloc(sizeof(*group), GFP_KERNEL); + if (!group) + return -ENOMEM; + + group->name = names[i]; -static const struct config_item_type uvcg_control_class_grp_type = { - .ct_owner = THIS_MODULE, + config_group_init_type_name(&group->group, group->name, + &uvcg_control_class_type); + configfs_add_default_group(&group->group, parent); + } + + return 0; +} + +static const struct uvcg_config_group_type uvcg_control_class_grp_type = { + .type = { + .ct_owner = THIS_MODULE, + }, + .name = "class", + .create_children = uvcg_control_class_create_children, }; /* ----------------------------------------------------------------------------- * control */ -static struct config_group uvcg_control_grp; - -static const struct config_item_type uvcg_control_grp_type = { - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_control_grp_type = { + .type = { + .ct_owner = THIS_MODULE, + }, + .name = "control", + .children = (const struct uvcg_config_group_type*[]) { + &uvcg_control_header_grp_type, + &uvcg_processing_grp_type, + &uvcg_terminal_grp_type, + &uvcg_control_class_grp_type, + NULL, + }, }; /* -----------------------------------------------------------------------------@@ -602,12 +706,9 @@ static const struct config_item_type uvcg_control_grp_type = { * streaming/mjpeg */ -static struct config_group uvcg_uncompressed_grp; -static struct config_group uvcg_mjpeg_grp; - -static struct config_item *fmt_parent[] = { - &uvcg_uncompressed_grp.cg_item, - &uvcg_mjpeg_grp.cg_item, +static const char * const uvcg_format_names[] = { + "uncompressed", + "mjpeg", }; enum uvcg_format_type {@@ -733,10 +834,22 @@ static int uvcg_streaming_header_allow_link(struct config_item *src, goto out; } - for (i = 0; i < ARRAY_SIZE(fmt_parent); ++i) - if (target->ci_parent == fmt_parent[i]) + /* + * Linking is only allowed to direct children of the format nodes + * (streaming/uncompressed or streaming/mjpeg nodes). First check that + * the grand-parent of the target matches the grand-parent of the source + * (the streaming node), and then verify that the target parent is a + * format node. + */ + if (src->ci_parent->ci_parent != target->ci_parent->ci_parent) + goto out; + + for (i = 0; i < ARRAY_SIZE(uvcg_format_names); ++i) { + if (!strcmp(target->ci_parent->ci_name, uvcg_format_names[i])) break; - if (i == ARRAY_SIZE(fmt_parent)) + } + + if (i == ARRAY_SIZE(uvcg_format_names)) goto out; target_fmt = container_of(to_config_group(target), struct uvcg_format,@@ -881,16 +994,17 @@ static void uvcg_streaming_header_drop(struct config_group *group, kfree(h); } -static struct config_group uvcg_streaming_header_grp; - static struct configfs_group_operations uvcg_streaming_header_grp_ops = { .make_item = uvcg_streaming_header_make, .drop_item = uvcg_streaming_header_drop, }; -static const struct config_item_type uvcg_streaming_header_grp_type = { - .ct_group_ops = &uvcg_streaming_header_grp_ops, - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_streaming_header_grp_type = { + .type = { + .ct_group_ops = &uvcg_streaming_header_grp_ops, + .ct_owner = THIS_MODULE, + }, + .name = "header", }; /* -----------------------------------------------------------------------------@@ -1462,9 +1576,12 @@ static struct configfs_group_operations uvcg_uncompressed_grp_ops = { .drop_item = uvcg_uncompressed_drop, }; -static const struct config_item_type uvcg_uncompressed_grp_type = { - .ct_group_ops = &uvcg_uncompressed_grp_ops, - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_uncompressed_grp_type = { + .type = { + .ct_group_ops = &uvcg_uncompressed_grp_ops, + .ct_owner = THIS_MODULE, + }, + .name = "uncompressed", }; /* -----------------------------------------------------------------------------@@ -1659,17 +1776,18 @@ static struct configfs_group_operations uvcg_mjpeg_grp_ops = { .drop_item = uvcg_mjpeg_drop, }; -static const struct config_item_type uvcg_mjpeg_grp_type = { - .ct_group_ops = &uvcg_mjpeg_grp_ops, - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_mjpeg_grp_type = { + .type = { + .ct_group_ops = &uvcg_mjpeg_grp_ops, + .ct_owner = THIS_MODULE, + }, + .name = "mjpeg", }; /* ----------------------------------------------------------------------------- * streaming/color_matching/default */ -static struct config_group uvcg_default_color_matching_grp; - #define UVCG_DEFAULT_COLOR_MATCHING_ATTR(cname, aname, conv) \ static ssize_t uvcg_default_color_matching_##cname##_show( \ struct config_item *item, char *page) \@@ -1717,41 +1835,52 @@ static struct configfs_attribute *uvcg_default_color_matching_attrs[] = { NULL, }; -static const struct config_item_type uvcg_default_color_matching_type = { - .ct_attrs = uvcg_default_color_matching_attrs, - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_default_color_matching_type = { + .type = { + .ct_attrs = uvcg_default_color_matching_attrs, + .ct_owner = THIS_MODULE, + }, + .name = "default", }; /* ----------------------------------------------------------------------------- * streaming/color_matching */ -static struct config_group uvcg_color_matching_grp; - -static const struct config_item_type uvcg_color_matching_grp_type = { - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_color_matching_grp_type = { + .type = { + .ct_owner = THIS_MODULE, + }, + .name = "color_matching", + .children = (const struct uvcg_config_group_type*[]) { + &uvcg_default_color_matching_type, + NULL, + }, }; /* ----------------------------------------------------------------------------- * streaming/class/{fs|hs|ss} */ -static struct config_group uvcg_streaming_class_fs_grp; -static struct config_group uvcg_streaming_class_hs_grp; -static struct config_group uvcg_streaming_class_ss_grp; +struct uvcg_streaming_class_group { + struct config_group group; + const char *name; +}; static inline struct uvc_descriptor_header ***__uvcg_get_stream_class_arr(struct config_item *i, struct f_uvc_opts *o) { - struct config_group *group = to_config_group(i); + struct uvcg_streaming_class_group *group = + container_of(i, struct uvcg_streaming_class_group, + group.cg_item); - if (group == &uvcg_streaming_class_fs_grp) + if (!strcmp(group->name, "fs")) return &o->uvc_fs_streaming_cls; - if (group == &uvcg_streaming_class_hs_grp) + if (!strcmp(group->name, "hs")) return &o->uvc_hs_streaming_cls; - if (group == &uvcg_streaming_class_ss_grp) + if (!strcmp(group->name, "ss")) return &o->uvc_ss_streaming_cls; return NULL;@@ -2083,20 +2212,53 @@ static const struct config_item_type uvcg_streaming_class_type = { * streaming/class */ -static struct config_group uvcg_streaming_class_grp; +static int uvcg_streaming_class_create_children(struct config_group *parent) +{ + static const char * const names[] = { "fs", "hs", "ss" }; + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(names); ++i) { + struct uvcg_streaming_class_group *group; + + group = kzalloc(sizeof(*group), GFP_KERNEL); + if (!group) + return -ENOMEM; + + group->name = names[i]; + + config_group_init_type_name(&group->group, group->name, + &uvcg_streaming_class_type); + configfs_add_default_group(&group->group, parent); + } + + return 0; +} -static const struct config_item_type uvcg_streaming_class_grp_type = { - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_streaming_class_grp_type = { + .type = { + .ct_owner = THIS_MODULE, + }, + .name = "class", + .create_children = uvcg_streaming_class_create_children, }; /* ----------------------------------------------------------------------------- * streaming */ -static struct config_group uvcg_streaming_grp; - -static const struct config_item_type uvcg_streaming_grp_type = { - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvcg_streaming_grp_type = { + .type = { + .ct_owner = THIS_MODULE, + }, + .name = "streaming", + .children = (const struct uvcg_config_group_type*[]) { + &uvcg_streaming_header_grp_type, + &uvcg_uncompressed_grp_type, + &uvcg_mjpeg_grp_type, + &uvcg_color_matching_grp_type, + &uvcg_streaming_class_grp_type, + NULL, + }, }; /* -----------------------------------------------------------------------------@@ -2179,123 +2341,31 @@ static struct configfs_attribute *uvc_attrs[] = { NULL, }; -static const struct config_item_type uvc_func_type = { - .ct_item_ops = &uvc_item_ops, - .ct_attrs = uvc_attrs, - .ct_owner = THIS_MODULE, +static const struct uvcg_config_group_type uvc_func_type = { + .type = { + .ct_item_ops = &uvc_item_ops, + .ct_attrs = uvc_attrs, + .ct_owner = THIS_MODULE, + }, + .name = "", + .children = (const struct uvcg_config_group_type*[]) { + &uvcg_control_grp_type, + &uvcg_streaming_grp_type, + NULL, + }, }; int uvcg_attach_configfs(struct f_uvc_opts *opts) { - config_group_init_type_name(&uvcg_control_header_grp, - "header", - &uvcg_control_header_grp_type); - - config_group_init_type_name(&uvcg_default_processing_grp, - "default", &uvcg_default_processing_type); - config_group_init_type_name(&uvcg_processing_grp, - "processing", &uvcg_processing_grp_type); - configfs_add_default_group(&uvcg_default_processing_grp, - &uvcg_processing_grp); - - config_group_init_type_name(&uvcg_default_camera_grp, - "default", &uvcg_default_camera_type); - config_group_init_type_name(&uvcg_camera_grp, - "camera", &uvcg_camera_grp_type); - configfs_add_default_group(&uvcg_default_camera_grp, - &uvcg_camera_grp); - - config_group_init_type_name(&uvcg_default_output_grp, - "default", &uvcg_default_output_type); - config_group_init_type_name(&uvcg_output_grp, - "output", &uvcg_output_grp_type); - configfs_add_default_group(&uvcg_default_output_grp, - &uvcg_output_grp); - - config_group_init_type_name(&uvcg_terminal_grp, - "terminal", &uvcg_terminal_grp_type); - configfs_add_default_group(&uvcg_camera_grp, - &uvcg_terminal_grp); - configfs_add_default_group(&uvcg_output_grp, - &uvcg_terminal_grp); - - config_group_init_type_name(&uvcg_control_class_fs_grp, - "fs", &uvcg_control_class_type); - config_group_init_type_name(&uvcg_control_class_ss_grp, - "ss", &uvcg_control_class_type); - config_group_init_type_name(&uvcg_control_class_grp, - "class", - &uvcg_control_class_grp_type); - configfs_add_default_group(&uvcg_control_class_fs_grp, - &uvcg_control_class_grp); - configfs_add_default_group(&uvcg_control_class_ss_grp, - &uvcg_control_class_grp); - - config_group_init_type_name(&uvcg_control_grp, - "control", - &uvcg_control_grp_type); - configfs_add_default_group(&uvcg_control_header_grp, - &uvcg_control_grp); - configfs_add_default_group(&uvcg_processing_grp, - &uvcg_control_grp); - configfs_add_default_group(&uvcg_terminal_grp, - &uvcg_control_grp); - configfs_add_default_group(&uvcg_control_class_grp, - &uvcg_control_grp); - - config_group_init_type_name(&uvcg_streaming_header_grp, - "header", - &uvcg_streaming_header_grp_type); - config_group_init_type_name(&uvcg_uncompressed_grp, - "uncompressed", - &uvcg_uncompressed_grp_type); - config_group_init_type_name(&uvcg_mjpeg_grp, - "mjpeg", - &uvcg_mjpeg_grp_type); - config_group_init_type_name(&uvcg_default_color_matching_grp, - "default", - &uvcg_default_color_matching_type); - config_group_init_type_name(&uvcg_color_matching_grp, - "color_matching", - &uvcg_color_matching_grp_type); - configfs_add_default_group(&uvcg_default_color_matching_grp, - &uvcg_color_matching_grp); - - config_group_init_type_name(&uvcg_streaming_class_fs_grp, - "fs", &uvcg_streaming_class_type); - config_group_init_type_name(&uvcg_streaming_class_hs_grp, - "hs", &uvcg_streaming_class_type); - config_group_init_type_name(&uvcg_streaming_class_ss_grp, - "ss", &uvcg_streaming_class_type); - config_group_init_type_name(&uvcg_streaming_class_grp, - "class", &uvcg_streaming_class_grp_type); - configfs_add_default_group(&uvcg_streaming_class_fs_grp, - &uvcg_streaming_class_grp); - configfs_add_default_group(&uvcg_streaming_class_hs_grp, - &uvcg_streaming_class_grp); - configfs_add_default_group(&uvcg_streaming_class_ss_grp, - &uvcg_streaming_class_grp); - - config_group_init_type_name(&uvcg_streaming_grp, - "streaming", &uvcg_streaming_grp_type); - configfs_add_default_group(&uvcg_streaming_header_grp, - &uvcg_streaming_grp); - configfs_add_default_group(&uvcg_uncompressed_grp, - &uvcg_streaming_grp); - configfs_add_default_group(&uvcg_mjpeg_grp, - &uvcg_streaming_grp); - configfs_add_default_group(&uvcg_color_matching_grp, - &uvcg_streaming_grp); - configfs_add_default_group(&uvcg_streaming_class_grp, - &uvcg_streaming_grp); - - config_group_init_type_name(&opts->func_inst.group, - "", - &uvc_func_type); - configfs_add_default_group(&uvcg_control_grp, - &opts->func_inst.group); - configfs_add_default_group(&uvcg_streaming_grp, - &opts->func_inst.group); + int ret; - return 0; + config_group_init_type_name(&opts->func_inst.group, uvc_func_type.name, + &uvc_func_type.type); + + ret = uvcg_config_create_children(&opts->func_inst.group, + &uvc_func_type); + if (ret < 0) + config_group_put(&opts->func_inst.group); + + return ret; }