| Message ID | 20240613161045.29606-9-kabel@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Updates for turris-mox-rwtm driver | expand |
On Thu, 13 Jun 2024, Marek Behún wrote: > In order to create attribute files in /sys/firmware/turris-mox-rwtm, > this driver creates it's own kobject type. > > Simplify this by dropping this own kobject creation, and instead > creating standard device attribute files. > > For backwards compatibility with sysfs ABI, create a symlink > /sys/firmware/turris-mox-rwtm, pointing to this device's sysfs > directory. > > Signed-off-by: Marek Behún <kabel@kernel.org> Much better, thanks. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
On Thu, Jun 13, 2024 at 6:11 PM Marek Behún <kabel@kernel.org> wrote: > > In order to create attribute files in /sys/firmware/turris-mox-rwtm, > this driver creates it's own kobject type. its > Simplify this by dropping this own kobject creation, and instead > creating standard device attribute files. > > For backwards compatibility with sysfs ABI, create a symlink > /sys/firmware/turris-mox-rwtm, pointing to this device's sysfs > directory. ... > +static void rwtm_firmware_symlink_drop(void *) Interesting, can we actually name the parameter, like "unused"? > +{ > + sysfs_remove_link(firmware_kobj, DRIVER_NAME); But why not provide a fimware_kobj pointer as a parameter? > +} ... > + /* > + * For sysfs ABI compatibility, create symlink > + * /sys/firmware/turris-mox-rwtm to this device's sysfs directory. > + */ > + ret = sysfs_create_link(firmware_kobj, &dev->kobj, DRIVER_NAME); > + if (!ret) > + devm_add_action_or_reset(dev, rwtm_firmware_symlink_drop, NULL); This means that it will remove the link in case devm_add_action() fails. Is it okay?
On Thu, Jun 13, 2024, at 22:32, Andy Shevchenko wrote: > On Thu, Jun 13, 2024 at 6:11 PM Marek Behún <kabel@kernel.org> wrote: > > >> +static void rwtm_firmware_symlink_drop(void *) > > Interesting, can we actually name the parameter, like "unused"? Agreed. I was surprised that the compiler doesn't warn about it and checked: apparently this is a c23 language feature, so newer versions of gcc now treats it as a gnu extension for --std=gnu11 as well. gcc-10 and older versions however fail: error: parameter name omitted and clang-19 still warns warning: omitting the parameter name in a function definition is a C2x extension [-Wc2x-extensions] Arnd
On Thu, 13 Jun 2024 22:32:28 +0200 Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > On Thu, Jun 13, 2024 at 6:11 PM Marek Behún <kabel@kernel.org> wrote: > > > > In order to create attribute files in /sys/firmware/turris-mox-rwtm, > > this driver creates it's own kobject type. > > its > > > Simplify this by dropping this own kobject creation, and instead > > creating standard device attribute files. > > > > For backwards compatibility with sysfs ABI, create a symlink > > /sys/firmware/turris-mox-rwtm, pointing to this device's sysfs > > directory. > > ... > > > > +static void rwtm_firmware_symlink_drop(void *) > > Interesting, can we actually name the parameter, like "unused"? > > > +{ > > + sysfs_remove_link(firmware_kobj, DRIVER_NAME); > > But why not provide a fimware_kobj pointer as a parameter? > > > +} > > ... > > > + /* > > + * For sysfs ABI compatibility, create symlink > > + * /sys/firmware/turris-mox-rwtm to this device's sysfs directory. > > + */ > > + ret = sysfs_create_link(firmware_kobj, &dev->kobj, DRIVER_NAME); > > + if (!ret) > > + devm_add_action_or_reset(dev, rwtm_firmware_symlink_drop, NULL); > > This means that it will remove the link in case devm_add_action() > fails. Is it okay? IMO rather to drop the symlink (which is created for backwards compatibility anyway) in the improbable case that devm_add_action() fails, then than to leave it dangling there on driver unbind.
On Thu, 13 Jun 2024 22:32:28 +0200 Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > On Thu, Jun 13, 2024 at 6:11 PM Marek Behún <kabel@kernel.org> wrote: > > > > In order to create attribute files in /sys/firmware/turris-mox-rwtm, > > this driver creates it's own kobject type. > > its > > > Simplify this by dropping this own kobject creation, and instead > > creating standard device attribute files. > > > > For backwards compatibility with sysfs ABI, create a symlink > > /sys/firmware/turris-mox-rwtm, pointing to this device's sysfs > > directory. > > ... > > > > +static void rwtm_firmware_symlink_drop(void *) > > Interesting, can we actually name the parameter, like "unused"? > > > +{ > > + sysfs_remove_link(firmware_kobj, DRIVER_NAME); > > But why not provide a fimware_kobj pointer as a parameter? > > > +} > > ... > > > + /* > > + * For sysfs ABI compatibility, create symlink > > + * /sys/firmware/turris-mox-rwtm to this device's sysfs directory. > > + */ > > + ret = sysfs_create_link(firmware_kobj, &dev->kobj, DRIVER_NAME); > > + if (!ret) > > + devm_add_action_or_reset(dev, rwtm_firmware_symlink_drop, NULL); > > This means that it will remove the link in case devm_add_action() > fails. Is it okay? > Alternatively I could fail .probe() in case devm_add_action() fails. It is improbable anyway.
diff --git a/drivers/firmware/turris-mox-rwtm.c b/drivers/firmware/turris-mox-rwtm.c index 75a98386a2b0..d17dc0679439 100644 --- a/drivers/firmware/turris-mox-rwtm.c +++ b/drivers/firmware/turris-mox-rwtm.c @@ -21,7 +21,6 @@ #include <linux/module.h> #include <linux/mutex.h> #include <linux/platform_device.h> -#include <linux/slab.h> #include <linux/sysfs.h> #include <linux/types.h> @@ -60,13 +59,10 @@ enum mbox_cmd { MBOX_CMD_OTP_WRITE = 8, }; -struct mox_kobject; - struct mox_rwtm { struct device *dev; struct mbox_client mbox_client; struct mbox_chan *mbox; - struct mox_kobject *kobj; struct hwrng hwrng; struct armada_37xx_rwtm_rx_msg reply; @@ -100,59 +96,17 @@ struct mox_rwtm { #endif }; -struct mox_kobject { - struct kobject kobj; - struct mox_rwtm *rwtm; -}; - -static inline struct kobject *rwtm_to_kobj(struct mox_rwtm *rwtm) -{ - return &rwtm->kobj->kobj; -} - -static inline struct mox_rwtm *to_rwtm(struct kobject *kobj) -{ - return container_of(kobj, struct mox_kobject, kobj)->rwtm; -} - -static void mox_kobj_release(struct kobject *kobj) -{ - kfree(to_rwtm(kobj)->kobj); -} - -static const struct kobj_type mox_kobj_ktype = { - .release = mox_kobj_release, - .sysfs_ops = &kobj_sysfs_ops, -}; - -static int mox_kobj_create(struct mox_rwtm *rwtm) -{ - rwtm->kobj = kzalloc(sizeof(*rwtm->kobj), GFP_KERNEL); - if (!rwtm->kobj) - return -ENOMEM; - - kobject_init(rwtm_to_kobj(rwtm), &mox_kobj_ktype); - if (kobject_add(rwtm_to_kobj(rwtm), firmware_kobj, "turris-mox-rwtm")) { - kobject_put(rwtm_to_kobj(rwtm)); - return -ENXIO; - } - - rwtm->kobj->rwtm = rwtm; - - return 0; -} - #define MOX_ATTR_RO(name, format, cat) \ static ssize_t \ -name##_show(struct kobject *kobj, struct kobj_attribute *a, \ +name##_show(struct device *dev, struct device_attribute *a, \ char *buf) \ { \ - struct mox_rwtm *rwtm = to_rwtm(kobj); \ + struct mox_rwtm *rwtm = dev_get_drvdata(dev); \ if (!rwtm->has_##cat) \ return -ENODATA; \ return sprintf(buf, format, rwtm->name); \ } \ -static struct kobj_attribute mox_attr_##name = __ATTR_RO(name) +static DEVICE_ATTR_RO(name) MOX_ATTR_RO(serial_number, "%016llX\n", board_info); MOX_ATTR_RO(board_version, "%i\n", board_info); @@ -161,6 +115,17 @@ MOX_ATTR_RO(mac_address1, "%pM\n", board_info); MOX_ATTR_RO(mac_address2, "%pM\n", board_info); MOX_ATTR_RO(pubkey, "%s\n", pubkey); +static struct attribute *turris_mox_rwtm_attrs[] = { + &dev_attr_serial_number.attr, + &dev_attr_board_version.attr, + &dev_attr_ram_size.attr, + &dev_attr_mac_address1.attr, + &dev_attr_mac_address2.attr, + &dev_attr_pubkey.attr, + NULL +}; +ATTRIBUTE_GROUPS(turris_mox_rwtm); + static int mox_get_status(enum mbox_cmd cmd, u32 retval) { if (MBOX_STS_CMD(retval) != cmd) @@ -175,16 +140,6 @@ static int mox_get_status(enum mbox_cmd cmd, u32 retval) return MBOX_STS_VALUE(retval); } -static const struct attribute *mox_rwtm_attrs[] = { - &mox_attr_serial_number.attr, - &mox_attr_board_version.attr, - &mox_attr_ram_size.attr, - &mox_attr_mac_address1.attr, - &mox_attr_mac_address2.attr, - &mox_attr_pubkey.attr, - NULL -}; - static void mox_rwtm_rx_callback(struct mbox_client *cl, void *data) { struct mox_rwtm *rwtm = dev_get_drvdata(cl->dev); @@ -487,6 +442,11 @@ static inline void rwtm_unregister_debugfs(struct mox_rwtm *rwtm) } #endif +static void rwtm_firmware_symlink_drop(void *) +{ + sysfs_remove_link(firmware_kobj, DRIVER_NAME); +} + static int turris_mox_rwtm_probe(struct platform_device *pdev) { struct mox_rwtm *rwtm; @@ -503,18 +463,6 @@ static int turris_mox_rwtm_probe(struct platform_device *pdev) if (!rwtm->buf) return -ENOMEM; - ret = mox_kobj_create(rwtm); - if (ret < 0) { - dev_err(dev, "Cannot create turris-mox-rwtm kobject!\n"); - return ret; - } - - ret = sysfs_create_files(rwtm_to_kobj(rwtm), mox_rwtm_attrs); - if (ret < 0) { - dev_err(dev, "Cannot create sysfs files!\n"); - goto put_kobj; - } - platform_set_drvdata(pdev, rwtm); mutex_init(&rwtm->busy); @@ -528,7 +476,7 @@ static int turris_mox_rwtm_probe(struct platform_device *pdev) if (ret != -EPROBE_DEFER) dev_err(dev, "Cannot request mailbox channel: %i\n", ret); - goto remove_files; + return ret; } init_completion(&rwtm->cmd_done); @@ -562,14 +510,18 @@ static int turris_mox_rwtm_probe(struct platform_device *pdev) dev_info(dev, "HWRNG successfully registered\n"); + /* + * For sysfs ABI compatibility, create symlink + * /sys/firmware/turris-mox-rwtm to this device's sysfs directory. + */ + ret = sysfs_create_link(firmware_kobj, &dev->kobj, DRIVER_NAME); + if (!ret) + devm_add_action_or_reset(dev, rwtm_firmware_symlink_drop, NULL); + return 0; free_channel: mbox_free_channel(rwtm->mbox); -remove_files: - sysfs_remove_files(rwtm_to_kobj(rwtm), mox_rwtm_attrs); -put_kobj: - kobject_put(rwtm_to_kobj(rwtm)); return ret; } @@ -578,8 +530,6 @@ static void turris_mox_rwtm_remove(struct platform_device *pdev) struct mox_rwtm *rwtm = platform_get_drvdata(pdev); rwtm_unregister_debugfs(rwtm); - sysfs_remove_files(rwtm_to_kobj(rwtm), mox_rwtm_attrs); - kobject_put(rwtm_to_kobj(rwtm)); mbox_free_channel(rwtm->mbox); } @@ -597,6 +547,7 @@ static struct platform_driver turris_mox_rwtm_driver = { .driver = { .name = DRIVER_NAME, .of_match_table = turris_mox_rwtm_match, + .dev_groups = turris_mox_rwtm_groups, }, }; module_platform_driver(turris_mox_rwtm_driver);
In order to create attribute files in /sys/firmware/turris-mox-rwtm, this driver creates it's own kobject type. Simplify this by dropping this own kobject creation, and instead creating standard device attribute files. For backwards compatibility with sysfs ABI, create a symlink /sys/firmware/turris-mox-rwtm, pointing to this device's sysfs directory. Signed-off-by: Marek Behún <kabel@kernel.org> --- drivers/firmware/turris-mox-rwtm.c | 107 ++++++++--------------------- 1 file changed, 29 insertions(+), 78 deletions(-)