The kernel provides the macro MODULE_DEVICE_TABLE() where driver authors can specify their device type and their array of device_ids and thereby trigger the generation of the appropriate MODULE_ALIAS() output. This is opposed to having to specify one MODULE_ALIAS() for each device. The WMI device type is currently not supported.
While using MODULE_DEVICE_TABLE() does increase the complexity as well as spreading out the implementation across the kernel, it does come with some benefits too; * It makes different drivers look more similar; if you can specify the array of device_ids any device type specific input to MODULE_ALIAS() will automatically be generated for you. * It helps each driver avoid keeping multiple versions of the same information in sync. That is, both the array of device_ids and the potential multitude of MODULE_ALIAS()'s. Add WMI support to MODULE_DEVICE_TABLE() by adding info about struct wmi_device_id in devicetable-offsets.c and add a WMI entry point in file2alias.c. The type argument for MODULE_DEVICE_TABLE(type, name) is wmi. Suggested-by: Pali Rohár <pali.ro...@gmail.com> Signed-off-by: Mattias Jacobsson <2...@mok.nu> --- What do you think about writing it this way now, pretty much the same as before, but now using the macro ALIAS_SIZE instead of a hardcoded value? Also, as I mentioned before, I've submitted the ALIAS_SIZE patch and have recieved a question on which tree the patch should be go through. See the original question on [1]. I don't mind either way, do you have a preference on this? [1]: https://lore.kernel.org/lkml/cak7lnaqz7pdz4+uzu-ft4v8yw9ougz6e++9xsshwjvalj3g...@mail.gmail.com -- scripts/mod/devicetable-offsets.c | 3 +++ scripts/mod/file2alias.c | 23 +++++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c index 293004499b4d..99276a422e77 100644 --- a/scripts/mod/devicetable-offsets.c +++ b/scripts/mod/devicetable-offsets.c @@ -225,5 +225,8 @@ int main(void) DEVID_FIELD(typec_device_id, svid); DEVID_FIELD(typec_device_id, mode); + DEVID(wmi_device_id); + DEVID_FIELD(wmi_device_id, guid_string); + return 0; } diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index afe22af20d7d..6dedc31a4925 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -37,6 +37,7 @@ typedef unsigned char __u8; typedef struct { __u8 b[16]; } uuid_le; +#define UUID_STRING_LEN 36 /* Big exception to the "don't include kernel headers into userspace, which * even potentially has different endianness and word sizes, since @@ -1290,6 +1291,27 @@ static int do_typec_entry(const char *filename, void *symval, char *alias) return 1; } +/* Looks like: wmi:guid */ +static int do_wmi_entry(const char *filename, void *symval, char *alias) +{ + int len; + DEF_FIELD_ADDR(symval, wmi_device_id, guid_string); + + if (strlen(*guid_string) != UUID_STRING_LEN) { + warn("Invalid WMI device id 'wmi:%s' in '%s'\n", + *guid_string, filename); + return 0; + } + + len = snprintf(alias, ALIAS_SIZE, WMI_MODULE_PREFIX "%s", *guid_string); + if (len < 0 || len >= ALIAS_SIZE) { + warn("Could not generate all MODULE_ALIAS's in '%s'\n", + filename); + return 0; + } + return 1; +} + /* Does namelen bytes of name exactly match the symbol? */ static bool sym_is(const char *name, unsigned namelen, const char *symbol) { @@ -1360,6 +1382,7 @@ static const struct devtable devtable[] = { {"fslmc", SIZE_fsl_mc_device_id, do_fsl_mc_entry}, {"tbsvc", SIZE_tb_service_id, do_tbsvc_entry}, {"typec", SIZE_typec_device_id, do_typec_entry}, + {"wmi", SIZE_wmi_device_id, do_wmi_entry}, }; /* Create MODULE_ALIAS() statements. -- 2.20.1
