The dcdbas driver is used to call SMI handlers for both, dcdbas and
dell-smbios-smm. Both drivers allocate a buffer for communicating
with the SMI handler. The physical buffer address is then passed to
the called SMI handler via %ebx.
Unfortunately this doesn't work when running in Xen dom0, as the
physical address obtained via virt_to_phys() is only a guest physical
address, and not a machine physical address as needed by SMI.
The problem in dcdbas is easy to correct, as dcdbas is using
dma_alloc_coherent() for allocating the buffer, and the machine
physical address is available via the DMA address returned in the DMA
handle.
In order to avoid duplicating the buffer allocation code in
dell-smbios-smm, add a generic buffer allocation function to dcdbas
and use it for both drivers. This is especially fine regarding driver
dependencies, as dell-smbios-smm is already calling dcdbas to generate
the SMI request.
Signed-off-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20220318150950.16843-1-jgross@suse.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
dell-smbios is depended on by dell-laptop and that has this same table +
some extra entries for chassis-type 30, 31 and 32.
Since dell-laptop will already auto-load based on the DMI table in there
(which also is more complete) and since dell-laptop will then bring in
the dell-smbios module, the only scenario I can think of where this DMI
table inside dell-smbios-smm.c is useful is if users have the dell-laptop
module disabled and they want to use the sysfs interface offered by
dell-smbios-smm.c. But that is such a corner case, even requiring a custom
kernel build, that it does not weigh up against having this duplicate
table, which as the current state already shows can only grow stale.
Users who do hit this corner-case can always explicitly modprobe /
insmod the module.
Cc: Mario Limonciello <mario.limonciello@outlook.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210802120734.36732-1-hdegoede@redhat.com
A user without a Dell system doesn't need to pick any of these
drivers.
Users with a Dell system can enable this submenu and all drivers
behind it will be enabled.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Link: https://lore.kernel.org/r/20210203195832.2950605-1-mario.limonciello@dell.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
