On Tue, Jan 25, 2022 at 7:30 AM Robert Kiraly <me@xxxxxxxxxxxxx> wrote: > > This is a simple ACPI patch. I'm submitting a revised version to > linux-acpi per Rafael Wysocki and linux-cxl per Dan Williams. > > The patch has been moved to the message body and a Signed-off-by tag has > been added. Thunderbird has added CRs so "patch -p1 -l" is needed. To > address other points: > > Q. Dan Williams said: Yes, although I don't see much incremental benefit > to developers publishing a root only raw table... So, not opposed to the > patch, but I want to direct you to the sysfs representation of the CEDT > and CFMWS in /sys/bus/cxl/devices... Platform firmware CXL details are > modeled as "CXL root" objects in the /sys/bus/cxl device model. > > A. The patch is being submitted in connection with work on a CXL bridge. > The developers would like to express appreciation for the "sysfs" point. > They find it useful to be able to do initialization through the table > but will look at the "sysfs" approach. > > Q. Rafael J. Wysocki said: I'm not sure why the #ifdef is needed. > > A. I reviewed cxl-next and decided to add the #ifdef to ensure that the > code would compile regardless of the direction that the codebase takes. ACPI_SIG_CEDT is defined in 5.17-rc1 AFAICS, so the #ifdef is redundant. > ==== start of patch ==== > Subject: Make ACPI subsystem provide CEDT table > Signed-off-by: Robert Kiraly <me@xxxxxxxxxxxxx> > > This is a simple patch to the ACPI subsystem. The patch adds ACPI > _SIG_CEDT to table_sigs[] in "drivers/acpi/tables.c". > > Presently, CXL code isn't able to make use of the CEDT table at > the initrd stage. Subsequent to the change, the CEDT table can be > used. > > If a developer plans to use the CEDT table to program the CXL > ports, this change is needed. Otherwise, it isn't expected to > make a difference. > > I certify compliance with Developer’s Certificate of Origin 1.1 > as listed in: > https://www.kernel.org/doc/html/v4.10/process/submitting-patches. > html > > --- linux-5.16.old/drivers/acpi/tables.c > +++ linux-5.16/drivers/acpi/tables.c > @@ -500,6 +500,9 @@ > ACPI_SIG_WDDT, ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, > ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, > ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT, > +#ifdef ACPI_SIG_CEDT > + ACPI_SIG_CEDT, > +#endif > ACPI_SIG_NHLT }; > > #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header) > ==== end of patch ==== > >
