| Message ID | 1434666968-1543-2-git-send-email-al.stone@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 06/19/2015 06:36 AM, Al Stone wrote: > Add the ACPI_SPEC_VERSION() macro to build a proper version number from > a major and minor revision number. Add also the ACPI_FADT_SPEC_VERSION > that constructs a proper version number from the entries in the current > FADT. > > These macros are added in order to simplify retrieving and comparing ACPI > specification version numbers, since this is becoming a more frequent need. > In particular, there are some architectures that require at least a certain > version of the spec, and there are differences in some structure sizes that > have changed with recent versions but can only be tracked by spec version > number. > > Signed-off-by: Al Stone <al.stone@linaro.org> > --- > include/linux/acpi.h | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index a4acb55..33ed313 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -48,6 +48,11 @@ > #include <acpi/acpi_io.h> > #include <asm/acpi.h> > > +#define ACPI_SPEC_VERSION(major, minor) ((major<<8)|minor) and minor comments for code style ((major<<8)|minor) - > ((major << 8) | minor) other than that: Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Thanks Hanjun > +#define ACPI_FADT_SPEC_VERSION \ > + ACPI_SPEC_VERSION(acpi_gbl_FADT.header.revision, \ > + acpi_gbl_FADT.minor_revision) > + > static inline acpi_handle acpi_device_handle(struct acpi_device *adev) > { > return adev ? adev->handle : NULL; >
On 06/30/2015 02:12 PM, Rafael J. Wysocki wrote: > Hi Al, > > On Fri, Jun 19, 2015 at 12:36 AM, Al Stone <al.stone@linaro.org> wrote: >> Add the ACPI_SPEC_VERSION() macro to build a proper version number from >> a major and minor revision number. Add also the ACPI_FADT_SPEC_VERSION >> that constructs a proper version number from the entries in the current >> FADT. >> >> These macros are added in order to simplify retrieving and comparing ACPI >> specification version numbers, since this is becoming a more frequent need. >> In particular, there are some architectures that require at least a certain >> version of the spec, and there are differences in some structure sizes that >> have changed with recent versions but can only be tracked by spec version >> number. >> >> Signed-off-by: Al Stone <al.stone@linaro.org> >> --- >> include/linux/acpi.h | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/include/linux/acpi.h b/include/linux/acpi.h >> index a4acb55..33ed313 100644 >> --- a/include/linux/acpi.h >> +++ b/include/linux/acpi.h >> @@ -48,6 +48,11 @@ >> #include <acpi/acpi_io.h> >> #include <asm/acpi.h> >> >> +#define ACPI_SPEC_VERSION(major, minor) ((major<<8)|minor) > > One nit here. > > acpi_gbl_FADT.header.revision is of type u8 originally, so shifting it > by 8 bit positions only works due to some implicit type casting I > suppose. Bah. That was being sloppy on my part. Sorry about that. Will fix. > Moreover, it is not entirely clear why the macro is specific to the > computation of the ACPI spec version. As far as I know, that's the only way to extract the spec version from tables; I don't recall there being any other table with that info. Since I will likely use this again, it seemed to make sense at the time. > So I'd drop ACPI_SPEC_VERSION and only define ACPI_FADT_SPEC_VERSION > as something like > > #define ACPI_FADT_SPEC_VERSION (((unsigned > int)acpi_gbl_FADT.header.revision << 8) | (unsigned > int)acpi_gbl_FADT.minor_revision) > > Thanks, > Rafael > Sure. That makes sense. It makes it clearer that this is the version just from the FADT. I'll do that.
diff --git a/include/linux/acpi.h b/include/linux/acpi.h index a4acb55..33ed313 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -48,6 +48,11 @@ #include <acpi/acpi_io.h> #include <asm/acpi.h> +#define ACPI_SPEC_VERSION(major, minor) ((major<<8)|minor) +#define ACPI_FADT_SPEC_VERSION \ + ACPI_SPEC_VERSION(acpi_gbl_FADT.header.revision, \ + acpi_gbl_FADT.minor_revision) + static inline acpi_handle acpi_device_handle(struct acpi_device *adev) { return adev ? adev->handle : NULL;
Add the ACPI_SPEC_VERSION() macro to build a proper version number from a major and minor revision number. Add also the ACPI_FADT_SPEC_VERSION that constructs a proper version number from the entries in the current FADT. These macros are added in order to simplify retrieving and comparing ACPI specification version numbers, since this is becoming a more frequent need. In particular, there are some architectures that require at least a certain version of the spec, and there are differences in some structure sizes that have changed with recent versions but can only be tracked by spec version number. Signed-off-by: Al Stone <al.stone@linaro.org> --- include/linux/acpi.h | 5 +++++ 1 file changed, 5 insertions(+)