On 07/02/2015 11:23 PM, Hanjun Guo wrote:
Hi Rafael,
On 2015/7/3 8:21, Rafael J. Wysocki wrote:
On Thursday, July 02, 2015 05:48:34 PM Al Stone wrote:
Add the __ACPI_FADT_SPEC_VERSION() helper macro to build a proper version number from a major and minor revision number. Add also macros that use the helper to construct the current version from the values in the FADT (i.e., ACPI_FADT_SPEC_VERSION) and both the 5.1 and 6.0 versions.
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.
Fixes: aeb823bbacc2 (ACPICA: ACPI 6.0: Add changes for FADT table.) Signed-off-by: Al Stone al.stone@linaro.org
include/linux/acpi.h | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/include/linux/acpi.h b/include/linux/acpi.h index c471dfc..0e525e8 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -48,6 +48,16 @@ #include <acpi/acpi_io.h> #include <asm/acpi.h> +#define __ACPI_FADT_SPEC_VERSION(major, minor) \
- ((unsigned int)major << 8 | (unsigned int)minor)
+#define ACPI_FADT_SPEC_VERSION \
- __ACPI_FADT_SPEC_VERSION(acpi_gbl_FADT.header.revision, \
acpi_gbl_FADT.minor_revision)+#define ACPI_FADT_SPEC_VERSION_51 __ACPI_FADT_SPEC_VERSION(5, 1) +#define ACPI_FADT_SPEC_VERSION_60 __ACPI_FADT_SPEC_VERSION(6, 0)
I'd add underscores here, eg. ACPI_FADT_SPEC_VERSION_6_0
Agreed.
Will do. This was a flip of the coin, on my part.
And what if there is 5.2 or even 5.3?
Hmm, do you mean in the future or just now? for both two cases, only 5.1 and 5.1 errata (still has the same ACPI version with 5.1) will be available, then jump to 6.0 and going forward if new versions in the future.
I'm not sure if I understand your question correctly, if not, please correct me :)
Thanks Hanjun
I'm not sure I understand the question, either. Traditionally, the spec versioning has been exclusively linear -- i.e., now that 6.0 has replaced 5.1, there will be no more 5.x. There may be errata published (e.g., there was a 5.1A, and a 6.0A is forthcoming) but the errata are not encoded in tables anywhere since they are meant only as corrections to the base version. This is unlikely to change, but not impossible, of course :).
The only reason for putting in macros for 5.1 and 6.0 is that those are the versions that I'm concerned with for this particular fix and I know I will use them. If others are needed, I'd have those that need them add them.