| Message ID | 20200212110540.83559-1-mika.westerberg@linux.intel.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [1/3] ACPICA: Introduce ACPI_ACCESS_BIT_WIDTH() macro | expand |
On Wed, 12 Feb 2020 14:05:38 +0300, Mika Westerberg wrote: > Sometimes it is useful to find the access_width field value in bytes and > not in bits so add a helper that can be used for this purpose. s/ACPI_ACCESS_BIT_WIDTH/ACPI_ACCESS_BYTE_WIDTH/ in the subject. > > Suggested-by: Jean Delvare <jdelvare@suse.de> > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> > --- > include/acpi/actypes.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h > index a2583c2bc054..77d40b02f62a 100644 > --- a/include/acpi/actypes.h > +++ b/include/acpi/actypes.h > @@ -537,6 +537,7 @@ typedef u64 acpi_integer; > * struct acpi_resource_generic_register. > */ > #define ACPI_ACCESS_BIT_WIDTH(size) (1 << ((size) + 2)) > +#define ACPI_ACCESS_BYTE_WIDTH(size) (ACPI_ACCESS_BIT_WIDTH(size) / 8) One of the points of having this macro being to avoid needless math, I'd rather do: #define ACPI_ACCESS_BYTE_WIDTH(size) (1 << ((size) - 1)) Some compilers might be able to optimize it, but maybe not all, and I see little point in giving the compiler more work anyway when it can be easily avoided. You may also want to replace "bit" by "bit or byte in the comment right before the macros. > > /******************************************************************************* > * Reviewed-by: Jean Delvare <jdelvare@suse.de>
On Wed, Feb 12, 2020 at 12:52:44PM +0100, Jean Delvare wrote: > On Wed, 12 Feb 2020 14:05:38 +0300, Mika Westerberg wrote: > > Sometimes it is useful to find the access_width field value in bytes and > > not in bits so add a helper that can be used for this purpose. > > s/ACPI_ACCESS_BIT_WIDTH/ACPI_ACCESS_BYTE_WIDTH/ in the subject. Indeed. > > Suggested-by: Jean Delvare <jdelvare@suse.de> > > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> > > --- > > include/acpi/actypes.h | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h > > index a2583c2bc054..77d40b02f62a 100644 > > --- a/include/acpi/actypes.h > > +++ b/include/acpi/actypes.h > > @@ -537,6 +537,7 @@ typedef u64 acpi_integer; > > * struct acpi_resource_generic_register. > > */ > > #define ACPI_ACCESS_BIT_WIDTH(size) (1 << ((size) + 2)) > > +#define ACPI_ACCESS_BYTE_WIDTH(size) (ACPI_ACCESS_BIT_WIDTH(size) / 8) > > One of the points of having this macro being to avoid needless math, > I'd rather do: > > #define ACPI_ACCESS_BYTE_WIDTH(size) (1 << ((size) - 1)) > > Some compilers might be able to optimize it, but maybe not all, and I > see little point in giving the compiler more work anyway when it can be > easily avoided. > > You may also want to replace "bit" by "bit or byte in the comment right > before the macros. OK, I'll do that. > > > > /******************************************************************************* > > * > > Reviewed-by: Jean Delvare <jdelvare@suse.de> Thanks!
diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h index a2583c2bc054..77d40b02f62a 100644 --- a/include/acpi/actypes.h +++ b/include/acpi/actypes.h @@ -537,6 +537,7 @@ typedef u64 acpi_integer; * struct acpi_resource_generic_register. */ #define ACPI_ACCESS_BIT_WIDTH(size) (1 << ((size) + 2)) +#define ACPI_ACCESS_BYTE_WIDTH(size) (ACPI_ACCESS_BIT_WIDTH(size) / 8) /******************************************************************************* *
Sometimes it is useful to find the access_width field value in bytes and not in bits so add a helper that can be used for this purpose. Suggested-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> --- include/acpi/actypes.h | 1 + 1 file changed, 1 insertion(+)