Hello Jiri, On Wed, Jan 19, 2011 at 01:43:57PM +0100, Jiri Slaby wrote: > On 01/19/2011 09:54 AM, Uwe Kleine-König wrote: > > On Tue, Jan 18, 2011 at 09:37:15PM -0800, Greg KH wrote: > >> On Tue, Jan 18, 2011 at 04:39:11PM +0100, Uwe Kleine-König wrote: > >>> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > >>> --- > >>> drivers/staging/hv/osd.h | 5 ++--- > >>> 1 files changed, 2 insertions(+), 3 deletions(-) > >>> > >>> diff --git a/drivers/staging/hv/osd.h b/drivers/staging/hv/osd.h > >>> index ce064e8..61ae54c 100644 > >>> --- a/drivers/staging/hv/osd.h > >>> +++ b/drivers/staging/hv/osd.h > >>> @@ -28,10 +28,9 @@ > >>> #include <linux/workqueue.h> > >>> > >>> /* Defines */ > >>> -#define ALIGN_UP(value, align) (((value) & (align-1)) ? \ > >>> - (((value) + (align-1)) & ~(align-1)) : \ > >>> - (value)) > >>> +#define ALIGN_UP(value, align) ALIGN((value), (align)) > >> > >> How about dropping ALIGN_UP entirely and just using the built-in ALIGN() > >> macro instead? > > Can do. > > > >>> #define ALIGN_DOWN(value, align) ((value) & ~(align-1)) > >> > >> Any chance to get rid of this as well with the ALIGN() macro, or is that > >> really not possible? > > it would be > > > > #define ALIGN_DOWN(value, align) ALIGN((value) - (align) + 1, (align)) > > > > I think, but as it's only used once it might be easier to just use ALIGN > > there, too. > > > > BTW, it's used as follows: > > > > #define NUM_PAGES_SPANNED(addr, len) ((ALIGN(addr+len, PAGE_SIZE) - \ > > ALIGN_DOWN(addr, PAGE_SIZE)) >> \ > > PAGE_SHIFT) > > (DIV_ROUND_UP(addr+len, PAGE_SIZE) - ((addr) >> PAGE_SHIFT))) > > or maybe better > > (PAGE_ALIGN(addr+len) >> PAGE_SHIFT - ((addr) >> PAGE_SHIFT)) > > > I wonder if there is already a function yielding this value? > > Wouldn't > > > > ((addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT) + 1 > > No, this won't work (it's not equivalent). Ah, this fails if addr + len is page aligned. ((addr + len - 1) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT) + 1 would work, but I like (PAGE_ALIGN(addr+len) >> PAGE_SHIFT - ((addr) >> PAGE_SHIFT)) better. (In fact these two are equivalent: PAGE_ALIGN(addr+len) >> PAGE_SHIFT = __ALIGN_KERNEL(addr+len, PAGE_SIZE) >> PAGE_SHIFT = __ALIGN_KERNEL_MASK(addr+len, PAGE_SIZE - 1) >> PAGE_SHIFT = ((addr + len + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1)) >> PAGE_SHIFT = (addr + len + PAGE_SIZE - 1) >> PAGE_SHIFT = (addr + len - 1) >> PAGE_SHIFT + 1 Greg: should I send an updated patch or do you modify NUM_PAGES_SPANNED accordingly? Thanks Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
