thanks. done in v8 I am sending right now. On Mon, Feb 8, 2016 at 3:36 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Sun, 7 Feb 2016 17:08:45 -0800 David Decotigny <ddecotig@xxxxxxxxx> wrote: > >> From: David Decotigny <decot@xxxxxxxxxxxx> >> >> Aimed at transferring bitmaps to/from user-space in a 32/64-bit agnostic >> way. >> >> Tested: >> unit tests (next patch) on qemu i386, x86_64, ppc, ppc64 BE and LE, >> ARM. >> >> @@ -1060,6 +1062,90 @@ int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) >> EXPORT_SYMBOL(bitmap_allocate_region); >> >> /** >> + * bitmap_from_u32array - copy the contents of a u32 array of bits to bitmap >> + * @bitmap: array of unsigned longs, the destination bitmap, non NULL >> + * @nbits: number of bits in @bitmap >> + * @buf: array of u32 (in host byte order), the source bitmap, non NULL >> + * @nwords: number of u32 words in @buf >> + * >> + * copy min(nbits, 32*nwords) bits from @buf to @bitmap, remaining >> + * bits between nword and nbits in @bitmap (if any) are cleared. In >> + * last word of @bitmap, the bits beyond nbits (if any) are kept >> + * unchanged. >> + */ > > This will leave the caller not knowing how many valid bits are actually > present in the resulting bitmap. To determine that, the caller will > need to perform (duplicated) math on `nbits' and `nwords'. > >> +void bitmap_from_u32array(unsigned long *bitmap, unsigned int nbits, >> + const u32 *buf, unsigned int nwords) > > So how about we make this return the number of valid bits in *bitmap? > >> +/** >> + * bitmap_to_u32array - copy the contents of bitmap to a u32 array of bits >> + * @buf: array of u32 (in host byte order), the dest bitmap, non NULL >> + * @nwords: number of u32 words in @buf >> + * @bitmap: array of unsigned longs, the source bitmap, non NULL >> + * @nbits: number of bits in @bitmap >> + * >> + * copy min(nbits, 32*nwords) bits from @bitmap to @buf. Remaining >> + * bits after nbits in @buf (if any) are cleared. >> + */ >> +void bitmap_to_u32array(u32 *buf, unsigned int nwords, >> + const unsigned long *bitmap, unsigned int nbits) > > Ditto. > >
