On Fri, 20 Feb 2009, Ira Snyder wrote: > On Fri, Feb 20, 2009 at 03:56:39PM -0600, Matt Sealey wrote: > > Am I correct in saying that cpu_to_le32 and le32_to_cpu are the > > functions/macros I need to use to do byte swapping to make everything > > go little endian (and back again when I read them back in the kernel)? > > > > Or is there some cleverer way already implemented in the kernel? > > I would say that the __raw_readl() reads in cpu order. If you wanted to > convert that to le32, you'd use cpu_to_le32().
Well... __raw_readl() does read in cpu order. But since you're reading from the PCI bus, which is little endian, you actually read a little endian value. So you should use le32_to_cpu() to convert it to a native value. (yes, at the lowest level, cpu_to_le32() and le32_to_cpu() do the same thing on PPC: byte swapping 32-bit data). With kind regards, Geert Uytterhoeven Software Architect Sony Techsoft Centre Europe The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium Phone: +32 (0)2 700 8453 Fax: +32 (0)2 700 8622 E-mail: geert.uytterhoe...@sonycom.com Internet: http://www.sony-europe.com/ A division of Sony Europe (Belgium) N.V. VAT BE 0413.825.160 · RPR Brussels Fortis · BIC GEBABEBB · IBAN BE41293037680010 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
