+ cris/ia64/mn10300/openrisc maintainers On 2017/12/25 9:09, Yisheng Xie wrote: > hi Christophe and Greg, > > On 2017/12/24 16:55, christophe leroy wrote: >> >> >> Le 23/12/2017 à 16:57, Guenter Roeck a écrit : >>> On 12/23/2017 05:48 AM, Greg KH wrote: >>>> On Sat, Dec 23, 2017 at 06:55:25PM +0800, Yisheng Xie wrote: >>>>> Hi all, >>>>> >>>>> When I tried to use devm_ioremap function and review related code, I found >>>>> devm_ioremap and devm_ioremap_nocache is almost the same with each other, >>>>> except one use ioremap while the other use ioremap_nocache. >>>> >>>> For all arches? Really? Look at MIPS, and x86, they have different >>>> functions. >>>> >>> >>> Both mips and x86 end up mapping the same function, but other arches don't. >>> mn10300 is one where ioremap and ioremap_nocache are definitely different. >> >> alpha: identical >> arc: identical >> arm: identical >> arm64: identical >> cris: different <== >> frv: identical >> hexagone: identical >> ia64: different <== >> m32r: identical >> m68k: identical >> metag: identical >> microblaze: identical >> mips: identical >> mn10300: different <== >> nios: identical >> openrisc: different <== >> parisc: identical >> riscv: identical >> s390: identical >> sh: identical >> sparc: identical >> tile: identical >> um: rely on asm/generic >> unicore32: identical >> x86: identical >> asm/generic (no mmu): identical > > Wow, that's correct, sorry for I have just checked the main archs, I means > x86,arm, arm64, mips. > > However, I stall have no idea about why these 4 archs want different ioremap > function with others. Drivers seems cannot aware this? If driver call ioremap > want he really want for there 4 archs, cache or nocache? Could you please help about this? it is out of my knowledge. Thanks Yisheng > >> >> So 4 among all arches seems to have ioremap() and ioremap_nocache() being different. >> >> Could we have a define set by the 4 arches on which ioremap() and ioremap_nocache() are different, something like HAVE_DIFFERENT_IOREMAP_NOCACHE ? > > Then, what the HAVE_DIFFERENT_IOREMAP_NOCACHE is uesed for ? > > Thanks > Yisheng >> >> Christophe >> >>> >>> Guenter >>> >>>>> While ioremap's >>>>> default function is ioremap_nocache, so devm_ioremap_nocache also have the >>>>> same function with devm_ioremap, which can just be killed to reduce the size >>>>> of devres.o(from 20304 bytes to 18992 bytes in my compile environment). >>>>> >>>>> I have posted two versions, which use macro instead of function for >>>>> devm_ioremap_nocache[1] or devm_ioremap[2]. And Greg suggest me to kill >>>>> devm_ioremap_nocache for no need to keep a macro around for the duplicate >>>>> thing. So here comes v3 and please help to review. >>>> >>>> I don't think this can be done, what am I missing? These functions are >>>> not identical, sorry for missing that before. > > Never mind, I should checked all the arches, sorry about that. > >>>> >>>> thanks, >>>> >>>> greg k-h >>>> >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in >>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> --- >> L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. >> https://www.avast.com/antivirus >> >> >> . >> > > > . > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
