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? > > 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 > > > . >
