> Which memory barrier do I require if I need to ensure that a > copy_to_user(dest, src, len) completes before the next statement?
Define "completes" > > copy_to_user(dest, src, len) ; > //rmb(); OR wmb(); OR barrier(); OR mb(); ?????? Usually none of them > If I'm writing to hardware, and need to ensure the correct order, I'll > use wmb(), right? No > e.g.: > > #define HW_address1 20 > #define HW_address2 40 > > *((int *)HW_address1) = 0x00000001; > wmb(); // is this good??? > *((int *)HW_address2) = 0x00000010; Linux doesn't define directly poking kernel addresses to hit hardware as valid (and on many platforms it doesn't work). Use readl/writel and their ordering is defined. Read Documentation/io_ordering.txt and Docuemntation/pci.txt - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
