On Wed, Apr 4, 2018 at 7:40 AM, Ivan Gorinov <ivan.gori...@intel.com> wrote: > On Wed, Apr 04, 2018 at 12:15:24PM +0800, Bin Meng wrote: >> > Doesn't readX/writeX imply a single I/O operation? >> > It may be misleading to define it as two. >> > >> > Assuming MMX or SSE2 to be supported by all x86 processors, 64-bit I/O >> > registers can be accessed as a single operation even in 32-bit code: >> > >> >> Adding such requirement (MMX or SSE2) to U-Boot is not good. Why do we >> require MMX or SSE2 for readq? Can we use general purpose registers? > > In 32-bit code, we can't make a 64-bit memory read operation using only > general purpose registers.
Exactly, that's why you have to use non-atomic variants. -- With Best Regards, Andy Shevchenko _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot