lkml.org 
[lkml]   [2014]   [Mar]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [PATCH 4/8] tty/serial: add generic serial earlycon
    From
    On Mon, Mar 24, 2014 at 6:29 AM, Arnd Bergmann <arnd@arndb.de> wrote:
    > On Monday 24 March 2014 11:22:03 Catalin Marinas wrote:
    >> On Fri, Mar 21, 2014 at 09:08:44PM +0000, Rob Herring wrote:
    >> > diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
    >> > new file mode 100644
    >> > index 0000000..241757a
    >> > --- /dev/null
    >> > +++ b/drivers/tty/serial/earlycon.c
    >> [...]
    >> > +static void __iomem * __init earlycon_map(unsigned long paddr, size_t size)
    >> > +{
    >> > + void __iomem *base;
    >> > +#ifdef CONFIG_FIX_EARLYCON_MEM
    >> > + set_fixmap_nocache(FIX_EARLYCON_MEM_BASE, paddr & PAGE_MASK);
    >> > + base = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
    >> > + base += paddr & ~PAGE_MASK;
    >> > +#else
    >> > + base = ioremap_nocache(paddr, size);
    >> > +#endif
    >>
    >> Just curious why not set_fixmap_io (and plain ioremap)?
    >
    > Good point. Note that ioremap_nocache() is the same as ioremap()
    > on *all* architectures.

    I investigated this before adding this to arm64. set_fixmap_io and
    set_fixmap_nocache are not the same settings on x86. Whether the
    mapping type really matters on x86 or not, I don't know. So I added
    the nocache variant to arm64 to avoid a change to x86.

    Rob


    \
     
     \ /
      Last update: 2014-03-24 15:21    [W:8.675 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site