lkml.org 
[lkml]   [2008]   [Apr]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    SubjectRe: [PATCH] x86: GEODE: cache results from geode_has_vsa2() and uninline
    On Tue, 29 Apr 2008 01:32:13 -0400
    Andres Salomon <dilinger@queued.net> wrote:

    > On Mon, 28 Apr 2008 20:06:51 -0700
    > Andrew Morton <akpm@linux-foundation.org> wrote:
    >
    > > On Mon, 21 Apr 2008 17:02:30 -0400 Andres Salomon <dilinger@queued.net> wrote:
    > >
    > > > + if (!is_geode() || geode_has_vsa2())
    > >
    > > geode_has_vsa2() is a fairly expensive-looking function and afacit only
    > > needs to be evaluated once per boot. Perhaps we should cache it somewhere?
    > >
    >
    > How about this?
    >

    Looks sane. Although one wonders if it should be cached as one of the
    standard x86 feature bit thingies which show up in /proc/cpuinfo's 'flags'
    field.

    > +static int has_vsa2 = -1;
    > +
    > +int geode_has_vsa2(void)
    > +{
    > + if (has_vsa2 == -1) {
    > + /*
    > + * The VSA has virtual registers that we can query for a
    > + * signature.
    > + */
    > + outw(VSA_VR_UNLOCK, VSA_VRC_INDEX);
    > + outw(VSA_VR_SIGNATURE, VSA_VRC_INDEX);
    > +
    > + has_vsa2 = (inw(VSA_VRC_DATA) == VSA_SIG);
    > + }
    > +
    > + return has_vsa2;
    > +}
    > +EXPORT_SYMBOL_GPL(geode_has_vsa2);

    nit:

    --- a/arch/x86/kernel/geode_32.c
    +++ a/arch/x86/kernel/geode_32.c
    @@ -161,10 +161,10 @@ void geode_gpio_setup_event(unsigned int
    }
    EXPORT_SYMBOL_GPL(geode_gpio_setup_event);

    -static int has_vsa2 = -1;
    -
    int geode_has_vsa2(void)
    {
    + static int has_vsa2 = -1;
    +
    if (has_vsa2 == -1) {
    /*
    * The VSA has virtual registers that we can query for a


    \
     
     \ /
      Last update: 2008-04-29 22:43    [W:4.091 / U:0.908 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site