From mboxrd@z Thu Jan  1 00:00:00 1970
From: mark.rutland@arm.com (Mark Rutland)
Date: Mon, 21 Jan 2013 09:22:40 +0000
Subject: [PATCH v2 3/9] ARM: PRIMA2: initialize l2x0 according to mach
 from DT
In-Reply-To: <CAGsJ_4wXRsaX99NQNYPAqAc-9TpzXNpDB0X6y9D18ka4szPMAw@mail.gmail.com>
References: <1358315610-25001-1-git-send-email-Barry.Song@csr.com>
 <1358315610-25001-3-git-send-email-Barry.Song@csr.com>
 <20130116120318.GD10218@e106331-lin.cambridge.arm.com>
 <CAGsJ_4wXRsaX99NQNYPAqAc-9TpzXNpDB0X6y9D18ka4szPMAw@mail.gmail.com>
Message-ID: <20130121092240.GD15707@e106331-lin.cambridge.arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Sat, Jan 19, 2013 at 04:21:47AM +0000, Barry Song wrote:
> Hi Mark,
> 
> 2013/1/16 Mark Rutland <mark.rutland@arm.com>:
> > On Wed, Jan 16, 2013 at 05:53:29AM +0000, Barry Song wrote:
> >> From: Barry Song <Baohua.Song@csr.com>
> >>
> >> prima2 and marco have diffetent l2 cache configuration, so
> >> we initialize l2x0 cache based on dtb given to kernel.
> >>
> >> Signed-off-by: Barry Song <Baohua.Song@csr.com>
> >> Cc: Mark Rutland <mark.rutland@arm.com>
> >> ---
> >>  arch/arm/mach-prima2/l2x0.c |   29 ++++++++++++++++++++++++-----
> >>  1 files changed, 24 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/arch/arm/mach-prima2/l2x0.c b/arch/arm/mach-prima2/l2x0.c
> >> index c998377..e41ecd2 100644
> >> --- a/arch/arm/mach-prima2/l2x0.c
> >> +++ b/arch/arm/mach-prima2/l2x0.c
> >> @@ -11,19 +11,38 @@
> >>  #include <linux/of.h>
> >>  #include <asm/hardware/cache-l2x0.h>
> >>
> >> -static struct of_device_id prima2_l2x0_ids[]  = {
> >> -     { .compatible = "sirf,prima2-pl310-cache" },
> >> +struct l2x0_aux
> >> +{
> >> +     u32 val;
> >> +     u32 mask;
> >> +};
> >> +
> >> +static struct l2x0_aux prima2_l2x0_aux __initconst = {
> >> +     0x40000,
> >> +     0,
> >> +};
> >
> > That 0x40000 is a bit opaque. Now would be a good time to make it a bit more
> > legible. Am I right in saying that's (2 << L2X0_AUX_CTRL_WAY_SIZE_SHIFT) ?
> >
> > It'd also be nice if you used designated initializers:
> >
> > static struct l2x0_aux prima2_l2x0_aux __initconst = {
> >         .val    = (2 << L2X0_AUX_CTRL_WAY_SIZE_SHIFT),
> >         .mask   = 0,
> > };
> 
> good. and make prima2 have consistent style with marco.
> 
> >
> >> +
> >> +static struct l2x0_aux marco_l2x0_aux __initconst = {
> >> +     (2 << L2X0_AUX_CTRL_WAY_SIZE_SHIFT) |
> >> +             (1 << L2X0_AUX_CTRL_ASSOCIATIVITY_SHIFT),
> >> +     L2X0_AUX_CTRL_MASK,
> >> +};
> >
> > And here too:
> >
> > static struct l2x0_aux marco_l2x0_aux __initconst = {
> >         .val    = (2 << L2X0_AUX_CTRL_WAY_SIZE_SHIFT) |
> >                         (1 << L2X0_AUX_CTRL_ASSOCIATIVITY_SHIFT),
> >         .mask   = L2X0_AUX_CTRL_MASK,
> > };
> >
> >> +
> >> +static struct of_device_id sirf_l2x0_ids[] __initconst = {
> >> +     { .compatible = "sirf,prima2-pl310-cache", .data = &prima2_l2x0_aux, },
> >> +     { .compatible = "sirf,marco-pl310-cache", .data = &marco_l2x0_aux, },
> >>       {},
> >>  };
> >
> > I took a look at of_match_node, and it seems that the first match found in an
> > of_match_table will be returned first, rather than finding the match earliest
> > in a device node's compatible list. This is somewhat counter-intuitive.
> >
> > Therefore, the marco variant should be listed first, or it will get initialised
> > with the prima2 configuration values.
> 
> sorry. i don't get it.  do you mean .data(prima2_l2x0_aux) will be
> returned for marco?
> 
> here l2 node in matco.dts  without "sirf,prima2-pl310-cache"  will
> only have "sirf,marco-pl310-cache" and l2 node in prima2.dts without
> "sirf,marco-pl310-cache" will only have "sirf,prima2-pl310-cache"

Ah, I missed that they were mutually exclusive. As long as the node only has
one of these entries in its compatible list it'll be fine as-is.

> >
> >>
> >>  static int __init sirfsoc_l2x0_init(void)
> >>  {
> >>       struct device_node *np;
> >> +     const struct l2x0_aux *aux;
> >>
> >> -     np = of_find_matching_node(NULL, prima2_l2x0_ids);
> >> +     np = of_find_matching_node(NULL, sirf_l2x0_ids);
> >>       if (np) {
> >> -             pr_info("Initializing prima2 L2 cache\n");
> >> -             return l2x0_of_init(0x40000, 0);
> >> +             aux = of_match_node(sirf_l2x0_ids, np)->data;
> >> +             return l2x0_of_init(aux->val, aux->mask);
> >>       }
> >>
> >>       return 0;
> >> --
> >> 1.7.5.4
> >>
> >>
> >
> > With those changes:
> >
> > Reviewed-by: Mark Rutland <mark.rutland@arm.com>
> >
> > Thanks,
> > Mark.
> 
> -barry
> 

Thanks,
Mark.