From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Zr5Th-0006JY-ST for barebox@lists.infradead.org; Tue, 27 Oct 2015 14:43:59 +0000 Date: Tue, 27 Oct 2015 15:43:35 +0100 From: Sascha Hauer Message-ID: <20151027144335.GL25308@pengutronix.de> References: <1445877229-14319-1-git-send-email-l.stach@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1445877229-14319-1-git-send-email-l.stach@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH] ARM: imx6: add OF fixup to delete nonexistent CPU cores To: Lucas Stach Cc: barebox@lists.infradead.org On Mon, Oct 26, 2015 at 05:33:49PM +0100, Lucas Stach wrote: > Make sure that the DT passed to Linux reflects the actual number of CPU > cores present in the system by reading the SCU configuration. As both > the Q and DL variants of the MX6 have versions with cores fused away, > but the DTs have the maximum number of cores specified, this just deletes > any nonexistent CPU core nodes. > > Signed-off-by: Lucas Stach > --- > arch/arm/mach-imx/imx6.c | 34 ++++++++++++++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > > diff --git a/arch/arm/mach-imx/imx6.c b/arch/arm/mach-imx/imx6.c > index c49de49209f3..c2a4d62c51da 100644 > --- a/arch/arm/mach-imx/imx6.c > +++ b/arch/arm/mach-imx/imx6.c > @@ -238,3 +238,37 @@ static int imx6_mmu_init(void) > return 0; > } > postmmu_initcall(imx6_mmu_init); > + > +#define SCU_CONFIG 0x04 > + > +static int imx6_fixup_cpus(struct device_node *root, void *context) > +{ > + struct device_node *cpus_node, *np, *tmp; > + unsigned long scu_phys_base; > + unsigned int max_core_index; > + > + cpus_node = of_find_node_by_name(root, "cpus"); > + if (!cpus_node) > + return 0; > + > + /* get actual number of available CPU cores from SCU */ > + asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (scu_phys_base)); > + max_core_index = (readl(IOMEM(scu_phys_base) + SCU_CONFIG) & 0x03); > + > + for_each_child_of_node_safe(cpus_node, tmp, np) { > + u32 cpu_index; > + > + if (of_property_read_u32(np, "reg", &cpu_index)) > + continue; > + > + if (cpu_index > max_core_index) > + of_delete_node(np); > + } > + > + return 0; > +} > + > +static int imx6_fixup_cpus_register(void) { > + return of_register_fixup(imx6_fixup_cpus, NULL); > +} > +device_initcall(imx6_fixup_cpus_register); Please make sure we do this on i.MX6 only. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox