From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 3/9] ARM: tegra: # of CPU cores detection w/ & w/o HAVE_ARM_SCU
Date: Thu, 20 Dec 2012 11:17:08 +0000 [thread overview]
Message-ID: <50D2F3B4.3040302@arm.com> (raw)
In-Reply-To: <1355996654-6579-4-git-send-email-hdoyu@nvidia.com>
On 20/12/12 09:44, Hiroshi Doyu wrote:
> The method to detect the number of CPU cores on Cortex-A9 MPCore and
> Cortex-A15 MPCore is different. On Cortex-A9 MPCore we can get this
> information from the Snoop Control Unit(SCU). On Cortex-A15 MPCore we
> have to read it from the system coprocessor(CP15), because the SCU on
> Cortex-A15 MPCore does not have software readable registers. This
> patch selects the correct method at runtime based on the CPU ID.
>
> Signed-off-by: Hiroshi Doyu <hdoyu@nvidia•com>
> ---
> arch/arm/mach-tegra/platsmp.c | 31 ++++++++++++++++++++++++++++---
> 1 file changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c
> index 1b926df..68e76ef 100644
> --- a/arch/arm/mach-tegra/platsmp.c
> +++ b/arch/arm/mach-tegra/platsmp.c
> @@ -23,6 +23,7 @@
> #include <asm/hardware/gic.h>
> #include <asm/mach-types.h>
> #include <asm/smp_scu.h>
> +#include <asm/cputype.h>
>
> #include <mach/powergate.h>
>
> @@ -34,9 +35,13 @@
> #include "common.h"
> #include "iomap.h"
>
> +#define CPU_MASK 0xff0ffff0
> +#define CPU_CORTEX_A9 0x410fc090
> +#define CPU_CORTEX_A15 0x410fc0f0
> +
> extern void tegra_secondary_startup(void);
>
> -static void __iomem *scu_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE);
> +static void __iomem *scu_base;
>
> #define EVP_CPU_RESET_VECTOR \
> (IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE) + 0x100)
> @@ -149,7 +154,26 @@ done:
> */
> static void __init tegra_smp_init_cpus(void)
> {
> - unsigned int i, ncores = scu_get_core_count(scu_base);
> + unsigned int i, cpu_id, ncores;
> + u32 l2ctlr;
> + phys_addr_t pa;
> +
> + cpu_id = read_cpuid(CPUID_ID) & CPU_MASK;
> + switch (cpu_id) {
> + case CPU_CORTEX_A15:
> + asm("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr));
> + ncores = ((l2ctlr >> 24) & 3) + 1;
Please, do not do that. It doesn't scale to multiple clusters. Instead,
you can now rely on arm_dt_init_cpu_maps() to do the right thing as long
as your device tree exposes all the cpu nodes.
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2012-12-20 11:17 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-20 9:43 [PATCH 0/9] ARM: Initial support for Tegra 114 SoC Hiroshi Doyu
2012-12-20 9:43 ` [PATCH 1/9] ARM: tegra: fuse: Add chipid TEGRA114 0x35 Hiroshi Doyu
2012-12-20 9:44 ` [PATCH 2/9] HACK: ARM: tegra: Use CLK_IGNORE_UNUSED for Tegra 114 SoC Hiroshi Doyu
2012-12-20 9:44 ` [PATCH 3/9] ARM: tegra: # of CPU cores detection w/ & w/o HAVE_ARM_SCU Hiroshi Doyu
2012-12-20 10:06 ` Felipe Balbi
2012-12-20 11:21 ` Hiroshi Doyu
2012-12-20 18:18 ` Felipe Balbi
2012-12-20 11:17 ` Marc Zyngier [this message]
2012-12-20 11:26 ` Hiroshi Doyu
2012-12-20 11:32 ` Marc Zyngier
2012-12-20 9:44 ` [PATCH 4/9] clocksource: tegra: Reorganize funcs by clock functionarities Hiroshi Doyu
2012-12-20 9:44 ` [PATCH 5/9] clocksource: tegra: Enable ARM arch_timer with TSC Hiroshi Doyu
2012-12-20 11:01 ` Marc Zyngier
2012-12-20 11:57 ` Hiroshi Doyu
2012-12-20 12:05 ` Marc Zyngier
2012-12-20 12:22 ` Peter De Schrijver
2012-12-20 12:33 ` Marc Zyngier
2012-12-20 12:55 ` Peter De Schrijver
2012-12-20 13:32 ` Marc Zyngier
2012-12-20 14:42 ` Hiroshi Doyu
2012-12-20 17:09 ` Marc Zyngier
2012-12-20 22:13 ` Peter De Schrijver
2012-12-20 13:25 ` Hiroshi Doyu
2012-12-20 13:33 ` Marc Zyngier
2012-12-20 9:44 ` [PATCH 6/9] ARM: dt: tegra114: Add new SoC base, Tegra 114 SoC Hiroshi Doyu
2012-12-20 11:27 ` Marc Zyngier
2012-12-29 6:39 ` Olof Johansson
2012-12-31 7:12 ` Hiroshi Doyu
2012-12-20 9:44 ` [PATCH 7/9] ARM: dt: tegra114: Add new board, Dalmore Hiroshi Doyu
2012-12-20 9:44 ` [PATCH 8/9] ARM: dt: tegra114: Add new board, Pluto Hiroshi Doyu
2012-12-20 9:44 ` [PATCH 9/9] ARM: tegra: Add initial support for Tegra 114 SoC Hiroshi Doyu
2013-01-03 16:28 ` Arnd Bergmann
2013-01-04 7:16 ` Hiroshi Doyu
2012-12-24 9:58 ` [PATCH 0/9] ARM: Initial " Mark Zhang
2013-01-03 14:06 ` Hiroshi Doyu
2013-01-03 21:00 ` Thierry Reding
2013-01-03 21:16 ` Stephen Warren
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