From 33419a69a56436dda8e9187cf09ff0bde74d8a01 Mon Sep 17 00:00:00 2001 From: Bastian Hecht Date: Wed, 9 Jan 2013 19:41:51 +0000 Subject: [PATCH] ARM: SH-Mobile: sh73a0: Secondary CPUs handle own SCU flags When booting secondary CPUs we have used the main CPU to set up the Snoop Control Unit flags of these CPUs. It is a cleaner approach if every CPU takes care of its own flags. We avoid the need for locking and the program logic is more concise. With this patch the file headsmp-sh73a0.S is added that contains a startup vector for secondary CPUs that sets up its own SCU flags. Further in sh73a0_smp_prepare_cpus() we can rely on the generic ARM helper scu_power_mode(). This is possible as we don't cross borders anymore (every CPU handles its own flags) and need no locking. So we can throw out the needless function modify_scu_cpu_psr(). Signed-off-by: Bastian Hecht Signed-off-by: Simon Horman --- arch/arm/mach-shmobile/Makefile | 2 +- arch/arm/mach-shmobile/headsmp-sh73a0.S | 50 ++++++++++++++++++++++++++++ arch/arm/mach-shmobile/include/mach/common.h | 1 + arch/arm/mach-shmobile/smp-sh73a0.c | 30 +++-------------- 4 files changed, 56 insertions(+), 27 deletions(-) create mode 100644 arch/arm/mach-shmobile/headsmp-sh73a0.S diff --git a/arch/arm/mach-shmobile/Makefile b/arch/arm/mach-shmobile/Makefile index f6aba6d..700e662 100644 --- a/arch/arm/mach-shmobile/Makefile +++ b/arch/arm/mach-shmobile/Makefile @@ -15,7 +15,7 @@ obj-$(CONFIG_ARCH_EMEV2) += setup-emev2.o clock-emev2.o # SMP objects smp-y := platsmp.o headsmp.o smp-$(CONFIG_HOTPLUG_CPU) += hotplug.o -smp-$(CONFIG_ARCH_SH73A0) += smp-sh73a0.o +smp-$(CONFIG_ARCH_SH73A0) += smp-sh73a0.o headsmp-sh73a0.o smp-$(CONFIG_ARCH_R8A7779) += smp-r8a7779.o smp-$(CONFIG_ARCH_EMEV2) += smp-emev2.o diff --git a/arch/arm/mach-shmobile/headsmp-sh73a0.S b/arch/arm/mach-shmobile/headsmp-sh73a0.S new file mode 100644 index 0000000..bec4c0d --- /dev/null +++ b/arch/arm/mach-shmobile/headsmp-sh73a0.S @@ -0,0 +1,50 @@ +/* + * SMP support for SoC sh73a0 + * + * Copyright (C) 2012 Bastian Hecht + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include +#include +#include + + __CPUINIT +/* + * Reset vector for secondary CPUs. + * + * First we turn on L1 cache coherency for our CPU. Then we jump to + * shmobile_invalidate_start that invalidates the cache and hands over control + * to the common ARM startup code. + * This function will be mapped to address 0 by the SBAR register. + * A normal branch is out of range here so we need a long jump. We jump to + * the physical address as the MMU is still turned off. + */ + .align 12 +ENTRY(sh73a0_secondary_vector) + mrc p15, 0, r0, c0, c0, 5 @ read MIPDR + and r0, r0, #3 @ mask out cpu ID + lsl r0, r0, #3 @ we will shift by cpu_id * 8 bits + mov r1, #0xf0000000 @ SCU base address + ldr r2, [r1, #8] @ SCU Power Status Register + mov r3, #3 + bic r2, r2, r3, lsl r0 @ Clear bits of our CPU (Run Mode) + str r2, [r1, #8] @ write back + + ldr pc, 1f +1: .long shmobile_invalidate_start - PAGE_OFFSET + PLAT_PHYS_OFFSET +ENDPROC(sh73a0_secondary_vector) diff --git a/arch/arm/mach-shmobile/include/mach/common.h b/arch/arm/mach-shmobile/include/mach/common.h index c0ab595..4b1af93 100644 --- a/arch/arm/mach-shmobile/include/mach/common.h +++ b/arch/arm/mach-shmobile/include/mach/common.h @@ -41,6 +41,7 @@ extern void sh73a0_add_standard_devices(void); extern void sh73a0_clock_init(void); extern void sh73a0_pinmux_init(void); extern void sh73a0_pm_init(void); +extern void sh73a0_secondary_vector(void); extern struct clk sh73a0_extal1_clk; extern struct clk sh73a0_extal2_clk; extern struct clk sh73a0_extcki_clk; diff --git a/arch/arm/mach-shmobile/smp-sh73a0.c b/arch/arm/mach-shmobile/smp-sh73a0.c index 5c5bcb5..430b44e 100644 --- a/arch/arm/mach-shmobile/smp-sh73a0.c +++ b/arch/arm/mach-shmobile/smp-sh73a0.c @@ -41,9 +41,6 @@ static void __iomem *scu_base_addr(void) return (void __iomem *)0xf0000000; } -static DEFINE_SPINLOCK(scu_lock); -static unsigned long tmp; - #ifdef CONFIG_HAVE_ARM_TWD static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, 0xf0000600, 29); void __init sh73a0_register_twd(void) @@ -52,20 +49,6 @@ void __init sh73a0_register_twd(void) } #endif -static void modify_scu_cpu_psr(unsigned long set, unsigned long clr) -{ - void __iomem *scu_base = scu_base_addr(); - - spin_lock(&scu_lock); - tmp = __raw_readl(scu_base + 8); - tmp &= ~clr; - tmp |= set; - spin_unlock(&scu_lock); - - /* disable cache coherency after releasing the lock */ - __raw_writel(tmp, scu_base + 8); -} - static unsigned int __init sh73a0_get_core_count(void) { void __iomem *scu_base = scu_base_addr(); @@ -82,9 +65,6 @@ static int __cpuinit sh73a0_boot_secondary(unsigned int cpu, struct task_struct { cpu = cpu_logical_map(cpu); - /* enable cache coherency */ - modify_scu_cpu_psr(0, 3 << (cpu * 8)); - if (((__raw_readl(PSTR) >> (4 * cpu)) & 3) == 3) __raw_writel(1 << cpu, WUPCR); /* wake up */ else @@ -95,16 +75,14 @@ static int __cpuinit sh73a0_boot_secondary(unsigned int cpu, struct task_struct static void __init sh73a0_smp_prepare_cpus(unsigned int max_cpus) { - int cpu = cpu_logical_map(0); - scu_enable(scu_base_addr()); - /* Map the reset vector (in headsmp.S) */ + /* Map the reset vector (in headsmp-sh73a0.S) */ __raw_writel(0, APARMBAREA); /* 4k */ - __raw_writel(__pa(shmobile_secondary_vector), SBAR); + __raw_writel(__pa(sh73a0_secondary_vector), SBAR); - /* enable cache coherency on CPU0 */ - modify_scu_cpu_psr(0, 3 << (cpu * 8)); + /* enable cache coherency on booting CPU */ + scu_power_mode(scu_base_addr(), SCU_PM_NORMAL); } static void __init sh73a0_smp_init_cpus(void) -- 2.7.4