From aa7eb2bb4e4a22e41bbe4612ff46e5885b13c33e Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Wed, 20 Mar 2013 13:50:12 +0100 Subject: arm: zynq: Add smp support Zynq is dual core Cortex A9 which starts always at zero. Using simple trampoline ensure long jump to secondary_startup code. Signed-off-by: Michal Simek Signed-off-by: Steffen Trumtrar diff --git a/arch/arm/mach-zynq/Kconfig b/arch/arm/mach-zynq/Kconfig index d70651e..f4a7e63 100644 --- a/arch/arm/mach-zynq/Kconfig +++ b/arch/arm/mach-zynq/Kconfig @@ -8,6 +8,7 @@ config ARCH_ZYNQ select ICST select MIGHT_HAVE_CACHE_L2X0 select USE_OF + select HAVE_SMP select SPARSE_IRQ select CADENCE_TTC_TIMER help diff --git a/arch/arm/mach-zynq/Makefile b/arch/arm/mach-zynq/Makefile index 13ee09b..b595d22 100644 --- a/arch/arm/mach-zynq/Makefile +++ b/arch/arm/mach-zynq/Makefile @@ -4,3 +4,4 @@ # Common support obj-y := common.o slcr.o +obj-$(CONFIG_SMP) += headsmp.o platsmp.o diff --git a/arch/arm/mach-zynq/common.c b/arch/arm/mach-zynq/common.c index e1b6131..5bfe703 100644 --- a/arch/arm/mach-zynq/common.c +++ b/arch/arm/mach-zynq/common.c @@ -104,6 +104,7 @@ static const char * const zynq_dt_match[] = { }; MACHINE_START(XILINX_EP107, "Xilinx Zynq Platform") + .smp = smp_ops(zynq_smp_ops), .map_io = zynq_map_io, .init_irq = irqchip_init, .init_machine = zynq_init_machine, diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h index d7ec3ca..fd308f8 100644 --- a/arch/arm/mach-zynq/common.h +++ b/arch/arm/mach-zynq/common.h @@ -19,6 +19,17 @@ extern int zynq_slcr_init(void); extern void zynq_slcr_system_reset(void); +extern void zynq_slcr_cpu_stop(int cpu); +extern void zynq_slcr_cpu_start(int cpu); + +#ifdef CONFIG_SMP +extern void secondary_startup(void); +extern char zynq_secondary_trampoline; +extern char zynq_secondary_trampoline_jump; +extern char zynq_secondary_trampoline_end; +extern int __cpuinit zynq_cpun_start(u32 address, int cpu); +extern struct smp_operations zynq_smp_ops __initdata; +#endif extern void __iomem *zynq_slcr_base; extern void __iomem *zynq_scu_base; diff --git a/arch/arm/mach-zynq/headsmp.S b/arch/arm/mach-zynq/headsmp.S new file mode 100644 index 0000000..d183cd2 --- /dev/null +++ b/arch/arm/mach-zynq/headsmp.S @@ -0,0 +1,24 @@ +/* + * Copyright (c) 2013 Steffen Trumtrar + * Copyright (c) 2012-2013 Xilinx + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include +#include + + __CPUINIT + +ENTRY(zynq_secondary_trampoline) + ldr r0, [pc] + bx r0 +.globl zynq_secondary_trampoline_jump +zynq_secondary_trampoline_jump: + /* Space for jumping address */ + .word /* cpu 1 */ +.globl zynq_secondary_trampoline_end +zynq_secondary_trampoline_end: + +ENDPROC(zynq_secondary_trampoline) diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c new file mode 100644 index 0000000..cdfd888 --- /dev/null +++ b/arch/arm/mach-zynq/platsmp.c @@ -0,0 +1,149 @@ +/* + * This file contains Xilinx specific SMP code, used to start up + * the second processor. + * + * Copyright (C) 2011-2013 Xilinx + * + * based on linux/arch/arm/mach-realview/platsmp.c + * + * Copyright (C) 2002 ARM Ltd. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include "common.h" + +/* + * Store number of cores in the system + * Because of scu_get_core_count() must be in __init section and can't + * be called from zynq_cpun_start() because it is in __cpuinit section. + */ +static int ncores; + +/* Secondary CPU kernel startup is a 2 step process. The primary CPU + * starts the secondary CPU by giving it the address of the kernel and + * then sending it an event to wake it up. The secondary CPU then + * starts the kernel and tells the primary CPU it's up and running. + */ +static void __cpuinit zynq_secondary_init(unsigned int cpu) +{ + /* + * if any interrupts are already enabled for the primary + * core (e.g. timer irq), then they will not have been enabled + * for us: do so + */ + gic_secondary_init(0); +} + +int __cpuinit zynq_cpun_start(u32 address, int cpu) +{ + u32 trampoline_code_size = &zynq_secondary_trampoline_end - + &zynq_secondary_trampoline; + + if (cpu > ncores) { + pr_warn("CPU No. is not available in the system\n"); + return -1; + } + + /* MS: Expectation that SLCR are directly map and accessible */ + /* Not possible to jump to non aligned address */ + if (!(address & 3) && (!address || (address >= trampoline_code_size))) { + /* Store pointer to ioremap area which points to address 0x0 */ + static u8 __iomem *zero; + u32 trampoline_size = &zynq_secondary_trampoline_jump - + &zynq_secondary_trampoline; + + zynq_slcr_cpu_stop(cpu); + + if (__pa(PAGE_OFFSET)) { + zero = ioremap(0, trampoline_code_size); + if (!zero) { + pr_warn("BOOTUP jump vectors not accessible\n"); + return -1; + } + } else { + zero = (__force u8 __iomem *)PAGE_OFFSET; + } + + /* + * This is elegant way how to jump to any address + * 0x0: Load address at 0x8 to r0 + * 0x4: Jump by mov instruction + * 0x8: Jumping address + */ + memcpy((__force void *)zero, &zynq_secondary_trampoline, + trampoline_size); + writel(address, zero + trampoline_size); + + flush_cache_all(); + outer_flush_range(0, trampoline_code_size); + smp_wmb(); + + if (__pa(PAGE_OFFSET)) + iounmap(zero); + + zynq_slcr_cpu_start(cpu); + + return 0; + } + + pr_warn("Can't start CPU%d: Wrong starting address %x\n", cpu, address); + + return -1; +} +EXPORT_SYMBOL(zynq_cpun_start); + +static int __cpuinit zynq_boot_secondary(unsigned int cpu, + struct task_struct *idle) +{ + return zynq_cpun_start(virt_to_phys(secondary_startup), cpu); +} + +/* + * Initialise the CPU possible map early - this describes the CPUs + * which may be present or become present in the system. + */ +static void __init zynq_smp_init_cpus(void) +{ + int i; + + ncores = scu_get_core_count(zynq_scu_base); + + for (i = 0; i < ncores && i < CONFIG_NR_CPUS; i++) + set_cpu_possible(i, true); +} + +static void __init zynq_smp_prepare_cpus(unsigned int max_cpus) +{ + int i; + + /* + * Initialise the present map, which describes the set of CPUs + * actually populated at the present time. + */ + for (i = 0; i < max_cpus; i++) + set_cpu_present(i, true); + + scu_enable(zynq_scu_base); +} + +struct smp_operations zynq_smp_ops __initdata = { + .smp_init_cpus = zynq_smp_init_cpus, + .smp_prepare_cpus = zynq_smp_prepare_cpus, + .smp_secondary_init = zynq_secondary_init, + .smp_boot_secondary = zynq_boot_secondary, +}; diff --git a/arch/arm/mach-zynq/slcr.c b/arch/arm/mach-zynq/slcr.c index d58c996..c70969b 100644 --- a/arch/arm/mach-zynq/slcr.c +++ b/arch/arm/mach-zynq/slcr.c @@ -33,6 +33,11 @@ #define SLCR_UNLOCK 0x8 /* SCLR unlock register */ #define SLCR_PS_RST_CTRL_OFFSET 0x200 /* PS Software Reset Control */ + +#define SLCR_A9_CPU_CLKSTOP 0x10 +#define SLCR_A9_CPU_RST 0x1 + +#define SLCR_A9_CPU_RST_CTRL 0x244 /* CPU Software Reset Control */ #define SLCR_REBOOT_STATUS 0x258 /* PS Reboot Status */ void __iomem *zynq_slcr_base; @@ -62,6 +67,30 @@ void zynq_slcr_system_reset(void) } /** + * zynq_slcr_cpu_start - Start cpu + * @cpu: cpu number + */ +void zynq_slcr_cpu_start(int cpu) +{ + /* enable CPUn */ + writel(SLCR_A9_CPU_CLKSTOP << cpu, + zynq_slcr_base + SLCR_A9_CPU_RST_CTRL); + /* enable CLK for CPUn */ + writel(0x0 << cpu, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL); +} + +/** + * zynq_slcr_cpu_stop - Stop cpu + * @cpu: cpu number + */ +void zynq_slcr_cpu_stop(int cpu) +{ + /* stop CLK and reset CPUn */ + writel((SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu, + zynq_slcr_base + SLCR_A9_CPU_RST_CTRL); +} + +/** * zynq_slcr_init * Returns 0 on success, negative errno otherwise. * -- cgit v0.10.2