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author | Andreas Färber <afaerber@suse.de> | 2017-02-26 17:25:21 +0100 |
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committer | Andreas Färber <afaerber@suse.de> | 2017-06-21 18:17:39 +0200 |
commit | 172067e0bc8721af3e8626596f91b03f691e88a8 (patch) | |
tree | df996a45c3ed4ef2441009fddc37f20a74eaef26 /arch/arm/mach-actions | |
parent | MAINTAINERS: Add Actions Semi Owl section (diff) | |
download | linux-172067e0bc8721af3e8626596f91b03f691e88a8.tar.xz linux-172067e0bc8721af3e8626596f91b03f691e88a8.zip |
ARM: owl: Implement CPU enable-method for S500
Allow to bring up CPU1.
Based on LeMaker linux-actions tree.
Signed-off-by: Andreas Färber <afaerber@suse.de>
Diffstat (limited to 'arch/arm/mach-actions')
-rw-r--r-- | arch/arm/mach-actions/Makefile | 3 | ||||
-rw-r--r-- | arch/arm/mach-actions/headsmp.S | 68 | ||||
-rw-r--r-- | arch/arm/mach-actions/platsmp.c | 166 |
3 files changed, 237 insertions, 0 deletions
diff --git a/arch/arm/mach-actions/Makefile b/arch/arm/mach-actions/Makefile index 561b0f39e3f8..eeb3896e4952 100644 --- a/arch/arm/mach-actions/Makefile +++ b/arch/arm/mach-actions/Makefile @@ -1 +1,4 @@ obj-y += owl.o +obj-${CONFIG_SMP} += platsmp.o headsmp.o + +AFLAGS_headsmp.o := -Wa,-march=armv7-a diff --git a/arch/arm/mach-actions/headsmp.S b/arch/arm/mach-actions/headsmp.S new file mode 100644 index 000000000000..dc4832fc101a --- /dev/null +++ b/arch/arm/mach-actions/headsmp.S @@ -0,0 +1,68 @@ +/* + * Copyright 2012 Actions Semi Inc. + * Author: Actions Semi, Inc. + * + * 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. + */ + +#include <linux/linkage.h> +#include <linux/init.h> + +ENTRY(owl_v7_invalidate_l1) + mov r0, #0 + mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache + mcr p15, 2, r0, c0, c0, 0 + mrc p15, 1, r0, c0, c0, 0 + + ldr r1, =0x7fff + and r2, r1, r0, lsr #13 + + ldr r1, =0x3ff + + and r3, r1, r0, lsr #3 @ NumWays - 1 + add r2, r2, #1 @ NumSets + + and r0, r0, #0x7 + add r0, r0, #4 @ SetShift + + clz r1, r3 @ WayShift + add r4, r3, #1 @ NumWays +1: sub r2, r2, #1 @ NumSets-- + mov r3, r4 @ Temp = NumWays +2: subs r3, r3, #1 @ Temp-- + mov r5, r3, lsl r1 + mov r6, r2, lsl r0 + orr r5, r5, r6 @ Reg = (Temp<<WayShift)|(NumSets<<SetShift) + mcr p15, 0, r5, c7, c6, 2 + bgt 2b + cmp r2, #0 + bgt 1b + dsb + isb + mov pc, lr +ENDPROC(owl_v7_invalidate_l1) + +ENTRY(owl_secondary_startup) + mrc p15, 0, r0, c0, c0, 5 + and r0, r0, #0xf + adr r4, 1f + ldmia r4, {r5, r6} + sub r4, r4, r5 + add r6, r6, r4 +pen: + ldr r7, [r6] + cmp r7, r0 + bne pen + + /* + * we've been released from the holding pen: secondary_stack + * should now contain the SVC stack for this core + */ + bl owl_v7_invalidate_l1 + b secondary_startup + +1: .long . + .long pen_release diff --git a/arch/arm/mach-actions/platsmp.c b/arch/arm/mach-actions/platsmp.c new file mode 100644 index 000000000000..9d3601ebe535 --- /dev/null +++ b/arch/arm/mach-actions/platsmp.c @@ -0,0 +1,166 @@ +/* + * Actions Semi Leopard + * + * This file is based on arm realview smp platform. + * + * Copyright 2012 Actions Semi Inc. + * Author: Actions Semi, Inc. + * + * Copyright (c) 2017 Andreas Färber + * + * 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. + */ + +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/smp.h> +#include <asm/cacheflush.h> +#include <asm/smp_plat.h> +#include <asm/smp_scu.h> + +#define OWL_CPU1_ADDR 0x50 +#define OWL_CPU1_FLAG 0x5c + +#define OWL_CPUx_FLAG_BOOT 0x55aa + +static void __iomem *scu_base_addr; +static void __iomem *timer_base_addr; +static int ncores; + +static DEFINE_SPINLOCK(boot_lock); + +static void write_pen_release(int val) +{ + pen_release = val; + smp_wmb(); + __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); + outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); +} + +static void s500_smp_secondary_init(unsigned int cpu) +{ + /* + * let the primary processor know we're out of the + * pen, then head off into the C entry point + */ + write_pen_release(-1); + + spin_lock(&boot_lock); + spin_unlock(&boot_lock); +} + +void owl_secondary_startup(void); + +static int s500_wakeup_secondary(unsigned int cpu) +{ + if (cpu > 3) + return -EINVAL; + + switch (cpu) { + case 2: + case 3: + /* CPU2/3 are power-gated */ + return -EINVAL; + } + + /* wait for CPUx to run to WFE instruction */ + udelay(200); + + writel(virt_to_phys(owl_secondary_startup), + timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4); + writel(OWL_CPUx_FLAG_BOOT, + timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4); + + dsb_sev(); + mb(); + + return 0; +} + +static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle) +{ + unsigned long timeout; + int ret; + + ret = s500_wakeup_secondary(cpu); + if (ret) + return ret; + + udelay(10); + + spin_lock(&boot_lock); + + /* + * The secondary processor is waiting to be released from + * the holding pen - release it, then wait for it to flag + * that it has been released by resetting pen_release. + */ + write_pen_release(cpu_logical_map(cpu)); + smp_send_reschedule(cpu); + + timeout = jiffies + (1 * HZ); + while (time_before(jiffies, timeout)) { + if (pen_release == -1) + break; + } + + writel(0, timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4); + writel(0, timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4); + + spin_unlock(&boot_lock); + + return pen_release != -1 ? -ENOSYS : 0; +} + +static void __init s500_smp_prepare_cpus(unsigned int max_cpus) +{ + struct device_node *node; + + node = of_find_compatible_node(NULL, NULL, "actions,s500-timer"); + if (!node) { + pr_err("%s: missing timer\n", __func__); + return; + } + + timer_base_addr = of_iomap(node, 0); + if (!timer_base_addr) { + pr_err("%s: could not map timer registers\n", __func__); + return; + } + + if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) { + node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu"); + if (!node) { + pr_err("%s: missing scu\n", __func__); + return; + } + + scu_base_addr = of_iomap(node, 0); + if (!scu_base_addr) { + pr_err("%s: could not map scu registers\n", __func__); + return; + } + + /* + * While the number of cpus is gathered from dt, also get the + * number of cores from the scu to verify this value when + * booting the cores. + */ + ncores = scu_get_core_count(scu_base_addr); + pr_debug("%s: ncores %d\n", __func__, ncores); + + scu_enable(scu_base_addr); + } +} + +static const struct smp_operations s500_smp_ops __initconst = { + .smp_prepare_cpus = s500_smp_prepare_cpus, + .smp_secondary_init = s500_smp_secondary_init, + .smp_boot_secondary = s500_smp_boot_secondary, +}; +CPU_METHOD_OF_DECLARE(s500_smp, "actions,s500-smp", &s500_smp_ops); |