diff options
Diffstat (limited to 'kernel/arch/arm/mach-uniphier/platsmp.c')
| -rw-r--r-- | kernel/arch/arm/mach-uniphier/platsmp.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-uniphier/platsmp.c b/kernel/arch/arm/mach-uniphier/platsmp.c new file mode 100644 index 000000000..f05776646 --- /dev/null +++ b/kernel/arch/arm/mach-uniphier/platsmp.c @@ -0,0 +1,209 @@ +/* + * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com> + * + * 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. + */ + +#define pr_fmt(fmt) "uniphier: " fmt + +#include <linux/init.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/sizes.h> +#include <asm/cacheflush.h> +#include <asm/hardware/cache-uniphier.h> +#include <asm/pgtable.h> +#include <asm/smp.h> +#include <asm/smp_scu.h> + +/* + * The secondary CPUs check this register from the boot ROM for the jump + * destination. After that, it can be reused as a scratch register. + */ +#define UNIPHIER_SBC_ROM_BOOT_RSV2 0x1208 + +static void __iomem *uniphier_smp_rom_boot_rsv2; +static unsigned int uniphier_smp_max_cpus; + +extern char uniphier_smp_trampoline; +extern char uniphier_smp_trampoline_jump; +extern char uniphier_smp_trampoline_poll_addr; +extern char uniphier_smp_trampoline_end; + +/* + * Copy trampoline code to the tail of the 1st section of the page table used + * in the boot ROM. This area is directly accessible by the secondary CPUs + * for all the UniPhier SoCs. + */ +static const phys_addr_t uniphier_smp_trampoline_dest_end = SECTION_SIZE; +static phys_addr_t uniphier_smp_trampoline_dest; + +static int __init uniphier_smp_copy_trampoline(phys_addr_t poll_addr) +{ + size_t trmp_size; + static void __iomem *trmp_base; + + if (!uniphier_cache_l2_is_enabled()) { + pr_warn("outer cache is needed for SMP, but not enabled\n"); + return -ENODEV; + } + + uniphier_cache_l2_set_locked_ways(1); + + outer_flush_all(); + + trmp_size = &uniphier_smp_trampoline_end - &uniphier_smp_trampoline; + uniphier_smp_trampoline_dest = uniphier_smp_trampoline_dest_end - + trmp_size; + + uniphier_cache_l2_touch_range(uniphier_smp_trampoline_dest, + uniphier_smp_trampoline_dest_end); + + trmp_base = ioremap_cache(uniphier_smp_trampoline_dest, trmp_size); + if (!trmp_base) { + pr_err("failed to map trampoline destination area\n"); + return -ENOMEM; + } + + memcpy(trmp_base, &uniphier_smp_trampoline, trmp_size); + + writel(virt_to_phys(secondary_startup), + trmp_base + (&uniphier_smp_trampoline_jump - + &uniphier_smp_trampoline)); + + writel(poll_addr, trmp_base + (&uniphier_smp_trampoline_poll_addr - + &uniphier_smp_trampoline)); + + flush_cache_all(); /* flush out trampoline code to outer cache */ + + iounmap(trmp_base); + + return 0; +} + +static int __init uniphier_smp_prepare_trampoline(unsigned int max_cpus) +{ + struct device_node *np; + struct resource res; + phys_addr_t rom_rsv2_phys; + int ret; + + np = of_find_compatible_node(NULL, NULL, + "socionext,uniphier-system-bus-controller"); + ret = of_address_to_resource(np, 1, &res); + if (ret) { + pr_err("failed to get resource of system-bus-controller\n"); + return ret; + } + + rom_rsv2_phys = res.start + UNIPHIER_SBC_ROM_BOOT_RSV2; + + ret = uniphier_smp_copy_trampoline(rom_rsv2_phys); + if (ret) + return ret; + + uniphier_smp_rom_boot_rsv2 = ioremap(rom_rsv2_phys, sizeof(SZ_4)); + if (!uniphier_smp_rom_boot_rsv2) { + pr_err("failed to map ROM_BOOT_RSV2 register\n"); + return -ENOMEM; + } + + writel(uniphier_smp_trampoline_dest, uniphier_smp_rom_boot_rsv2); + asm("sev"); /* Bring up all secondary CPUs to the trampoline code */ + + uniphier_smp_max_cpus = max_cpus; /* save for later use */ + + return 0; +} + +static void __init uniphier_smp_unprepare_trampoline(void) +{ + iounmap(uniphier_smp_rom_boot_rsv2); + + if (uniphier_smp_trampoline_dest) + outer_inv_range(uniphier_smp_trampoline_dest, + uniphier_smp_trampoline_dest_end); + + uniphier_cache_l2_set_locked_ways(0); +} + +static int __init uniphier_smp_enable_scu(void) +{ + unsigned long scu_base_phys = 0; + void __iomem *scu_base; + + if (scu_a9_has_base()) + scu_base_phys = scu_a9_get_base(); + + if (!scu_base_phys) { + pr_err("failed to get scu base\n"); + return -ENODEV; + } + + scu_base = ioremap(scu_base_phys, SZ_128); + if (!scu_base) { + pr_err("failed to map scu base\n"); + return -ENOMEM; + } + + scu_enable(scu_base); + iounmap(scu_base); + + return 0; +} + +static void __init uniphier_smp_prepare_cpus(unsigned int max_cpus) +{ + static cpumask_t only_cpu_0 = { CPU_BITS_CPU0 }; + int ret; + + ret = uniphier_smp_prepare_trampoline(max_cpus); + if (ret) + goto err; + + ret = uniphier_smp_enable_scu(); + if (ret) + goto err; + + return; +err: + pr_warn("disabling SMP\n"); + init_cpu_present(&only_cpu_0); + uniphier_smp_unprepare_trampoline(); +} + +static int __init uniphier_smp_boot_secondary(unsigned int cpu, + struct task_struct *idle) +{ + if (WARN_ON_ONCE(!uniphier_smp_rom_boot_rsv2)) + return -EFAULT; + + writel(cpu, uniphier_smp_rom_boot_rsv2); + readl(uniphier_smp_rom_boot_rsv2); /* relax */ + + asm("sev"); /* wake up secondary CPUs sleeping in the trampoline */ + + if (cpu == uniphier_smp_max_cpus - 1) { + /* clean up resources if this is the last CPU */ + uniphier_smp_unprepare_trampoline(); + } + + return 0; +} + +static struct smp_operations uniphier_smp_ops __initdata = { + .smp_prepare_cpus = uniphier_smp_prepare_cpus, + .smp_boot_secondary = uniphier_smp_boot_secondary, +}; +CPU_METHOD_OF_DECLARE(uniphier_smp, "socionext,uniphier-smp", + &uniphier_smp_ops); |