X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Farch%2Farm64%2Fkernel%2Fsmp_spin_table.c;fp=kernel%2Farch%2Farm64%2Fkernel%2Fsmp_spin_table.c;h=14944e5b28dace9ea083e74f4849d4f40eadef95;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/arch/arm64/kernel/smp_spin_table.c b/kernel/arch/arm64/kernel/smp_spin_table.c new file mode 100644 index 000000000..14944e5b2 --- /dev/null +++ b/kernel/arch/arm64/kernel/smp_spin_table.c @@ -0,0 +1,127 @@ +/* + * Spin Table SMP initialisation + * + * Copyright (C) 2013 ARM Ltd. + * + * 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. + * + * 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, see . + */ + +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +extern void secondary_holding_pen(void); +volatile unsigned long secondary_holding_pen_release = INVALID_HWID; + +static phys_addr_t cpu_release_addr[NR_CPUS]; + +/* + * Write secondary_holding_pen_release in a way that is guaranteed to be + * visible to all observers, irrespective of whether they're taking part + * in coherency or not. This is necessary for the hotplug code to work + * reliably. + */ +static void write_pen_release(u64 val) +{ + void *start = (void *)&secondary_holding_pen_release; + unsigned long size = sizeof(secondary_holding_pen_release); + + secondary_holding_pen_release = val; + __flush_dcache_area(start, size); +} + + +static int smp_spin_table_cpu_init(struct device_node *dn, unsigned int cpu) +{ + /* + * Determine the address from which the CPU is polling. + */ + if (of_property_read_u64(dn, "cpu-release-addr", + &cpu_release_addr[cpu])) { + pr_err("CPU %d: missing or invalid cpu-release-addr property\n", + cpu); + + return -1; + } + + return 0; +} + +static int smp_spin_table_cpu_prepare(unsigned int cpu) +{ + __le64 __iomem *release_addr; + + if (!cpu_release_addr[cpu]) + return -ENODEV; + + /* + * The cpu-release-addr may or may not be inside the linear mapping. + * As ioremap_cache will either give us a new mapping or reuse the + * existing linear mapping, we can use it to cover both cases. In + * either case the memory will be MT_NORMAL. + */ + release_addr = ioremap_cache(cpu_release_addr[cpu], + sizeof(*release_addr)); + if (!release_addr) + return -ENOMEM; + + /* + * We write the release address as LE regardless of the native + * endianess of the kernel. Therefore, any boot-loaders that + * read this address need to convert this address to the + * boot-loader's endianess before jumping. This is mandated by + * the boot protocol. + */ + writeq_relaxed(__pa(secondary_holding_pen), release_addr); + __flush_dcache_area((__force void *)release_addr, + sizeof(*release_addr)); + + /* + * Send an event to wake up the secondary CPU. + */ + sev(); + + iounmap(release_addr); + + return 0; +} + +static int smp_spin_table_cpu_boot(unsigned int cpu) +{ + /* + * Update the pen release flag. + */ + write_pen_release(cpu_logical_map(cpu)); + + /* + * Send an event, causing the secondaries to read pen_release. + */ + sev(); + + return 0; +} + +const struct cpu_operations smp_spin_table_ops = { + .name = "spin-table", + .cpu_init = smp_spin_table_cpu_init, + .cpu_prepare = smp_spin_table_cpu_prepare, + .cpu_boot = smp_spin_table_cpu_boot, +};