diff options
Diffstat (limited to 'arch/mips/sgi-ip30/ip30-smp.c')
| -rw-r--r-- | arch/mips/sgi-ip30/ip30-smp.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip30/ip30-smp.c b/arch/mips/sgi-ip30/ip30-smp.c new file mode 100644 index 0000000000..4bfe654602 --- /dev/null +++ b/arch/mips/sgi-ip30/ip30-smp.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ip30-smp.c: SMP on IP30 architecture. + * Based off of the original IP30 SMP code, with inspiration from ip27-smp.c + * and smp-bmips.c. + * + * Copyright (C) 2005-2007 Stanislaw Skowronek <skylark@unaligned.org> + * 2006-2007, 2014-2015 Joshua Kinard <kumba@gentoo.org> + * 2009 Johannes Dickgreber <tanzy@gmx.de> + */ + +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/sched/task_stack.h> + +#include <asm/time.h> +#include <asm/sgi/heart.h> + +#include "ip30-common.h" + +#define MPCONF_MAGIC 0xbaddeed2 +#define MPCONF_ADDR 0xa800000000000600L +#define MPCONF_SIZE 0x80 +#define MPCONF(x) (MPCONF_ADDR + (x) * MPCONF_SIZE) + +/* HEART can theoretically do 4 CPUs, but only 2 are physically possible */ +#define MP_NCPU 2 + +struct mpconf { + u32 magic; + u32 prid; + u32 physid; + u32 virtid; + u32 scachesz; + u16 fanloads; + u16 res; + void *launch; + void *rendezvous; + u64 res2[3]; + void *stackaddr; + void *lnch_parm; + void *rndv_parm; + u32 idleflag; +}; + +static void ip30_smp_send_ipi_single(int cpu, u32 action) +{ + int irq; + + switch (action) { + case SMP_RESCHEDULE_YOURSELF: + irq = HEART_L2_INT_RESCHED_CPU_0; + break; + case SMP_CALL_FUNCTION: + irq = HEART_L2_INT_CALL_CPU_0; + break; + default: + panic("IP30: Unknown action value in %s!\n", __func__); + } + + irq += cpu; + + /* Poke the other CPU -- it's got mail! */ + heart_write(BIT_ULL(irq), &heart_regs->set_isr); +} + +static void ip30_smp_send_ipi_mask(const struct cpumask *mask, u32 action) +{ + u32 i; + + for_each_cpu(i, mask) + ip30_smp_send_ipi_single(i, action); +} + +static void __init ip30_smp_setup(void) +{ + int i; + int ncpu = 0; + struct mpconf *mpc; + + init_cpu_possible(cpumask_of(0)); + + /* Scan the MPCONF structure and enumerate available CPUs. */ + for (i = 0; i < MP_NCPU; i++) { + mpc = (struct mpconf *)MPCONF(i); + if (mpc->magic == MPCONF_MAGIC) { + set_cpu_possible(i, true); + __cpu_number_map[i] = ++ncpu; + __cpu_logical_map[ncpu] = i; + pr_info("IP30: Slot: %d, PrID: %.8x, PhyID: %d, VirtID: %d\n", + i, mpc->prid, mpc->physid, mpc->virtid); + } + } + pr_info("IP30: Detected %d CPU(s) present.\n", ncpu); + + /* + * Set the coherency algorithm to '5' (cacheable coherent + * exclusive on write). This is needed on IP30 SMP, especially + * for R14000 CPUs, otherwise, instruction bus errors will + * occur upon reaching userland. + */ + change_c0_config(CONF_CM_CMASK, CONF_CM_CACHABLE_COW); +} + +static void __init ip30_smp_prepare_cpus(unsigned int max_cpus) +{ + /* nothing to do here */ +} + +static int __init ip30_smp_boot_secondary(int cpu, struct task_struct *idle) +{ + struct mpconf *mpc = (struct mpconf *)MPCONF(cpu); + + /* Stack pointer (sp). */ + mpc->stackaddr = (void *)__KSTK_TOS(idle); + + /* Global pointer (gp). */ + mpc->lnch_parm = task_thread_info(idle); + + mb(); /* make sure stack and lparm are written */ + + /* Boot CPUx. */ + mpc->launch = smp_bootstrap; + + /* CPUx now executes smp_bootstrap, then ip30_smp_finish */ + return 0; +} + +static void __init ip30_smp_init_cpu(void) +{ + ip30_per_cpu_init(); +} + +static void __init ip30_smp_finish(void) +{ + enable_percpu_irq(get_c0_compare_int(), IRQ_TYPE_NONE); + local_irq_enable(); +} + +struct plat_smp_ops __read_mostly ip30_smp_ops = { + .send_ipi_single = ip30_smp_send_ipi_single, + .send_ipi_mask = ip30_smp_send_ipi_mask, + .smp_setup = ip30_smp_setup, + .prepare_cpus = ip30_smp_prepare_cpus, + .boot_secondary = ip30_smp_boot_secondary, + .init_secondary = ip30_smp_init_cpu, + .smp_finish = ip30_smp_finish, + .prepare_boot_cpu = ip30_smp_init_cpu, +}; |