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Diffstat (limited to 'arch/powerpc/platforms/cell/smp.c')
| -rw-r--r-- | arch/powerpc/platforms/cell/smp.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/cell/smp.c b/arch/powerpc/platforms/cell/smp.c new file mode 100644 index 000000000..31ce00b52 --- /dev/null +++ b/arch/powerpc/platforms/cell/smp.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * SMP support for BPA machines. + * + * Dave Engebretsen, Peter Bergner, and + * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com + * + * Plus various changes from other IBM teams... + */ + +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/smp.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/cache.h> +#include <linux/err.h> +#include <linux/device.h> +#include <linux/cpu.h> +#include <linux/pgtable.h> + +#include <asm/ptrace.h> +#include <linux/atomic.h> +#include <asm/irq.h> +#include <asm/page.h> +#include <asm/io.h> +#include <asm/smp.h> +#include <asm/paca.h> +#include <asm/machdep.h> +#include <asm/cputable.h> +#include <asm/firmware.h> +#include <asm/rtas.h> +#include <asm/cputhreads.h> +#include <asm/code-patching.h> + +#include "interrupt.h" +#include <asm/udbg.h> + +#ifdef DEBUG +#define DBG(fmt...) udbg_printf(fmt) +#else +#define DBG(fmt...) +#endif + +/* + * The Primary thread of each non-boot processor was started from the OF client + * interface by prom_hold_cpus and is spinning on secondary_hold_spinloop. + */ +static cpumask_t of_spin_map; + +/** + * smp_startup_cpu() - start the given cpu + * + * At boot time, there is nothing to do for primary threads which were + * started from Open Firmware. For anything else, call RTAS with the + * appropriate start location. + * + * Returns: + * 0 - failure + * 1 - success + */ +static inline int smp_startup_cpu(unsigned int lcpu) +{ + int status; + unsigned long start_here = + __pa(ppc_function_entry(generic_secondary_smp_init)); + unsigned int pcpu; + int start_cpu; + + if (cpumask_test_cpu(lcpu, &of_spin_map)) + /* Already started by OF and sitting in spin loop */ + return 1; + + pcpu = get_hard_smp_processor_id(lcpu); + + /* + * If the RTAS start-cpu token does not exist then presume the + * cpu is already spinning. + */ + start_cpu = rtas_token("start-cpu"); + if (start_cpu == RTAS_UNKNOWN_SERVICE) + return 1; + + status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, lcpu); + if (status != 0) { + printk(KERN_ERR "start-cpu failed: %i\n", status); + return 0; + } + + return 1; +} + +static void smp_cell_setup_cpu(int cpu) +{ + if (cpu != boot_cpuid) + iic_setup_cpu(); + + /* + * change default DABRX to allow user watchpoints + */ + mtspr(SPRN_DABRX, DABRX_KERNEL | DABRX_USER); +} + +static int smp_cell_kick_cpu(int nr) +{ + if (nr < 0 || nr >= nr_cpu_ids) + return -EINVAL; + + if (!smp_startup_cpu(nr)) + return -ENOENT; + + /* + * The processor is currently spinning, waiting for the + * cpu_start field to become non-zero After we set cpu_start, + * the processor will continue on to secondary_start + */ + paca_ptrs[nr]->cpu_start = 1; + + return 0; +} + +static struct smp_ops_t bpa_iic_smp_ops = { + .message_pass = iic_message_pass, + .probe = iic_request_IPIs, + .kick_cpu = smp_cell_kick_cpu, + .setup_cpu = smp_cell_setup_cpu, + .cpu_bootable = smp_generic_cpu_bootable, +}; + +/* This is called very early */ +void __init smp_init_cell(void) +{ + int i; + + DBG(" -> smp_init_cell()\n"); + + smp_ops = &bpa_iic_smp_ops; + + /* Mark threads which are still spinning in hold loops. */ + if (cpu_has_feature(CPU_FTR_SMT)) { + for_each_present_cpu(i) { + if (cpu_thread_in_core(i) == 0) + cpumask_set_cpu(i, &of_spin_map); + } + } else + cpumask_copy(&of_spin_map, cpu_present_mask); + + cpumask_clear_cpu(boot_cpuid, &of_spin_map); + + /* Non-lpar has additional take/give timebase */ + if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { + smp_ops->give_timebase = rtas_give_timebase; + smp_ops->take_timebase = rtas_take_timebase; + } + + DBG(" <- smp_init_cell()\n"); +} |