[MIPS] Add support for MIPS CMP platform.

Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 265 insertions, 0 deletions

diff --git a/arch/mips/kernel/smp-cmp.c b/arch/mips/kernel/smp-cmp.c
new file mode 100644
index 000000000000..ca476c4f62a5
--- /dev/null
+++ b/arch/mips/kernel/smp-cmp.c
@@ -0,0 +1,265 @@
+/*
+ *  This program is free software; you can distribute 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 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, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Copyright (C) 2007 MIPS Technologies, Inc.
+ *    Chris Dearman (chris@mips.com)
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/cpumask.h>
+#include <linux/interrupt.h>
+#include <linux/compiler.h>
+
+#include <asm/atomic.h>
+#include <asm/cacheflush.h>
+#include <asm/cpu.h>
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/hardirq.h>
+#include <asm/mmu_context.h>
+#include <asm/smp.h>
+#include <asm/time.h>
+#include <asm/mipsregs.h>
+#include <asm/mipsmtregs.h>
+#include <asm/mips_mt.h>
+
+/*
+ * Crude manipulation of the CPU masks to control which
+ * which CPU's are brought online during initialisation
+ *
+ * Beware... this needs to be called after CPU discovery
+ * but before CPU bringup
+ */
+static int __init allowcpus(char *str)
+{
+        cpumask_t cpu_allow_map;
+        char buf[256];
+        int len;
+
+        cpus_clear(cpu_allow_map);
+        if (cpulist_parse(str, cpu_allow_map) == 0) {
+                cpu_set(0, cpu_allow_map);
+                cpus_and(cpu_possible_map, cpu_possible_map, cpu_allow_map);
+                len = cpulist_scnprintf(buf, sizeof(buf)-1, cpu_possible_map);
+                buf[len] = '\0';
+                pr_debug("Allowable CPUs: %s\n", buf);
+                return 1;
+        } else
+                return 0;
+}
+__setup("allowcpus=", allowcpus);
+
+static void ipi_call_function(unsigned int cpu)
+{
+        unsigned int action = 0;
+
+        pr_debug("CPU%d: %s cpu %d status %08x\n",
+                 smp_processor_id(), __func__, cpu, read_c0_status());
+
+        switch (cpu) {
+        case 0:
+                action = GIC_IPI_EXT_INTR_CALLFNC_VPE0;
+                break;
+        case 1:
+                action = GIC_IPI_EXT_INTR_CALLFNC_VPE1;
+                break;
+        case 2:
+                action = GIC_IPI_EXT_INTR_CALLFNC_VPE2;
+                break;
+        case 3:
+                action = GIC_IPI_EXT_INTR_CALLFNC_VPE3;
+                break;
+        }
+        gic_send_ipi(action);
+}
+
+
+static void ipi_resched(unsigned int cpu)
+{
+        unsigned int action = 0;
+
+        pr_debug("CPU%d: %s cpu %d status %08x\n",
+                 smp_processor_id(), __func__, cpu, read_c0_status());
+
+        switch (cpu) {
+        case 0:
+                action = GIC_IPI_EXT_INTR_RESCHED_VPE0;
+                break;
+        case 1:
+                action = GIC_IPI_EXT_INTR_RESCHED_VPE1;
+                break;
+        case 2:
+                action = GIC_IPI_EXT_INTR_RESCHED_VPE2;
+                break;
+        case 3:
+                action = GIC_IPI_EXT_INTR_RESCHED_VPE3;
+                break;
+        }
+        gic_send_ipi(action);
+}
+
+/*
+ * FIXME: This isn't restricted to CMP
+ * The SMVP kernel could use GIC interrupts if available
+ */
+void cmp_send_ipi_single(int cpu, unsigned int action)
+{
+        unsigned long flags;
+
+        local_irq_save(flags);
+
+        switch (action) {
+        case SMP_CALL_FUNCTION:
+                ipi_call_function(cpu);
+                break;
+
+        case SMP_RESCHEDULE_YOURSELF:
+                ipi_resched(cpu);
+                break;
+        }
+
+        local_irq_restore(flags);
+}
+
+static void cmp_send_ipi_mask(cpumask_t mask, unsigned int action)
+{
+        unsigned int i;
+
+        for_each_cpu_mask(i, mask)
+                cmp_send_ipi_single(i, action);
+}
+
+static void cmp_init_secondary(void)
+{
+        struct cpuinfo_mips *c = &current_cpu_data;
+
+        /* Assume GIC is present */
+        change_c0_status(ST0_IM, STATUSF_IP3 | STATUSF_IP4 | STATUSF_IP6 |
+                                 STATUSF_IP7);
+
+        /* Enable per-cpu interrupts: platform specific */
+
+        c->core = (read_c0_ebase() >> 1) & 0xff;
+#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC)
+        c->vpe_id = (read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) & TCBIND_CURVPE;
+#endif
+#ifdef CONFIG_MIPS_MT_SMTC
+        c->tc_id  = (read_c0_tcbind() >> TCBIND_CURTC_SHIFT) & TCBIND_CURTC;
+#endif
+}
+
+static void cmp_smp_finish(void)
+{
+        pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
+
+        /* CDFIXME: remove this? */
+        write_c0_compare(read_c0_count() + (8 * mips_hpt_frequency / HZ));
+
+#ifdef CONFIG_MIPS_MT_FPAFF
+        /* If we have an FPU, enroll ourselves in the FPU-full mask */
+        if (cpu_has_fpu)
+                cpu_set(smp_processor_id(), mt_fpu_cpumask);
+#endif /* CONFIG_MIPS_MT_FPAFF */
+
+        local_irq_enable();
+}
+
+static void cmp_cpus_done(void)
+{
+        pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
+}
+
+/*
+ * Setup the PC, SP, and GP of a secondary processor and start it running
+ * smp_bootstrap is the place to resume from
+ * __KSTK_TOS(idle) is apparently the stack pointer
+ * (unsigned long)idle->thread_info the gp
+ */
+static void cmp_boot_secondary(int cpu, struct task_struct *idle)
+{
+        struct thread_info *gp = task_thread_info(idle);
+        unsigned long sp = __KSTK_TOS(idle);
+        unsigned long pc = (unsigned long)&smp_bootstrap;
+        unsigned long a0 = 0;
+
+        pr_debug("SMPCMP: CPU%d: %s cpu %d\n", smp_processor_id(),
+                __func__, cpu);
+
+#if 0
+        /* Needed? */
+        flush_icache_range((unsigned long)gp,
+                           (unsigned long)(gp + sizeof(struct thread_info)));
+#endif
+
+        amon_cpu_start(cpu, pc, sp, gp, a0);
+}
+
+/*
+ * Common setup before any secondaries are started
+ */
+void __init cmp_smp_setup(void)
+{
+        int i;
+        int ncpu = 0;
+
+        pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
+
+#ifdef CONFIG_MIPS_MT_FPAFF
+        /* If we have an FPU, enroll ourselves in the FPU-full mask */
+        if (cpu_has_fpu)
+                cpu_set(0, mt_fpu_cpumask);
+#endif /* CONFIG_MIPS_MT_FPAFF */
+
+        for (i = 1; i < NR_CPUS; i++) {
+                if (amon_cpu_avail(i)) {
+                        cpu_set(i, phys_cpu_present_map);
+                        __cpu_number_map[i]     = ++ncpu;
+                        __cpu_logical_map[ncpu] = i;
+                }
+        }
+
+        if (cpu_has_mipsmt) {
+                unsigned int nvpe, mvpconf0 = read_c0_mvpconf0();
+
+                nvpe = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
+                smp_num_siblings = nvpe;
+        }
+        pr_info("Detected %i available secondary CPU(s)\n", ncpu);
+}
+
+void __init cmp_prepare_cpus(unsigned int max_cpus)
+{
+        pr_debug("SMPCMP: CPU%d: %s max_cpus=%d\n",
+                 smp_processor_id(), __func__, max_cpus);
+
+        /*
+         * FIXME: some of these options are per-system, some per-core and
+         * some per-cpu
+         */
+        mips_mt_set_cpuoptions();
+}
+
+struct plat_smp_ops cmp_smp_ops = {
+        .send_ipi_single        = cmp_send_ipi_single,
+        .send_ipi_mask          = cmp_send_ipi_mask,
+        .init_secondary         = cmp_init_secondary,
+        .smp_finish             = cmp_smp_finish,
+        .cpus_done              = cmp_cpus_done,
+        .boot_secondary         = cmp_boot_secondary,
+        .smp_setup              = cmp_smp_setup,
+        .prepare_cpus           = cmp_prepare_cpus,
+};