[RFC,XEN,20/23] riscv: Add smpboot.c

Commit Message

Bobby Eshleman Jan. 22, 2020, 1:58 a.m. UTC

From: Alistair Francis <[e-mail]>

Signed-off-by: Alistair Francis <[e-mail]>
---
 xen/arch/riscv/smpboot.c | 114 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 xen/arch/riscv/smpboot.c

Patch

diff --git a/xen/arch/riscv/smpboot.c b/xen/arch/riscv/smpboot.c
new file mode 100644
index 0000000000..f125179a3e
--- /dev/null
+++ b/xen/arch/riscv/smpboot.c
@@ -0,0 +1,114 @@ 
+/*
+ * Dummy smpboot support
+ *
+ * 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.
+ */
+
+#include <xen/cpu.h>
+#include <xen/cpumask.h>
+#include <xen/delay.h>
+#include <xen/domain_page.h>
+#include <public/domctl.h>
+#include <xen/errno.h>
+#include <xen/init.h>
+#include <xen/mm.h>
+#include <xen/sched.h>
+#include <xen/smp.h>
+#include <xen/softirq.h>
+#include <xen/timer.h>
+#include <xen/warning.h>
+#include <xen/irq.h>
+#include <xen/console.h>
+
+cpumask_t cpu_online_map;
+cpumask_t cpu_present_map;
+cpumask_t cpu_possible_map;
+
+/* Fake one node for now. See also include/asm-arm/numa.h */
+nodemask_t __read_mostly node_online_map = { { [0] = 1UL } };
+
+/* Boot cpu data */
+struct init_info init_data =
+{
+};
+
+/* Shared state for coordinating CPU teardown */
+static bool cpu_is_dead;
+
+/* ID of the PCPU we're running on */
+DEFINE_PER_CPU(unsigned int, cpu_id);
+/* XXX these seem awfully x86ish... */
+/* representing HT siblings of each logical CPU */
+DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_mask);
+/* representing HT and core siblings of each logical CPU */
+DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_mask);
+
+/*
+ * By default non-boot CPUs not identical to the boot CPU will be
+ * parked.
+ */
+static bool __read_mostly opt_hmp_unsafe = false;
+boolean_param("hmp-unsafe", opt_hmp_unsafe);
+
+int __cpu_up(unsigned int cpu)
+{
+    printk("Bringing up CPU%d\n", cpu);
+
+    console_start_sync(); /* Secondary may use early_printk */
+
+    /* TODO */
+
+    return 0;
+}
+
+/* Shut down the current CPU */
+void __cpu_disable(void)
+{
+    unsigned int cpu = get_processor_id();
+
+    /* TODO */
+
+    /* It's now safe to remove this processor from the online map */
+    cpumask_clear_cpu(cpu, &cpu_online_map);
+
+    smp_mb();
+
+    /* Return to caller; eventually the IPI mechanism will unwind and the 
+     * scheduler will drop to the idle loop, which will call stop_cpu(). */
+}
+
+void __cpu_die(unsigned int cpu)
+{
+    unsigned int i = 0;
+
+    while ( !cpu_is_dead )
+    {
+        mdelay(100);
+        cpu_relax();
+        process_pending_softirqs();
+        if ( (++i % 10) == 0 )
+            printk(KERN_ERR "CPU %u still not dead...\n", cpu);
+        smp_mb();
+    }
+    cpu_is_dead = false;
+    smp_mb();
+}
+
+void stop_cpu(void)
+{
+    local_irq_disable();
+    cpu_is_dead = true;
+
+    /* TODO */
+
+    while ( 1 )
+        wait_for_interrupt();
+}