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-rw-r--r--arch/sparc/kernel/devices.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/sparc/kernel/devices.c b/arch/sparc/kernel/devices.c
new file mode 100644
index 000000000..23b6e50d4
--- /dev/null
+++ b/arch/sparc/kernel/devices.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/* devices.c: Initial scan of the prom device tree for important
+ * Sparc device nodes which we need to find.
+ *
+ * This is based on the sparc64 version, but sun4m doesn't always use
+ * the hardware MIDs, so be careful.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
+ */
+
+#include <linux/kernel.h>
+#include <linux/threads.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+
+#include <asm/page.h>
+#include <asm/oplib.h>
+#include <asm/prom.h>
+#include <asm/smp.h>
+#include <asm/cpudata.h>
+#include <asm/cpu_type.h>
+#include <asm/setup.h>
+
+#include "kernel.h"
+
+static char *cpu_mid_prop(void)
+{
+ if (sparc_cpu_model == sun4d)
+ return "cpu-id";
+ return "mid";
+}
+
+static int check_cpu_node(phandle nd, int *cur_inst,
+ int (*compare)(phandle, int, void *), void *compare_arg,
+ phandle *prom_node, int *mid)
+{
+ if (!compare(nd, *cur_inst, compare_arg)) {
+ if (prom_node)
+ *prom_node = nd;
+ if (mid) {
+ *mid = prom_getintdefault(nd, cpu_mid_prop(), 0);
+ if (sparc_cpu_model == sun4m)
+ *mid &= 3;
+ }
+ return 0;
+ }
+
+ (*cur_inst)++;
+
+ return -ENODEV;
+}
+
+static int __cpu_find_by(int (*compare)(phandle, int, void *),
+ void *compare_arg, phandle *prom_node, int *mid)
+{
+ struct device_node *dp;
+ int cur_inst;
+
+ cur_inst = 0;
+ for_each_node_by_type(dp, "cpu") {
+ int err = check_cpu_node(dp->phandle, &cur_inst,
+ compare, compare_arg,
+ prom_node, mid);
+ if (!err) {
+ of_node_put(dp);
+ return 0;
+ }
+ }
+
+ return -ENODEV;
+}
+
+static int cpu_instance_compare(phandle nd, int instance, void *_arg)
+{
+ int desired_instance = (int) _arg;
+
+ if (instance == desired_instance)
+ return 0;
+ return -ENODEV;
+}
+
+int cpu_find_by_instance(int instance, phandle *prom_node, int *mid)
+{
+ return __cpu_find_by(cpu_instance_compare, (void *)instance,
+ prom_node, mid);
+}
+
+static int cpu_mid_compare(phandle nd, int instance, void *_arg)
+{
+ int desired_mid = (int) _arg;
+ int this_mid;
+
+ this_mid = prom_getintdefault(nd, cpu_mid_prop(), 0);
+ if (this_mid == desired_mid
+ || (sparc_cpu_model == sun4m && (this_mid & 3) == desired_mid))
+ return 0;
+ return -ENODEV;
+}
+
+int cpu_find_by_mid(int mid, phandle *prom_node)
+{
+ return __cpu_find_by(cpu_mid_compare, (void *)mid,
+ prom_node, NULL);
+}
+
+/* sun4m uses truncated mids since we base the cpuid on the ttable/irqset
+ * address (0-3). This gives us the true hardware mid, which might have
+ * some other bits set. On 4d hardware and software mids are the same.
+ */
+int cpu_get_hwmid(phandle prom_node)
+{
+ return prom_getintdefault(prom_node, cpu_mid_prop(), -ENODEV);
+}
+
+void __init device_scan(void)
+{
+ printk(KERN_NOTICE "Booting Linux...\n");
+
+#ifndef CONFIG_SMP
+ {
+ phandle cpu_node;
+ int err;
+ err = cpu_find_by_instance(0, &cpu_node, NULL);
+ if (err) {
+ /* Probably a sun4e, Sun is trying to trick us ;-) */
+ prom_printf("No cpu nodes, cannot continue\n");
+ prom_halt();
+ }
+ cpu_data(0).clock_tick = prom_getintdefault(cpu_node,
+ "clock-frequency",
+ 0);
+ }
+#endif /* !CONFIG_SMP */
+
+ auxio_probe();
+ auxio_power_probe();
+}