@@ -13,6 +13,7 @@ CORE_OBJS += timer.o i2c.o rtc.o flash.o sensor.o ipmi-opal.o
CORE_OBJS += flash-subpartition.o bitmap.o buddy.o pci-quirk.o powercap.o psr.o
CORE_OBJS += pci-dt-slot.o direct-controls.o cpufeatures.o
CORE_OBJS += flash-firmware-versions.o opal-dump.o
+CORE_OBJS += hwprobe.o
ifeq ($(SKIBOOT_GCOV),1)
CORE_OBJS += gcov-profiling.o
new file mode 100644
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+/* Copyright 2021 Stewart Smith */
+
+#define pr_fmt(fmt) "HWPROBE: " fmt
+#include <skiboot.h>
+#include <string.h>
+
+static bool hwprobe_deps_satisfied(const struct hwprobe *hwp)
+{
+ struct hwprobe *hwprobe;
+ const char **dep;
+ unsigned int i;
+
+ dep = hwp->deps;
+ if (dep == NULL)
+ return true;
+
+
+ prlog(PR_TRACE, "Checking deps for %s\n", hwp->name);
+
+ while (*dep != NULL) {
+ prlog(PR_TRACE, "Checking %s dep %s\n", hwp->name, *dep);
+ hwprobe = &__hwprobes_start;
+ for (i = 0; &hwprobe[i] < &__hwprobes_end; i++) {
+ if(strcmp(hwprobe[i].name, *dep) == 0 &&
+ !hwprobe[i].probed)
+ return false;
+ }
+ dep++;
+ }
+
+ prlog(PR_TRACE, "deps for %s are satisfied!\n", hwp->name);
+ return true;
+
+}
+
+void probe_hardware(void)
+{
+ struct hwprobe *hwprobe;
+ unsigned int i;
+ bool work_todo = true;
+ bool did_something = true;
+
+ while (work_todo) {
+ work_todo = false;
+ did_something = false;
+ hwprobe = &__hwprobes_start;
+ prlog(PR_DEBUG, "Begin loop\n");
+ for (i = 0; &hwprobe[i] < &__hwprobes_end; i++) {
+ if (hwprobe[i].probed)
+ continue;
+ if (hwprobe_deps_satisfied(&hwprobe[i])) {
+ prlog(PR_DEBUG, "Probing %s...\n", hwprobe[i].name);
+ if (hwprobe[i].probe)
+ hwprobe[i].probe();
+ did_something = true;
+ hwprobe[i].probed = true;
+ } else {
+ prlog(PR_DEBUG, "Dependencies for %s not yet satisfied, skipping\n",
+ hwprobe[i].name);
+ work_todo = true;
+ }
+ }
+
+ if (work_todo && !did_something) {
+ prlog(PR_ERR, "Cannot satisfy dependencies! Bailing out\n");
+ break;
+ }
+ }
+}
@@ -1372,6 +1372,9 @@ void __noreturn __nomcount main_cpu_entry(const void *fdt)
probe_npu2();
probe_npu3();
+ /* Probe all HWPROBE hardware we have code linked for*/
+ probe_hardware();
+
/* Initialize PCI */
pci_init_slots();
@@ -1,5 +1,7 @@
// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
-/* Copyright 2013-2019 IBM Corp. */
+/* Copyright 2013-2019 IBM Corp.
+ * Copyright 2021 Stewart Smith
+ */
#ifndef __SKIBOOT_H
#define __SKIBOOT_H
@@ -341,4 +343,39 @@ extern int fake_nvram_info(uint32_t *total_size);
extern int fake_nvram_start_read(void *dst, uint32_t src, uint32_t len);
extern int fake_nvram_write(uint32_t offset, void *src, uint32_t size);
+/*
+ * A bunch of hardware needs to be probed, sometimes in a particular order.
+ * Very simple dependency graph, with a even simpler way to resolve it.
+ * But it means we can now at link time choose what hardware we support.
+ * This struct should not be defined directly but with the macros.
+ */
+struct hwprobe {
+ const char *name;
+ void (*probe)(void);
+
+ bool probed;
+
+ /* NULL or NULL-terminated array of strings */
+ const char **deps;
+};
+
+#define DEFINE_HWPROBE(__name, __probe) \
+static const struct hwprobe __used __section(".hwprobes") hwprobe_##__name = { \
+ .name = #__name, \
+ .probe = __probe, \
+ .deps = NULL, \
+}
+
+#define DEFINE_HWPROBE_DEPS(__name, __probe, ...) \
+static const struct hwprobe __used __section(".hwprobes") hwprobe_##__name = { \
+ .name = #__name, \
+ .probe = __probe, \
+ .deps = (const char *[]){ __VA_ARGS__, NULL}, \
+}
+
+extern struct hwprobe __hwprobes_start;
+extern struct hwprobe __hwprobes_end;
+
+extern void probe_hardware(void);
+
#endif /* __SKIBOOT_H */
@@ -164,6 +164,12 @@ SECTIONS
__platforms_end = .;
}
+ .hwprobes : {
+ __hwprobes_start = .;
+ KEEP(*(.hwprobes))
+ __hwprobes_end = .;
+ }
+
/* Relocations */
. = ALIGN(0x10);
.dynamic : {