platform: generic: Tenstorrent Atlantis support

Add the Tenstorrent Atlantis as a generic-platform. This initial support
enables the single_fw_region option, and verifies and prints HART PMA
CSR configuration.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260424062520.238403-1-npiggin@gmail.com
Signed-off-by: Anup Patel <anup@brainfault.org>

platform/generic/tenstorrent/atlantis.c

@@ -0,0 +1,50 @@
+/*
+ * SPDX-FileCopyrightText: (c) 2025-2026 Tenstorrent USA, Inc.
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <platform_override.h>
+#include <libfdt.h>
+#include <sbi/sbi_error.h>
+#include <sbi/sbi_hart.h>
+#include <sbi/sbi_system.h>
+#include <sbi/sbi_console.h>
+
+#include <tenstorrent/ascalon.h>
+#include <tenstorrent/pma.h>
+
+static int tt_atlantis_final_init(bool cold_boot)
+{
+	if (cold_boot) {
+		/* Boot firmware sets HART PMAs. Read and verify them. */
+		tt_ascalon_discover_pmas_from_boot_hart();
+	} else {
+		/* Verify nonboot HARTs have PMAs matching boot HART */
+		tt_ascalon_verify_pmas_nonboot_hart();
+	}
+
+	return generic_final_init(cold_boot);
+}
+
+static bool tt_atlantis_single_fw_region(void)
+{
+	return true;
+}
+
+static int tt_atlantis_platform_init(const void *fdt, int nodeoff, const struct fdt_match *match)
+{
+	generic_platform_ops.final_init = tt_atlantis_final_init;
+	generic_platform_ops.single_fw_region = tt_atlantis_single_fw_region;
+
+	return 0;
+}
+
+static const struct fdt_match tt_atlantis_match[] = {
+	{ .compatible = "tenstorrent,atlantis" },
+	{ },
+};
+
+const struct fdt_driver tenstorrent_atlantis = {
+	.match_table = tt_atlantis_match,
+	.init = tt_atlantis_platform_init,
+};