MIPS: Octeon: Add support for accessing the boot vector.

Used by the Octeon watchdog driver to get the address of the
firmware boot vector.

Signed-off-by: Steven J. Hill <steven.hill@cavium.com>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-watchdog@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17206/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 53 insertions, 0 deletions

diff --git a/arch/mips/include/asm/octeon/cvmx-boot-vector.h b/arch/mips/include/asm/octeon/cvmx-boot-vector.h
new file mode 100644
index 000000000000..8db08241d53c
--- /dev/null
+++ b/arch/mips/include/asm/octeon/cvmx-boot-vector.h
@@ -0,0 +1,53 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2003-2017 Cavium, Inc.
+ */
+
+#ifndef __CVMX_BOOT_VECTOR_H__
+#define __CVMX_BOOT_VECTOR_H__
+
+#include <asm/octeon/octeon.h>
+
+/*
+ * The boot vector table is made up of an array of 1024 elements of
+ * struct cvmx_boot_vector_element.  There is one entry for each
+ * possible MIPS CPUNum, indexed by the CPUNum.
+ *
+ * Once cvmx_boot_vector_get() returns a non-NULL value (indicating
+ * success), NMI to a core will cause execution to transfer to the
+ * target_ptr location for that core's entry in the vector table.
+ *
+ * The struct cvmx_boot_vector_element fields app0, app1, and app2 can
+ * be used by the application that has set the target_ptr in any
+ * application specific manner, they are not touched by the vectoring
+ * code.
+ *
+ * The boot vector code clobbers the CP0_DESAVE register, and on
+ * OCTEON II and later CPUs also clobbers CP0_KScratch2.  All GP
+ * registers are preserved, except on pre-OCTEON II CPUs, where k1 is
+ * clobbered.
+ *
+ */
+
+
+/*
+ * Applications install the boot bus code in cvmx-boot-vector.c, which
+ * uses this magic:
+ */
+#define OCTEON_BOOT_MOVEABLE_MAGIC1 0xdb00110ad358eacdull
+
+struct cvmx_boot_vector_element {
+	/* kseg0 or xkphys address of target code. */
+	uint64_t target_ptr;
+	/* Three application specific arguments. */
+	uint64_t app0;
+	uint64_t app1;
+	uint64_t app2;
+};
+
+struct cvmx_boot_vector_element *cvmx_boot_vector_get(void);
+
+#endif /* __CVMX_BOOT_VECTOR_H__ */