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-rw-r--r--drivers/watchdog/octeon-wdt-nmi.S90
1 files changed, 90 insertions, 0 deletions
diff --git a/drivers/watchdog/octeon-wdt-nmi.S b/drivers/watchdog/octeon-wdt-nmi.S
new file mode 100644
index 000000000..97f6eb7b5
--- /dev/null
+++ b/drivers/watchdog/octeon-wdt-nmi.S
@@ -0,0 +1,90 @@
+/*
+ * 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) 2007-2017 Cavium, Inc.
+ */
+#include <asm/asm.h>
+#include <asm/regdef.h>
+
+#define CVMSEG_BASE -32768
+#define CVMSEG_SIZE 6912
+#define SAVE_REG(r) sd $r, CVMSEG_BASE + CVMSEG_SIZE - ((32 - r) * 8)($0)
+
+ NESTED(octeon_wdt_nmi_stage2, 0, sp)
+ .set push
+ .set noreorder
+ .set noat
+ /* Clear Dcache so cvmseg works right. */
+ cache 1,0($0)
+ /* Use K0 to do a read/modify/write of CVMMEMCTL */
+ dmfc0 k0, $11, 7
+ /* Clear out the size of CVMSEG */
+ dins k0, $0, 0, 6
+ /* Set CVMSEG to its largest value */
+ ori k0, k0, 0x1c0 | 54
+ /* Store the CVMMEMCTL value */
+ dmtc0 k0, $11, 7
+ /*
+ * Restore K0 from the debug scratch register, it was saved in
+ * the boot-vector code.
+ */
+ dmfc0 k0, $31
+
+ /*
+ * Save all registers to the top CVMSEG. This shouldn't
+ * corrupt any state used by the kernel. Also all registers
+ * should have the value right before the NMI.
+ */
+ SAVE_REG(0)
+ SAVE_REG(1)
+ SAVE_REG(2)
+ SAVE_REG(3)
+ SAVE_REG(4)
+ SAVE_REG(5)
+ SAVE_REG(6)
+ SAVE_REG(7)
+ SAVE_REG(8)
+ SAVE_REG(9)
+ SAVE_REG(10)
+ SAVE_REG(11)
+ SAVE_REG(12)
+ SAVE_REG(13)
+ SAVE_REG(14)
+ SAVE_REG(15)
+ SAVE_REG(16)
+ SAVE_REG(17)
+ SAVE_REG(18)
+ SAVE_REG(19)
+ SAVE_REG(20)
+ SAVE_REG(21)
+ SAVE_REG(22)
+ SAVE_REG(23)
+ SAVE_REG(24)
+ SAVE_REG(25)
+ SAVE_REG(26)
+ SAVE_REG(27)
+ SAVE_REG(28)
+ SAVE_REG(29)
+ SAVE_REG(30)
+ SAVE_REG(31)
+ /* Write zero to all CVMSEG locations per Core-15169 */
+ dli a0, CVMSEG_SIZE - (33 * 8)
+1: sd zero, CVMSEG_BASE(a0)
+ daddiu a0, a0, -8
+ bgez a0, 1b
+ nop
+ /* Set the stack to begin right below the registers */
+ dli sp, CVMSEG_BASE + CVMSEG_SIZE - (32 * 8)
+ /* Load the address of the third stage handler */
+ dla $25, octeon_wdt_nmi_stage3
+ /* Call the third stage handler */
+ jal $25
+ /* a0 is the address of the saved registers */
+ move a0, sp
+ /* Loop forvever if we get here. */
+2: b 2b
+ nop
+ .set pop
+ END(octeon_wdt_nmi_stage2)