Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 202 insertions, 0 deletions

diff --git a/arch/mips/kernel/cps-vec-ns16550.S b/arch/mips/kernel/cps-vec-ns16550.S
new file mode 100644
index 000000000..b37af23a5
--- /dev/null
+++ b/arch/mips/kernel/cps-vec-ns16550.S
@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Paul Burton <paul.burton@mips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <asm/addrspace.h>
+#include <asm/asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/mipsregs.h>
+#include <asm/regdef.h>
+#include <linux/serial_reg.h>
+
+#define UART_TX_OFS	(UART_TX << CONFIG_MIPS_CPS_NS16550_SHIFT)
+#define UART_LSR_OFS	(UART_LSR << CONFIG_MIPS_CPS_NS16550_SHIFT)
+
+/**
+ * _mips_cps_putc() - write a character to the UART
+ * @a0: ASCII character to write
+ * @t9: UART base address
+ */
+LEAF(_mips_cps_putc)
+1:	lw		t0, UART_LSR_OFS(t9)
+	andi		t0, t0, UART_LSR_TEMT
+	beqz		t0, 1b
+	sb		a0, UART_TX_OFS(t9)
+	jr		ra
+	END(_mips_cps_putc)
+
+/**
+ * _mips_cps_puts() - write a string to the UART
+ * @a0: pointer to NULL-terminated ASCII string
+ * @t9: UART base address
+ *
+ * Write a null-terminated ASCII string to the UART.
+ */
+NESTED(_mips_cps_puts, 0, ra)
+	move		s7, ra
+	move		s6, a0
+
+1:	lb		a0, 0(s6)
+	beqz		a0, 2f
+	jal		_mips_cps_putc
+	PTR_ADDIU	s6, s6, 1
+	b		1b
+
+2:	jr		s7
+	END(_mips_cps_puts)
+
+/**
+ * _mips_cps_putx4 - write a 4b hex value to the UART
+ * @a0: the 4b value to write to the UART
+ * @t9: UART base address
+ *
+ * Write a single hexadecimal character to the UART.
+ */
+NESTED(_mips_cps_putx4, 0, ra)
+	andi		a0, a0, 0xf
+	li		t0, '0'
+	blt		a0, 10, 1f
+	li		t0, 'a'
+	addiu		a0, a0, -10
+1:	addu		a0, a0, t0
+	b		_mips_cps_putc
+	END(_mips_cps_putx4)
+
+/**
+ * _mips_cps_putx8 - write an 8b hex value to the UART
+ * @a0: the 8b value to write to the UART
+ * @t9: UART base address
+ *
+ * Write an 8 bit value (ie. 2 hexadecimal characters) to the UART.
+ */
+NESTED(_mips_cps_putx8, 0, ra)
+	move		s3, ra
+	move		s2, a0
+	srl		a0, a0, 4
+	jal		_mips_cps_putx4
+	move		a0, s2
+	move		ra, s3
+	b		_mips_cps_putx4
+	END(_mips_cps_putx8)
+
+/**
+ * _mips_cps_putx16 - write a 16b hex value to the UART
+ * @a0: the 16b value to write to the UART
+ * @t9: UART base address
+ *
+ * Write a 16 bit value (ie. 4 hexadecimal characters) to the UART.
+ */
+NESTED(_mips_cps_putx16, 0, ra)
+	move		s5, ra
+	move		s4, a0
+	srl		a0, a0, 8
+	jal		_mips_cps_putx8
+	move		a0, s4
+	move		ra, s5
+	b		_mips_cps_putx8
+	END(_mips_cps_putx16)
+
+/**
+ * _mips_cps_putx32 - write a 32b hex value to the UART
+ * @a0: the 32b value to write to the UART
+ * @t9: UART base address
+ *
+ * Write a 32 bit value (ie. 8 hexadecimal characters) to the UART.
+ */
+NESTED(_mips_cps_putx32, 0, ra)
+	move		s7, ra
+	move		s6, a0
+	srl		a0, a0, 16
+	jal		_mips_cps_putx16
+	move		a0, s6
+	move		ra, s7
+	b		_mips_cps_putx16
+	END(_mips_cps_putx32)
+
+#ifdef CONFIG_64BIT
+
+/**
+ * _mips_cps_putx64 - write a 64b hex value to the UART
+ * @a0: the 64b value to write to the UART
+ * @t9: UART base address
+ *
+ * Write a 64 bit value (ie. 16 hexadecimal characters) to the UART.
+ */
+NESTED(_mips_cps_putx64, 0, ra)
+	move		sp, ra
+	move		s8, a0
+	dsrl32		a0, a0, 0
+	jal		_mips_cps_putx32
+	move		a0, s8
+	move		ra, sp
+	b		_mips_cps_putx32
+	END(_mips_cps_putx64)
+
+#define _mips_cps_putxlong _mips_cps_putx64
+
+#else /* !CONFIG_64BIT */
+
+#define _mips_cps_putxlong _mips_cps_putx32
+
+#endif /* !CONFIG_64BIT */
+
+/**
+ * mips_cps_bev_dump() - dump relevant exception state to UART
+ * @a0: pointer to NULL-terminated ASCII string naming the exception
+ *
+ * Write information that may be useful in debugging an exception to the
+ * UART configured by CONFIG_MIPS_CPS_NS16550_*. As this BEV exception
+ * will only be run if something goes horribly wrong very early during
+ * the bringup of a core and it is very likely to be unsafe to perform
+ * memory accesses at that point (cache state indeterminate, EVA may not
+ * be configured, coherence may be disabled) let alone have a stack,
+ * this is all written in assembly using only registers & unmapped
+ * uncached access to the UART registers.
+ */
+LEAF(mips_cps_bev_dump)
+	move		s0, ra
+	move		s1, a0
+
+	li		t9, CKSEG1ADDR(CONFIG_MIPS_CPS_NS16550_BASE)
+
+	PTR_LA		a0, str_newline
+	jal		_mips_cps_puts
+	PTR_LA		a0, str_bev
+	jal		_mips_cps_puts
+	move		a0, s1
+	jal		_mips_cps_puts
+	PTR_LA		a0, str_newline
+	jal		_mips_cps_puts
+	PTR_LA		a0, str_newline
+	jal		_mips_cps_puts
+
+#define DUMP_COP0_REG(reg, name, sz, _mfc0)		\
+	PTR_LA		a0, 8f;				\
+	jal		_mips_cps_puts;			\
+	_mfc0		a0, reg;			\
+	jal		_mips_cps_putx##sz;		\
+	PTR_LA		a0, str_newline;		\
+	jal		_mips_cps_puts;			\
+	TEXT(name)
+
+	DUMP_COP0_REG(CP0_CAUSE,    "Cause:    0x", 32, mfc0)
+	DUMP_COP0_REG(CP0_STATUS,   "Status:   0x", 32, mfc0)
+	DUMP_COP0_REG(CP0_EBASE,    "EBase:    0x", long, MFC0)
+	DUMP_COP0_REG(CP0_BADVADDR, "BadVAddr: 0x", long, MFC0)
+	DUMP_COP0_REG(CP0_BADINSTR, "BadInstr: 0x", 32, mfc0)
+
+	PTR_LA		a0, str_newline
+	jal		_mips_cps_puts
+	jr		s0
+	END(mips_cps_bev_dump)
+
+.pushsection	.data
+str_bev: .asciiz "BEV Exception: "
+str_newline: .asciiz "\r\n"
+.popsection