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diff --git a/kernel/arch/arm/include/debug/tegra.S b/kernel/arch/arm/include/debug/tegra.S
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+++ b/kernel/arch/arm/include/debug/tegra.S
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+/*
+ * Copyright (C) 2010,2011 Google, Inc.
+ * Copyright (C) 2011-2012 NVIDIA CORPORATION. All Rights Reserved.
+ *
+ * Author:
+ * Colin Cross <ccross@google.com>
+ * Erik Gilling <konkers@google.com>
+ * Doug Anderson <dianders@chromium.org>
+ * Stephen Warren <swarren@nvidia.com>
+ *
+ * Portions based on mach-omap2's debug-macro.S
+ * Copyright (C) 1994-1999 Russell King
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/serial_reg.h>
+
+#define UART_SHIFT 2
+
+/* Physical addresses */
+#define TEGRA_CLK_RESET_BASE 0x60006000
+#define TEGRA_APB_MISC_BASE 0x70000000
+#define TEGRA_UARTA_BASE 0x70006000
+#define TEGRA_UARTB_BASE 0x70006040
+#define TEGRA_UARTC_BASE 0x70006200
+#define TEGRA_UARTD_BASE 0x70006300
+#define TEGRA_UARTE_BASE 0x70006400
+#define TEGRA_PMC_BASE 0x7000e400
+
+#define TEGRA_CLK_RST_DEVICES_L (TEGRA_CLK_RESET_BASE + 0x04)
+#define TEGRA_CLK_RST_DEVICES_H (TEGRA_CLK_RESET_BASE + 0x08)
+#define TEGRA_CLK_RST_DEVICES_U (TEGRA_CLK_RESET_BASE + 0x0c)
+#define TEGRA_CLK_OUT_ENB_L (TEGRA_CLK_RESET_BASE + 0x10)
+#define TEGRA_CLK_OUT_ENB_H (TEGRA_CLK_RESET_BASE + 0x14)
+#define TEGRA_CLK_OUT_ENB_U (TEGRA_CLK_RESET_BASE + 0x18)
+#define TEGRA_PMC_SCRATCH20 (TEGRA_PMC_BASE + 0xa0)
+#define TEGRA_APB_MISC_GP_HIDREV (TEGRA_APB_MISC_BASE + 0x804)
+
+/*
+ * Must be section-aligned since a section mapping is used early on.
+ * Must not overlap with regions in mach-tegra/io.c:tegra_io_desc[].
+ */
+#define UART_VIRTUAL_BASE 0xfe800000
+
+#define checkuart(rp, rv, lhu, bit, uart) \
+ /* Load address of CLK_RST register */ \
+ ldr rp, =TEGRA_CLK_RST_DEVICES_##lhu ; \
+ /* Load value from CLK_RST register */ \
+ ldr rp, [rp, #0] ; \
+ /* Test UART's reset bit */ \
+ tst rp, #(1 << bit) ; \
+ /* If set, can't use UART; jump to save no UART */ \
+ bne 90f ; \
+ /* Load address of CLK_OUT_ENB register */ \
+ ldr rp, =TEGRA_CLK_OUT_ENB_##lhu ; \
+ /* Load value from CLK_OUT_ENB register */ \
+ ldr rp, [rp, #0] ; \
+ /* Test UART's clock enable bit */ \
+ tst rp, #(1 << bit) ; \
+ /* If clear, can't use UART; jump to save no UART */ \
+ beq 90f ; \
+ /* Passed all tests, load address of UART registers */ \
+ ldr rp, =TEGRA_UART##uart##_BASE ; \
+ /* Jump to save UART address */ \
+ b 91f
+
+ .macro addruart, rp, rv, tmp
+ adr \rp, 99f @ actual addr of 99f
+ ldr \rv, [\rp] @ linked addr is stored there
+ sub \rv, \rv, \rp @ offset between the two
+ ldr \rp, [\rp, #4] @ linked tegra_uart_config
+ sub \tmp, \rp, \rv @ actual tegra_uart_config
+ ldr \rp, [\tmp] @ Load tegra_uart_config
+ cmp \rp, #1 @ needs initialization?
+ bne 100f @ no; go load the addresses
+ mov \rv, #0 @ yes; record init is done
+ str \rv, [\tmp]
+
+#ifdef CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA
+ /* Check ODMDATA */
+10: ldr \rp, =TEGRA_PMC_SCRATCH20
+ ldr \rp, [\rp, #0] @ Load PMC_SCRATCH20
+ lsr \rv, \rp, #18 @ 19:18 are console type
+ and \rv, \rv, #3
+ cmp \rv, #2 @ 2 and 3 mean DCC, UART
+ beq 11f @ some boards swap the meaning
+ cmp \rv, #3 @ so accept either
+ bne 90f
+11: lsr \rv, \rp, #15 @ 17:15 are UART ID
+ and \rv, #7
+ cmp \rv, #0 @ UART 0?
+ beq 20f
+ cmp \rv, #1 @ UART 1?
+ beq 21f
+ cmp \rv, #2 @ UART 2?
+ beq 22f
+ cmp \rv, #3 @ UART 3?
+ beq 23f
+ cmp \rv, #4 @ UART 4?
+ beq 24f
+ b 90f @ invalid
+#endif
+
+#if defined(CONFIG_TEGRA_DEBUG_UARTA) || \
+ defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
+ /* Check UART A validity */
+20: checkuart(\rp, \rv, L, 6, A)
+#endif
+
+#if defined(CONFIG_TEGRA_DEBUG_UARTB) || \
+ defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
+ /* Check UART B validity */
+21: checkuart(\rp, \rv, L, 7, B)
+#endif
+
+#if defined(CONFIG_TEGRA_DEBUG_UARTC) || \
+ defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
+ /* Check UART C validity */
+22: checkuart(\rp, \rv, H, 23, C)
+#endif
+
+#if defined(CONFIG_TEGRA_DEBUG_UARTD) || \
+ defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
+ /* Check UART D validity */
+23: checkuart(\rp, \rv, U, 1, D)
+#endif
+
+#if defined(CONFIG_TEGRA_DEBUG_UARTE) || \
+ defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
+ /* Check UART E validity */
+24:
+ checkuart(\rp, \rv, U, 2, E)
+#endif
+
+ /* No valid UART found */
+90: mov \rp, #0
+ /* fall through */
+
+ /* Record whichever UART we chose */
+91: str \rp, [\tmp, #4] @ Store in tegra_uart_phys
+ cmp \rp, #0 @ Valid UART address?
+ bne 92f @ Yes, go process it
+ str \rp, [\tmp, #8] @ Store 0 in tegra_uart_virt
+ b 100f @ Done
+92: and \rv, \rp, #0xffffff @ offset within 1MB section
+ add \rv, \rv, #UART_VIRTUAL_BASE
+ str \rv, [\tmp, #8] @ Store in tegra_uart_virt
+ b 100f
+
+ .align
+99: .word .
+ .word tegra_uart_config
+ .ltorg
+
+ /* Load previously selected UART address */
+100: ldr \rp, [\tmp, #4] @ Load tegra_uart_phys
+ ldr \rv, [\tmp, #8] @ Load tegra_uart_virt
+ .endm
+
+/*
+ * Code below is swiped from <asm/hardware/debug-8250.S>, but add an extra
+ * check to make sure that the UART address is actually valid.
+ */
+
+ .macro senduart, rd, rx
+ cmp \rx, #0
+ strneb \rd, [\rx, #UART_TX << UART_SHIFT]
+1001:
+ .endm
+
+ .macro busyuart, rd, rx
+ cmp \rx, #0
+ beq 1002f
+1001: ldrb \rd, [\rx, #UART_LSR << UART_SHIFT]
+ and \rd, \rd, #UART_LSR_THRE
+ teq \rd, #UART_LSR_THRE
+ bne 1001b
+1002:
+ .endm
+
+ .macro waituart, rd, rx
+#ifdef FLOW_CONTROL
+ cmp \rx, #0
+ beq 1002f
+1001: ldrb \rd, [\rx, #UART_MSR << UART_SHIFT]
+ tst \rd, #UART_MSR_CTS
+ beq 1001b
+1002:
+#endif
+ .endm
+
+/*
+ * Storage for the state maintained by the macros above.
+ *
+ * In the kernel proper, this data is located in arch/arm/mach-tegra/tegra.c.
+ * That's because this header is included from multiple files, and we only
+ * want a single copy of the data. In particular, the UART probing code above
+ * assumes it's running using physical addresses. This is true when this file
+ * is included from head.o, but not when included from debug.o. So we need
+ * to share the probe results between the two copies, rather than having
+ * to re-run the probing again later.
+ *
+ * In the decompressor, we put the symbol/storage right here, since common.c
+ * isn't included in the decompressor build. This symbol gets put in .text
+ * even though it's really data, since .data is discarded from the
+ * decompressor. Luckily, .text is writeable in the decompressor, unless
+ * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug.
+ */
+#if defined(ZIMAGE)
+tegra_uart_config:
+ /* Debug UART initialization required */
+ .word 1
+ /* Debug UART physical address */
+ .word 0
+ /* Debug UART virtual address */
+ .word 0
+#endif