MIPS: Add debugfs file to print the segmentation control registers (29f9087c) · Commits · 戴 / test

arch/mips/kernel/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -30,6 +30,7 @@ obj-$(CONFIG_CSRC_R4K) += csrc-r4k.o
		obj-$(CONFIG_CSRC_SB1250) += csrc-sb1250.o
		obj-$(CONFIG_SYNC_R4K) += sync-r4k.o

		obj-$(CONFIG_DEBUG_FS) += segment.o
		obj-$(CONFIG_STACKTRACE) += stacktrace.o
		obj-$(CONFIG_MODULES) += mips_ksyms.o module.o
		obj-$(CONFIG_MODULES_USE_ELF_RELA) += module-rela.o

arch/mips/kernel/segment.c

0 → 100644

+110 −0

Original line number	Diff line number	Diff line
		/*
		* 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) 2013 Imagination Technologies Ltd.
		*/

		#include <linux/kernel.h>
		#include <linux/debugfs.h>
		#include <linux/seq_file.h>
		#include <asm/cpu.h>
		#include <asm/mipsregs.h>

		static void build_segment_config(char *str, unsigned int cfg)
		{
		unsigned int am;
		static const char * const am_str[] = {
		"UK", "MK", "MSK", "MUSK", "MUSUK", "USK",
		"RSRVD", "UUSK"};

		/* Segment access mode. */
		am = (cfg & MIPS_SEGCFG_AM) >> MIPS_SEGCFG_AM_SHIFT;
		str += sprintf(str, "%-5s", am_str[am]);

		/*
		* Access modes MK, MSK and MUSK are mapped segments. Therefore
		* there is no direct physical address mapping.
		*/
		if ((am == 0) \|\| (am > 3)) {
		str += sprintf(str, " %03lx",
		((cfg & MIPS_SEGCFG_PA) >> MIPS_SEGCFG_PA_SHIFT));
		str += sprintf(str, " %01ld",
		((cfg & MIPS_SEGCFG_C) >> MIPS_SEGCFG_C_SHIFT));
		} else {
		str += sprintf(str, " UND");
		str += sprintf(str, " U");
		}

		/* Exception configuration. */
		str += sprintf(str, " %01ld\n",
		((cfg & MIPS_SEGCFG_EU) >> MIPS_SEGCFG_EU_SHIFT));
		}

		static int show_segments(struct seq_file m, void v)
		{
		unsigned int segcfg;
		char str[42];

		seq_puts(m, "Segment Virtual Size Access Mode Physical Caching EU\n");
		seq_puts(m, "------- ------- ---- ----------- -------- ------- --\n");

		segcfg = read_c0_segctl0();
		build_segment_config(str, segcfg);
		seq_printf(m, " 0 e0000000 512M %s", str);

		segcfg >>= 16;
		build_segment_config(str, segcfg);
		seq_printf(m, " 1 c0000000 512M %s", str);

		segcfg = read_c0_segctl1();
		build_segment_config(str, segcfg);
		seq_printf(m, " 2 a0000000 512M %s", str);

		segcfg >>= 16;
		build_segment_config(str, segcfg);
		seq_printf(m, " 3 80000000 512M %s", str);

		segcfg = read_c0_segctl2();
		build_segment_config(str, segcfg);
		seq_printf(m, " 4 40000000 1G %s", str);

		segcfg >>= 16;
		build_segment_config(str, segcfg);
		seq_printf(m, " 5 00000000 1G %s\n", str);

		return 0;
		}

		static int segments_open(struct inode inode, struct file file)
		{
		return single_open(file, show_segments, NULL);
		}

		static const struct file_operations segments_fops = {
		.open = segments_open,
		.read = seq_read,
		.llseek = seq_lseek,
		.release = single_release,
		};

		static int __init segments_info(void)
		{
		extern struct dentry *mips_debugfs_dir;
		struct dentry *segments;

		if (cpu_has_segments) {
		if (!mips_debugfs_dir)
		return -ENODEV;

		segments = debugfs_create_file("segments", S_IRUGO,
		mips_debugfs_dir, NULL,
		&segments_fops);
		if (!segments)
		return -ENOMEM;
		}
		return 0;
		}

		device_initcall(segments_info);

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