From 29f9087c52d19067a1eccfd5c0a4a0045cf3ea04 Mon Sep 17 00:00:00 2001 From: "Steven J. Hill" Date: Thu, 14 Nov 2013 16:12:32 +0000 Subject: [PATCH] MIPS: Add debugfs file to print the segmentation control registers Add a new mips/segments debugfs file to print the 6 segmentation control registers for supported cores. A sample from a proAptiv core is given below: Signed-off-by: John Crispin Patchwork: http://patchwork.linux-mips.org/patch/6137/ Segment Virtual Size Access Mode Physical Caching EU ------- ------- ---- ----------- -------- ------- -- 0 e0000000 512M MK UND U 0 1 c0000000 512M MSK UND U 0 2 a0000000 512M UK 000 2 0 3 80000000 512M UK 000 3 0 4 40000000 1G MUSK UND U 1 5 00000000 1G MUSK UND U 1 Reviewed-by: James Hogan Signed-off-by: Steven J. Hill Signed-off-by: Markos Chandras --- arch/mips/kernel/Makefile | 1 + arch/mips/kernel/segment.c | 110 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 111 insertions(+) create mode 100644 arch/mips/kernel/segment.c diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile index 1c1b717..b95eb741 100644 --- a/arch/mips/kernel/Makefile +++ b/arch/mips/kernel/Makefile @@ -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 diff --git a/arch/mips/kernel/segment.c b/arch/mips/kernel/segment.c new file mode 100644 index 0000000..076ead2 --- /dev/null +++ b/arch/mips/kernel/segment.c @@ -0,0 +1,110 @@ +/* + * 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 +#include +#include +#include +#include + +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); -- 2.7.4