linux/arch/mips/kernel/segment.c
Greg Kroah-Hartman d8140426bc
mips: kernel: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Yangtao Li <tiny.windzz@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Marcin Nowakowski <marcin.nowakowski@mips.com>
Cc: Yasha Cherikovsky <yasha.che3@gmail.com>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
2019-01-22 11:17:20 -08:00

105 lines
2.8 KiB
C

/*
* 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/debug.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 unless it becomes
* unmapped uncached at error level due to EU.
*/
if ((am == 0) || (am > 3) || (cfg & MIPS_SEGCFG_EU))
str += sprintf(str, " %03lx",
((cfg & MIPS_SEGCFG_PA) >> MIPS_SEGCFG_PA_SHIFT));
else
str += sprintf(str, " UND");
if ((am == 0) || (am > 3))
str += sprintf(str, " %01ld",
((cfg & MIPS_SEGCFG_C) >> MIPS_SEGCFG_C_SHIFT));
else
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)
{
if (cpu_has_segments)
debugfs_create_file("segments", S_IRUGO, mips_debugfs_dir, NULL,
&segments_fops);
return 0;
}
device_initcall(segments_info);