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Commit 0261a508 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
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powerpc/mm: dump segment registers on book3s/32 



This patch creates a debugfs file to see content of
segment registers

  # cat /sys/kernel/debug/segment_registers
  ---[ User Segments ]---
  0x00000000-0x0fffffff Kern key 1 User key 1 VSID 0xade2b0
  0x10000000-0x1fffffff Kern key 1 User key 1 VSID 0xade3c1
  0x20000000-0x2fffffff Kern key 1 User key 1 VSID 0xade4d2
  0x30000000-0x3fffffff Kern key 1 User key 1 VSID 0xade5e3
  0x40000000-0x4fffffff Kern key 1 User key 1 VSID 0xade6f4
  0x50000000-0x5fffffff Kern key 1 User key 1 VSID 0xade805
  0x60000000-0x6fffffff Kern key 1 User key 1 VSID 0xade916
  0x70000000-0x7fffffff Kern key 1 User key 1 VSID 0xadea27
  0x80000000-0x8fffffff Kern key 1 User key 1 VSID 0xadeb38
  0x90000000-0x9fffffff Kern key 1 User key 1 VSID 0xadec49
  0xa0000000-0xafffffff Kern key 1 User key 1 VSID 0xaded5a
  0xb0000000-0xbfffffff Kern key 1 User key 1 VSID 0xadee6b

  ---[ Kernel Segments ]---
  0xc0000000-0xcfffffff Kern key 0 User key 1 VSID 0x000ccc
  0xd0000000-0xdfffffff Kern key 0 User key 1 VSID 0x000ddd
  0xe0000000-0xefffffff Kern key 0 User key 1 VSID 0x000eee
  0xf0000000-0xffffffff Kern key 0 User key 1 VSID 0x000fff

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
[mpe: Move it under /sys/kernel/debug/powerpc, make sr_init() __init]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent b682c869

arch/powerpc/mm/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ ifdef CONFIG_PPC_PTDUMP 
obj-$(CONFIG_4xx)		+= dump_linuxpagetables-generic.o

obj-$(CONFIG_PPC_8xx)		+= dump_linuxpagetables-8xx.o

obj-$(CONFIG_PPC_BOOK3E_MMU)	+= dump_linuxpagetables-generic.o

obj-$(CONFIG_PPC_BOOK3S_32)	+= dump_linuxpagetables-generic.o

obj-$(CONFIG_PPC_BOOK3S_32)	+= dump_linuxpagetables-generic.o dump_sr.o

obj-$(CONFIG_PPC_BOOK3S_64)	+= dump_linuxpagetables-book3s64.o

endif

obj-$(CONFIG_PPC_HTDUMP)	+= dump_hashpagetable.o

arch/powerpc/mm/dump_sr.c

0 → 100644
+64 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

/*

 * Copyright 2018, Christophe Leroy CS S.I.

 * <christophe.leroy@c-s.fr>

 *

 * This dumps the content of Segment Registers

 */



#include <asm/debugfs.h>



static void seg_show(struct seq_file *m, int i)

{

	u32 val = mfsrin(i << 28);



	seq_printf(m, "0x%01x0000000-0x%01xfffffff ", i, i);

	seq_printf(m, "Kern key %d ", (val >> 30) & 1);

	seq_printf(m, "User key %d ", (val >> 29) & 1);

	if (val & 0x80000000) {

		seq_printf(m, "Device 0x%03x", (val >> 20) & 0x1ff);

		seq_printf(m, "-0x%05x", val & 0xfffff);

	} else {

		if (val & 0x10000000)

			seq_puts(m, "No Exec ");

		seq_printf(m, "VSID 0x%06x", val & 0xffffff);

	}

	seq_puts(m, "\n");

}



static int sr_show(struct seq_file *m, void *v)

{

	int i;



	seq_puts(m, "---[ User Segments ]---\n");

	for (i = 0; i < TASK_SIZE >> 28; i++)

		seg_show(m, i);



	seq_puts(m, "\n---[ Kernel Segments ]---\n");

	for (; i < 16; i++)

		seg_show(m, i);



	return 0;

}



static int sr_open(struct inode *inode, struct file *file)

{

	return single_open(file, sr_show, NULL);

}



static const struct file_operations sr_fops = {

	.open		= sr_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= single_release,

};



static int __init sr_init(void)

{

	struct dentry *debugfs_file;



	debugfs_file = debugfs_create_file("segment_registers", 0400,

					   powerpc_debugfs_root, NULL, &sr_fops);

	return debugfs_file ? 0 : -ENOMEM;

}

device_initcall(sr_init);