mirror of
https://github.com/raspberrypi/linux.git
synced 2025-12-22 17:52:09 +00:00
81c3d637c3
This patch adds debugfs interface to export Hardware Trace Macro (HTM) function data in a LPAR. New hypervisor call "H_HTM" has been defined to setup, configure, control and dump the HTM data. This patch supports only dumping of HTM data in a LPAR. New debugfs folder called "htmdump" has been added under /sys/kernel/debug/arch path which contains files need to pass required parameters for the H_HTM dump function. New Kconfig option called "CONFIG_HTMDUMP" is added in platform/pseries for the same. With this module loaded, list of files in debugfs path /sys/kernel/debug/powerpc/htmdump coreindexonchip htmtype nodalchipindex nodeindex trace Signed-off-by: Abhishek Dubey <adubey@linux.ibm.com> Co-developed-by: Madhavan Srinivasan <maddy@linux.ibm.com> Reviewed-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20250113164039.302017-2-adubey@linux.ibm.com
122 lines
2.8 KiB
C
122 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright (C) IBM Corporation, 2024
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "htmdump: " fmt
|
|
|
|
#include <linux/debugfs.h>
|
|
#include <linux/module.h>
|
|
#include <asm/io.h>
|
|
#include <asm/machdep.h>
|
|
#include <asm/plpar_wrappers.h>
|
|
|
|
static void *htm_buf;
|
|
static u32 nodeindex;
|
|
static u32 nodalchipindex;
|
|
static u32 coreindexonchip;
|
|
static u32 htmtype;
|
|
static struct dentry *htmdump_debugfs_dir;
|
|
|
|
static ssize_t htmdump_read(struct file *filp, char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
void *htm_buf = filp->private_data;
|
|
unsigned long page, read_size, available;
|
|
loff_t offset;
|
|
long rc;
|
|
|
|
page = ALIGN_DOWN(*ppos, PAGE_SIZE);
|
|
offset = (*ppos) % PAGE_SIZE;
|
|
|
|
rc = htm_get_dump_hardware(nodeindex, nodalchipindex, coreindexonchip,
|
|
htmtype, virt_to_phys(htm_buf), PAGE_SIZE, page);
|
|
|
|
switch (rc) {
|
|
case H_SUCCESS:
|
|
/* H_PARTIAL for the case where all available data can't be
|
|
* returned due to buffer size constraint.
|
|
*/
|
|
case H_PARTIAL:
|
|
break;
|
|
/* H_NOT_AVAILABLE indicates reading from an offset outside the range,
|
|
* i.e. past end of file.
|
|
*/
|
|
case H_NOT_AVAILABLE:
|
|
return 0;
|
|
case H_BUSY:
|
|
case H_LONG_BUSY_ORDER_1_MSEC:
|
|
case H_LONG_BUSY_ORDER_10_MSEC:
|
|
case H_LONG_BUSY_ORDER_100_MSEC:
|
|
case H_LONG_BUSY_ORDER_1_SEC:
|
|
case H_LONG_BUSY_ORDER_10_SEC:
|
|
case H_LONG_BUSY_ORDER_100_SEC:
|
|
return -EBUSY;
|
|
case H_PARAMETER:
|
|
case H_P2:
|
|
case H_P3:
|
|
case H_P4:
|
|
case H_P5:
|
|
case H_P6:
|
|
return -EINVAL;
|
|
case H_STATE:
|
|
return -EIO;
|
|
case H_AUTHORITY:
|
|
return -EPERM;
|
|
}
|
|
|
|
available = PAGE_SIZE;
|
|
read_size = min(count, available);
|
|
*ppos += read_size;
|
|
return simple_read_from_buffer(ubuf, count, &offset, htm_buf, available);
|
|
}
|
|
|
|
static const struct file_operations htmdump_fops = {
|
|
.llseek = NULL,
|
|
.read = htmdump_read,
|
|
.open = simple_open,
|
|
};
|
|
|
|
static int htmdump_init_debugfs(void)
|
|
{
|
|
htm_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!htm_buf) {
|
|
pr_err("Failed to allocate htmdump buf\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
htmdump_debugfs_dir = debugfs_create_dir("htmdump",
|
|
arch_debugfs_dir);
|
|
|
|
debugfs_create_u32("nodeindex", 0600,
|
|
htmdump_debugfs_dir, &nodeindex);
|
|
debugfs_create_u32("nodalchipindex", 0600,
|
|
htmdump_debugfs_dir, &nodalchipindex);
|
|
debugfs_create_u32("coreindexonchip", 0600,
|
|
htmdump_debugfs_dir, &coreindexonchip);
|
|
debugfs_create_u32("htmtype", 0600,
|
|
htmdump_debugfs_dir, &htmtype);
|
|
debugfs_create_file("trace", 0400, htmdump_debugfs_dir, htm_buf, &htmdump_fops);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init htmdump_init(void)
|
|
{
|
|
if (htmdump_init_debugfs())
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit htmdump_exit(void)
|
|
{
|
|
debugfs_remove_recursive(htmdump_debugfs_dir);
|
|
kfree(htm_buf);
|
|
}
|
|
|
|
module_init(htmdump_init);
|
|
module_exit(htmdump_exit);
|
|
MODULE_DESCRIPTION("PHYP Hardware Trace Macro (HTM) data dumper");
|
|
MODULE_LICENSE("GPL");
|