arch/s390/kernel/os_info.c

Source file repositories/reference/linux-study-clean/arch/s390/kernel/os_info.c

File Facts

System
Linux kernel
Corpus path
arch/s390/kernel/os_info.c
Extension
.c
Size
5014 bytes
Lines
197
Domain
Architecture Layer
Bucket
arch/s390
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * OS info memory interface
 *
 * Copyright IBM Corp. 2012
 * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
 */

#define pr_fmt(fmt) "os_info: " fmt

#include <linux/crash_dump.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <asm/checksum.h>
#include <asm/abs_lowcore.h>
#include <asm/os_info.h>
#include <asm/physmem_info.h>
#include <asm/maccess.h>
#include <asm/asm-offsets.h>
#include <asm/sections.h>
#include <asm/ipl.h>

/*
 * OS info structure has to be page aligned
 */
static struct os_info os_info __page_aligned_data;

/*
 * Compute checksum over OS info structure
 */
u32 os_info_csum(struct os_info *os_info)
{
	int size = sizeof(*os_info) - offsetof(struct os_info, version_major);
	return (__force u32)cksm(&os_info->version_major, size, 0);
}

/*
 * Add crashkernel info to OS info and update checksum
 */
void os_info_crashkernel_add(unsigned long base, unsigned long size)
{
	os_info.crashkernel_addr = (u64)(unsigned long)base;
	os_info.crashkernel_size = (u64)(unsigned long)size;
	os_info.csum = os_info_csum(&os_info);
}

/*
 * Add OS info data entry and update checksum
 */
void os_info_entry_add_data(int nr, void *ptr, u64 size)
{
	os_info.entry[nr].addr = __pa(ptr);
	os_info.entry[nr].size = size;
	os_info.entry[nr].csum = (__force u32)cksm(ptr, size, 0);
	os_info.csum = os_info_csum(&os_info);
}

/*
 * Add OS info value entry and update checksum
 */
void os_info_entry_add_val(int nr, u64 value)
{
	os_info.entry[nr].val = value;
	os_info.entry[nr].size = 0;
	os_info.entry[nr].csum = 0;
	os_info.csum = os_info_csum(&os_info);
}

/*
 * Initialize OS info structure and set lowcore pointer
 */
void __init os_info_init(void)
{
	struct lowcore *abs_lc;

	BUILD_BUG_ON(sizeof(struct os_info) != PAGE_SIZE);
	os_info.version_major = OS_INFO_VERSION_MAJOR;
	os_info.version_minor = OS_INFO_VERSION_MINOR;
	os_info.magic = OS_INFO_MAGIC;
	os_info_entry_add_val(OS_INFO_IDENTITY_BASE, __identity_base);
	os_info_entry_add_val(OS_INFO_KASLR_OFFSET, kaslr_offset());
	os_info_entry_add_val(OS_INFO_KASLR_OFF_PHYS, __kaslr_offset_phys);
	os_info_entry_add_val(OS_INFO_VMEMMAP, (unsigned long)vmemmap);
	os_info_entry_add_val(OS_INFO_AMODE31_START, AMODE31_START);
	os_info_entry_add_val(OS_INFO_AMODE31_END, AMODE31_END);
	os_info_entry_add_val(OS_INFO_IMAGE_START, (unsigned long)_stext);
	os_info_entry_add_val(OS_INFO_IMAGE_END, (unsigned long)_end);
	os_info_entry_add_val(OS_INFO_IMAGE_PHYS, __pa_symbol(_stext));
	os_info.csum = os_info_csum(&os_info);
	abs_lc = get_abs_lowcore();

Annotation

Implementation Notes