arch/powerpc/mm/init-common.c

Source file repositories/reference/linux-study-clean/arch/powerpc/mm/init-common.c

File Facts

System
Linux kernel
Corpus path
arch/powerpc/mm/init-common.c
Extension
.c
Size
4579 bytes
Lines
168
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration 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-or-later
/*
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  Dave Engebretsen <engebret@us.ibm.com>
 *      Rework for PPC64 port.
 */

#undef DEBUG

#include <linux/string.h>
#include <linux/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/kup.h>
#include <asm/smp.h>

phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull;
EXPORT_SYMBOL_GPL(memstart_addr);
phys_addr_t kernstart_addr __ro_after_init;
EXPORT_SYMBOL_GPL(kernstart_addr);
unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE;
EXPORT_SYMBOL_GPL(kernstart_virt_addr);

bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
#ifdef CONFIG_KFENCE
bool __ro_after_init kfence_disabled;
bool __ro_after_init kfence_early_init = !!CONFIG_KFENCE_SAMPLE_INTERVAL;
#endif

static int __init parse_nosmep(char *p)
{
	if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
		return 0;

	disable_kuep = true;
	pr_warn("Disabling Kernel Userspace Execution Prevention\n");
	return 0;
}
early_param("nosmep", parse_nosmep);

static int __init parse_nosmap(char *p)
{
	disable_kuap = true;
	pr_warn("Disabling Kernel Userspace Access Protection\n");
	return 0;
}
early_param("nosmap", parse_nosmap);

void __weak setup_kuep(bool disabled)
{
	if (!IS_ENABLED(CONFIG_PPC_KUEP) || disabled)
		return;

	if (smp_processor_id() != boot_cpuid)
		return;

	pr_info("Activating Kernel Userspace Execution Prevention\n");
}

void setup_kup(void)
{
	setup_kuap(disable_kuap);
	setup_kuep(disable_kuep);
}

#define CTOR(shift) static void ctor_##shift(void *addr) \
{							\
	memset(addr, 0, sizeof(pgd_t) << (shift));	\
}

CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7);
CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15);

static inline void (*ctor(int shift))(void *)
{
	BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15);

	switch (shift) {
	case 0: return ctor_0;
	case 1: return ctor_1;
	case 2: return ctor_2;

Annotation

Implementation Notes