// 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 <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/kup.h>
static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
static int __init parse_nosmep(char *p)
{
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 __ref setup_kup(void)
{
setup_kuep(disable_kuep);
setup_kuap(disable_kuap);
}
#define CTOR(shift) static void ctor_##shift(void *addr) \
{ \
memset(addr, 0, sizeof(void *) << (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;
case 3: return ctor_3;
case 4: return ctor_4;
case 5: return ctor_5;
case 6: return ctor_6;
case 7: return ctor_7;
case 8: return ctor_8;
case 9: return ctor_9;
case 10: return ctor_10;
case 11: return ctor_11;
case 12: return ctor_12;
case 13: return ctor_13;
case 14: return ctor_14;
case 15: return ctor_15;
}
return NULL;
}
struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1];
EXPORT_SYMBOL_GPL(pgtable_cache); /* used by kvm_hv module */
/*
* Create a kmem_cache() for pagetables. This is not used for PTE
* pages - they're linked to struct page, come from the normal free
* pages pool and have a different entry size (see real_pte_t) to
* everything else. Caches created by this function are used for all
* the higher level pagetables, and for hugepage pagetables.
*/
void pgtable_cache_add(unsigned int shift)
{
char *name;
unsigned long table_size = sizeof(void *) << shift;
unsigned long align = table_size;
/* When batching pgtable pointers for RCU freeing, we store
* the index size in the low bits. Table alignment must be
* big enough to fit it.
*
* Likewise, hugeapge pagetable pointers contain a (different)
* shift value in the low bits. All tables must be aligned so
* as to leave enough 0 bits in the address to contain it. */
unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
HUGEPD_SHIFT_MASK + 1);
struct kmem_cache *new;
/* It would be nice if this was a BUILD_BUG_ON(), but at the
* moment, gcc doesn't seem to recognize is_power_of_2 as a
* constant expression, so so much for that. */
BUG_ON(!is_power_of_2(minalign));
BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
if (PGT_CACHE(shift))
return; /* Already have a cache of this size */
align = max_t(unsigned long, align, minalign);
name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
new = kmem_cache_create(name, table_size, align, 0, ctor(shift));
if (!new)
panic("Could not allocate pgtable cache for order %d", shift);
kfree(name);
pgtable_cache[shift] = new;
pr_debug("Allocated pgtable cache for order %d\n", shift);
}
EXPORT_SYMBOL_GPL(pgtable_cache_add); /* used by kvm_hv module */
void pgtable_cache_init(void)
{
pgtable_cache_add(PGD_INDEX_SIZE);
if (PMD_CACHE_INDEX)
pgtable_cache_add(PMD_CACHE_INDEX);
/*
* In all current configs, when the PUD index exists it's the
* same size as either the pgd or pmd index except with THP enabled
* on book3s 64
*/
if (PUD_CACHE_INDEX)
pgtable_cache_add(PUD_CACHE_INDEX);
}
