[linux-2.6-block.git] / arch / powerpc / mm / init-common.c

// 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;
	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(pgd_t) << 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.
	 */
	unsigned long minalign = MAX_PGTABLE_INDEX_SIZE + 1;
	struct kmem_cache *new = NULL;

	/* 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);
	if (name)
		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);
}
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* PowerPC version
	4	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
	5	*
	6	* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
	7	* and Cort Dougan (PReP) (cort@cs.nmt.edu)
	8	* Copyright (C) 1996 Paul Mackerras
	9	*
	10	* Derived from "arch/i386/mm/init.c"
	11	* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
	12	*
	13	* Dave Engebretsen <engebret@us.ibm.com>
	14	* Rework for PPC64 port.
	15	*/
	16
	17	#undef DEBUG
	18
	19	#include <linux/string.h>
	20	#include <linux/pgtable.h>
	21	#include <asm/pgalloc.h>
	22	#include <asm/kup.h>
	23	#include <asm/smp.h>
	24
	25	phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull;
	26	EXPORT_SYMBOL_GPL(memstart_addr);
	27	phys_addr_t kernstart_addr __ro_after_init;
	28	EXPORT_SYMBOL_GPL(kernstart_addr);
	29	unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE;
	30	EXPORT_SYMBOL_GPL(kernstart_virt_addr);
	31
	32	bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
	33	bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
	34	#ifdef CONFIG_KFENCE
	35	bool __ro_after_init kfence_disabled;
	36	bool __ro_after_init kfence_early_init = !!CONFIG_KFENCE_SAMPLE_INTERVAL;
	37	#endif
	38
	39	static int __init parse_nosmep(char *p)
	40	{
	41	if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
	42	return 0;
	43
	44	disable_kuep = true;
	45	pr_warn("Disabling Kernel Userspace Execution Prevention\n");
	46	return 0;
	47	}
	48	early_param("nosmep", parse_nosmep);
	49
	50	static int __init parse_nosmap(char *p)
	51	{
	52	disable_kuap = true;
	53	pr_warn("Disabling Kernel Userspace Access Protection\n");
	54	return 0;
	55	}
	56	early_param("nosmap", parse_nosmap);
	57
	58	void __weak setup_kuep(bool disabled)
	59	{
	60	if (!IS_ENABLED(CONFIG_PPC_KUEP) \|\| disabled)
	61	return;
	62
	63	if (smp_processor_id() != boot_cpuid)
	64	return;
	65
	66	pr_info("Activating Kernel Userspace Execution Prevention\n");
	67	}
	68
	69	void setup_kup(void)
	70	{
	71	setup_kuap(disable_kuap);
	72	setup_kuep(disable_kuep);
	73	}
	74
	75	#define CTOR(shift) static void ctor_##shift(void *addr) \
	76	{ \
	77	memset(addr, 0, sizeof(pgd_t) << (shift)); \
	78	}
	79
	80	CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7);
	81	CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15);
	82
	83	static inline void (ctor(int shift))(void )
	84	{
	85	BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15);
	86
	87	switch (shift) {
	88	case 0: return ctor_0;
	89	case 1: return ctor_1;
	90	case 2: return ctor_2;
	91	case 3: return ctor_3;
	92	case 4: return ctor_4;
	93	case 5: return ctor_5;
	94	case 6: return ctor_6;
	95	case 7: return ctor_7;
	96	case 8: return ctor_8;
	97	case 9: return ctor_9;
	98	case 10: return ctor_10;
	99	case 11: return ctor_11;
	100	case 12: return ctor_12;
	101	case 13: return ctor_13;
	102	case 14: return ctor_14;
	103	case 15: return ctor_15;
	104	}
	105	return NULL;
	106	}
	107
	108	struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1];
	109	EXPORT_SYMBOL_GPL(pgtable_cache); /* used by kvm_hv module */
	110
	111	/*
	112	* Create a kmem_cache() for pagetables. This is not used for PTE
	113	* pages - they're linked to struct page, come from the normal free
	114	* pages pool and have a different entry size (see real_pte_t) to
	115	* everything else. Caches created by this function are used for all
	116	* the higher level pagetables, and for hugepage pagetables.
	117	*/
	118	void pgtable_cache_add(unsigned int shift)
	119	{
	120	char *name;
	121	unsigned long table_size = sizeof(pgd_t) << shift;
	122	unsigned long align = table_size;
	123
	124	/* When batching pgtable pointers for RCU freeing, we store
	125	* the index size in the low bits. Table alignment must be
	126	* big enough to fit it.
	127	*/
	128	unsigned long minalign = MAX_PGTABLE_INDEX_SIZE + 1;
	129	struct kmem_cache *new = NULL;
	130
	131	/* It would be nice if this was a BUILD_BUG_ON(), but at the
	132	* moment, gcc doesn't seem to recognize is_power_of_2 as a
	133	* constant expression, so so much for that. */
	134	BUG_ON(!is_power_of_2(minalign));
	135	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
	136
	137	if (PGT_CACHE(shift))
	138	return; /* Already have a cache of this size */
	139
	140	align = max_t(unsigned long, align, minalign);
	141	name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
	142	if (name)
	143	new = kmem_cache_create(name, table_size, align, 0, ctor(shift));
	144	if (!new)
	145	panic("Could not allocate pgtable cache for order %d", shift);
	146
	147	kfree(name);
	148	pgtable_cache[shift] = new;
	149
	150	pr_debug("Allocated pgtable cache for order %d\n", shift);
	151	}
	152	EXPORT_SYMBOL_GPL(pgtable_cache_add); /* used by kvm_hv module */
	153
	154	void pgtable_cache_init(void)
	155	{
	156	pgtable_cache_add(PGD_INDEX_SIZE);
	157
	158	if (PMD_CACHE_INDEX)
	159	pgtable_cache_add(PMD_CACHE_INDEX);
	160	/*
	161	* In all current configs, when the PUD index exists it's the
	162	* same size as either the pgd or pmd index except with THP enabled
	163	* on book3s 64
	164	*/
	165	if (PUD_CACHE_INDEX)
	166	pgtable_cache_add(PUD_CACHE_INDEX);
	167	}