Commit e86935f7 authored by Huacai Chen's avatar Huacai Chen
Browse files

LoongArch: Add ARCH_HAS_SET_MEMORY support 



Add set_memory_ro/rw/x/nx architecture hooks to change the page
attribution.

Use own set_memory.h rather than generic set_memory.h (i.e.
include/asm-generic/set_memory.h), because we want to add other function
prototypes here.

Note: We can only set attributes for KVRANGE/XKVRANGE kernel addresses.

Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 34e3c450

arch/loongarch/Kconfig

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@@ -25,6 +25,7 @@ config LOONGARCH 
	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE

	select ARCH_HAS_PTE_DEVMAP

	select ARCH_HAS_PTE_SPECIAL

	select ARCH_HAS_SET_MEMORY

	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST

	select ARCH_INLINE_READ_LOCK if !PREEMPTION

	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION

arch/loongarch/include/asm/set_memory.h

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/* SPDX-License-Identifier: GPL-2.0-only */

/*

 * Copyright (C) 2024 Loongson Technology Corporation Limited

 */



#ifndef _ASM_LOONGARCH_SET_MEMORY_H

#define _ASM_LOONGARCH_SET_MEMORY_H



/*

 * Functions to change memory attributes.

 */

int set_memory_x(unsigned long addr, int numpages);

int set_memory_nx(unsigned long addr, int numpages);

int set_memory_ro(unsigned long addr, int numpages);

int set_memory_rw(unsigned long addr, int numpages);



#endif /* _ASM_LOONGARCH_SET_MEMORY_H */

arch/loongarch/mm/Makefile

+2 −1
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@@ -4,7 +4,8 @@ 
#



obj-y				+= init.o cache.o tlb.o tlbex.o extable.o \

				   fault.o ioremap.o maccess.o mmap.o pgtable.o page.o

				   fault.o ioremap.o maccess.o mmap.o pgtable.o \

				   page.o pageattr.o



obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o

obj-$(CONFIG_KASAN)		+= kasan_init.o

arch/loongarch/mm/pageattr.c

0 → 100644
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// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2024 Loongson Technology Corporation Limited

 */



#include <linux/pagewalk.h>

#include <linux/pgtable.h>

#include <asm/set_memory.h>

#include <asm/tlbflush.h>



struct pageattr_masks {

	pgprot_t set_mask;

	pgprot_t clear_mask;

};



static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk)

{

	unsigned long new_val = val;

	struct pageattr_masks *masks = walk->private;



	new_val &= ~(pgprot_val(masks->clear_mask));

	new_val |= (pgprot_val(masks->set_mask));



	return new_val;

}



static int pageattr_pgd_entry(pgd_t *pgd, unsigned long addr,

			      unsigned long next, struct mm_walk *walk)

{

	pgd_t val = pgdp_get(pgd);



	if (pgd_leaf(val)) {

		val = __pgd(set_pageattr_masks(pgd_val(val), walk));

		set_pgd(pgd, val);

	}



	return 0;

}



static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr,

			      unsigned long next, struct mm_walk *walk)

{

	p4d_t val = p4dp_get(p4d);



	if (p4d_leaf(val)) {

		val = __p4d(set_pageattr_masks(p4d_val(val), walk));

		set_p4d(p4d, val);

	}



	return 0;

}



static int pageattr_pud_entry(pud_t *pud, unsigned long addr,

			      unsigned long next, struct mm_walk *walk)

{

	pud_t val = pudp_get(pud);



	if (pud_leaf(val)) {

		val = __pud(set_pageattr_masks(pud_val(val), walk));

		set_pud(pud, val);

	}



	return 0;

}



static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr,

			      unsigned long next, struct mm_walk *walk)

{

	pmd_t val = pmdp_get(pmd);



	if (pmd_leaf(val)) {

		val = __pmd(set_pageattr_masks(pmd_val(val), walk));

		set_pmd(pmd, val);

	}



	return 0;

}



static int pageattr_pte_entry(pte_t *pte, unsigned long addr,

			      unsigned long next, struct mm_walk *walk)

{

	pte_t val = ptep_get(pte);



	val = __pte(set_pageattr_masks(pte_val(val), walk));

	set_pte(pte, val);



	return 0;

}



static int pageattr_pte_hole(unsigned long addr, unsigned long next,

			     int depth, struct mm_walk *walk)

{

	return 0;

}



static const struct mm_walk_ops pageattr_ops = {

	.pgd_entry = pageattr_pgd_entry,

	.p4d_entry = pageattr_p4d_entry,

	.pud_entry = pageattr_pud_entry,

	.pmd_entry = pageattr_pmd_entry,

	.pte_entry = pageattr_pte_entry,

	.pte_hole = pageattr_pte_hole,

	.walk_lock = PGWALK_RDLOCK,

};



static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask, pgprot_t clear_mask)

{

	int ret;

	unsigned long start = addr;

	unsigned long end = start + PAGE_SIZE * numpages;

	struct pageattr_masks masks = {

		.set_mask = set_mask,

		.clear_mask = clear_mask

	};



	if (!numpages)

		return 0;



	mmap_write_lock(&init_mm);

	ret = walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL, &masks);

	mmap_write_unlock(&init_mm);



	flush_tlb_kernel_range(start, end);



	return ret;

}



int set_memory_x(unsigned long addr, int numpages)

{

	if (addr < vm_map_base)

		return 0;



	return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_NO_EXEC));

}



int set_memory_nx(unsigned long addr, int numpages)

{

	if (addr < vm_map_base)

		return 0;



	return __set_memory(addr, numpages, __pgprot(_PAGE_NO_EXEC), __pgprot(0));

}



int set_memory_ro(unsigned long addr, int numpages)

{

	if (addr < vm_map_base)

		return 0;



	return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_WRITE | _PAGE_DIRTY));

}



int set_memory_rw(unsigned long addr, int numpages)

{

	if (addr < vm_map_base)

		return 0;



	return __set_memory(addr, numpages, __pgprot(_PAGE_WRITE | _PAGE_DIRTY), __pgprot(0));

}