Commit 0490d6d7 authored by Heiko Carstens's avatar Heiko Carstens Committed by Vasily Gorbik
Browse files

s390/mm: enable ARCH_HAS_SET_DIRECT_MAP 



Implement the set_direct_map_*() API, which allows to invalidate and set
default permissions to pages within the direct mapping.

Note that kernel_page_present(), which is also supposed to be part of this
API, is intentionally not implemented. The reason for this is that
kernel_page_present() is only used (and currently only makes sense) for
suspend/resume, which isn't supported on s390.

Reviewed-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 17c51b1b

arch/s390/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ config S390 
	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS

	select ARCH_HAS_PTE_SPECIAL

	select ARCH_HAS_SCALED_CPUTIME

	select ARCH_HAS_SET_DIRECT_MAP

	select ARCH_HAS_SET_MEMORY

	select ARCH_HAS_STRICT_KERNEL_RWX

	select ARCH_HAS_STRICT_MODULE_RWX

arch/s390/include/asm/set_memory.h

+7 −0
Original line number Diff line number Diff line
@@ -12,6 +12,8 @@ enum { 
	_SET_MEMORY_NX_BIT,

	_SET_MEMORY_X_BIT,

	_SET_MEMORY_4K_BIT,

	_SET_MEMORY_INV_BIT,

	_SET_MEMORY_DEF_BIT,

};



#define SET_MEMORY_RO	BIT(_SET_MEMORY_RO_BIT)
@@ -19,6 +21,8 @@ enum { 
#define SET_MEMORY_NX	BIT(_SET_MEMORY_NX_BIT)

#define SET_MEMORY_X	BIT(_SET_MEMORY_X_BIT)

#define SET_MEMORY_4K	BIT(_SET_MEMORY_4K_BIT)

#define SET_MEMORY_INV	BIT(_SET_MEMORY_INV_BIT)

#define SET_MEMORY_DEF	BIT(_SET_MEMORY_DEF_BIT)



int __set_memory(unsigned long addr, int numpages, unsigned long flags);
@@ -58,4 +62,7 @@ static inline int set_memory_4k(unsigned long addr, int numpages) 
	return __set_memory(addr, numpages, SET_MEMORY_4K);

}



int set_direct_map_invalid_noflush(struct page *page);

int set_direct_map_default_noflush(struct page *page);



#endif

arch/s390/mm/pageattr.c

+35 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>

 */

#include <linux/hugetlb.h>

#include <linux/vmalloc.h>

#include <linux/mm.h>

#include <asm/cacheflush.h>

#include <asm/facility.h>
@@ -101,6 +102,14 @@ static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end, 
			new = set_pte_bit(new, __pgprot(_PAGE_NOEXEC));

		else if (flags & SET_MEMORY_X)

			new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC));

		if (flags & SET_MEMORY_INV) {

			new = set_pte_bit(new, __pgprot(_PAGE_INVALID));

		} else if (flags & SET_MEMORY_DEF) {

			new = __pte(pte_val(new) & PAGE_MASK);

			new = set_pte_bit(new, PAGE_KERNEL);

			if (!MACHINE_HAS_NX)

				new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC));

		}

		pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE);

		ptep++;

		addr += PAGE_SIZE;
@@ -151,6 +160,14 @@ static void modify_pmd_page(pmd_t *pmdp, unsigned long addr, 
		new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));

	else if (flags & SET_MEMORY_X)

		new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));

	if (flags & SET_MEMORY_INV) {

		new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_INVALID));

	} else if (flags & SET_MEMORY_DEF) {

		new = __pmd(pmd_val(new) & PMD_MASK);

		new = set_pmd_bit(new, SEGMENT_KERNEL);

		if (!MACHINE_HAS_NX)

			new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));

	}

	pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);

}
@@ -232,6 +249,14 @@ static void modify_pud_page(pud_t *pudp, unsigned long addr, 
		new = set_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));

	else if (flags & SET_MEMORY_X)

		new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));

	if (flags & SET_MEMORY_INV) {

		new = set_pud_bit(new, __pgprot(_REGION_ENTRY_INVALID));

	} else if (flags & SET_MEMORY_DEF) {

		new = __pud(pud_val(new) & PUD_MASK);

		new = set_pud_bit(new, REGION3_KERNEL);

		if (!MACHINE_HAS_NX)

			new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));

	}

	pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);

}
@@ -325,6 +350,16 @@ int __set_memory(unsigned long addr, int numpages, unsigned long flags) 
	return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags);

}



int set_direct_map_invalid_noflush(struct page *page)

{

	return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_INV);

}



int set_direct_map_default_noflush(struct page *page)

{

	return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_DEF);

}



#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)



static void ipte_range(pte_t *pte, unsigned long address, int nr)