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: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Heiko Carstens 2023-04-14 14:30:44 +02:00 committed by Vasily Gorbik
parent 17c51b1ba9
commit 0490d6d7ba
3 changed files with 43 additions and 0 deletions

View File

@ -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

View File

@ -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

View File

@ -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)