Commit b3e1a00c authored by Heiko Carstens's avatar Heiko Carstens
Browse files

s390/mm: implement set_memory_4k() 

Implement set_memory_4k() which will split any present large or huge
mapping in the given range to a 4k mapping.

Link: https://lore.kernel.org/r/20210728190254.3921642-2-hca@linux.ibm.com


Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 00e67bf0

arch/s390/include/asm/set_memory.h

+6 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ extern struct mutex cpa_mutex; 
#define SET_MEMORY_RW	2UL

#define SET_MEMORY_NX	4UL

#define SET_MEMORY_X	8UL

#define SET_MEMORY_4K  16UL



int __set_memory(unsigned long addr, int numpages, unsigned long flags);
@@ -33,4 +34,9 @@ static inline int set_memory_x(unsigned long addr, int numpages) 
	return __set_memory(addr, numpages, SET_MEMORY_X);

}



static inline int set_memory_4k(unsigned long addr, int numpages)

{

	return __set_memory(addr, numpages, SET_MEMORY_4K);

}



#endif

arch/s390/mm/pageattr.c

+12 −2
Original line number Diff line number Diff line
@@ -85,6 +85,8 @@ static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end, 
{

	pte_t *ptep, new;



	if ((flags & SET_MEMORY_4K) == SET_MEMORY_4K)

		return 0;

	ptep = pte_offset_kernel(pmdp, addr);

	do {

		new = *ptep;
@@ -155,6 +157,7 @@ static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end, 
			  unsigned long flags)

{

	unsigned long next;

	int need_split;

	pmd_t *pmdp;

	int rc = 0;
@@ -164,7 +167,10 @@ static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end, 
			return -EINVAL;

		next = pmd_addr_end(addr, end);

		if (pmd_large(*pmdp)) {

			if (addr & ~PMD_MASK || addr + PMD_SIZE > next) {

			need_split  = !!(flags & SET_MEMORY_4K);

			need_split |= !!(addr & ~PMD_MASK);

			need_split |= !!(addr + PMD_SIZE > next);

			if (need_split) {

				rc = split_pmd_page(pmdp, addr);

				if (rc)

					return rc;
@@ -232,6 +238,7 @@ static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end, 
			  unsigned long flags)

{

	unsigned long next;

	int need_split;

	pud_t *pudp;

	int rc = 0;
@@ -241,7 +248,10 @@ static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end, 
			return -EINVAL;

		next = pud_addr_end(addr, end);

		if (pud_large(*pudp)) {

			if (addr & ~PUD_MASK || addr + PUD_SIZE > next) {

			need_split  = !!(flags & SET_MEMORY_4K);

			need_split |= !!(addr & ~PUD_MASK);

			need_split |= !!(addr + PUD_SIZE > next);

			if (need_split) {

				rc = split_pud_page(pudp, addr);

				if (rc)

					break;