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linux/arch/s390/mm/pageattr.c
Heiko Carstens 869a9dbc10 s390/mm,pageattr: don't use pte_val()/pXd_val() as lvalue 
Convert pgtable code so pte_val()/pXd_val() aren't used as lvalue
anymore. This allows in later step to convert pte_val()/pXd_val() to
functions, which in turn makes it impossible to use these macros to
modify page table entries like they have been used before.

Therefore a construct like this:

        pte_val(*pte) = __pa(addr) | prot;

which would directly write into a page table, isn't possible anymore
with the last step of this series.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
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>
2022-03-01 21:05:10 +01:00

374 lines
9.0 KiB
C
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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corp. 2011
* Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
*/
#include <linux/hugetlb.h>
#include <linux/mm.h>
#include <asm/cacheflush.h>
#include <asm/facility.h>
#include <asm/pgalloc.h>
#include <asm/kfence.h>
#include <asm/page.h>
#include <asm/set_memory.h>
static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
{
asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],1,0"
: [addr] "+a" (addr) : [skey] "d" (skey));
return addr;
}
void __storage_key_init_range(unsigned long start, unsigned long end)
{
unsigned long boundary, size;
while (start < end) {
if (MACHINE_HAS_EDAT1) {
/* set storage keys for a 1MB frame */
size = 1UL << 20;
boundary = (start + size) & ~(size - 1);
if (boundary <= end) {
do {
start = sske_frame(start, PAGE_DEFAULT_KEY);
} while (start < boundary);
continue;
}
}
page_set_storage_key(start, PAGE_DEFAULT_KEY, 1);
start += PAGE_SIZE;
}
}
#ifdef CONFIG_PROC_FS
atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX];
void arch_report_meminfo(struct seq_file *m)
{
seq_printf(m, "DirectMap4k: %8lu kB\n",
atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_4K]) << 2);
seq_printf(m, "DirectMap1M: %8lu kB\n",
atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_1M]) << 10);
seq_printf(m, "DirectMap2G: %8lu kB\n",
atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_2G]) << 21);
}
#endif /* CONFIG_PROC_FS */
static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr,
unsigned long dtt)
{
unsigned long *table, mask;
mask = 0;
if (MACHINE_HAS_EDAT2) {
switch (dtt) {
case CRDTE_DTT_REGION3:
mask = ~(PTRS_PER_PUD * sizeof(pud_t) - 1);
break;
case CRDTE_DTT_SEGMENT:
mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
break;
case CRDTE_DTT_PAGE:
mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1);
break;
}
table = (unsigned long *)((unsigned long)old & mask);
crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce);
} else if (MACHINE_HAS_IDTE) {
cspg(old, *old, new);
} else {
csp((unsigned int *)old + 1, *old, new);
}
}
static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end,
unsigned long flags)
{
pte_t *ptep, new;
if (flags == SET_MEMORY_4K)
return 0;
ptep = pte_offset_kernel(pmdp, addr);
do {
new = *ptep;
if (pte_none(new))
return -EINVAL;
if (flags & SET_MEMORY_RO)
new = pte_wrprotect(new);
else if (flags & SET_MEMORY_RW)
new = pte_mkwrite(pte_mkdirty(new));
if (flags & SET_MEMORY_NX)
new = set_pte_bit(new, __pgprot(_PAGE_NOEXEC));
else if (flags & SET_MEMORY_X)
new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC));
pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE);
ptep++;
addr += PAGE_SIZE;
cond_resched();
} while (addr < end);
return 0;
}
static int split_pmd_page(pmd_t *pmdp, unsigned long addr)
{
unsigned long pte_addr, prot;
pte_t *pt_dir, *ptep;
pmd_t new;
int i, ro, nx;
pt_dir = vmem_pte_alloc();
if (!pt_dir)
return -ENOMEM;
pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT;
ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT);
nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC);
prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL);
if (!nx)
prot &= ~_PAGE_NOEXEC;
ptep = pt_dir;
for (i = 0; i < PTRS_PER_PTE; i++) {
set_pte(ptep, __pte(pte_addr | prot));
pte_addr += PAGE_SIZE;
ptep++;
}
new = __pmd(__pa(pt_dir) | _SEGMENT_ENTRY);
pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE);
update_page_count(PG_DIRECT_MAP_1M, -1);
return 0;
}
static void modify_pmd_page(pmd_t *pmdp, unsigned long addr,
unsigned long flags)
{
pmd_t new = *pmdp;
if (flags & SET_MEMORY_RO)
new = pmd_wrprotect(new);
else if (flags & SET_MEMORY_RW)
new = pmd_mkwrite(pmd_mkdirty(new));
if (flags & SET_MEMORY_NX)
new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));
else if (flags & SET_MEMORY_X)
new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));
pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
}
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;
pmdp = pmd_offset(pudp, addr);
do {
if (pmd_none(*pmdp))
return -EINVAL;
next = pmd_addr_end(addr, end);
if (pmd_large(*pmdp)) {
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;
continue;
}
modify_pmd_page(pmdp, addr, flags);
} else {
rc = walk_pte_level(pmdp, addr, next, flags);
if (rc)
return rc;
}
pmdp++;
addr = next;
cond_resched();
} while (addr < end);
return rc;
}
static int split_pud_page(pud_t *pudp, unsigned long addr)
{
unsigned long pmd_addr, prot;
pmd_t *pm_dir, *pmdp;
pud_t new;
int i, ro, nx;
pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
if (!pm_dir)
return -ENOMEM;
pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT;
ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT);
nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC);
prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL);
if (!nx)
prot &= ~_SEGMENT_ENTRY_NOEXEC;
pmdp = pm_dir;
for (i = 0; i < PTRS_PER_PMD; i++) {
set_pmd(pmdp, __pmd(pmd_addr | prot));
pmd_addr += PMD_SIZE;
pmdp++;
}
new = __pud(__pa(pm_dir) | _REGION3_ENTRY);
pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD);
update_page_count(PG_DIRECT_MAP_2G, -1);
return 0;
}
static void modify_pud_page(pud_t *pudp, unsigned long addr,
unsigned long flags)
{
pud_t new = *pudp;
if (flags & SET_MEMORY_RO)
new = pud_wrprotect(new);
else if (flags & SET_MEMORY_RW)
new = pud_mkwrite(pud_mkdirty(new));
if (flags & SET_MEMORY_NX)
new = set_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));
else if (flags & SET_MEMORY_X)
new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));
pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
}
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;
pudp = pud_offset(p4d, addr);
do {
if (pud_none(*pudp))
return -EINVAL;
next = pud_addr_end(addr, end);
if (pud_large(*pudp)) {
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;
continue;
}
modify_pud_page(pudp, addr, flags);
} else {
rc = walk_pmd_level(pudp, addr, next, flags);
}
pudp++;
addr = next;
cond_resched();
} while (addr < end && !rc);
return rc;
}
static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end,
unsigned long flags)
{
unsigned long next;
p4d_t *p4dp;
int rc = 0;
p4dp = p4d_offset(pgd, addr);
do {
if (p4d_none(*p4dp))
return -EINVAL;
next = p4d_addr_end(addr, end);
rc = walk_pud_level(p4dp, addr, next, flags);
p4dp++;
addr = next;
cond_resched();
} while (addr < end && !rc);
return rc;
}
DEFINE_MUTEX(cpa_mutex);
static int change_page_attr(unsigned long addr, unsigned long end,
unsigned long flags)
{
unsigned long next;
int rc = -EINVAL;
pgd_t *pgdp;
if (addr == end)
return 0;
if (end >= MODULES_END)
return -EINVAL;
mutex_lock(&cpa_mutex);
pgdp = pgd_offset_k(addr);
do {
if (pgd_none(*pgdp))
break;
next = pgd_addr_end(addr, end);
rc = walk_p4d_level(pgdp, addr, next, flags);
if (rc)
break;
cond_resched();
} while (pgdp++, addr = next, addr < end && !rc);
mutex_unlock(&cpa_mutex);
return rc;
}
int __set_memory(unsigned long addr, int numpages, unsigned long flags)
{
if (!MACHINE_HAS_NX)
flags &= ~(SET_MEMORY_NX | SET_MEMORY_X);
if (!flags)
return 0;
addr &= PAGE_MASK;
return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags);
}
#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
static void ipte_range(pte_t *pte, unsigned long address, int nr)
{
int i;
if (test_facility(13)) {
__ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL);
return;
}
for (i = 0; i < nr; i++) {
__ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL);
address += PAGE_SIZE;
pte++;
}
}
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
unsigned long address;
pte_t *ptep, pte;
int nr, i, j;
for (i = 0; i < numpages;) {
address = (unsigned long)page_to_virt(page + i);
ptep = virt_to_kpte(address);
nr = (unsigned long)ptep >> ilog2(sizeof(long));
nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
nr = min(numpages - i, nr);
if (enable) {
for (j = 0; j < nr; j++) {
pte = clear_pte_bit(*ptep, __pgprot(_PAGE_INVALID));
set_pte(ptep, pte);
address += PAGE_SIZE;
ptep++;
}
} else {
ipte_range(ptep, address, nr);
}
i += nr;
}
}
#endif /* CONFIG_DEBUG_PAGEALLOC */
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