forked from Minki/linux
s390/vmem: consolidate vmem_add_range() and vmem_remove_range()
We want to have only a single pagetable walker and reuse the same functionality for vmemmap handling. Let's start by consolidating vmem_add_range() and vmem_remove_range(), converting it into a recursive implementation. A recursive implementation makes it easier to expand individual cases without harming readability. In addition, we minimize traversing the whole hierarchy over and over again. One change is that we don't unmap large PMDs/PUDs when not completely covered by the request, something that should never happen with direct mappings, unless one would be removing in other granularity than added, which would be broken already. Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200722094558.9828-3-david@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
David Hildenbrand
Heiko Carstens
parent
8398b226b8
commit
3e0d3e408e
@ -54,88 +54,218 @@ pte_t __ref *vmem_pte_alloc(void)
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return pte;
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}
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static void modify_pte_table(pmd_t *pmd, unsigned long addr, unsigned long end,
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bool add)
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{
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unsigned long prot, pages = 0;
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pte_t *pte;
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prot = pgprot_val(PAGE_KERNEL);
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if (!MACHINE_HAS_NX)
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prot &= ~_PAGE_NOEXEC;
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pte = pte_offset_kernel(pmd, addr);
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for (; addr < end; addr += PAGE_SIZE, pte++) {
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if (!add) {
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if (pte_none(*pte))
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continue;
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pte_clear(&init_mm, addr, pte);
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} else if (pte_none(*pte)) {
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pte_val(*pte) = addr | prot;
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} else
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continue;
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pages++;
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}
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update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages);
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}
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static int modify_pmd_table(pud_t *pud, unsigned long addr, unsigned long end,
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bool add)
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{
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unsigned long next, prot, pages = 0;
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int ret = -ENOMEM;
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pmd_t *pmd;
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pte_t *pte;
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prot = pgprot_val(SEGMENT_KERNEL);
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if (!MACHINE_HAS_NX)
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prot &= ~_SEGMENT_ENTRY_NOEXEC;
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pmd = pmd_offset(pud, addr);
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for (; addr < end; addr = next, pmd++) {
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next = pmd_addr_end(addr, end);
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if (!add) {
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if (pmd_none(*pmd))
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continue;
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if (pmd_large(*pmd) && !add) {
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if (IS_ALIGNED(addr, PMD_SIZE) &&
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IS_ALIGNED(next, PMD_SIZE)) {
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pmd_clear(pmd);
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pages++;
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}
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continue;
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}
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} else if (pmd_none(*pmd)) {
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if (IS_ALIGNED(addr, PMD_SIZE) &&
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IS_ALIGNED(next, PMD_SIZE) &&
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MACHINE_HAS_EDAT1 && addr &&
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!debug_pagealloc_enabled()) {
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pmd_val(*pmd) = addr | prot;
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pages++;
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continue;
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}
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pte = vmem_pte_alloc();
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if (!pte)
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goto out;
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pmd_populate(&init_mm, pmd, pte);
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} else if (pmd_large(*pmd))
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continue;
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modify_pte_table(pmd, addr, next, add);
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}
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ret = 0;
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out:
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update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages);
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return ret;
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}
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static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
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bool add)
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{
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unsigned long next, prot, pages = 0;
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int ret = -ENOMEM;
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pud_t *pud;
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pmd_t *pmd;
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prot = pgprot_val(REGION3_KERNEL);
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if (!MACHINE_HAS_NX)
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prot &= ~_REGION_ENTRY_NOEXEC;
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pud = pud_offset(p4d, addr);
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for (; addr < end; addr = next, pud++) {
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next = pud_addr_end(addr, end);
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if (!add) {
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if (pud_none(*pud))
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continue;
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if (pud_large(*pud)) {
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if (IS_ALIGNED(addr, PUD_SIZE) &&
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IS_ALIGNED(next, PUD_SIZE)) {
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pud_clear(pud);
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pages++;
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}
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continue;
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}
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} else if (pud_none(*pud)) {
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if (IS_ALIGNED(addr, PUD_SIZE) &&
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IS_ALIGNED(next, PUD_SIZE) &&
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MACHINE_HAS_EDAT2 && addr &&
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!debug_pagealloc_enabled()) {
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pud_val(*pud) = addr | prot;
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pages++;
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continue;
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}
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pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
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if (!pmd)
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goto out;
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pud_populate(&init_mm, pud, pmd);
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} else if (pud_large(*pud))
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continue;
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ret = modify_pmd_table(pud, addr, next, add);
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if (ret)
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goto out;
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}
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ret = 0;
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out:
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update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages);
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return ret;
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}
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static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
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bool add)
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{
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unsigned long next;
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int ret = -ENOMEM;
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p4d_t *p4d;
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pud_t *pud;
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p4d = p4d_offset(pgd, addr);
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for (; addr < end; addr = next, p4d++) {
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next = p4d_addr_end(addr, end);
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if (!add) {
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if (p4d_none(*p4d))
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continue;
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} else if (p4d_none(*p4d)) {
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pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
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if (!pud)
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goto out;
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}
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ret = modify_pud_table(p4d, addr, next, add);
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if (ret)
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goto out;
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}
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ret = 0;
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out:
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return ret;
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}
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static int modify_pagetable(unsigned long start, unsigned long end, bool add)
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{
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unsigned long addr, next;
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int ret = -ENOMEM;
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pgd_t *pgd;
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p4d_t *p4d;
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if (WARN_ON_ONCE(!PAGE_ALIGNED(start | end)))
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return -EINVAL;
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for (addr = start; addr < end; addr = next) {
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next = pgd_addr_end(addr, end);
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pgd = pgd_offset_k(addr);
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if (!add) {
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if (pgd_none(*pgd))
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continue;
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} else if (pgd_none(*pgd)) {
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p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
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if (!p4d)
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goto out;
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pgd_populate(&init_mm, pgd, p4d);
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}
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ret = modify_p4d_table(pgd, addr, next, add);
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if (ret)
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goto out;
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}
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ret = 0;
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out:
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if (!add)
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flush_tlb_kernel_range(start, end);
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return ret;
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}
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static int add_pagetable(unsigned long start, unsigned long end)
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{
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return modify_pagetable(start, end, true);
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}
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static int remove_pagetable(unsigned long start, unsigned long end)
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{
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return modify_pagetable(start, end, false);
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}
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/*
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* Add a physical memory range to the 1:1 mapping.
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*/
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static int vmem_add_range(unsigned long start, unsigned long size)
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{
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unsigned long pgt_prot, sgt_prot, r3_prot;
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unsigned long pages4k, pages1m, pages2g;
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unsigned long end = start + size;
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unsigned long address = start;
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pgd_t *pg_dir;
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p4d_t *p4_dir;
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pud_t *pu_dir;
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pmd_t *pm_dir;
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pte_t *pt_dir;
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int ret = -ENOMEM;
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pgt_prot = pgprot_val(PAGE_KERNEL);
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sgt_prot = pgprot_val(SEGMENT_KERNEL);
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r3_prot = pgprot_val(REGION3_KERNEL);
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if (!MACHINE_HAS_NX) {
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pgt_prot &= ~_PAGE_NOEXEC;
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sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
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r3_prot &= ~_REGION_ENTRY_NOEXEC;
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}
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pages4k = pages1m = pages2g = 0;
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while (address < end) {
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pg_dir = pgd_offset_k(address);
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if (pgd_none(*pg_dir)) {
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p4_dir = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
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if (!p4_dir)
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goto out;
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pgd_populate(&init_mm, pg_dir, p4_dir);
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}
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p4_dir = p4d_offset(pg_dir, address);
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if (p4d_none(*p4_dir)) {
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pu_dir = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
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if (!pu_dir)
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goto out;
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p4d_populate(&init_mm, p4_dir, pu_dir);
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}
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pu_dir = pud_offset(p4_dir, address);
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if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address &&
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!(address & ~PUD_MASK) && (address + PUD_SIZE <= end) &&
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!debug_pagealloc_enabled()) {
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pud_val(*pu_dir) = address | r3_prot;
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address += PUD_SIZE;
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pages2g++;
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continue;
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}
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if (pud_none(*pu_dir)) {
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pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
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if (!pm_dir)
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goto out;
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pud_populate(&init_mm, pu_dir, pm_dir);
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}
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pm_dir = pmd_offset(pu_dir, address);
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if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
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!(address & ~PMD_MASK) && (address + PMD_SIZE <= end) &&
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!debug_pagealloc_enabled()) {
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pmd_val(*pm_dir) = address | sgt_prot;
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address += PMD_SIZE;
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pages1m++;
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continue;
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}
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if (pmd_none(*pm_dir)) {
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pt_dir = vmem_pte_alloc();
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if (!pt_dir)
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goto out;
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pmd_populate(&init_mm, pm_dir, pt_dir);
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}
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pt_dir = pte_offset_kernel(pm_dir, address);
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pte_val(*pt_dir) = address | pgt_prot;
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address += PAGE_SIZE;
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pages4k++;
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}
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ret = 0;
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out:
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update_page_count(PG_DIRECT_MAP_4K, pages4k);
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update_page_count(PG_DIRECT_MAP_1M, pages1m);
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update_page_count(PG_DIRECT_MAP_2G, pages2g);
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return ret;
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return add_pagetable(start, start + size);
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}
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/*
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@ -144,58 +274,7 @@ out:
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*/
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static void vmem_remove_range(unsigned long start, unsigned long size)
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{
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unsigned long pages4k, pages1m, pages2g;
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unsigned long end = start + size;
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unsigned long address = start;
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pgd_t *pg_dir;
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p4d_t *p4_dir;
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pud_t *pu_dir;
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pmd_t *pm_dir;
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pte_t *pt_dir;
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pages4k = pages1m = pages2g = 0;
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while (address < end) {
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pg_dir = pgd_offset_k(address);
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if (pgd_none(*pg_dir)) {
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address += PGDIR_SIZE;
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continue;
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}
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p4_dir = p4d_offset(pg_dir, address);
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if (p4d_none(*p4_dir)) {
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address += P4D_SIZE;
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continue;
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}
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pu_dir = pud_offset(p4_dir, address);
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if (pud_none(*pu_dir)) {
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address += PUD_SIZE;
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continue;
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}
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if (pud_large(*pu_dir)) {
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pud_clear(pu_dir);
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address += PUD_SIZE;
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pages2g++;
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continue;
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}
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pm_dir = pmd_offset(pu_dir, address);
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if (pmd_none(*pm_dir)) {
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address += PMD_SIZE;
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continue;
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}
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if (pmd_large(*pm_dir)) {
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pmd_clear(pm_dir);
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address += PMD_SIZE;
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pages1m++;
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continue;
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}
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pt_dir = pte_offset_kernel(pm_dir, address);
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pte_clear(&init_mm, address, pt_dir);
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address += PAGE_SIZE;
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pages4k++;
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}
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flush_tlb_kernel_range(start, end);
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update_page_count(PG_DIRECT_MAP_4K, -pages4k);
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update_page_count(PG_DIRECT_MAP_1M, -pages1m);
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update_page_count(PG_DIRECT_MAP_2G, -pages2g);
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remove_pagetable(start, start + size);
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}
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/*
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