Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 669 insertions, 0 deletions

diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
new file mode 100644
index 0000000000..6d276103c6
--- /dev/null
+++ b/arch/s390/mm/vmem.c
@@ -0,0 +1,669 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    Copyright IBM Corp. 2006
+ */
+
+#include <linux/memory_hotplug.h>
+#include <linux/memblock.h>
+#include <linux/pfn.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/hugetlb.h>
+#include <linux/slab.h>
+#include <linux/sort.h>
+#include <asm/page-states.h>
+#include <asm/cacheflush.h>
+#include <asm/nospec-branch.h>
+#include <asm/pgalloc.h>
+#include <asm/setup.h>
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+#include <asm/set_memory.h>
+
+static DEFINE_MUTEX(vmem_mutex);
+
+static void __ref *vmem_alloc_pages(unsigned int order)
+{
+	unsigned long size = PAGE_SIZE << order;
+
+	if (slab_is_available())
+		return (void *)__get_free_pages(GFP_KERNEL, order);
+	return memblock_alloc(size, size);
+}
+
+static void vmem_free_pages(unsigned long addr, int order)
+{
+	/* We don't expect boot memory to be removed ever. */
+	if (!slab_is_available() ||
+	    WARN_ON_ONCE(PageReserved(virt_to_page((void *)addr))))
+		return;
+	free_pages(addr, order);
+}
+
+void *vmem_crst_alloc(unsigned long val)
+{
+	unsigned long *table;
+
+	table = vmem_alloc_pages(CRST_ALLOC_ORDER);
+	if (!table)
+		return NULL;
+	crst_table_init(table, val);
+	if (slab_is_available())
+		arch_set_page_dat(virt_to_page(table), CRST_ALLOC_ORDER);
+	return table;
+}
+
+pte_t __ref *vmem_pte_alloc(void)
+{
+	unsigned long size = PTRS_PER_PTE * sizeof(pte_t);
+	pte_t *pte;
+
+	if (slab_is_available())
+		pte = (pte_t *) page_table_alloc(&init_mm);
+	else
+		pte = (pte_t *) memblock_alloc(size, size);
+	if (!pte)
+		return NULL;
+	memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
+	return pte;
+}
+
+static void vmem_pte_free(unsigned long *table)
+{
+	/* We don't expect boot memory to be removed ever. */
+	if (!slab_is_available() ||
+	    WARN_ON_ONCE(PageReserved(virt_to_page(table))))
+		return;
+	page_table_free(&init_mm, table);
+}
+
+#define PAGE_UNUSED 0xFD
+
+/*
+ * The unused vmemmap range, which was not yet memset(PAGE_UNUSED) ranges
+ * from unused_sub_pmd_start to next PMD_SIZE boundary.
+ */
+static unsigned long unused_sub_pmd_start;
+
+static void vmemmap_flush_unused_sub_pmd(void)
+{
+	if (!unused_sub_pmd_start)
+		return;
+	memset((void *)unused_sub_pmd_start, PAGE_UNUSED,
+	       ALIGN(unused_sub_pmd_start, PMD_SIZE) - unused_sub_pmd_start);
+	unused_sub_pmd_start = 0;
+}
+
+static void vmemmap_mark_sub_pmd_used(unsigned long start, unsigned long end)
+{
+	/*
+	 * As we expect to add in the same granularity as we remove, it's
+	 * sufficient to mark only some piece used to block the memmap page from
+	 * getting removed (just in case the memmap never gets initialized,
+	 * e.g., because the memory block never gets onlined).
+	 */
+	memset((void *)start, 0, sizeof(struct page));
+}
+
+static void vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
+{
+	/*
+	 * We only optimize if the new used range directly follows the
+	 * previously unused range (esp., when populating consecutive sections).
+	 */
+	if (unused_sub_pmd_start == start) {
+		unused_sub_pmd_start = end;
+		if (likely(IS_ALIGNED(unused_sub_pmd_start, PMD_SIZE)))
+			unused_sub_pmd_start = 0;
+		return;
+	}
+	vmemmap_flush_unused_sub_pmd();
+	vmemmap_mark_sub_pmd_used(start, end);
+}
+
+static void vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
+{
+	unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
+
+	vmemmap_flush_unused_sub_pmd();
+
+	/* Could be our memmap page is filled with PAGE_UNUSED already ... */
+	vmemmap_mark_sub_pmd_used(start, end);
+
+	/* Mark the unused parts of the new memmap page PAGE_UNUSED. */
+	if (!IS_ALIGNED(start, PMD_SIZE))
+		memset((void *)page, PAGE_UNUSED, start - page);
+	/*
+	 * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
+	 * consecutive sections. Remember for the last added PMD the last
+	 * unused range in the populated PMD.
+	 */
+	if (!IS_ALIGNED(end, PMD_SIZE))
+		unused_sub_pmd_start = end;
+}
+
+/* Returns true if the PMD is completely unused and can be freed. */
+static bool vmemmap_unuse_sub_pmd(unsigned long start, unsigned long end)
+{
+	unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
+
+	vmemmap_flush_unused_sub_pmd();
+	memset((void *)start, PAGE_UNUSED, end - start);
+	return !memchr_inv((void *)page, PAGE_UNUSED, PMD_SIZE);
+}
+
+/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
+static int __ref modify_pte_table(pmd_t *pmd, unsigned long addr,
+				  unsigned long end, bool add, bool direct)
+{
+	unsigned long prot, pages = 0;
+	int ret = -ENOMEM;
+	pte_t *pte;
+
+	prot = pgprot_val(PAGE_KERNEL);
+	if (!MACHINE_HAS_NX)
+		prot &= ~_PAGE_NOEXEC;
+
+	pte = pte_offset_kernel(pmd, addr);
+	for (; addr < end; addr += PAGE_SIZE, pte++) {
+		if (!add) {
+			if (pte_none(*pte))
+				continue;
+			if (!direct)
+				vmem_free_pages((unsigned long) pfn_to_virt(pte_pfn(*pte)), 0);
+			pte_clear(&init_mm, addr, pte);
+		} else if (pte_none(*pte)) {
+			if (!direct) {
+				void *new_page = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
+
+				if (!new_page)
+					goto out;
+				set_pte(pte, __pte(__pa(new_page) | prot));
+			} else {
+				set_pte(pte, __pte(__pa(addr) | prot));
+			}
+		} else {
+			continue;
+		}
+		pages++;
+	}
+	ret = 0;
+out:
+	if (direct)
+		update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages);
+	return ret;
+}
+
+static void try_free_pte_table(pmd_t *pmd, unsigned long start)
+{
+	pte_t *pte;
+	int i;
+
+	/* We can safely assume this is fully in 1:1 mapping & vmemmap area */
+	pte = pte_offset_kernel(pmd, start);
+	for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
+		if (!pte_none(*pte))
+			return;
+	}
+	vmem_pte_free((unsigned long *) pmd_deref(*pmd));
+	pmd_clear(pmd);
+}
+
+/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
+static int __ref modify_pmd_table(pud_t *pud, unsigned long addr,
+				  unsigned long end, bool add, bool direct)
+{
+	unsigned long next, prot, pages = 0;
+	int ret = -ENOMEM;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	prot = pgprot_val(SEGMENT_KERNEL);
+	if (!MACHINE_HAS_NX)
+		prot &= ~_SEGMENT_ENTRY_NOEXEC;
+
+	pmd = pmd_offset(pud, addr);
+	for (; addr < end; addr = next, pmd++) {
+		next = pmd_addr_end(addr, end);
+		if (!add) {
+			if (pmd_none(*pmd))
+				continue;
+			if (pmd_large(*pmd)) {
+				if (IS_ALIGNED(addr, PMD_SIZE) &&
+				    IS_ALIGNED(next, PMD_SIZE)) {
+					if (!direct)
+						vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
+					pmd_clear(pmd);
+					pages++;
+				} else if (!direct && vmemmap_unuse_sub_pmd(addr, next)) {
+					vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
+					pmd_clear(pmd);
+				}
+				continue;
+			}
+		} else if (pmd_none(*pmd)) {
+			if (IS_ALIGNED(addr, PMD_SIZE) &&
+			    IS_ALIGNED(next, PMD_SIZE) &&
+			    MACHINE_HAS_EDAT1 && direct &&
+			    !debug_pagealloc_enabled()) {
+				set_pmd(pmd, __pmd(__pa(addr) | prot));
+				pages++;
+				continue;
+			} else if (!direct && MACHINE_HAS_EDAT1) {
+				void *new_page;
+
+				/*
+				 * Use 1MB frames for vmemmap if available. We
+				 * always use large frames even if they are only
+				 * partially used. Otherwise we would have also
+				 * page tables since vmemmap_populate gets
+				 * called for each section separately.
+				 */
+				new_page = vmemmap_alloc_block(PMD_SIZE, NUMA_NO_NODE);
+				if (new_page) {
+					set_pmd(pmd, __pmd(__pa(new_page) | prot));
+					if (!IS_ALIGNED(addr, PMD_SIZE) ||
+					    !IS_ALIGNED(next, PMD_SIZE)) {
+						vmemmap_use_new_sub_pmd(addr, next);
+					}
+					continue;
+				}
+			}
+			pte = vmem_pte_alloc();
+			if (!pte)
+				goto out;
+			pmd_populate(&init_mm, pmd, pte);
+		} else if (pmd_large(*pmd)) {
+			if (!direct)
+				vmemmap_use_sub_pmd(addr, next);
+			continue;
+		}
+		ret = modify_pte_table(pmd, addr, next, add, direct);
+		if (ret)
+			goto out;
+		if (!add)
+			try_free_pte_table(pmd, addr & PMD_MASK);
+	}
+	ret = 0;
+out:
+	if (direct)
+		update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages);
+	return ret;
+}
+
+static void try_free_pmd_table(pud_t *pud, unsigned long start)
+{
+	pmd_t *pmd;
+	int i;
+
+	pmd = pmd_offset(pud, start);
+	for (i = 0; i < PTRS_PER_PMD; i++, pmd++)
+		if (!pmd_none(*pmd))
+			return;
+	vmem_free_pages(pud_deref(*pud), CRST_ALLOC_ORDER);
+	pud_clear(pud);
+}
+
+static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
+			    bool add, bool direct)
+{
+	unsigned long next, prot, pages = 0;
+	int ret = -ENOMEM;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	prot = pgprot_val(REGION3_KERNEL);
+	if (!MACHINE_HAS_NX)
+		prot &= ~_REGION_ENTRY_NOEXEC;
+	pud = pud_offset(p4d, addr);
+	for (; addr < end; addr = next, pud++) {
+		next = pud_addr_end(addr, end);
+		if (!add) {
+			if (pud_none(*pud))
+				continue;
+			if (pud_large(*pud)) {
+				if (IS_ALIGNED(addr, PUD_SIZE) &&
+				    IS_ALIGNED(next, PUD_SIZE)) {
+					pud_clear(pud);
+					pages++;
+				}
+				continue;
+			}
+		} else if (pud_none(*pud)) {
+			if (IS_ALIGNED(addr, PUD_SIZE) &&
+			    IS_ALIGNED(next, PUD_SIZE) &&
+			    MACHINE_HAS_EDAT2 && direct &&
+			    !debug_pagealloc_enabled()) {
+				set_pud(pud, __pud(__pa(addr) | prot));
+				pages++;
+				continue;
+			}
+			pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
+			if (!pmd)
+				goto out;
+			pud_populate(&init_mm, pud, pmd);
+		} else if (pud_large(*pud)) {
+			continue;
+		}
+		ret = modify_pmd_table(pud, addr, next, add, direct);
+		if (ret)
+			goto out;
+		if (!add)
+			try_free_pmd_table(pud, addr & PUD_MASK);
+	}
+	ret = 0;
+out:
+	if (direct)
+		update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages);
+	return ret;
+}
+
+static void try_free_pud_table(p4d_t *p4d, unsigned long start)
+{
+	pud_t *pud;
+	int i;
+
+	pud = pud_offset(p4d, start);
+	for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
+		if (!pud_none(*pud))
+			return;
+	}
+	vmem_free_pages(p4d_deref(*p4d), CRST_ALLOC_ORDER);
+	p4d_clear(p4d);
+}
+
+static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
+			    bool add, bool direct)
+{
+	unsigned long next;
+	int ret = -ENOMEM;
+	p4d_t *p4d;
+	pud_t *pud;
+
+	p4d = p4d_offset(pgd, addr);
+	for (; addr < end; addr = next, p4d++) {
+		next = p4d_addr_end(addr, end);
+		if (!add) {
+			if (p4d_none(*p4d))
+				continue;
+		} else if (p4d_none(*p4d)) {
+			pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
+			if (!pud)
+				goto out;
+			p4d_populate(&init_mm, p4d, pud);
+		}
+		ret = modify_pud_table(p4d, addr, next, add, direct);
+		if (ret)
+			goto out;
+		if (!add)
+			try_free_pud_table(p4d, addr & P4D_MASK);
+	}
+	ret = 0;
+out:
+	return ret;
+}
+
+static void try_free_p4d_table(pgd_t *pgd, unsigned long start)
+{
+	p4d_t *p4d;
+	int i;
+
+	p4d = p4d_offset(pgd, start);
+	for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
+		if (!p4d_none(*p4d))
+			return;
+	}
+	vmem_free_pages(pgd_deref(*pgd), CRST_ALLOC_ORDER);
+	pgd_clear(pgd);
+}
+
+static int modify_pagetable(unsigned long start, unsigned long end, bool add,
+			    bool direct)
+{
+	unsigned long addr, next;
+	int ret = -ENOMEM;
+	pgd_t *pgd;
+	p4d_t *p4d;
+
+	if (WARN_ON_ONCE(!PAGE_ALIGNED(start | end)))
+		return -EINVAL;
+	/* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
+	if (WARN_ON_ONCE(end > VMALLOC_START))
+		return -EINVAL;
+	for (addr = start; addr < end; addr = next) {
+		next = pgd_addr_end(addr, end);
+		pgd = pgd_offset_k(addr);
+
+		if (!add) {
+			if (pgd_none(*pgd))
+				continue;
+		} else if (pgd_none(*pgd)) {
+			p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
+			if (!p4d)
+				goto out;
+			pgd_populate(&init_mm, pgd, p4d);
+		}
+		ret = modify_p4d_table(pgd, addr, next, add, direct);
+		if (ret)
+			goto out;
+		if (!add)
+			try_free_p4d_table(pgd, addr & PGDIR_MASK);
+	}
+	ret = 0;
+out:
+	if (!add)
+		flush_tlb_kernel_range(start, end);
+	return ret;
+}
+
+static int add_pagetable(unsigned long start, unsigned long end, bool direct)
+{
+	return modify_pagetable(start, end, true, direct);
+}
+
+static int remove_pagetable(unsigned long start, unsigned long end, bool direct)
+{
+	return modify_pagetable(start, end, false, direct);
+}
+
+/*
+ * Add a physical memory range to the 1:1 mapping.
+ */
+static int vmem_add_range(unsigned long start, unsigned long size)
+{
+	start = (unsigned long)__va(start);
+	return add_pagetable(start, start + size, true);
+}
+
+/*
+ * Remove a physical memory range from the 1:1 mapping.
+ */
+static void vmem_remove_range(unsigned long start, unsigned long size)
+{
+	start = (unsigned long)__va(start);
+	remove_pagetable(start, start + size, true);
+}
+
+/*
+ * Add a backed mem_map array to the virtual mem_map array.
+ */
+int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
+			       struct vmem_altmap *altmap)
+{
+	int ret;
+
+	mutex_lock(&vmem_mutex);
+	/* We don't care about the node, just use NUMA_NO_NODE on allocations */
+	ret = add_pagetable(start, end, false);
+	if (ret)
+		remove_pagetable(start, end, false);
+	mutex_unlock(&vmem_mutex);
+	return ret;
+}
+
+void vmemmap_free(unsigned long start, unsigned long end,
+		  struct vmem_altmap *altmap)
+{
+	mutex_lock(&vmem_mutex);
+	remove_pagetable(start, end, false);
+	mutex_unlock(&vmem_mutex);
+}
+
+void vmem_remove_mapping(unsigned long start, unsigned long size)
+{
+	mutex_lock(&vmem_mutex);
+	vmem_remove_range(start, size);
+	mutex_unlock(&vmem_mutex);
+}
+
+struct range arch_get_mappable_range(void)
+{
+	struct range mhp_range;
+
+	mhp_range.start = 0;
+	mhp_range.end = max_mappable - 1;
+	return mhp_range;
+}
+
+int vmem_add_mapping(unsigned long start, unsigned long size)
+{
+	struct range range = arch_get_mappable_range();
+	int ret;
+
+	if (start < range.start ||
+	    start + size > range.end + 1 ||
+	    start + size < start)
+		return -ERANGE;
+
+	mutex_lock(&vmem_mutex);
+	ret = vmem_add_range(start, size);
+	if (ret)
+		vmem_remove_range(start, size);
+	mutex_unlock(&vmem_mutex);
+	return ret;
+}
+
+/*
+ * Allocate new or return existing page-table entry, but do not map it
+ * to any physical address. If missing, allocate segment- and region-
+ * table entries along. Meeting a large segment- or region-table entry
+ * while traversing is an error, since the function is expected to be
+ * called against virtual regions reserved for 4KB mappings only.
+ */
+pte_t *vmem_get_alloc_pte(unsigned long addr, bool alloc)
+{
+	pte_t *ptep = NULL;
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	pgd = pgd_offset_k(addr);
+	if (pgd_none(*pgd)) {
+		if (!alloc)
+			goto out;
+		p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
+		if (!p4d)
+			goto out;
+		pgd_populate(&init_mm, pgd, p4d);
+	}
+	p4d = p4d_offset(pgd, addr);
+	if (p4d_none(*p4d)) {
+		if (!alloc)
+			goto out;
+		pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
+		if (!pud)
+			goto out;
+		p4d_populate(&init_mm, p4d, pud);
+	}
+	pud = pud_offset(p4d, addr);
+	if (pud_none(*pud)) {
+		if (!alloc)
+			goto out;
+		pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
+		if (!pmd)
+			goto out;
+		pud_populate(&init_mm, pud, pmd);
+	} else if (WARN_ON_ONCE(pud_large(*pud))) {
+		goto out;
+	}
+	pmd = pmd_offset(pud, addr);
+	if (pmd_none(*pmd)) {
+		if (!alloc)
+			goto out;
+		pte = vmem_pte_alloc();
+		if (!pte)
+			goto out;
+		pmd_populate(&init_mm, pmd, pte);
+	} else if (WARN_ON_ONCE(pmd_large(*pmd))) {
+		goto out;
+	}
+	ptep = pte_offset_kernel(pmd, addr);
+out:
+	return ptep;
+}
+
+int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc)
+{
+	pte_t *ptep, pte;
+
+	if (!IS_ALIGNED(addr, PAGE_SIZE))
+		return -EINVAL;
+	ptep = vmem_get_alloc_pte(addr, alloc);
+	if (!ptep)
+		return -ENOMEM;
+	__ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
+	pte = mk_pte_phys(phys, prot);
+	set_pte(ptep, pte);
+	return 0;
+}
+
+int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot)
+{
+	int rc;
+
+	mutex_lock(&vmem_mutex);
+	rc = __vmem_map_4k_page(addr, phys, prot, true);
+	mutex_unlock(&vmem_mutex);
+	return rc;
+}
+
+void vmem_unmap_4k_page(unsigned long addr)
+{
+	pte_t *ptep;
+
+	mutex_lock(&vmem_mutex);
+	ptep = virt_to_kpte(addr);
+	__ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
+	pte_clear(&init_mm, addr, ptep);
+	mutex_unlock(&vmem_mutex);
+}
+
+void __init vmem_map_init(void)
+{
+	__set_memory_rox(_stext, _etext);
+	__set_memory_ro(_etext, __end_rodata);
+	__set_memory_rox(_sinittext, _einittext);
+	__set_memory_rox(__stext_amode31, __etext_amode31);
+	/*
+	 * If the BEAR-enhancement facility is not installed the first
+	 * prefix page is used to return to the previous context with
+	 * an LPSWE instruction and therefore must be executable.
+	 */
+	if (!static_key_enabled(&cpu_has_bear))
+		set_memory_x(0, 1);
+	if (debug_pagealloc_enabled()) {
+		/*
+		 * Use RELOC_HIDE() as long as __va(0) translates to NULL,
+		 * since performing pointer arithmetic on a NULL pointer
+		 * has undefined behavior and generates compiler warnings.
+		 */
+		__set_memory_4k(__va(0), RELOC_HIDE(__va(0), ident_map_size));
+	}
+	if (MACHINE_HAS_NX)
+		ctl_set_bit(0, 20);
+	pr_info("Write protected kernel read-only data: %luk\n",
+		(unsigned long)(__end_rodata - _stext) >> 10);
+}