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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/s390/mm/vmem.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/mm/vmem.c')
-rw-r--r--arch/s390/mm/vmem.c669
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);
+}