Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 526 insertions, 0 deletions

diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
new file mode 100644
index 000000000..0ec5b45b1
--- /dev/null
+++ b/arch/powerpc/mm/init_64.c
@@ -0,0 +1,526 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  PowerPC version
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
+ *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
+ *    Copyright (C) 1996 Paul Mackerras
+ *
+ *  Derived from "arch/i386/mm/init.c"
+ *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
+ *
+ *  Dave Engebretsen <engebret@us.ibm.com>
+ *      Rework for PPC64 port.
+ */
+
+#undef DEBUG
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/stddef.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/highmem.h>
+#include <linux/idr.h>
+#include <linux/nodemask.h>
+#include <linux/module.h>
+#include <linux/poison.h>
+#include <linux/memblock.h>
+#include <linux/hugetlb.h>
+#include <linux/slab.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+#include <linux/memremap.h>
+
+#include <asm/pgalloc.h>
+#include <asm/page.h>
+#include <asm/prom.h>
+#include <asm/rtas.h>
+#include <asm/io.h>
+#include <asm/mmu_context.h>
+#include <asm/mmu.h>
+#include <linux/uaccess.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/tlb.h>
+#include <asm/eeh.h>
+#include <asm/processor.h>
+#include <asm/mmzone.h>
+#include <asm/cputable.h>
+#include <asm/sections.h>
+#include <asm/iommu.h>
+#include <asm/vdso.h>
+#include <asm/hugetlb.h>
+
+#include <mm/mmu_decl.h>
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+/*
+ * Given an address within the vmemmap, determine the page that
+ * represents the start of the subsection it is within.  Note that we have to
+ * do this by hand as the proffered address may not be correctly aligned.
+ * Subtraction of non-aligned pointers produces undefined results.
+ */
+static struct page * __meminit vmemmap_subsection_start(unsigned long vmemmap_addr)
+{
+	unsigned long start_pfn;
+	unsigned long offset = vmemmap_addr - ((unsigned long)(vmemmap));
+
+	/* Return the pfn of the start of the section. */
+	start_pfn = (offset / sizeof(struct page)) & PAGE_SUBSECTION_MASK;
+	return pfn_to_page(start_pfn);
+}
+
+/*
+ * Since memory is added in sub-section chunks, before creating a new vmemmap
+ * mapping, the kernel should check whether there is an existing memmap mapping
+ * covering the new subsection added. This is needed because kernel can map
+ * vmemmap area using 16MB pages which will cover a memory range of 16G. Such
+ * a range covers multiple subsections (2M)
+ *
+ * If any subsection in the 16G range mapped by vmemmap is valid we consider the
+ * vmemmap populated (There is a page table entry already present). We can't do
+ * a page table lookup here because with the hash translation we don't keep
+ * vmemmap details in linux page table.
+ */
+static int __meminit vmemmap_populated(unsigned long vmemmap_addr, int vmemmap_map_size)
+{
+	struct page *start;
+	unsigned long vmemmap_end = vmemmap_addr + vmemmap_map_size;
+	start = vmemmap_subsection_start(vmemmap_addr);
+
+	for (; (unsigned long)start < vmemmap_end; start += PAGES_PER_SUBSECTION)
+		/*
+		 * pfn valid check here is intended to really check
+		 * whether we have any subsection already initialized
+		 * in this range.
+		 */
+		if (pfn_valid(page_to_pfn(start)))
+			return 1;
+
+	return 0;
+}
+
+/*
+ * vmemmap virtual address space management does not have a traditional page
+ * table to track which virtual struct pages are backed by physical mapping.
+ * The virtual to physical mappings are tracked in a simple linked list
+ * format. 'vmemmap_list' maintains the entire vmemmap physical mapping at
+ * all times where as the 'next' list maintains the available
+ * vmemmap_backing structures which have been deleted from the
+ * 'vmemmap_global' list during system runtime (memory hotplug remove
+ * operation). The freed 'vmemmap_backing' structures are reused later when
+ * new requests come in without allocating fresh memory. This pointer also
+ * tracks the allocated 'vmemmap_backing' structures as we allocate one
+ * full page memory at a time when we dont have any.
+ */
+struct vmemmap_backing *vmemmap_list;
+static struct vmemmap_backing *next;
+
+/*
+ * The same pointer 'next' tracks individual chunks inside the allocated
+ * full page during the boot time and again tracks the freed nodes during
+ * runtime. It is racy but it does not happen as they are separated by the
+ * boot process. Will create problem if some how we have memory hotplug
+ * operation during boot !!
+ */
+static int num_left;
+static int num_freed;
+
+static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node)
+{
+	struct vmemmap_backing *vmem_back;
+	/* get from freed entries first */
+	if (num_freed) {
+		num_freed--;
+		vmem_back = next;
+		next = next->list;
+
+		return vmem_back;
+	}
+
+	/* allocate a page when required and hand out chunks */
+	if (!num_left) {
+		next = vmemmap_alloc_block(PAGE_SIZE, node);
+		if (unlikely(!next)) {
+			WARN_ON(1);
+			return NULL;
+		}
+		num_left = PAGE_SIZE / sizeof(struct vmemmap_backing);
+	}
+
+	num_left--;
+
+	return next++;
+}
+
+static __meminit int vmemmap_list_populate(unsigned long phys,
+					   unsigned long start,
+					   int node)
+{
+	struct vmemmap_backing *vmem_back;
+
+	vmem_back = vmemmap_list_alloc(node);
+	if (unlikely(!vmem_back)) {
+		pr_debug("vmemap list allocation failed\n");
+		return -ENOMEM;
+	}
+
+	vmem_back->phys = phys;
+	vmem_back->virt_addr = start;
+	vmem_back->list = vmemmap_list;
+
+	vmemmap_list = vmem_back;
+	return 0;
+}
+
+static bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long start,
+				unsigned long page_size)
+{
+	unsigned long nr_pfn = page_size / sizeof(struct page);
+	unsigned long start_pfn = page_to_pfn((struct page *)start);
+
+	if ((start_pfn + nr_pfn - 1) > altmap->end_pfn)
+		return true;
+
+	if (start_pfn < altmap->base_pfn)
+		return true;
+
+	return false;
+}
+
+int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
+		struct vmem_altmap *altmap)
+{
+	bool altmap_alloc;
+	unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
+
+	/* Align to the page size of the linear mapping. */
+	start = ALIGN_DOWN(start, page_size);
+
+	pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node);
+
+	for (; start < end; start += page_size) {
+		void *p = NULL;
+		int rc;
+
+		/*
+		 * This vmemmap range is backing different subsections. If any
+		 * of that subsection is marked valid, that means we already
+		 * have initialized a page table covering this range and hence
+		 * the vmemmap range is populated.
+		 */
+		if (vmemmap_populated(start, page_size))
+			continue;
+
+		/*
+		 * Allocate from the altmap first if we have one. This may
+		 * fail due to alignment issues when using 16MB hugepages, so
+		 * fall back to system memory if the altmap allocation fail.
+		 */
+		if (altmap && !altmap_cross_boundary(altmap, start, page_size)) {
+			p = vmemmap_alloc_block_buf(page_size, node, altmap);
+			if (!p)
+				pr_debug("altmap block allocation failed, falling back to system memory");
+			else
+				altmap_alloc = true;
+		}
+		if (!p) {
+			p = vmemmap_alloc_block_buf(page_size, node, NULL);
+			altmap_alloc = false;
+		}
+		if (!p)
+			return -ENOMEM;
+
+		if (vmemmap_list_populate(__pa(p), start, node)) {
+			/*
+			 * If we don't populate vmemap list, we don't have
+			 * the ability to free the allocated vmemmap
+			 * pages in section_deactivate. Hence free them
+			 * here.
+			 */
+			int nr_pfns = page_size >> PAGE_SHIFT;
+			unsigned long page_order = get_order(page_size);
+
+			if (altmap_alloc)
+				vmem_altmap_free(altmap, nr_pfns);
+			else
+				free_pages((unsigned long)p, page_order);
+			return -ENOMEM;
+		}
+
+		pr_debug("      * %016lx..%016lx allocated at %p\n",
+			 start, start + page_size, p);
+
+		rc = vmemmap_create_mapping(start, page_size, __pa(p));
+		if (rc < 0) {
+			pr_warn("%s: Unable to create vmemmap mapping: %d\n",
+				__func__, rc);
+			return -EFAULT;
+		}
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+static unsigned long vmemmap_list_free(unsigned long start)
+{
+	struct vmemmap_backing *vmem_back, *vmem_back_prev;
+
+	vmem_back_prev = vmem_back = vmemmap_list;
+
+	/* look for it with prev pointer recorded */
+	for (; vmem_back; vmem_back = vmem_back->list) {
+		if (vmem_back->virt_addr == start)
+			break;
+		vmem_back_prev = vmem_back;
+	}
+
+	if (unlikely(!vmem_back))
+		return 0;
+
+	/* remove it from vmemmap_list */
+	if (vmem_back == vmemmap_list) /* remove head */
+		vmemmap_list = vmem_back->list;
+	else
+		vmem_back_prev->list = vmem_back->list;
+
+	/* next point to this freed entry */
+	vmem_back->list = next;
+	next = vmem_back;
+	num_freed++;
+
+	return vmem_back->phys;
+}
+
+void __ref vmemmap_free(unsigned long start, unsigned long end,
+		struct vmem_altmap *altmap)
+{
+	unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
+	unsigned long page_order = get_order(page_size);
+	unsigned long alt_start = ~0, alt_end = ~0;
+	unsigned long base_pfn;
+
+	start = ALIGN_DOWN(start, page_size);
+	if (altmap) {
+		alt_start = altmap->base_pfn;
+		alt_end = altmap->base_pfn + altmap->reserve + altmap->free;
+	}
+
+	pr_debug("vmemmap_free %lx...%lx\n", start, end);
+
+	for (; start < end; start += page_size) {
+		unsigned long nr_pages, addr;
+		struct page *page;
+
+		/*
+		 * We have already marked the subsection we are trying to remove
+		 * invalid. So if we want to remove the vmemmap range, we
+		 * need to make sure there is no subsection marked valid
+		 * in this range.
+		 */
+		if (vmemmap_populated(start, page_size))
+			continue;
+
+		addr = vmemmap_list_free(start);
+		if (!addr)
+			continue;
+
+		page = pfn_to_page(addr >> PAGE_SHIFT);
+		nr_pages = 1 << page_order;
+		base_pfn = PHYS_PFN(addr);
+
+		if (base_pfn >= alt_start && base_pfn < alt_end) {
+			vmem_altmap_free(altmap, nr_pages);
+		} else if (PageReserved(page)) {
+			/* allocated from bootmem */
+			if (page_size < PAGE_SIZE) {
+				/*
+				 * this shouldn't happen, but if it is
+				 * the case, leave the memory there
+				 */
+				WARN_ON_ONCE(1);
+			} else {
+				while (nr_pages--)
+					free_reserved_page(page++);
+			}
+		} else {
+			free_pages((unsigned long)(__va(addr)), page_order);
+		}
+
+		vmemmap_remove_mapping(start, page_size);
+	}
+}
+#endif
+void register_page_bootmem_memmap(unsigned long section_nr,
+				  struct page *start_page, unsigned long size)
+{
+}
+
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
+#ifdef CONFIG_PPC_BOOK3S_64
+unsigned int mmu_lpid_bits;
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+EXPORT_SYMBOL_GPL(mmu_lpid_bits);
+#endif
+unsigned int mmu_pid_bits;
+
+static bool disable_radix = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT);
+
+static int __init parse_disable_radix(char *p)
+{
+	bool val;
+
+	if (!p)
+		val = true;
+	else if (kstrtobool(p, &val))
+		return -EINVAL;
+
+	disable_radix = val;
+
+	return 0;
+}
+early_param("disable_radix", parse_disable_radix);
+
+/*
+ * If we're running under a hypervisor, we need to check the contents of
+ * /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do
+ * radix.  If not, we clear the radix feature bit so we fall back to hash.
+ */
+static void __init early_check_vec5(void)
+{
+	unsigned long root, chosen;
+	int size;
+	const u8 *vec5;
+	u8 mmu_supported;
+
+	root = of_get_flat_dt_root();
+	chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
+	if (chosen == -FDT_ERR_NOTFOUND) {
+		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
+		return;
+	}
+	vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size);
+	if (!vec5) {
+		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
+		return;
+	}
+	if (size <= OV5_INDX(OV5_MMU_SUPPORT)) {
+		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
+		return;
+	}
+
+	/* Check for supported configuration */
+	mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] &
+			OV5_FEAT(OV5_MMU_SUPPORT);
+	if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) {
+		/* Hypervisor only supports radix - check enabled && GTSE */
+		if (!early_radix_enabled()) {
+			pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
+		}
+		if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] &
+						OV5_FEAT(OV5_RADIX_GTSE))) {
+			cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
+		} else
+			cur_cpu_spec->mmu_features |= MMU_FTR_GTSE;
+		/* Do radix anyway - the hypervisor said we had to */
+		cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
+	} else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) {
+		/* Hypervisor only supports hash - disable radix */
+		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
+		cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
+	}
+}
+
+static int __init dt_scan_mmu_pid_width(unsigned long node,
+					   const char *uname, int depth,
+					   void *data)
+{
+	int size = 0;
+	const __be32 *prop;
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+
+	/* We are scanning "cpu" nodes only */
+	if (type == NULL || strcmp(type, "cpu") != 0)
+		return 0;
+
+	/* Find MMU LPID, PID register size */
+	prop = of_get_flat_dt_prop(node, "ibm,mmu-lpid-bits", &size);
+	if (prop && size == 4)
+		mmu_lpid_bits = be32_to_cpup(prop);
+
+	prop = of_get_flat_dt_prop(node, "ibm,mmu-pid-bits", &size);
+	if (prop && size == 4)
+		mmu_pid_bits = be32_to_cpup(prop);
+
+	if (!mmu_pid_bits && !mmu_lpid_bits)
+		return 0;
+
+	return 1;
+}
+
+void __init mmu_early_init_devtree(void)
+{
+	bool hvmode = !!(mfmsr() & MSR_HV);
+
+	/* Disable radix mode based on kernel command line. */
+	if (disable_radix) {
+		if (IS_ENABLED(CONFIG_PPC_64S_HASH_MMU))
+			cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
+		else
+			pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
+	}
+
+	of_scan_flat_dt(dt_scan_mmu_pid_width, NULL);
+	if (hvmode && !mmu_lpid_bits) {
+		if (early_cpu_has_feature(CPU_FTR_ARCH_207S))
+			mmu_lpid_bits = 12; /* POWER8-10 */
+		else
+			mmu_lpid_bits = 10; /* POWER7 */
+	}
+	if (!mmu_pid_bits) {
+		if (early_cpu_has_feature(CPU_FTR_ARCH_300))
+			mmu_pid_bits = 20; /* POWER9-10 */
+	}
+
+	/*
+	 * Check /chosen/ibm,architecture-vec-5 if running as a guest.
+	 * When running bare-metal, we can use radix if we like
+	 * even though the ibm,architecture-vec-5 property created by
+	 * skiboot doesn't have the necessary bits set.
+	 */
+	if (!hvmode)
+		early_check_vec5();
+
+	if (early_radix_enabled()) {
+		radix__early_init_devtree();
+
+		/*
+		 * We have finalized the translation we are going to use by now.
+		 * Radix mode is not limited by RMA / VRMA addressing.
+		 * Hence don't limit memblock allocations.
+		 */
+		ppc64_rma_size = ULONG_MAX;
+		memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
+	} else
+		hash__early_init_devtree();
+
+	if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
+		hugetlbpage_init_defaultsize();
+
+	if (!(cur_cpu_spec->mmu_features & MMU_FTR_HPTE_TABLE) &&
+	    !(cur_cpu_spec->mmu_features & MMU_FTR_TYPE_RADIX))
+		panic("kernel does not support any MMU type offered by platform");
+}
+#endif /* CONFIG_PPC_BOOK3S_64 */