1 files changed, 447 insertions, 0 deletions
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
new file mode 100644
index 000000000..b617b6945
--- /dev/null
+++ b/arch/powerpc/mm/mem.c
@@ -0,0 +1,447 @@
+// 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
+ *  PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
+ *
+ *  Derived from "arch/i386/mm/init.c"
+ *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
+ */
+
+#include <linux/memblock.h>
+#include <linux/highmem.h>
+#include <linux/suspend.h>
+#include <linux/dma-direct.h>
+#include <linux/execmem.h>
+#include <linux/vmalloc.h>
+
+#include <asm/swiotlb.h>
+#include <asm/machdep.h>
+#include <asm/rtas.h>
+#include <asm/kasan.h>
+#include <asm/svm.h>
+#include <asm/mmzone.h>
+#include <asm/ftrace.h>
+#include <asm/text-patching.h>
+#include <asm/setup.h>
+#include <asm/fixmap.h>
+
+#include <asm/fadump.h>
+#include <asm/kexec.h>
+#include <asm/kvm_ppc.h>
+
+#include <mm/mmu_decl.h>
+
+unsigned long long memory_limit __initdata;
+
+pgprot_t __phys_mem_access_prot(unsigned long pfn, unsigned long size,
+				pgprot_t vma_prot)
+{
+	if (ppc_md.phys_mem_access_prot)
+		return ppc_md.phys_mem_access_prot(pfn, size, vma_prot);
+
+	if (!page_is_ram(pfn))
+		vma_prot = pgprot_noncached(vma_prot);
+
+	return vma_prot;
+}
+EXPORT_SYMBOL(__phys_mem_access_prot);
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+static DEFINE_MUTEX(linear_mapping_mutex);
+
+#ifdef CONFIG_NUMA
+int memory_add_physaddr_to_nid(u64 start)
+{
+	return hot_add_scn_to_nid(start);
+}
+EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
+#endif
+
+int __weak create_section_mapping(unsigned long start, unsigned long end,
+				  int nid, pgprot_t prot)
+{
+	return -ENODEV;
+}
+
+int __weak remove_section_mapping(unsigned long start, unsigned long end)
+{
+	return -ENODEV;
+}
+
+int __ref arch_create_linear_mapping(int nid, u64 start, u64 size,
+				     struct mhp_params *params)
+{
+	int rc;
+
+	start = (unsigned long)__va(start);
+	mutex_lock(&linear_mapping_mutex);
+	rc = create_section_mapping(start, start + size, nid,
+				    params->pgprot);
+	mutex_unlock(&linear_mapping_mutex);
+	if (rc) {
+		pr_warn("Unable to create linear mapping for 0x%llx..0x%llx: %d\n",
+			start, start + size, rc);
+		return -EFAULT;
+	}
+	return 0;
+}
+
+void __ref arch_remove_linear_mapping(u64 start, u64 size)
+{
+	int ret;
+
+	/* Remove htab bolted mappings for this section of memory */
+	start = (unsigned long)__va(start);
+
+	mutex_lock(&linear_mapping_mutex);
+	ret = remove_section_mapping(start, start + size);
+	mutex_unlock(&linear_mapping_mutex);
+	if (ret)
+		pr_warn("Unable to remove linear mapping for 0x%llx..0x%llx: %d\n",
+			start, start + size, ret);
+
+	/* Ensure all vmalloc mappings are flushed in case they also
+	 * hit that section of memory
+	 */
+	vm_unmap_aliases();
+}
+
+/*
+ * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
+ * updating.
+ */
+static void update_end_of_memory_vars(u64 start, u64 size)
+{
+	unsigned long end_pfn = PFN_UP(start + size);
+
+	if (end_pfn > max_pfn) {
+		max_pfn = end_pfn;
+		max_low_pfn = end_pfn;
+		high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
+	}
+}
+
+int __ref add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
+		    struct mhp_params *params)
+{
+	int ret;
+
+	ret = __add_pages(nid, start_pfn, nr_pages, params);
+	if (ret)
+		return ret;
+
+	/* update max_pfn, max_low_pfn and high_memory */
+	update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
+				  nr_pages << PAGE_SHIFT);
+
+	return ret;
+}
+
+int __ref arch_add_memory(int nid, u64 start, u64 size,
+			  struct mhp_params *params)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long nr_pages = size >> PAGE_SHIFT;
+	int rc;
+
+	rc = arch_create_linear_mapping(nid, start, size, params);
+	if (rc)
+		return rc;
+	rc = add_pages(nid, start_pfn, nr_pages, params);
+	if (rc)
+		arch_remove_linear_mapping(start, size);
+	return rc;
+}
+
+void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap,
+			      struct dev_pagemap *pgmap)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long nr_pages = size >> PAGE_SHIFT;
+
+	__remove_pages(start_pfn, nr_pages, altmap, pgmap);
+	arch_remove_linear_mapping(start, size);
+}
+#endif
+
+#ifndef CONFIG_NUMA
+void __init mem_topology_setup(void)
+{
+	max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
+	min_low_pfn = MEMORY_START >> PAGE_SHIFT;
+#ifdef CONFIG_HIGHMEM
+	max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
+#endif
+
+	/* Place all memblock_regions in the same node and merge contiguous
+	 * memblock_regions
+	 */
+	memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
+}
+
+/* mark pages that don't exist as nosave */
+static int __init mark_nonram_nosave(void)
+{
+	unsigned long spfn, epfn, prev = 0;
+	int i;
+
+	for_each_mem_pfn_range(i, MAX_NUMNODES, &spfn, &epfn, NULL) {
+		if (prev && prev < spfn)
+			register_nosave_region(prev, spfn);
+
+		prev = epfn;
+	}
+
+	return 0;
+}
+#else /* CONFIG_NUMA */
+static int __init mark_nonram_nosave(void)
+{
+	return 0;
+}
+#endif
+
+/*
+ * Zones usage:
+ *
+ * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
+ * everything else. GFP_DMA32 page allocations automatically fall back to
+ * ZONE_DMA.
+ *
+ * By using 31-bit unconditionally, we can exploit zone_dma_limit to inform the
+ * generic DMA mapping code.  32-bit only devices (if not handled by an IOMMU
+ * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
+ * ZONE_DMA.
+ */
+void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
+{
+#ifdef CONFIG_ZONE_DMA
+	max_zone_pfns[ZONE_DMA] = min((zone_dma_limit >> PAGE_SHIFT) + 1, max_low_pfn);
+#endif
+	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
+#ifdef CONFIG_HIGHMEM
+	max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
+#endif
+}
+
+/*
+ * paging_init() sets up the page tables - in fact we've already done this.
+ */
+void __init paging_init(void)
+{
+	unsigned long long total_ram = memblock_phys_mem_size();
+	phys_addr_t top_of_ram = memblock_end_of_DRAM();
+	int zone_dma_bits;
+
+#ifdef CONFIG_HIGHMEM
+	unsigned long v = __fix_to_virt(FIX_KMAP_END);
+	unsigned long end = __fix_to_virt(FIX_KMAP_BEGIN);
+
+	for (; v < end; v += PAGE_SIZE)
+		map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
+
+	map_kernel_page(PKMAP_BASE, 0, __pgprot(0));	/* XXX gross */
+	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
+#endif /* CONFIG_HIGHMEM */
+
+	printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
+	       (unsigned long long)top_of_ram, total_ram);
+	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
+	       (long int)((top_of_ram - total_ram) >> 20));
+
+	/*
+	 * Allow 30-bit DMA for very limited Broadcom wifi chips on many
+	 * powerbooks.
+	 */
+	if (IS_ENABLED(CONFIG_PPC32))
+		zone_dma_bits = 30;
+	else
+		zone_dma_bits = 31;
+
+	zone_dma_limit = DMA_BIT_MASK(zone_dma_bits);
+
+	mark_nonram_nosave();
+}
+
+void __init arch_mm_preinit(void)
+{
+
+	/*
+	 * Reserve large chunks of memory for use by CMA for kdump, fadump, KVM
+	 * and hugetlb. These must be called after pageblock_order is
+	 * initialised.
+	 */
+	fadump_cma_init();
+	kdump_cma_reserve();
+	kvm_cma_reserve();
+
+	/*
+	 * book3s is limited to 16 page sizes due to encoding this in
+	 * a 4-bit field for slices.
+	 */
+	BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
+
+#ifdef CONFIG_SWIOTLB
+	/*
+	 * Some platforms (e.g. 85xx) limit DMA-able memory way below
+	 * 4G. We force memblock to bottom-up mode to ensure that the
+	 * memory allocated in swiotlb_init() is DMA-able.
+	 * As it's the last memblock allocation, no need to reset it
+	 * back to to-down.
+	 */
+	memblock_set_bottom_up(true);
+	swiotlb_init(ppc_swiotlb_enable, ppc_swiotlb_flags);
+#endif
+
+	kasan_late_init();
+
+#if defined(CONFIG_PPC_E500) && !defined(CONFIG_SMP)
+	/*
+	 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
+	 * functions.... do it here for the non-smp case.
+	 */
+	per_cpu(next_tlbcam_idx, smp_processor_id()) =
+		(mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
+#endif
+}
+
+void free_initmem(void)
+{
+	ppc_md.progress = ppc_printk_progress;
+	mark_initmem_nx();
+	free_initmem_default(POISON_FREE_INITMEM);
+	ftrace_free_init_tramp();
+}
+
+/*
+ * System memory should not be in /proc/iomem but various tools expect it
+ * (eg kdump).
+ */
+static int __init add_system_ram_resources(void)
+{
+	phys_addr_t start, end;
+	u64 i;
+
+	for_each_mem_range(i, &start, &end) {
+		struct resource *res;
+
+		res = kzalloc_obj(struct resource);
+		WARN_ON(!res);
+
+		if (res) {
+			res->name = "System RAM";
+			res->start = start;
+			/*
+			 * In memblock, end points to the first byte after
+			 * the range while in resourses, end points to the
+			 * last byte in the range.
+			 */
+			res->end = end - 1;
+			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+			WARN_ON(insert_resource(&iomem_resource, res) < 0);
+		}
+	}
+
+	return 0;
+}
+subsys_initcall(add_system_ram_resources);
+
+#ifdef CONFIG_STRICT_DEVMEM
+/*
+ * devmem_is_allowed(): check to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number.
+ *
+ * Access has to be given to non-kernel-ram areas as well, these contain the
+ * PCI mmio resources as well as potential bios/acpi data regions.
+ */
+int devmem_is_allowed(unsigned long pfn)
+{
+	if (page_is_rtas_user_buf(pfn))
+		return 1;
+	if (iomem_is_exclusive(PFN_PHYS(pfn)))
+		return 0;
+	if (!page_is_ram(pfn))
+		return 1;
+	return 0;
+}
+#endif /* CONFIG_STRICT_DEVMEM */
+
+#ifdef CONFIG_EXECMEM
+static struct execmem_info execmem_info __ro_after_init;
+
+#if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC_BOOK3S_603)
+static void prealloc_execmem_pgtable(void)
+{
+	unsigned long va;
+
+	for (va = ALIGN_DOWN(MODULES_VADDR, PGDIR_SIZE); va < MODULES_END; va += PGDIR_SIZE)
+		pte_alloc_kernel(pmd_off_k(va), va);
+}
+#else
+static void prealloc_execmem_pgtable(void) { }
+#endif
+
+struct execmem_info __init *execmem_arch_setup(void)
+{
+	pgprot_t kprobes_prot = strict_module_rwx_enabled() ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
+	pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
+	unsigned long fallback_start = 0, fallback_end = 0;
+	unsigned long start, end;
+
+	/*
+	 * BOOK3S_32 and 8xx define MODULES_VADDR for text allocations and
+	 * allow allocating data in the entire vmalloc space
+	 */
+#ifdef MODULES_VADDR
+	unsigned long limit = (unsigned long)_etext - SZ_32M;
+
+	/* First try within 32M limit from _etext to avoid branch trampolines */
+	if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit) {
+		start = limit;
+		fallback_start = MODULES_VADDR;
+		fallback_end = MODULES_END;
+	} else {
+		start = MODULES_VADDR;
+	}
+
+	end = MODULES_END;
+#else
+	start = VMALLOC_START;
+	end = VMALLOC_END;
+#endif
+
+	prealloc_execmem_pgtable();
+
+	execmem_info = (struct execmem_info){
+		.ranges = {
+			[EXECMEM_DEFAULT] = {
+				.start	= start,
+				.end	= end,
+				.pgprot	= prot,
+				.alignment = 1,
+				.fallback_start	= fallback_start,
+				.fallback_end	= fallback_end,
+			},
+			[EXECMEM_KPROBES] = {
+				.start	= VMALLOC_START,
+				.end	= VMALLOC_END,
+				.pgprot	= kprobes_prot,
+				.alignment = 1,
+			},
+			[EXECMEM_MODULE_DATA] = {
+				.start	= VMALLOC_START,
+				.end	= VMALLOC_END,
+				.pgprot	= PAGE_KERNEL,
+				.alignment = 1,
+			},
+		},
+	};
+
+	return &execmem_info;
+}
+#endif /* CONFIG_EXECMEM */