1 files changed, 488 insertions, 0 deletions
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
new file mode 100644
index 000000000..ce64bdb55
--- /dev/null
+++ b/arch/arm/mm/init.c
@@ -0,0 +1,488 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/arch/arm/mm/init.c
+ *
+ *  Copyright (C) 1995-2005 Russell King
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/swap.h>
+#include <linux/init.h>
+#include <linux/mman.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/task.h>
+#include <linux/export.h>
+#include <linux/nodemask.h>
+#include <linux/initrd.h>
+#include <linux/of_fdt.h>
+#include <linux/highmem.h>
+#include <linux/gfp.h>
+#include <linux/memblock.h>
+#include <linux/dma-map-ops.h>
+#include <linux/sizes.h>
+#include <linux/stop_machine.h>
+#include <linux/swiotlb.h>
+
+#include <asm/cp15.h>
+#include <asm/mach-types.h>
+#include <asm/memblock.h>
+#include <asm/memory.h>
+#include <asm/prom.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/set_memory.h>
+#include <asm/system_info.h>
+#include <asm/tlb.h>
+#include <asm/fixmap.h>
+#include <asm/ptdump.h>
+
+#include <asm/mach/arch.h>
+#include <asm/mach/map.h>
+
+#include "mm.h"
+
+#ifdef CONFIG_CPU_CP15_MMU
+unsigned long __init __clear_cr(unsigned long mask)
+{
+	cr_alignment = cr_alignment & ~mask;
+	return cr_alignment;
+}
+#endif
+
+#ifdef CONFIG_BLK_DEV_INITRD
+static int __init parse_tag_initrd(const struct tag *tag)
+{
+	pr_warn("ATAG_INITRD is deprecated; "
+		"please update your bootloader.\n");
+	phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
+	phys_initrd_size = tag->u.initrd.size;
+	return 0;
+}
+
+__tagtable(ATAG_INITRD, parse_tag_initrd);
+
+static int __init parse_tag_initrd2(const struct tag *tag)
+{
+	phys_initrd_start = tag->u.initrd.start;
+	phys_initrd_size = tag->u.initrd.size;
+	return 0;
+}
+
+__tagtable(ATAG_INITRD2, parse_tag_initrd2);
+#endif
+
+static void __init find_limits(unsigned long *min, unsigned long *max_low,
+			       unsigned long *max_high)
+{
+	*max_low = PFN_DOWN(memblock_get_current_limit());
+	*min = PFN_UP(memblock_start_of_DRAM());
+	*max_high = PFN_DOWN(memblock_end_of_DRAM());
+}
+
+#ifdef CONFIG_ZONE_DMA
+
+phys_addr_t arm_dma_zone_size __read_mostly;
+EXPORT_SYMBOL(arm_dma_zone_size);
+
+/*
+ * The DMA mask corresponding to the maximum bus address allocatable
+ * using GFP_DMA.  The default here places no restriction on DMA
+ * allocations.  This must be the smallest DMA mask in the system,
+ * so a successful GFP_DMA allocation will always satisfy this.
+ */
+phys_addr_t arm_dma_limit;
+unsigned long arm_dma_pfn_limit;
+#endif
+
+void __init setup_dma_zone(const struct machine_desc *mdesc)
+{
+#ifdef CONFIG_ZONE_DMA
+	if (mdesc->dma_zone_size) {
+		arm_dma_zone_size = mdesc->dma_zone_size;
+		arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
+	} else
+		arm_dma_limit = 0xffffffff;
+	arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
+#endif
+}
+
+static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
+	unsigned long max_high)
+{
+	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
+
+#ifdef CONFIG_ZONE_DMA
+	max_zone_pfn[ZONE_DMA] = min(arm_dma_pfn_limit, max_low);
+#endif
+	max_zone_pfn[ZONE_NORMAL] = max_low;
+#ifdef CONFIG_HIGHMEM
+	max_zone_pfn[ZONE_HIGHMEM] = max_high;
+#endif
+	free_area_init(max_zone_pfn);
+}
+
+#ifdef CONFIG_HAVE_ARCH_PFN_VALID
+int pfn_valid(unsigned long pfn)
+{
+	phys_addr_t addr = __pfn_to_phys(pfn);
+	unsigned long pageblock_size = PAGE_SIZE * pageblock_nr_pages;
+
+	if (__phys_to_pfn(addr) != pfn)
+		return 0;
+
+	/*
+	 * If address less than pageblock_size bytes away from a present
+	 * memory chunk there still will be a memory map entry for it
+	 * because we round freed memory map to the pageblock boundaries.
+	 */
+	if (memblock_overlaps_region(&memblock.memory,
+				     ALIGN_DOWN(addr, pageblock_size),
+				     pageblock_size))
+		return 1;
+
+	return 0;
+}
+EXPORT_SYMBOL(pfn_valid);
+#endif
+
+static bool arm_memblock_steal_permitted = true;
+
+phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
+{
+	phys_addr_t phys;
+
+	BUG_ON(!arm_memblock_steal_permitted);
+
+	phys = memblock_phys_alloc(size, align);
+	if (!phys)
+		panic("Failed to steal %pa bytes at %pS\n",
+		      &size, (void *)_RET_IP_);
+
+	memblock_phys_free(phys, size);
+	memblock_remove(phys, size);
+
+	return phys;
+}
+
+#ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
+void check_cpu_icache_size(int cpuid)
+{
+	u32 size, ctr;
+
+	asm("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr));
+
+	size = 1 << ((ctr & 0xf) + 2);
+	if (cpuid != 0 && icache_size != size)
+		pr_info("CPU%u: detected I-Cache line size mismatch, workaround enabled\n",
+			cpuid);
+	if (icache_size > size)
+		icache_size = size;
+}
+#endif
+
+void __init arm_memblock_init(const struct machine_desc *mdesc)
+{
+	/* Register the kernel text, kernel data and initrd with memblock. */
+	memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START);
+
+	reserve_initrd_mem();
+
+	arm_mm_memblock_reserve();
+
+	/* reserve any platform specific memblock areas */
+	if (mdesc->reserve)
+		mdesc->reserve();
+
+	early_init_fdt_scan_reserved_mem();
+
+	/* reserve memory for DMA contiguous allocations */
+	dma_contiguous_reserve(arm_dma_limit);
+
+	arm_memblock_steal_permitted = false;
+	memblock_dump_all();
+}
+
+void __init bootmem_init(void)
+{
+	memblock_allow_resize();
+
+	find_limits(&min_low_pfn, &max_low_pfn, &max_pfn);
+
+	early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT,
+		      (phys_addr_t)max_low_pfn << PAGE_SHIFT);
+
+	/*
+	 * sparse_init() tries to allocate memory from memblock, so must be
+	 * done after the fixed reservations
+	 */
+	sparse_init();
+
+	/*
+	 * Now free the memory - free_area_init needs
+	 * the sparse mem_map arrays initialized by sparse_init()
+	 * for memmap_init_zone(), otherwise all PFNs are invalid.
+	 */
+	zone_sizes_init(min_low_pfn, max_low_pfn, max_pfn);
+}
+
+/*
+ * Poison init memory with an undefined instruction (ARM) or a branch to an
+ * undefined instruction (Thumb).
+ */
+static inline void poison_init_mem(void *s, size_t count)
+{
+	u32 *p = (u32 *)s;
+	for (; count != 0; count -= 4)
+		*p++ = 0xe7fddef0;
+}
+
+static void __init free_highpages(void)
+{
+#ifdef CONFIG_HIGHMEM
+	unsigned long max_low = max_low_pfn;
+	phys_addr_t range_start, range_end;
+	u64 i;
+
+	/* set highmem page free */
+	for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
+				&range_start, &range_end, NULL) {
+		unsigned long start = PFN_UP(range_start);
+		unsigned long end = PFN_DOWN(range_end);
+
+		/* Ignore complete lowmem entries */
+		if (end <= max_low)
+			continue;
+
+		/* Truncate partial highmem entries */
+		if (start < max_low)
+			start = max_low;
+
+		for (; start < end; start++)
+			free_highmem_page(pfn_to_page(start));
+	}
+#endif
+}
+
+/*
+ * mem_init() marks the free areas in the mem_map and tells us how much
+ * memory is free.  This is done after various parts of the system have
+ * claimed their memory after the kernel image.
+ */
+void __init mem_init(void)
+{
+#ifdef CONFIG_ARM_LPAE
+	swiotlb_init(max_pfn > arm_dma_pfn_limit, SWIOTLB_VERBOSE);
+#endif
+
+	set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
+
+	/* this will put all unused low memory onto the freelists */
+	memblock_free_all();
+
+#ifdef CONFIG_SA1111
+	/* now that our DMA memory is actually so designated, we can free it */
+	free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
+#endif
+
+	free_highpages();
+
+	/*
+	 * Check boundaries twice: Some fundamental inconsistencies can
+	 * be detected at build time already.
+	 */
+#ifdef CONFIG_MMU
+	BUILD_BUG_ON(TASK_SIZE				> MODULES_VADDR);
+	BUG_ON(TASK_SIZE 				> MODULES_VADDR);
+#endif
+
+#ifdef CONFIG_HIGHMEM
+	BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
+	BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE	> PAGE_OFFSET);
+#endif
+}
+
+#ifdef CONFIG_STRICT_KERNEL_RWX
+struct section_perm {
+	const char *name;
+	unsigned long start;
+	unsigned long end;
+	pmdval_t mask;
+	pmdval_t prot;
+	pmdval_t clear;
+};
+
+/* First section-aligned location at or after __start_rodata. */
+extern char __start_rodata_section_aligned[];
+
+static struct section_perm nx_perms[] = {
+	/* Make pages tables, etc before _stext RW (set NX). */
+	{
+		.name	= "pre-text NX",
+		.start	= PAGE_OFFSET,
+		.end	= (unsigned long)_stext,
+		.mask	= ~PMD_SECT_XN,
+		.prot	= PMD_SECT_XN,
+	},
+	/* Make init RW (set NX). */
+	{
+		.name	= "init NX",
+		.start	= (unsigned long)__init_begin,
+		.end	= (unsigned long)_sdata,
+		.mask	= ~PMD_SECT_XN,
+		.prot	= PMD_SECT_XN,
+	},
+	/* Make rodata NX (set RO in ro_perms below). */
+	{
+		.name	= "rodata NX",
+		.start  = (unsigned long)__start_rodata_section_aligned,
+		.end    = (unsigned long)__init_begin,
+		.mask   = ~PMD_SECT_XN,
+		.prot   = PMD_SECT_XN,
+	},
+};
+
+static struct section_perm ro_perms[] = {
+	/* Make kernel code and rodata RX (set RO). */
+	{
+		.name	= "text/rodata RO",
+		.start  = (unsigned long)_stext,
+		.end    = (unsigned long)__init_begin,
+#ifdef CONFIG_ARM_LPAE
+		.mask   = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2),
+		.prot   = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
+#else
+		.mask   = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
+		.prot   = PMD_SECT_APX | PMD_SECT_AP_WRITE,
+		.clear  = PMD_SECT_AP_WRITE,
+#endif
+	},
+};
+
+/*
+ * Updates section permissions only for the current mm (sections are
+ * copied into each mm). During startup, this is the init_mm. Is only
+ * safe to be called with preemption disabled, as under stop_machine().
+ */
+static inline void section_update(unsigned long addr, pmdval_t mask,
+				  pmdval_t prot, struct mm_struct *mm)
+{
+	pmd_t *pmd;
+
+	pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, addr), addr), addr), addr);
+
+#ifdef CONFIG_ARM_LPAE
+	pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
+#else
+	if (addr & SECTION_SIZE)
+		pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
+	else
+		pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
+#endif
+	flush_pmd_entry(pmd);
+	local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
+}
+
+/* Make sure extended page tables are in use. */
+static inline bool arch_has_strict_perms(void)
+{
+	if (cpu_architecture() < CPU_ARCH_ARMv6)
+		return false;
+
+	return !!(get_cr() & CR_XP);
+}
+
+static void set_section_perms(struct section_perm *perms, int n, bool set,
+			      struct mm_struct *mm)
+{
+	size_t i;
+	unsigned long addr;
+
+	if (!arch_has_strict_perms())
+		return;
+
+	for (i = 0; i < n; i++) {
+		if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
+		    !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
+			pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
+				perms[i].name, perms[i].start, perms[i].end,
+				SECTION_SIZE);
+			continue;
+		}
+
+		for (addr = perms[i].start;
+		     addr < perms[i].end;
+		     addr += SECTION_SIZE)
+			section_update(addr, perms[i].mask,
+				set ? perms[i].prot : perms[i].clear, mm);
+	}
+
+}
+
+/**
+ * update_sections_early intended to be called only through stop_machine
+ * framework and executed by only one CPU while all other CPUs will spin and
+ * wait, so no locking is required in this function.
+ */
+static void update_sections_early(struct section_perm perms[], int n)
+{
+	struct task_struct *t, *s;
+
+	for_each_process(t) {
+		if (t->flags & PF_KTHREAD)
+			continue;
+		for_each_thread(t, s)
+			if (s->mm)
+				set_section_perms(perms, n, true, s->mm);
+	}
+	set_section_perms(perms, n, true, current->active_mm);
+	set_section_perms(perms, n, true, &init_mm);
+}
+
+static int __fix_kernmem_perms(void *unused)
+{
+	update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
+	return 0;
+}
+
+static void fix_kernmem_perms(void)
+{
+	stop_machine(__fix_kernmem_perms, NULL, NULL);
+}
+
+static int __mark_rodata_ro(void *unused)
+{
+	update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
+	return 0;
+}
+
+void mark_rodata_ro(void)
+{
+	stop_machine(__mark_rodata_ro, NULL, NULL);
+	debug_checkwx();
+}
+
+#else
+static inline void fix_kernmem_perms(void) { }
+#endif /* CONFIG_STRICT_KERNEL_RWX */
+
+void free_initmem(void)
+{
+	fix_kernmem_perms();
+
+	poison_init_mem(__init_begin, __init_end - __init_begin);
+	if (!machine_is_integrator() && !machine_is_cintegrator())
+		free_initmem_default(-1);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	if (start == initrd_start)
+		start = round_down(start, PAGE_SIZE);
+	if (end == initrd_end)
+		end = round_up(end, PAGE_SIZE);
+
+	poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
+	free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+#endif