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-rw-r--r--arch/powerpc/mm/init_32.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
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+++ b/arch/powerpc/mm/init_32.c
@@ -0,0 +1,133 @@
+// 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/module.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/init.h>
+#include <linux/highmem.h>
+#include <linux/initrd.h>
+#include <linux/pagemap.h>
+#include <linux/memblock.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/hugetlb.h>
+
+#include <asm/io.h>
+#include <asm/mmu.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/btext.h>
+#include <asm/tlb.h>
+#include <asm/sections.h>
+#include <asm/hugetlb.h>
+#include <asm/kup.h>
+#include <asm/kasan.h>
+
+#include <mm/mmu_decl.h>
+
+#if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL)
+/* The amount of lowmem must be within 0xF0000000 - KERNELBASE. */
+#if (CONFIG_LOWMEM_SIZE > (0xF0000000 - PAGE_OFFSET))
+#error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_KERNEL_START"
+#endif
+#endif
+#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
+
+phys_addr_t total_memory;
+phys_addr_t total_lowmem;
+
+#ifdef CONFIG_RELOCATABLE
+/* Used in __va()/__pa() */
+long long virt_phys_offset;
+EXPORT_SYMBOL(virt_phys_offset);
+#endif
+
+phys_addr_t lowmem_end_addr;
+
+int boot_mapsize;
+#ifdef CONFIG_PPC_PMAC
+unsigned long agp_special_page;
+EXPORT_SYMBOL(agp_special_page);
+#endif
+
+void MMU_init(void);
+
+/* max amount of low RAM to map in */
+unsigned long __max_low_memory = MAX_LOW_MEM;
+
+/*
+ * MMU_init sets up the basic memory mappings for the kernel,
+ * including both RAM and possibly some I/O regions,
+ * and sets up the page tables and the MMU hardware ready to go.
+ */
+void __init MMU_init(void)
+{
+ if (ppc_md.progress)
+ ppc_md.progress("MMU:enter", 0x111);
+
+ total_lowmem = total_memory = memblock_end_of_DRAM() - memstart_addr;
+ lowmem_end_addr = memstart_addr + total_lowmem;
+
+#ifdef CONFIG_PPC_85xx
+ /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB
+ * entries, so we need to adjust lowmem to match the amount we can map
+ * in the fixed entries */
+ adjust_total_lowmem();
+#endif /* CONFIG_PPC_85xx */
+
+ if (total_lowmem > __max_low_memory) {
+ total_lowmem = __max_low_memory;
+ lowmem_end_addr = memstart_addr + total_lowmem;
+#ifndef CONFIG_HIGHMEM
+ total_memory = total_lowmem;
+ memblock_enforce_memory_limit(total_lowmem);
+#endif /* CONFIG_HIGHMEM */
+ }
+
+ /* Initialize the MMU hardware */
+ if (ppc_md.progress)
+ ppc_md.progress("MMU:hw init", 0x300);
+ MMU_init_hw();
+
+ /* Map in all of RAM starting at KERNELBASE */
+ if (ppc_md.progress)
+ ppc_md.progress("MMU:mapin", 0x301);
+ mapin_ram();
+
+ /* Initialize early top-down ioremap allocator */
+ ioremap_bot = IOREMAP_TOP;
+
+ if (ppc_md.progress)
+ ppc_md.progress("MMU:exit", 0x211);
+
+ /* From now on, btext is no longer BAT mapped if it was at all */
+#ifdef CONFIG_BOOTX_TEXT
+ btext_unmap();
+#endif
+
+ kasan_mmu_init();
+
+ setup_kup();
+
+ update_mmu_feature_fixups(MMU_FTR_KUAP);
+
+ /* Shortly after that, the entire linear mapping will be available */
+ memblock_set_current_limit(lowmem_end_addr);
+}