Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 745 insertions, 0 deletions

diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c
new file mode 100644
index 000000000..2c15c86c7
--- /dev/null
+++ b/arch/powerpc/mm/nohash/tlb.c
@@ -0,0 +1,745 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * This file contains the routines for TLB flushing.
+ * On machines where the MMU does not use a hash table to store virtual to
+ * physical translations (ie, SW loaded TLBs or Book3E compilant processors,
+ * this does -not- include 603 however which shares the implementation with
+ * hash based processors)
+ *
+ *  -- BenH
+ *
+ * Copyright 2008,2009 Ben Herrenschmidt <benh@kernel.crashing.org>
+ *                     IBM Corp.
+ *
+ *  Derived from arch/ppc/mm/init.c:
+ *    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
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/preempt.h>
+#include <linux/spinlock.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+#include <linux/hugetlb.h>
+
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/tlb.h>
+#include <asm/code-patching.h>
+#include <asm/cputhreads.h>
+#include <asm/hugetlb.h>
+#include <asm/paca.h>
+
+#include <mm/mmu_decl.h>
+
+/*
+ * This struct lists the sw-supported page sizes.  The hardawre MMU may support
+ * other sizes not listed here.   The .ind field is only used on MMUs that have
+ * indirect page table entries.
+ */
+#ifdef CONFIG_PPC_E500
+struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
+	[MMU_PAGE_4K] = {
+		.shift	= 12,
+		.enc	= BOOK3E_PAGESZ_4K,
+	},
+	[MMU_PAGE_2M] = {
+		.shift	= 21,
+		.enc	= BOOK3E_PAGESZ_2M,
+	},
+	[MMU_PAGE_4M] = {
+		.shift	= 22,
+		.enc	= BOOK3E_PAGESZ_4M,
+	},
+	[MMU_PAGE_16M] = {
+		.shift	= 24,
+		.enc	= BOOK3E_PAGESZ_16M,
+	},
+	[MMU_PAGE_64M] = {
+		.shift	= 26,
+		.enc	= BOOK3E_PAGESZ_64M,
+	},
+	[MMU_PAGE_256M] = {
+		.shift	= 28,
+		.enc	= BOOK3E_PAGESZ_256M,
+	},
+	[MMU_PAGE_1G] = {
+		.shift	= 30,
+		.enc	= BOOK3E_PAGESZ_1GB,
+	},
+};
+
+static inline int mmu_get_tsize(int psize)
+{
+	return mmu_psize_defs[psize].enc;
+}
+#else
+static inline int mmu_get_tsize(int psize)
+{
+	/* This isn't used on !Book3E for now */
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_PPC_8xx
+struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
+	[MMU_PAGE_4K] = {
+		.shift	= 12,
+	},
+	[MMU_PAGE_16K] = {
+		.shift	= 14,
+	},
+	[MMU_PAGE_512K] = {
+		.shift	= 19,
+	},
+	[MMU_PAGE_8M] = {
+		.shift	= 23,
+	},
+};
+#endif
+
+/* The variables below are currently only used on 64-bit Book3E
+ * though this will probably be made common with other nohash
+ * implementations at some point
+ */
+#ifdef CONFIG_PPC64
+
+int mmu_pte_psize;		/* Page size used for PTE pages */
+int mmu_vmemmap_psize;		/* Page size used for the virtual mem map */
+int book3e_htw_mode;		/* HW tablewalk?  Value is PPC_HTW_* */
+unsigned long linear_map_top;	/* Top of linear mapping */
+
+
+/*
+ * Number of bytes to add to SPRN_SPRG_TLB_EXFRAME on crit/mcheck/debug
+ * exceptions.  This is used for bolted and e6500 TLB miss handlers which
+ * do not modify this SPRG in the TLB miss code; for other TLB miss handlers,
+ * this is set to zero.
+ */
+int extlb_level_exc;
+
+#endif /* CONFIG_PPC64 */
+
+#ifdef CONFIG_PPC_E500
+/* next_tlbcam_idx is used to round-robin tlbcam entry assignment */
+DEFINE_PER_CPU(int, next_tlbcam_idx);
+EXPORT_PER_CPU_SYMBOL(next_tlbcam_idx);
+#endif
+
+/*
+ * Base TLB flushing operations:
+ *
+ *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
+ *  - flush_tlb_page(vma, vmaddr) flushes one page
+ *  - flush_tlb_range(vma, start, end) flushes a range of pages
+ *  - flush_tlb_kernel_range(start, end) flushes kernel pages
+ *
+ *  - local_* variants of page and mm only apply to the current
+ *    processor
+ */
+
+#ifndef CONFIG_PPC_8xx
+/*
+ * These are the base non-SMP variants of page and mm flushing
+ */
+void local_flush_tlb_mm(struct mm_struct *mm)
+{
+	unsigned int pid;
+
+	preempt_disable();
+	pid = mm->context.id;
+	if (pid != MMU_NO_CONTEXT)
+		_tlbil_pid(pid);
+	preempt_enable();
+}
+EXPORT_SYMBOL(local_flush_tlb_mm);
+
+void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
+			    int tsize, int ind)
+{
+	unsigned int pid;
+
+	preempt_disable();
+	pid = mm ? mm->context.id : 0;
+	if (pid != MMU_NO_CONTEXT)
+		_tlbil_va(vmaddr, pid, tsize, ind);
+	preempt_enable();
+}
+
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
+{
+	__local_flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
+			       mmu_get_tsize(mmu_virtual_psize), 0);
+}
+EXPORT_SYMBOL(local_flush_tlb_page);
+#endif
+
+/*
+ * And here are the SMP non-local implementations
+ */
+#ifdef CONFIG_SMP
+
+static DEFINE_RAW_SPINLOCK(tlbivax_lock);
+
+struct tlb_flush_param {
+	unsigned long addr;
+	unsigned int pid;
+	unsigned int tsize;
+	unsigned int ind;
+};
+
+static void do_flush_tlb_mm_ipi(void *param)
+{
+	struct tlb_flush_param *p = param;
+
+	_tlbil_pid(p ? p->pid : 0);
+}
+
+static void do_flush_tlb_page_ipi(void *param)
+{
+	struct tlb_flush_param *p = param;
+
+	_tlbil_va(p->addr, p->pid, p->tsize, p->ind);
+}
+
+
+/* Note on invalidations and PID:
+ *
+ * We snapshot the PID with preempt disabled. At this point, it can still
+ * change either because:
+ * - our context is being stolen (PID -> NO_CONTEXT) on another CPU
+ * - we are invaliating some target that isn't currently running here
+ *   and is concurrently acquiring a new PID on another CPU
+ * - some other CPU is re-acquiring a lost PID for this mm
+ * etc...
+ *
+ * However, this shouldn't be a problem as we only guarantee
+ * invalidation of TLB entries present prior to this call, so we
+ * don't care about the PID changing, and invalidating a stale PID
+ * is generally harmless.
+ */
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+	unsigned int pid;
+
+	preempt_disable();
+	pid = mm->context.id;
+	if (unlikely(pid == MMU_NO_CONTEXT))
+		goto no_context;
+	if (!mm_is_core_local(mm)) {
+		struct tlb_flush_param p = { .pid = pid };
+		/* Ignores smp_processor_id() even if set. */
+		smp_call_function_many(mm_cpumask(mm),
+				       do_flush_tlb_mm_ipi, &p, 1);
+	}
+	_tlbil_pid(pid);
+ no_context:
+	preempt_enable();
+}
+EXPORT_SYMBOL(flush_tlb_mm);
+
+void __flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
+		      int tsize, int ind)
+{
+	struct cpumask *cpu_mask;
+	unsigned int pid;
+
+	/*
+	 * This function as well as __local_flush_tlb_page() must only be called
+	 * for user contexts.
+	 */
+	if (WARN_ON(!mm))
+		return;
+
+	preempt_disable();
+	pid = mm->context.id;
+	if (unlikely(pid == MMU_NO_CONTEXT))
+		goto bail;
+	cpu_mask = mm_cpumask(mm);
+	if (!mm_is_core_local(mm)) {
+		/* If broadcast tlbivax is supported, use it */
+		if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) {
+			int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL);
+			if (lock)
+				raw_spin_lock(&tlbivax_lock);
+			_tlbivax_bcast(vmaddr, pid, tsize, ind);
+			if (lock)
+				raw_spin_unlock(&tlbivax_lock);
+			goto bail;
+		} else {
+			struct tlb_flush_param p = {
+				.pid = pid,
+				.addr = vmaddr,
+				.tsize = tsize,
+				.ind = ind,
+			};
+			/* Ignores smp_processor_id() even if set in cpu_mask */
+			smp_call_function_many(cpu_mask,
+					       do_flush_tlb_page_ipi, &p, 1);
+		}
+	}
+	_tlbil_va(vmaddr, pid, tsize, ind);
+ bail:
+	preempt_enable();
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
+{
+#ifdef CONFIG_HUGETLB_PAGE
+	if (vma && is_vm_hugetlb_page(vma))
+		flush_hugetlb_page(vma, vmaddr);
+#endif
+
+	__flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
+			 mmu_get_tsize(mmu_virtual_psize), 0);
+}
+EXPORT_SYMBOL(flush_tlb_page);
+
+#endif /* CONFIG_SMP */
+
+#ifdef CONFIG_PPC_47x
+void __init early_init_mmu_47x(void)
+{
+#ifdef CONFIG_SMP
+	unsigned long root = of_get_flat_dt_root();
+	if (of_get_flat_dt_prop(root, "cooperative-partition", NULL))
+		mmu_clear_feature(MMU_FTR_USE_TLBIVAX_BCAST);
+#endif /* CONFIG_SMP */
+}
+#endif /* CONFIG_PPC_47x */
+
+/*
+ * Flush kernel TLB entries in the given range
+ */
+#ifndef CONFIG_PPC_8xx
+void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+#ifdef CONFIG_SMP
+	preempt_disable();
+	smp_call_function(do_flush_tlb_mm_ipi, NULL, 1);
+	_tlbil_pid(0);
+	preempt_enable();
+#else
+	_tlbil_pid(0);
+#endif
+}
+EXPORT_SYMBOL(flush_tlb_kernel_range);
+#endif
+
+/*
+ * Currently, for range flushing, we just do a full mm flush. This should
+ * be optimized based on a threshold on the size of the range, since
+ * some implementation can stack multiple tlbivax before a tlbsync but
+ * for now, we keep it that way
+ */
+void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+		     unsigned long end)
+
+{
+	if (end - start == PAGE_SIZE && !(start & ~PAGE_MASK))
+		flush_tlb_page(vma, start);
+	else
+		flush_tlb_mm(vma->vm_mm);
+}
+EXPORT_SYMBOL(flush_tlb_range);
+
+void tlb_flush(struct mmu_gather *tlb)
+{
+	flush_tlb_mm(tlb->mm);
+}
+
+/*
+ * Below are functions specific to the 64-bit variant of Book3E though that
+ * may change in the future
+ */
+
+#ifdef CONFIG_PPC64
+
+/*
+ * Handling of virtual linear page tables or indirect TLB entries
+ * flushing when PTE pages are freed
+ */
+void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address)
+{
+	int tsize = mmu_psize_defs[mmu_pte_psize].enc;
+
+	if (book3e_htw_mode != PPC_HTW_NONE) {
+		unsigned long start = address & PMD_MASK;
+		unsigned long end = address + PMD_SIZE;
+		unsigned long size = 1UL << mmu_psize_defs[mmu_pte_psize].shift;
+
+		/* This isn't the most optimal, ideally we would factor out the
+		 * while preempt & CPU mask mucking around, or even the IPI but
+		 * it will do for now
+		 */
+		while (start < end) {
+			__flush_tlb_page(tlb->mm, start, tsize, 1);
+			start += size;
+		}
+	} else {
+		unsigned long rmask = 0xf000000000000000ul;
+		unsigned long rid = (address & rmask) | 0x1000000000000000ul;
+		unsigned long vpte = address & ~rmask;
+
+		vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful;
+		vpte |= rid;
+		__flush_tlb_page(tlb->mm, vpte, tsize, 0);
+	}
+}
+
+static void __init setup_page_sizes(void)
+{
+	unsigned int tlb0cfg;
+	unsigned int tlb0ps;
+	unsigned int eptcfg;
+	int i, psize;
+
+#ifdef CONFIG_PPC_E500
+	unsigned int mmucfg = mfspr(SPRN_MMUCFG);
+	int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E);
+
+	if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
+		unsigned int tlb1cfg = mfspr(SPRN_TLB1CFG);
+		unsigned int min_pg, max_pg;
+
+		min_pg = (tlb1cfg & TLBnCFG_MINSIZE) >> TLBnCFG_MINSIZE_SHIFT;
+		max_pg = (tlb1cfg & TLBnCFG_MAXSIZE) >> TLBnCFG_MAXSIZE_SHIFT;
+
+		for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
+			struct mmu_psize_def *def;
+			unsigned int shift;
+
+			def = &mmu_psize_defs[psize];
+			shift = def->shift;
+
+			if (shift == 0 || shift & 1)
+				continue;
+
+			/* adjust to be in terms of 4^shift Kb */
+			shift = (shift - 10) >> 1;
+
+			if ((shift >= min_pg) && (shift <= max_pg))
+				def->flags |= MMU_PAGE_SIZE_DIRECT;
+		}
+
+		goto out;
+	}
+
+	if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) {
+		u32 tlb1cfg, tlb1ps;
+
+		tlb0cfg = mfspr(SPRN_TLB0CFG);
+		tlb1cfg = mfspr(SPRN_TLB1CFG);
+		tlb1ps = mfspr(SPRN_TLB1PS);
+		eptcfg = mfspr(SPRN_EPTCFG);
+
+		if ((tlb1cfg & TLBnCFG_IND) && (tlb0cfg & TLBnCFG_PT))
+			book3e_htw_mode = PPC_HTW_E6500;
+
+		/*
+		 * We expect 4K subpage size and unrestricted indirect size.
+		 * The lack of a restriction on indirect size is a Freescale
+		 * extension, indicated by PSn = 0 but SPSn != 0.
+		 */
+		if (eptcfg != 2)
+			book3e_htw_mode = PPC_HTW_NONE;
+
+		for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
+			struct mmu_psize_def *def = &mmu_psize_defs[psize];
+
+			if (!def->shift)
+				continue;
+
+			if (tlb1ps & (1U << (def->shift - 10))) {
+				def->flags |= MMU_PAGE_SIZE_DIRECT;
+
+				if (book3e_htw_mode && psize == MMU_PAGE_2M)
+					def->flags |= MMU_PAGE_SIZE_INDIRECT;
+			}
+		}
+
+		goto out;
+	}
+#endif
+
+	tlb0cfg = mfspr(SPRN_TLB0CFG);
+	tlb0ps = mfspr(SPRN_TLB0PS);
+	eptcfg = mfspr(SPRN_EPTCFG);
+
+	/* Look for supported direct sizes */
+	for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
+		struct mmu_psize_def *def = &mmu_psize_defs[psize];
+
+		if (tlb0ps & (1U << (def->shift - 10)))
+			def->flags |= MMU_PAGE_SIZE_DIRECT;
+	}
+
+	/* Indirect page sizes supported ? */
+	if ((tlb0cfg & TLBnCFG_IND) == 0 ||
+	    (tlb0cfg & TLBnCFG_PT) == 0)
+		goto out;
+
+	book3e_htw_mode = PPC_HTW_IBM;
+
+	/* Now, we only deal with one IND page size for each
+	 * direct size. Hopefully all implementations today are
+	 * unambiguous, but we might want to be careful in the
+	 * future.
+	 */
+	for (i = 0; i < 3; i++) {
+		unsigned int ps, sps;
+
+		sps = eptcfg & 0x1f;
+		eptcfg >>= 5;
+		ps = eptcfg & 0x1f;
+		eptcfg >>= 5;
+		if (!ps || !sps)
+			continue;
+		for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
+			struct mmu_psize_def *def = &mmu_psize_defs[psize];
+
+			if (ps == (def->shift - 10))
+				def->flags |= MMU_PAGE_SIZE_INDIRECT;
+			if (sps == (def->shift - 10))
+				def->ind = ps + 10;
+		}
+	}
+
+out:
+	/* Cleanup array and print summary */
+	pr_info("MMU: Supported page sizes\n");
+	for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
+		struct mmu_psize_def *def = &mmu_psize_defs[psize];
+		const char *__page_type_names[] = {
+			"unsupported",
+			"direct",
+			"indirect",
+			"direct & indirect"
+		};
+		if (def->flags == 0) {
+			def->shift = 0;	
+			continue;
+		}
+		pr_info("  %8ld KB as %s\n", 1ul << (def->shift - 10),
+			__page_type_names[def->flags & 0x3]);
+	}
+}
+
+static void __init setup_mmu_htw(void)
+{
+	/*
+	 * If we want to use HW tablewalk, enable it by patching the TLB miss
+	 * handlers to branch to the one dedicated to it.
+	 */
+
+	switch (book3e_htw_mode) {
+	case PPC_HTW_IBM:
+		patch_exception(0x1c0, exc_data_tlb_miss_htw_book3e);
+		patch_exception(0x1e0, exc_instruction_tlb_miss_htw_book3e);
+		break;
+#ifdef CONFIG_PPC_E500
+	case PPC_HTW_E6500:
+		extlb_level_exc = EX_TLB_SIZE;
+		patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
+		patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
+		break;
+#endif
+	}
+	pr_info("MMU: Book3E HW tablewalk %s\n",
+		book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
+}
+
+/*
+ * Early initialization of the MMU TLB code
+ */
+static void early_init_this_mmu(void)
+{
+	unsigned int mas4;
+
+	/* Set MAS4 based on page table setting */
+
+	mas4 = 0x4 << MAS4_WIMGED_SHIFT;
+	switch (book3e_htw_mode) {
+	case PPC_HTW_E6500:
+		mas4 |= MAS4_INDD;
+		mas4 |= BOOK3E_PAGESZ_2M << MAS4_TSIZED_SHIFT;
+		mas4 |= MAS4_TLBSELD(1);
+		mmu_pte_psize = MMU_PAGE_2M;
+		break;
+
+	case PPC_HTW_IBM:
+		mas4 |= MAS4_INDD;
+		mas4 |=	BOOK3E_PAGESZ_1M << MAS4_TSIZED_SHIFT;
+		mmu_pte_psize = MMU_PAGE_1M;
+		break;
+
+	case PPC_HTW_NONE:
+		mas4 |=	BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT;
+		mmu_pte_psize = mmu_virtual_psize;
+		break;
+	}
+	mtspr(SPRN_MAS4, mas4);
+
+#ifdef CONFIG_PPC_E500
+	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
+		unsigned int num_cams;
+		bool map = true;
+
+		/* use a quarter of the TLBCAM for bolted linear map */
+		num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
+
+		/*
+		 * Only do the mapping once per core, or else the
+		 * transient mapping would cause problems.
+		 */
+#ifdef CONFIG_SMP
+		if (hweight32(get_tensr()) > 1)
+			map = false;
+#endif
+
+		if (map)
+			linear_map_top = map_mem_in_cams(linear_map_top,
+							 num_cams, false, true);
+	}
+#endif
+
+	/* A sync won't hurt us after mucking around with
+	 * the MMU configuration
+	 */
+	mb();
+}
+
+static void __init early_init_mmu_global(void)
+{
+	/* XXX This should be decided at runtime based on supported
+	 * page sizes in the TLB, but for now let's assume 16M is
+	 * always there and a good fit (which it probably is)
+	 *
+	 * Freescale booke only supports 4K pages in TLB0, so use that.
+	 */
+	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
+		mmu_vmemmap_psize = MMU_PAGE_4K;
+	else
+		mmu_vmemmap_psize = MMU_PAGE_16M;
+
+	/* XXX This code only checks for TLB 0 capabilities and doesn't
+	 *     check what page size combos are supported by the HW. It
+	 *     also doesn't handle the case where a separate array holds
+	 *     the IND entries from the array loaded by the PT.
+	 */
+	/* Look for supported page sizes */
+	setup_page_sizes();
+
+	/* Look for HW tablewalk support */
+	setup_mmu_htw();
+
+#ifdef CONFIG_PPC_E500
+	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
+		if (book3e_htw_mode == PPC_HTW_NONE) {
+			extlb_level_exc = EX_TLB_SIZE;
+			patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
+			patch_exception(0x1e0,
+				exc_instruction_tlb_miss_bolted_book3e);
+		}
+	}
+#endif
+
+	/* Set the global containing the top of the linear mapping
+	 * for use by the TLB miss code
+	 */
+	linear_map_top = memblock_end_of_DRAM();
+
+	ioremap_bot = IOREMAP_BASE;
+}
+
+static void __init early_mmu_set_memory_limit(void)
+{
+#ifdef CONFIG_PPC_E500
+	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
+		/*
+		 * Limit memory so we dont have linear faults.
+		 * Unlike memblock_set_current_limit, which limits
+		 * memory available during early boot, this permanently
+		 * reduces the memory available to Linux.  We need to
+		 * do this because highmem is not supported on 64-bit.
+		 */
+		memblock_enforce_memory_limit(linear_map_top);
+	}
+#endif
+
+	memblock_set_current_limit(linear_map_top);
+}
+
+/* boot cpu only */
+void __init early_init_mmu(void)
+{
+	early_init_mmu_global();
+	early_init_this_mmu();
+	early_mmu_set_memory_limit();
+}
+
+void early_init_mmu_secondary(void)
+{
+	early_init_this_mmu();
+}
+
+void setup_initial_memory_limit(phys_addr_t first_memblock_base,
+				phys_addr_t first_memblock_size)
+{
+	/* On non-FSL Embedded 64-bit, we adjust the RMA size to match
+	 * the bolted TLB entry. We know for now that only 1G
+	 * entries are supported though that may eventually
+	 * change.
+	 *
+	 * on FSL Embedded 64-bit, usually all RAM is bolted, but with
+	 * unusual memory sizes it's possible for some RAM to not be mapped
+	 * (such RAM is not used at all by Linux, since we don't support
+	 * highmem on 64-bit).  We limit ppc64_rma_size to what would be
+	 * mappable if this memblock is the only one.  Additional memblocks
+	 * can only increase, not decrease, the amount that ends up getting
+	 * mapped.  We still limit max to 1G even if we'll eventually map
+	 * more.  This is due to what the early init code is set up to do.
+	 *
+	 * We crop it to the size of the first MEMBLOCK to
+	 * avoid going over total available memory just in case...
+	 */
+#ifdef CONFIG_PPC_E500
+	if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
+		unsigned long linear_sz;
+		unsigned int num_cams;
+
+		/* use a quarter of the TLBCAM for bolted linear map */
+		num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
+
+		linear_sz = map_mem_in_cams(first_memblock_size, num_cams,
+					    true, true);
+
+		ppc64_rma_size = min_t(u64, linear_sz, 0x40000000);
+	} else
+#endif
+		ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
+
+	/* Finally limit subsequent allocations */
+	memblock_set_current_limit(first_memblock_base + ppc64_rma_size);
+}
+#else /* ! CONFIG_PPC64 */
+void __init early_init_mmu(void)
+{
+#ifdef CONFIG_PPC_47x
+	early_init_mmu_47x();
+#endif
+}
+#endif /* CONFIG_PPC64 */