242 lines
6.2 KiB
C
242 lines
6.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Modifications by Matt Porter (mporter@mvista.com) to support
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* PPC44x Book E processors.
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*
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* This file contains the routines for initializing the MMU
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* on the 4xx series of chips.
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* -- paulus
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*
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* Derived from arch/ppc/mm/init.c:
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
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* and Cort Dougan (PReP) (cort@cs.nmt.edu)
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* Copyright (C) 1996 Paul Mackerras
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*
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* Derived from "arch/i386/mm/init.c"
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*/
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#include <linux/init.h>
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#include <linux/memblock.h>
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#include <asm/mmu.h>
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#include <asm/page.h>
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#include <asm/cacheflush.h>
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#include <asm/code-patching.h>
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#include <mm/mmu_decl.h>
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/* Used by the 44x TLB replacement exception handler.
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* Just needed it declared someplace.
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*/
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unsigned int tlb_44x_index; /* = 0 */
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unsigned int tlb_44x_hwater = PPC44x_TLB_SIZE - 1 - PPC44x_EARLY_TLBS;
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int icache_44x_need_flush;
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unsigned long tlb_47x_boltmap[1024/8];
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static void ppc44x_update_tlb_hwater(void)
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{
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/* The TLB miss handlers hard codes the watermark in a cmpli
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* instruction to improve performances rather than loading it
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* from the global variable. Thus, we patch the instructions
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* in the 2 TLB miss handlers when updating the value
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*/
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modify_instruction_site(&patch__tlb_44x_hwater_D, 0xffff, tlb_44x_hwater);
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modify_instruction_site(&patch__tlb_44x_hwater_I, 0xffff, tlb_44x_hwater);
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}
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/*
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* "Pins" a 256MB TLB entry in AS0 for kernel lowmem for 44x type MMU
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*/
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static void __init ppc44x_pin_tlb(unsigned int virt, unsigned int phys)
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{
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unsigned int entry = tlb_44x_hwater--;
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ppc44x_update_tlb_hwater();
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mtspr(SPRN_MMUCR, 0);
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__asm__ __volatile__(
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"tlbwe %2,%3,%4\n"
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"tlbwe %1,%3,%5\n"
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"tlbwe %0,%3,%6\n"
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:
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: "r" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
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"r" (phys),
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"r" (virt | PPC44x_TLB_VALID | PPC44x_TLB_256M),
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"r" (entry),
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"i" (PPC44x_TLB_PAGEID),
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"i" (PPC44x_TLB_XLAT),
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"i" (PPC44x_TLB_ATTRIB));
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}
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static int __init ppc47x_find_free_bolted(void)
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{
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unsigned int mmube0 = mfspr(SPRN_MMUBE0);
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unsigned int mmube1 = mfspr(SPRN_MMUBE1);
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if (!(mmube0 & MMUBE0_VBE0))
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return 0;
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if (!(mmube0 & MMUBE0_VBE1))
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return 1;
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if (!(mmube0 & MMUBE0_VBE2))
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return 2;
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if (!(mmube1 & MMUBE1_VBE3))
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return 3;
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if (!(mmube1 & MMUBE1_VBE4))
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return 4;
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if (!(mmube1 & MMUBE1_VBE5))
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return 5;
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return -1;
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}
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static void __init ppc47x_update_boltmap(void)
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{
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unsigned int mmube0 = mfspr(SPRN_MMUBE0);
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unsigned int mmube1 = mfspr(SPRN_MMUBE1);
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if (mmube0 & MMUBE0_VBE0)
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__set_bit((mmube0 >> MMUBE0_IBE0_SHIFT) & 0xff,
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tlb_47x_boltmap);
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if (mmube0 & MMUBE0_VBE1)
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__set_bit((mmube0 >> MMUBE0_IBE1_SHIFT) & 0xff,
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tlb_47x_boltmap);
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if (mmube0 & MMUBE0_VBE2)
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__set_bit((mmube0 >> MMUBE0_IBE2_SHIFT) & 0xff,
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tlb_47x_boltmap);
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if (mmube1 & MMUBE1_VBE3)
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__set_bit((mmube1 >> MMUBE1_IBE3_SHIFT) & 0xff,
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tlb_47x_boltmap);
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if (mmube1 & MMUBE1_VBE4)
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__set_bit((mmube1 >> MMUBE1_IBE4_SHIFT) & 0xff,
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tlb_47x_boltmap);
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if (mmube1 & MMUBE1_VBE5)
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__set_bit((mmube1 >> MMUBE1_IBE5_SHIFT) & 0xff,
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tlb_47x_boltmap);
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}
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/*
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* "Pins" a 256MB TLB entry in AS0 for kernel lowmem for 47x type MMU
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*/
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static void ppc47x_pin_tlb(unsigned int virt, unsigned int phys)
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{
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unsigned int rA;
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int bolted;
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/* Base rA is HW way select, way 0, bolted bit set */
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rA = 0x88000000;
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/* Look for a bolted entry slot */
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bolted = ppc47x_find_free_bolted();
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BUG_ON(bolted < 0);
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/* Insert bolted slot number */
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rA |= bolted << 24;
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pr_debug("256M TLB entry for 0x%08x->0x%08x in bolt slot %d\n",
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virt, phys, bolted);
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mtspr(SPRN_MMUCR, 0);
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__asm__ __volatile__(
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"tlbwe %2,%3,0\n"
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"tlbwe %1,%3,1\n"
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"tlbwe %0,%3,2\n"
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:
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: "r" (PPC47x_TLB2_SW | PPC47x_TLB2_SR |
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PPC47x_TLB2_SX
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#ifdef CONFIG_SMP
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| PPC47x_TLB2_M
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#endif
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),
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"r" (phys),
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"r" (virt | PPC47x_TLB0_VALID | PPC47x_TLB0_256M),
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"r" (rA));
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}
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void __init MMU_init_hw(void)
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{
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/* This is not useful on 47x but won't hurt either */
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ppc44x_update_tlb_hwater();
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flush_instruction_cache();
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}
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unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
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{
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unsigned long addr;
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unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);
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/* Pin in enough TLBs to cover any lowmem not covered by the
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* initial 256M mapping established in head_44x.S */
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for (addr = memstart + PPC_PIN_SIZE; addr < lowmem_end_addr;
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addr += PPC_PIN_SIZE) {
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if (mmu_has_feature(MMU_FTR_TYPE_47x))
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ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
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else
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ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
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}
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if (mmu_has_feature(MMU_FTR_TYPE_47x)) {
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ppc47x_update_boltmap();
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#ifdef DEBUG
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{
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int i;
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printk(KERN_DEBUG "bolted entries: ");
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for (i = 0; i < 255; i++) {
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if (test_bit(i, tlb_47x_boltmap))
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printk("%d ", i);
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}
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printk("\n");
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}
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#endif /* DEBUG */
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}
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return total_lowmem;
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}
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void setup_initial_memory_limit(phys_addr_t first_memblock_base,
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phys_addr_t first_memblock_size)
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{
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u64 size;
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#ifndef CONFIG_NONSTATIC_KERNEL
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/* We don't currently support the first MEMBLOCK not mapping 0
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* physical on those processors
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*/
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BUG_ON(first_memblock_base != 0);
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#endif
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/* 44x has a 256M TLB entry pinned at boot */
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size = (min_t(u64, first_memblock_size, PPC_PIN_SIZE));
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memblock_set_current_limit(first_memblock_base + size);
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}
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#ifdef CONFIG_SMP
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void __init mmu_init_secondary(int cpu)
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{
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unsigned long addr;
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unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);
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/* Pin in enough TLBs to cover any lowmem not covered by the
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* initial 256M mapping established in head_44x.S
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*
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* WARNING: This is called with only the first 256M of the
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* linear mapping in the TLB and we can't take faults yet
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* so beware of what this code uses. It runs off a temporary
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* stack. current (r2) isn't initialized, smp_processor_id()
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* will not work, current thread info isn't accessible, ...
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*/
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for (addr = memstart + PPC_PIN_SIZE; addr < lowmem_end_addr;
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addr += PPC_PIN_SIZE) {
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if (mmu_has_feature(MMU_FTR_TYPE_47x))
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ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
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else
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ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
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}
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}
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#endif /* CONFIG_SMP */
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