text: /*
   * Modifications by Kumar Gala (galak@kernel.crashing.org) to support
   * E500 Book E processors.
   *
   * Copyright 2004,2010 Freescale Semiconductor, Inc.
   *
   * This file contains the routines for initializing the MMU
   * on the 4xx series of chips.
   *  -- paulus
   *
   *  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
   *
   *  This program is free software; you can redistribute it and/or
   *  modify it under the terms of the GNU General Public License
   *  as published by the Free Software Foundation; either version
   *  2 of the License, or (at your option) any later version.
   *
   */
  
  #include <linux/signal.h>
  #include <linux/sched.h>
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/string.h>
  #include <linux/types.h>
  #include <linux/ptrace.h>
  #include <linux/mman.h>
  #include <linux/mm.h>
  #include <linux/swap.h>
  #include <linux/stddef.h>
  #include <linux/vmalloc.h>
  #include <linux/init.h>
  #include <linux/delay.h>
  #include <linux/highmem.h>
  #include <linux/memblock.h>
  
  #include <asm/pgalloc.h>
  #include <asm/prom.h>
  #include <asm/io.h>
  #include <asm/mmu_context.h>
  #include <asm/pgtable.h>
  #include <asm/mmu.h>
  #include <asm/uaccess.h>
  #include <asm/smp.h>
  #include <asm/machdep.h>
  #include <asm/setup.h>
  
  #include "mmu_decl.h"
  
  unsigned int tlbcam_index;
  
  #define NUM_TLBCAMS	(64)
  struct tlbcam TLBCAM[NUM_TLBCAMS];
  
  struct tlbcamrange {
  	unsigned long start;
  	unsigned long limit;
  	phys_addr_t phys;
  } tlbcam_addrs[NUM_TLBCAMS];
  
  extern unsigned int tlbcam_index;
  
  unsigned long tlbcam_sz(int idx)
  {
  	return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
  }
  
  /*
   * Return PA for this VA if it is mapped by a CAM, or 0
   */
  phys_addr_t v_mapped_by_tlbcam(unsigned long va)
  {
  	int b;
  	for (b = 0; b < tlbcam_index; ++b)
  		if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
  			return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
  	return 0;
  }
  
  /*
   * Return VA for a given PA or 0 if not mapped
   */
  unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
  {
  	int b;
  	for (b = 0; b < tlbcam_index; ++b)
  		if (pa >= tlbcam_addrs[b].phys
  			&& pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
  		              +tlbcam_addrs[b].phys)
  			return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
  	return 0;
  }
  
  /*
   * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
   * in particular size must be a power of 4 between 4k and the max supported by
   * an implementation; max may further be limited by what can be represented in
   * an unsigned long (for example, 32-bit implementations cannot support a 4GB
   * size).
   */
  static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
  		unsigned long size, unsigned long flags, unsigned int pid)
  {
  	unsigned int tsize;
  
  	tsize = __ilog2(size) - 10;
  
  #ifdef CONFIG_SMP
  	if ((flags & _PAGE_NO_CACHE) == 0)
  		flags |= _PAGE_COHERENT;
  #endif
  
  	TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
  	TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
  	TLBCAM[index].MAS2 = virt & PAGE_MASK;
  
  	TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
  	TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
  	TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
  	TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
  	TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
  
  	TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
  	TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
  	if (mmu_has_feature(MMU_FTR_BIG_PHYS))
  		TLBCAM[index].MAS7 = (u64)phys >> 32;
  
  	/* Below is unlikely -- only for large user pages or similar */
  	if (pte_user(flags)) {
  	   TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
  	   TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
  	}
  
  	tlbcam_addrs[index].start = virt;
  	tlbcam_addrs[index].limit = virt + size - 1;
  	tlbcam_addrs[index].phys = phys;
  
  	loadcam_entry(index);
  }
  
  unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
  			  phys_addr_t phys)
  {
  	unsigned int camsize = __ilog2(ram) & ~1U;
  	unsigned int align = __ffs(virt | phys) & ~1U;
  	unsigned long max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xf;
  
  	/* Convert (4^max) kB to (2^max) bytes */
  	max_cam = max_cam * 2 + 10;
  
  	if (camsize > align)
  		camsize = align;
  	if (camsize > max_cam)
  		camsize = max_cam;
  
  	return 1UL << camsize;
  }
  
  unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
  {
  	int i;
  	unsigned long virt = PAGE_OFFSET;
  	phys_addr_t phys = memstart_addr;
  	unsigned long amount_mapped = 0;
  
  	/* Calculate CAM values */
  	for (i = 0; ram && i < max_cam_idx; i++) {
  		unsigned long cam_sz;
  
  		cam_sz = calc_cam_sz(ram, virt, phys);
  		settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
  
  		ram -= cam_sz;
  		amount_mapped += cam_sz;
  		virt += cam_sz;
  		phys += cam_sz;
  	}
  	tlbcam_index = i;
  
  	return amount_mapped;
  }
  
  #ifdef CONFIG_PPC32
  
  #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
  #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
  #endif
  
  unsigned long __init mmu_mapin_ram(unsigned long top)
  {
  	return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
  }
  
  /*
   * MMU_init_hw does the chip-specific initialization of the MMU hardware.
   */
  void __init MMU_init_hw(void)
  {
  	flush_instruction_cache();
  }
  
  void __init adjust_total_lowmem(void)
  {
  	unsigned long ram;
  	int i;
  
  	/* adjust lowmem size to __max_low_memory */
  	ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
  
  	__max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
  
  	pr_info("Memory CAM mapping: ");
  	for (i = 0; i < tlbcam_index - 1; i++)
  		pr_cont("%lu/", tlbcam_sz(i) >> 20);
  	pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
  	        (unsigned int)((total_lowmem - __max_low_memory) >> 20));
  
  	memblock_set_current_limit(memstart_addr + __max_low_memory);
  }
  
  void setup_initial_memory_limit(phys_addr_t first_memblock_base,
  				phys_addr_t first_memblock_size)
  {
  	phys_addr_t limit = first_memblock_base + first_memblock_size;
  
  	/* 64M mapped initially according to head_fsl_booke.S */
  	memblock_set_current_limit(min_t(u64, limit, 0x04000000));
  }
  #endif
  