forked from Minki/linux
55fd766b5f
On Freescale parts typically have TLB array for large mappings that we can bolt the linear mapping into. We utilize the code that already exists on PPC32 on the 64-bit side to setup the linear mapping to be cover by bolted TLB entries. We utilize a quarter of the variable size TLB array for this purpose. Additionally, we limit the amount of memory to what we can cover via bolted entries so we don't get secondary faults in the TLB miss handlers. We should fix this limitation in the future. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
221 lines
5.9 KiB
C
221 lines
5.9 KiB
C
/*
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* Modifications by Kumar Gala (galak@kernel.crashing.org) to support
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* E500 Book E processors.
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*
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* Copyright 2004,2010 Freescale Semiconductor, Inc.
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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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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/ptrace.h>
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#include <linux/mman.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/stddef.h>
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#include <linux/vmalloc.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/highmem.h>
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#include <asm/pgalloc.h>
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#include <asm/prom.h>
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#include <asm/io.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/mmu.h>
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#include <asm/uaccess.h>
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#include <asm/smp.h>
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#include <asm/machdep.h>
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#include <asm/setup.h>
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#include "mmu_decl.h"
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unsigned int tlbcam_index;
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#define NUM_TLBCAMS (64)
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struct tlbcam TLBCAM[NUM_TLBCAMS];
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struct tlbcamrange {
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unsigned long start;
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unsigned long limit;
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phys_addr_t phys;
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} tlbcam_addrs[NUM_TLBCAMS];
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extern unsigned int tlbcam_index;
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unsigned long tlbcam_sz(int idx)
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{
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return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
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}
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/*
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* Return PA for this VA if it is mapped by a CAM, or 0
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*/
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phys_addr_t v_mapped_by_tlbcam(unsigned long va)
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{
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int b;
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for (b = 0; b < tlbcam_index; ++b)
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if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
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return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
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return 0;
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}
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/*
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* Return VA for a given PA or 0 if not mapped
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*/
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unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
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{
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int b;
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for (b = 0; b < tlbcam_index; ++b)
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if (pa >= tlbcam_addrs[b].phys
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&& pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
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+tlbcam_addrs[b].phys)
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return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
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return 0;
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}
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/*
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* Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
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* in particular size must be a power of 4 between 4k and 256M (or 1G, for cpus
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* that support extended page sizes). Note that while some cpus support a
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* page size of 4G, we don't allow its use here.
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*/
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static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
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unsigned long size, unsigned long flags, unsigned int pid)
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{
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unsigned int tsize, lz;
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asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (size));
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tsize = 21 - lz;
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#ifdef CONFIG_SMP
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if ((flags & _PAGE_NO_CACHE) == 0)
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flags |= _PAGE_COHERENT;
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#endif
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TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
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TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
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TLBCAM[index].MAS2 = virt & PAGE_MASK;
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TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
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TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
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TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
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TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
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TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
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TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
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TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
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if (mmu_has_feature(MMU_FTR_BIG_PHYS))
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TLBCAM[index].MAS7 = (u64)phys >> 32;
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/* Below is unlikely -- only for large user pages or similar */
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if (pte_user(flags)) {
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TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
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TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
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}
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tlbcam_addrs[index].start = virt;
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tlbcam_addrs[index].limit = virt + size - 1;
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tlbcam_addrs[index].phys = phys;
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loadcam_entry(index);
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}
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unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
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{
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int i;
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unsigned long virt = PAGE_OFFSET;
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phys_addr_t phys = memstart_addr;
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unsigned long amount_mapped = 0;
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unsigned long max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xf;
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/* Convert (4^max) kB to (2^max) bytes */
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max_cam = max_cam * 2 + 10;
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/* Calculate CAM values */
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for (i = 0; ram && i < max_cam_idx; i++) {
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unsigned int camsize = __ilog2(ram) & ~1U;
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unsigned int align = __ffs(virt | phys) & ~1U;
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unsigned long cam_sz;
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if (camsize > align)
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camsize = align;
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if (camsize > max_cam)
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camsize = max_cam;
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cam_sz = 1UL << camsize;
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settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
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ram -= cam_sz;
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amount_mapped += cam_sz;
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virt += cam_sz;
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phys += cam_sz;
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}
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tlbcam_index = i;
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return amount_mapped;
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}
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#ifdef CONFIG_PPC32
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#if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
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#error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
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#endif
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unsigned long __init mmu_mapin_ram(unsigned long top)
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{
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return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
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}
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/*
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* MMU_init_hw does the chip-specific initialization of the MMU hardware.
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*/
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void __init MMU_init_hw(void)
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{
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flush_instruction_cache();
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}
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void __init adjust_total_lowmem(void)
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{
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unsigned long ram;
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int i;
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/* adjust lowmem size to __max_low_memory */
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ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
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__max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
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pr_info("Memory CAM mapping: ");
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for (i = 0; i < tlbcam_index - 1; i++)
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pr_cont("%lu/", tlbcam_sz(i) >> 20);
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pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
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(unsigned int)((total_lowmem - __max_low_memory) >> 20));
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__initial_memory_limit_addr = memstart_addr + __max_low_memory;
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}
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#endif
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