873553b3d6
The CONFIG_FSL_BOOKE mmu setup code fails when CONFIG_HIGHMEM=y and the 3 fixed TLB entries cannot exactly map the lowmem size. Each TLB entry can map 4MB, 16MB, 64MB or 256MB, so the failure is observed when the kernel lowmem size is not equal to the sum of up to 3 of those values. Normally, memory is sized in nice numbers, but I observed this problem while testing a crash dump kernel. The failure can also be observed by artificially reducing the kernel's main memory via the mem= kernel command line parameter. This commit fixes the problem by setting __initial_memory_limit in adjust_total_lowmem(). Signed-off-by: Dale Farnsworth <dale@farnsworth.org> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
238 lines
6.1 KiB
C
238 lines
6.1 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 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/bootx.h>
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#include <asm/machdep.h>
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#include <asm/setup.h>
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extern void loadcam_entry(unsigned int index);
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unsigned int tlbcam_index;
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unsigned int num_tlbcam_entries;
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static unsigned long __cam0, __cam1, __cam2;
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extern unsigned long total_lowmem;
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extern unsigned long __max_low_memory;
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extern unsigned long __initial_memory_limit;
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#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
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#define NUM_TLBCAMS (16)
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struct tlbcam {
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u32 MAS0;
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u32 MAS1;
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u32 MAS2;
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u32 MAS3;
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u32 MAS7;
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} 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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/*
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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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unsigned long 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(unsigned long 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 one of the I/D BAT (block address translation) register pairs.
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* The parameters are not checked; in particular size must be a power
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* of 4 between 4k and 256M.
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*/
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void settlbcam(int index, unsigned long virt, phys_addr_t phys,
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unsigned int size, int flags, unsigned int pid)
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{
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unsigned int tsize, lz;
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asm ("cntlzw %0,%1" : "=r" (lz) : "r" (size));
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tsize = (21 - lz) / 2;
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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 & PAGE_MASK) | MAS3_SX | MAS3_SR;
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TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
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#ifndef CONFIG_KGDB /* want user access for breakpoints */
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if (flags & _PAGE_USER) {
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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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#else
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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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#endif
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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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void invalidate_tlbcam_entry(int index)
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{
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TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index);
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TLBCAM[index].MAS1 = ~MAS1_VALID;
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loadcam_entry(index);
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}
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void __init cam_mapin_ram(unsigned long cam0, unsigned long cam1,
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unsigned long cam2)
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{
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settlbcam(0, KERNELBASE, PPC_MEMSTART, cam0, _PAGE_KERNEL, 0);
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tlbcam_index++;
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if (cam1) {
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tlbcam_index++;
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settlbcam(1, KERNELBASE+cam0, PPC_MEMSTART+cam0, cam1, _PAGE_KERNEL, 0);
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}
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if (cam2) {
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tlbcam_index++;
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settlbcam(2, KERNELBASE+cam0+cam1, PPC_MEMSTART+cam0+cam1, cam2, _PAGE_KERNEL, 0);
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}
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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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unsigned long __init mmu_mapin_ram(void)
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{
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cam_mapin_ram(__cam0, __cam1, __cam2);
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return __cam0 + __cam1 + __cam2;
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}
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void __init
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adjust_total_lowmem(void)
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{
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unsigned long max_low_mem = MAX_LOW_MEM;
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unsigned long cam_max = 0x10000000;
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unsigned long ram;
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/* adjust CAM size to max_low_mem */
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if (max_low_mem < cam_max)
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cam_max = max_low_mem;
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/* adjust lowmem size to max_low_mem */
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if (max_low_mem < total_lowmem)
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ram = max_low_mem;
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else
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ram = total_lowmem;
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/* Calculate CAM values */
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__cam0 = 1UL << 2 * (__ilog2(ram) / 2);
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if (__cam0 > cam_max)
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__cam0 = cam_max;
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ram -= __cam0;
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if (ram) {
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__cam1 = 1UL << 2 * (__ilog2(ram) / 2);
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if (__cam1 > cam_max)
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__cam1 = cam_max;
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ram -= __cam1;
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}
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if (ram) {
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__cam2 = 1UL << 2 * (__ilog2(ram) / 2);
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if (__cam2 > cam_max)
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__cam2 = cam_max;
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ram -= __cam2;
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}
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printk(KERN_INFO "Memory CAM mapping: CAM0=%ldMb, CAM1=%ldMb,"
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" CAM2=%ldMb residual: %ldMb\n",
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__cam0 >> 20, __cam1 >> 20, __cam2 >> 20,
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(total_lowmem - __cam0 - __cam1 - __cam2) >> 20);
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__max_low_memory = max_low_mem = __cam0 + __cam1 + __cam2;
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__initial_memory_limit = __max_low_memory;
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}
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