kernel-hacking-2024-linux-s.../arch/powerpc/mm/fsl_booke_mmu.c
Dale Farnsworth e8b6376155 [POWERPC] 85xx: Respect KERNELBASE, PAGE_OFFSET, and PHYSICAL_START on e500
The e500 MMU init code previously assumed KERNELBASE always equaled
PAGE_OFFSET and PHYSICAL_START was 0.  This is useful for kdump
support as well as asymetric multicore.

For the initial kdump support the secondary kernel will run at 32M
but need access to all of memory so we bump the initial TLB up to
64M.  This also matches with the forth coming ePAPR spec.

Signed-off-by: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-01-23 19:34:36 -06:00

237 lines
6.1 KiB
C

/*
* Modifications by Kumar Gala (galak@kernel.crashing.org) to support
* E500 Book E processors.
*
* Copyright 2004 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 <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/bootx.h>
#include <asm/machdep.h>
#include <asm/setup.h>
extern void loadcam_entry(unsigned int index);
unsigned int tlbcam_index;
unsigned int num_tlbcam_entries;
static unsigned long __cam0, __cam1, __cam2;
extern unsigned long total_lowmem;
extern unsigned long __max_low_memory;
extern unsigned long __initial_memory_limit;
#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
#define NUM_TLBCAMS (16)
struct tlbcam {
u32 MAS0;
u32 MAS1;
u32 MAS2;
u32 MAS3;
u32 MAS7;
} TLBCAM[NUM_TLBCAMS];
struct tlbcamrange {
unsigned long start;
unsigned long limit;
phys_addr_t phys;
} tlbcam_addrs[NUM_TLBCAMS];
extern unsigned int tlbcam_index;
/*
* Return PA for this VA if it is mapped by a CAM, or 0
*/
unsigned long 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(unsigned long 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 one of the I/D BAT (block address translation) register pairs.
* The parameters are not checked; in particular size must be a power
* of 4 between 4k and 256M.
*/
void settlbcam(int index, unsigned long virt, phys_addr_t phys,
unsigned int size, int flags, unsigned int pid)
{
unsigned int tsize, lz;
asm ("cntlzw %0,%1" : "=r" (lz) : "r" (size));
tsize = (21 - lz) / 2;
#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 & PAGE_MASK) | MAS3_SX | MAS3_SR;
TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
#ifndef CONFIG_KGDB /* want user access for breakpoints */
if (flags & _PAGE_USER) {
TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
}
#else
TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
#endif
tlbcam_addrs[index].start = virt;
tlbcam_addrs[index].limit = virt + size - 1;
tlbcam_addrs[index].phys = phys;
loadcam_entry(index);
}
void invalidate_tlbcam_entry(int index)
{
TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index);
TLBCAM[index].MAS1 = ~MAS1_VALID;
loadcam_entry(index);
}
void __init cam_mapin_ram(unsigned long cam0, unsigned long cam1,
unsigned long cam2)
{
settlbcam(0, PAGE_OFFSET, PPC_MEMSTART, cam0, _PAGE_KERNEL, 0);
tlbcam_index++;
if (cam1) {
tlbcam_index++;
settlbcam(1, PAGE_OFFSET+cam0, PPC_MEMSTART+cam0, cam1, _PAGE_KERNEL, 0);
}
if (cam2) {
tlbcam_index++;
settlbcam(2, PAGE_OFFSET+cam0+cam1, PPC_MEMSTART+cam0+cam1, cam2, _PAGE_KERNEL, 0);
}
}
/*
* MMU_init_hw does the chip-specific initialization of the MMU hardware.
*/
void __init MMU_init_hw(void)
{
flush_instruction_cache();
}
unsigned long __init mmu_mapin_ram(void)
{
cam_mapin_ram(__cam0, __cam1, __cam2);
return __cam0 + __cam1 + __cam2;
}
void __init
adjust_total_lowmem(void)
{
unsigned long max_low_mem = MAX_LOW_MEM;
unsigned long cam_max = 0x10000000;
unsigned long ram;
/* adjust CAM size to max_low_mem */
if (max_low_mem < cam_max)
cam_max = max_low_mem;
/* adjust lowmem size to max_low_mem */
if (max_low_mem < total_lowmem)
ram = max_low_mem;
else
ram = total_lowmem;
/* Calculate CAM values */
__cam0 = 1UL << 2 * (__ilog2(ram) / 2);
if (__cam0 > cam_max)
__cam0 = cam_max;
ram -= __cam0;
if (ram) {
__cam1 = 1UL << 2 * (__ilog2(ram) / 2);
if (__cam1 > cam_max)
__cam1 = cam_max;
ram -= __cam1;
}
if (ram) {
__cam2 = 1UL << 2 * (__ilog2(ram) / 2);
if (__cam2 > cam_max)
__cam2 = cam_max;
ram -= __cam2;
}
printk(KERN_INFO "Memory CAM mapping: CAM0=%ldMb, CAM1=%ldMb,"
" CAM2=%ldMb residual: %ldMb\n",
__cam0 >> 20, __cam1 >> 20, __cam2 >> 20,
(total_lowmem - __cam0 - __cam1 - __cam2) >> 20);
__max_low_memory = max_low_mem = __cam0 + __cam1 + __cam2;
__initial_memory_limit = __max_low_memory;
}