linux/arch/powerpc/mm/fsl_booke_mmu.c

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/*
* 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/machdep.h>
#include <asm/setup.h>
#include "mmu_decl.h"
extern void loadcam_entry(unsigned int index);
unsigned int tlbcam_index;
static unsigned long cam[CONFIG_LOWMEM_CAM_NUM];
#define NUM_TLBCAMS (16)
#if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
#error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
#endif
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;
/*
* 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 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);
}
unsigned long __init mmu_mapin_ram(void)
{
unsigned long virt = PAGE_OFFSET;
phys_addr_t phys = memstart_addr;
while (cam[tlbcam_index] && tlbcam_index < ARRAY_SIZE(cam)) {
settlbcam(tlbcam_index, virt, phys, cam[tlbcam_index], _PAGE_KERNEL, 0);
virt += cam[tlbcam_index];
phys += cam[tlbcam_index];
tlbcam_index++;
}
return virt - PAGE_OFFSET;
}
/*
* 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)
{
phys_addr_t ram;
powerpc/fsl-booke: Allow larger CAM sizes than 256 MB The code that maps kernel low memory would only use page sizes up to 256 MB. On E500v2 pages up to 4 GB are supported. However, a page must be aligned to a multiple of the page's size. I.e. 256 MB pages must aligned to a 256 MB boundary. This was enforced by a requirement that the physical and virtual addresses of the start of lowmem be aligned to 256 MB. Clearly requiring 1GB or 4GB alignment to allow pages of that size isn't acceptable. To solve this, I simply have adjust_total_lowmem() take alignment into account when it decides what size pages to use. Give it PAGE_OFFSET = 0x7000_0000, PHYSICAL_START = 0x3000_0000, and 2GB of RAM, and it will map pages like this: PA 0x3000_0000 VA 0x7000_0000 Size 256 MB PA 0x4000_0000 VA 0x8000_0000 Size 1 GB PA 0x8000_0000 VA 0xC000_0000 Size 256 MB PA 0x9000_0000 VA 0xD000_0000 Size 256 MB PA 0xA000_0000 VA 0xE000_0000 Size 256 MB Because the lowmem mapping code now takes alignment into account, PHYSICAL_ALIGN can be lowered from 256 MB to 64 MB. Even lower might be possible. The lowmem code will work down to 4 kB but it's possible some of the boot code will fail before then. Poor alignment will force small pages to be used, which combined with the limited number of TLB1 pages available, will result in very little memory getting mapped. So alignments less than 64 MB probably aren't very useful anyway. Signed-off-by: Trent Piepho <tpiepho@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-12-09 03:34:59 +00:00
unsigned int max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xff;
char buf[ARRAY_SIZE(cam) * 5 + 1], *p = buf;
int i;
powerpc/fsl-booke: Allow larger CAM sizes than 256 MB The code that maps kernel low memory would only use page sizes up to 256 MB. On E500v2 pages up to 4 GB are supported. However, a page must be aligned to a multiple of the page's size. I.e. 256 MB pages must aligned to a 256 MB boundary. This was enforced by a requirement that the physical and virtual addresses of the start of lowmem be aligned to 256 MB. Clearly requiring 1GB or 4GB alignment to allow pages of that size isn't acceptable. To solve this, I simply have adjust_total_lowmem() take alignment into account when it decides what size pages to use. Give it PAGE_OFFSET = 0x7000_0000, PHYSICAL_START = 0x3000_0000, and 2GB of RAM, and it will map pages like this: PA 0x3000_0000 VA 0x7000_0000 Size 256 MB PA 0x4000_0000 VA 0x8000_0000 Size 1 GB PA 0x8000_0000 VA 0xC000_0000 Size 256 MB PA 0x9000_0000 VA 0xD000_0000 Size 256 MB PA 0xA000_0000 VA 0xE000_0000 Size 256 MB Because the lowmem mapping code now takes alignment into account, PHYSICAL_ALIGN can be lowered from 256 MB to 64 MB. Even lower might be possible. The lowmem code will work down to 4 kB but it's possible some of the boot code will fail before then. Poor alignment will force small pages to be used, which combined with the limited number of TLB1 pages available, will result in very little memory getting mapped. So alignments less than 64 MB probably aren't very useful anyway. Signed-off-by: Trent Piepho <tpiepho@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-12-09 03:34:59 +00:00
unsigned long virt = PAGE_OFFSET & 0xffffffffUL;
unsigned long phys = memstart_addr & 0xffffffffUL;
powerpc/fsl-booke: Allow larger CAM sizes than 256 MB The code that maps kernel low memory would only use page sizes up to 256 MB. On E500v2 pages up to 4 GB are supported. However, a page must be aligned to a multiple of the page's size. I.e. 256 MB pages must aligned to a 256 MB boundary. This was enforced by a requirement that the physical and virtual addresses of the start of lowmem be aligned to 256 MB. Clearly requiring 1GB or 4GB alignment to allow pages of that size isn't acceptable. To solve this, I simply have adjust_total_lowmem() take alignment into account when it decides what size pages to use. Give it PAGE_OFFSET = 0x7000_0000, PHYSICAL_START = 0x3000_0000, and 2GB of RAM, and it will map pages like this: PA 0x3000_0000 VA 0x7000_0000 Size 256 MB PA 0x4000_0000 VA 0x8000_0000 Size 1 GB PA 0x8000_0000 VA 0xC000_0000 Size 256 MB PA 0x9000_0000 VA 0xD000_0000 Size 256 MB PA 0xA000_0000 VA 0xE000_0000 Size 256 MB Because the lowmem mapping code now takes alignment into account, PHYSICAL_ALIGN can be lowered from 256 MB to 64 MB. Even lower might be possible. The lowmem code will work down to 4 kB but it's possible some of the boot code will fail before then. Poor alignment will force small pages to be used, which combined with the limited number of TLB1 pages available, will result in very little memory getting mapped. So alignments less than 64 MB probably aren't very useful anyway. Signed-off-by: Trent Piepho <tpiepho@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-12-09 03:34:59 +00:00
/* Convert (4^max) kB to (2^max) bytes */
max_cam = max_cam * 2 + 10;
/* adjust lowmem size to __max_low_memory */
ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
/* Calculate CAM values */
__max_low_memory = 0;
for (i = 0; ram && i < ARRAY_SIZE(cam); i++) {
unsigned int camsize = __ilog2(ram) & ~1U;
powerpc/fsl-booke: Allow larger CAM sizes than 256 MB The code that maps kernel low memory would only use page sizes up to 256 MB. On E500v2 pages up to 4 GB are supported. However, a page must be aligned to a multiple of the page's size. I.e. 256 MB pages must aligned to a 256 MB boundary. This was enforced by a requirement that the physical and virtual addresses of the start of lowmem be aligned to 256 MB. Clearly requiring 1GB or 4GB alignment to allow pages of that size isn't acceptable. To solve this, I simply have adjust_total_lowmem() take alignment into account when it decides what size pages to use. Give it PAGE_OFFSET = 0x7000_0000, PHYSICAL_START = 0x3000_0000, and 2GB of RAM, and it will map pages like this: PA 0x3000_0000 VA 0x7000_0000 Size 256 MB PA 0x4000_0000 VA 0x8000_0000 Size 1 GB PA 0x8000_0000 VA 0xC000_0000 Size 256 MB PA 0x9000_0000 VA 0xD000_0000 Size 256 MB PA 0xA000_0000 VA 0xE000_0000 Size 256 MB Because the lowmem mapping code now takes alignment into account, PHYSICAL_ALIGN can be lowered from 256 MB to 64 MB. Even lower might be possible. The lowmem code will work down to 4 kB but it's possible some of the boot code will fail before then. Poor alignment will force small pages to be used, which combined with the limited number of TLB1 pages available, will result in very little memory getting mapped. So alignments less than 64 MB probably aren't very useful anyway. Signed-off-by: Trent Piepho <tpiepho@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-12-09 03:34:59 +00:00
unsigned int align = __ffs(virt | phys) & ~1U;
if (camsize > align)
camsize = align;
if (camsize > max_cam)
camsize = max_cam;
powerpc/fsl-booke: Allow larger CAM sizes than 256 MB The code that maps kernel low memory would only use page sizes up to 256 MB. On E500v2 pages up to 4 GB are supported. However, a page must be aligned to a multiple of the page's size. I.e. 256 MB pages must aligned to a 256 MB boundary. This was enforced by a requirement that the physical and virtual addresses of the start of lowmem be aligned to 256 MB. Clearly requiring 1GB or 4GB alignment to allow pages of that size isn't acceptable. To solve this, I simply have adjust_total_lowmem() take alignment into account when it decides what size pages to use. Give it PAGE_OFFSET = 0x7000_0000, PHYSICAL_START = 0x3000_0000, and 2GB of RAM, and it will map pages like this: PA 0x3000_0000 VA 0x7000_0000 Size 256 MB PA 0x4000_0000 VA 0x8000_0000 Size 1 GB PA 0x8000_0000 VA 0xC000_0000 Size 256 MB PA 0x9000_0000 VA 0xD000_0000 Size 256 MB PA 0xA000_0000 VA 0xE000_0000 Size 256 MB Because the lowmem mapping code now takes alignment into account, PHYSICAL_ALIGN can be lowered from 256 MB to 64 MB. Even lower might be possible. The lowmem code will work down to 4 kB but it's possible some of the boot code will fail before then. Poor alignment will force small pages to be used, which combined with the limited number of TLB1 pages available, will result in very little memory getting mapped. So alignments less than 64 MB probably aren't very useful anyway. Signed-off-by: Trent Piepho <tpiepho@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-12-09 03:34:59 +00:00
cam[i] = 1UL << camsize;
ram -= cam[i];
__max_low_memory += cam[i];
powerpc/fsl-booke: Allow larger CAM sizes than 256 MB The code that maps kernel low memory would only use page sizes up to 256 MB. On E500v2 pages up to 4 GB are supported. However, a page must be aligned to a multiple of the page's size. I.e. 256 MB pages must aligned to a 256 MB boundary. This was enforced by a requirement that the physical and virtual addresses of the start of lowmem be aligned to 256 MB. Clearly requiring 1GB or 4GB alignment to allow pages of that size isn't acceptable. To solve this, I simply have adjust_total_lowmem() take alignment into account when it decides what size pages to use. Give it PAGE_OFFSET = 0x7000_0000, PHYSICAL_START = 0x3000_0000, and 2GB of RAM, and it will map pages like this: PA 0x3000_0000 VA 0x7000_0000 Size 256 MB PA 0x4000_0000 VA 0x8000_0000 Size 1 GB PA 0x8000_0000 VA 0xC000_0000 Size 256 MB PA 0x9000_0000 VA 0xD000_0000 Size 256 MB PA 0xA000_0000 VA 0xE000_0000 Size 256 MB Because the lowmem mapping code now takes alignment into account, PHYSICAL_ALIGN can be lowered from 256 MB to 64 MB. Even lower might be possible. The lowmem code will work down to 4 kB but it's possible some of the boot code will fail before then. Poor alignment will force small pages to be used, which combined with the limited number of TLB1 pages available, will result in very little memory getting mapped. So alignments less than 64 MB probably aren't very useful anyway. Signed-off-by: Trent Piepho <tpiepho@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-12-09 03:34:59 +00:00
virt += cam[i];
phys += cam[i];
p += sprintf(p, "%lu/", cam[i] >> 20);
}
for (; i < ARRAY_SIZE(cam); i++)
p += sprintf(p, "0/");
p[-1] = '\0';
pr_info("Memory CAM mapping: %s Mb, residual: %ldMb\n", buf,
(total_lowmem - __max_low_memory) >> 20);
__initial_memory_limit_addr = memstart_addr + __max_low_memory;
}