linux/arch/powerpc/mm/44x_mmu.c
Suzuki Poulose 0f890c8d20 powerpc: Rename mapping based RELOCATABLE to DYNAMIC_MEMSTART for BookE
The current implementation of CONFIG_RELOCATABLE in BookE is based
on mapping the page aligned kernel load address to KERNELBASE. This
approach however is not enough for platforms, where the TLB page size
is large (e.g, 256M on 44x). So we are renaming the RELOCATABLE used
currently in BookE to DYNAMIC_MEMSTART to reflect the actual method.

The CONFIG_RELOCATABLE for PPC32(BookE) based on processing of the
dynamic relocations will be introduced in the later in the patch series.

This change would allow the use of the old method of RELOCATABLE for
platforms which can afford to enforce the page alignment (platforms with
smaller TLB size).

Changes since v3:

* Introduced a new config, NONSTATIC_KERNEL, to denote a kernel which is
  either a RELOCATABLE or DYNAMIC_MEMSTART(Suggested by: Josh Boyer)

Suggested-by: Scott Wood <scottwood@freescale.com>
Tested-by: Scott Wood <scottwood@freescale.com>

Signed-off-by: Suzuki K. Poulose <suzuki@in.ibm.com>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux ppc dev <linuxppc-dev@lists.ozlabs.org>
Signed-off-by: Josh Boyer <jwboyer@gmail.com>
2011-12-20 10:20:19 -05:00

256 lines
6.7 KiB
C

/*
* Modifications by Matt Porter (mporter@mvista.com) to support
* PPC44x Book E processors.
*
* 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/init.h>
#include <linux/memblock.h>
#include <asm/mmu.h>
#include <asm/system.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
#include "mmu_decl.h"
/* Used by the 44x TLB replacement exception handler.
* Just needed it declared someplace.
*/
unsigned int tlb_44x_index; /* = 0 */
unsigned int tlb_44x_hwater = PPC44x_TLB_SIZE - 1 - PPC44x_EARLY_TLBS;
int icache_44x_need_flush;
unsigned long tlb_47x_boltmap[1024/8];
static void __cpuinit ppc44x_update_tlb_hwater(void)
{
extern unsigned int tlb_44x_patch_hwater_D[];
extern unsigned int tlb_44x_patch_hwater_I[];
/* The TLB miss handlers hard codes the watermark in a cmpli
* instruction to improve performances rather than loading it
* from the global variable. Thus, we patch the instructions
* in the 2 TLB miss handlers when updating the value
*/
tlb_44x_patch_hwater_D[0] = (tlb_44x_patch_hwater_D[0] & 0xffff0000) |
tlb_44x_hwater;
flush_icache_range((unsigned long)&tlb_44x_patch_hwater_D[0],
(unsigned long)&tlb_44x_patch_hwater_D[1]);
tlb_44x_patch_hwater_I[0] = (tlb_44x_patch_hwater_I[0] & 0xffff0000) |
tlb_44x_hwater;
flush_icache_range((unsigned long)&tlb_44x_patch_hwater_I[0],
(unsigned long)&tlb_44x_patch_hwater_I[1]);
}
/*
* "Pins" a 256MB TLB entry in AS0 for kernel lowmem for 44x type MMU
*/
static void __init ppc44x_pin_tlb(unsigned int virt, unsigned int phys)
{
unsigned int entry = tlb_44x_hwater--;
ppc44x_update_tlb_hwater();
mtspr(SPRN_MMUCR, 0);
__asm__ __volatile__(
"tlbwe %2,%3,%4\n"
"tlbwe %1,%3,%5\n"
"tlbwe %0,%3,%6\n"
:
: "r" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
"r" (phys),
"r" (virt | PPC44x_TLB_VALID | PPC44x_TLB_256M),
"r" (entry),
"i" (PPC44x_TLB_PAGEID),
"i" (PPC44x_TLB_XLAT),
"i" (PPC44x_TLB_ATTRIB));
}
static int __init ppc47x_find_free_bolted(void)
{
unsigned int mmube0 = mfspr(SPRN_MMUBE0);
unsigned int mmube1 = mfspr(SPRN_MMUBE1);
if (!(mmube0 & MMUBE0_VBE0))
return 0;
if (!(mmube0 & MMUBE0_VBE1))
return 1;
if (!(mmube0 & MMUBE0_VBE2))
return 2;
if (!(mmube1 & MMUBE1_VBE3))
return 3;
if (!(mmube1 & MMUBE1_VBE4))
return 4;
if (!(mmube1 & MMUBE1_VBE5))
return 5;
return -1;
}
static void __init ppc47x_update_boltmap(void)
{
unsigned int mmube0 = mfspr(SPRN_MMUBE0);
unsigned int mmube1 = mfspr(SPRN_MMUBE1);
if (mmube0 & MMUBE0_VBE0)
__set_bit((mmube0 >> MMUBE0_IBE0_SHIFT) & 0xff,
tlb_47x_boltmap);
if (mmube0 & MMUBE0_VBE1)
__set_bit((mmube0 >> MMUBE0_IBE1_SHIFT) & 0xff,
tlb_47x_boltmap);
if (mmube0 & MMUBE0_VBE2)
__set_bit((mmube0 >> MMUBE0_IBE2_SHIFT) & 0xff,
tlb_47x_boltmap);
if (mmube1 & MMUBE1_VBE3)
__set_bit((mmube1 >> MMUBE1_IBE3_SHIFT) & 0xff,
tlb_47x_boltmap);
if (mmube1 & MMUBE1_VBE4)
__set_bit((mmube1 >> MMUBE1_IBE4_SHIFT) & 0xff,
tlb_47x_boltmap);
if (mmube1 & MMUBE1_VBE5)
__set_bit((mmube1 >> MMUBE1_IBE5_SHIFT) & 0xff,
tlb_47x_boltmap);
}
/*
* "Pins" a 256MB TLB entry in AS0 for kernel lowmem for 47x type MMU
*/
static void __cpuinit ppc47x_pin_tlb(unsigned int virt, unsigned int phys)
{
unsigned int rA;
int bolted;
/* Base rA is HW way select, way 0, bolted bit set */
rA = 0x88000000;
/* Look for a bolted entry slot */
bolted = ppc47x_find_free_bolted();
BUG_ON(bolted < 0);
/* Insert bolted slot number */
rA |= bolted << 24;
pr_debug("256M TLB entry for 0x%08x->0x%08x in bolt slot %d\n",
virt, phys, bolted);
mtspr(SPRN_MMUCR, 0);
__asm__ __volatile__(
"tlbwe %2,%3,0\n"
"tlbwe %1,%3,1\n"
"tlbwe %0,%3,2\n"
:
: "r" (PPC47x_TLB2_SW | PPC47x_TLB2_SR |
PPC47x_TLB2_SX
#ifdef CONFIG_SMP
| PPC47x_TLB2_M
#endif
),
"r" (phys),
"r" (virt | PPC47x_TLB0_VALID | PPC47x_TLB0_256M),
"r" (rA));
}
void __init MMU_init_hw(void)
{
/* This is not useful on 47x but won't hurt either */
ppc44x_update_tlb_hwater();
flush_instruction_cache();
}
unsigned long __init mmu_mapin_ram(unsigned long top)
{
unsigned long addr;
unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);
/* Pin in enough TLBs to cover any lowmem not covered by the
* initial 256M mapping established in head_44x.S */
for (addr = memstart + PPC_PIN_SIZE; addr < lowmem_end_addr;
addr += PPC_PIN_SIZE) {
if (mmu_has_feature(MMU_FTR_TYPE_47x))
ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
else
ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
}
if (mmu_has_feature(MMU_FTR_TYPE_47x)) {
ppc47x_update_boltmap();
#ifdef DEBUG
{
int i;
printk(KERN_DEBUG "bolted entries: ");
for (i = 0; i < 255; i++) {
if (test_bit(i, tlb_47x_boltmap))
printk("%d ", i);
}
printk("\n");
}
#endif /* DEBUG */
}
return total_lowmem;
}
void setup_initial_memory_limit(phys_addr_t first_memblock_base,
phys_addr_t first_memblock_size)
{
u64 size;
#ifndef CONFIG_NONSTATIC_KERNEL
/* We don't currently support the first MEMBLOCK not mapping 0
* physical on those processors
*/
BUG_ON(first_memblock_base != 0);
#endif
/* 44x has a 256M TLB entry pinned at boot */
size = (min_t(u64, first_memblock_size, PPC_PIN_SIZE));
memblock_set_current_limit(first_memblock_base + size);
}
#ifdef CONFIG_SMP
void __cpuinit mmu_init_secondary(int cpu)
{
unsigned long addr;
unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);
/* Pin in enough TLBs to cover any lowmem not covered by the
* initial 256M mapping established in head_44x.S
*
* WARNING: This is called with only the first 256M of the
* linear mapping in the TLB and we can't take faults yet
* so beware of what this code uses. It runs off a temporary
* stack. current (r2) isn't initialized, smp_processor_id()
* will not work, current thread info isn't accessible, ...
*/
for (addr = memstart + PPC_PIN_SIZE; addr < lowmem_end_addr;
addr += PPC_PIN_SIZE) {
if (mmu_has_feature(MMU_FTR_TYPE_47x))
ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
else
ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
}
}
#endif /* CONFIG_SMP */